Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (27 commits)
  lguest: use __PAGE_KERNEL instead of _PAGE_KERNEL
  lguest: Use explicit includes rateher than indirect
  lguest: get rid of lg variable assignments
  lguest: change gpte_addr header
  lguest: move changed bitmap to lg_cpu
  lguest: move last_pages to lg_cpu
  lguest: change last_guest to last_cpu
  lguest: change spte_addr header
  lguest: per-vcpu lguest pgdir management
  lguest: make pending notifications per-vcpu
  lguest: makes special fields be per-vcpu
  lguest: per-vcpu lguest task management
  lguest: replace lguest_arch with lg_cpu_arch.
  lguest: make registers per-vcpu
  lguest: make emulate_insn receive a vcpu struct.
  lguest: map_switcher_in_guest() per-vcpu
  lguest: per-vcpu interrupt processing.
  lguest: per-vcpu lguest timers
  lguest: make hypercalls use the vcpu struct
  lguest: make write() operation smp aware
  ...

Manual conflict resolved (maybe even correctly, who knows) in
drivers/lguest/x86/core.c

9 files changed, 513 insertions, 445 deletions

diff --git a/drivers/Makefile b/drivers/Makefile
index 9e1f808..0ee9a8a 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -72,7 +72,7 @@ obj-$(CONFIG_ISDN)		+= isdn/
 obj-$(CONFIG_EDAC)		+= edac/
 obj-$(CONFIG_MCA)		+= mca/
 obj-$(CONFIG_EISA)		+= eisa/
-obj-$(CONFIG_LGUEST_GUEST)	+= lguest/
+obj-y				+= lguest/
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_CPU_IDLE)		+= cpuidle/
 obj-$(CONFIG_MMC)		+= mmc/
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index cb4c670..7743d73 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -151,43 +151,43 @@ int lguest_address_ok(const struct lguest *lg,
 /* This routine copies memory from the Guest.  Here we can see how useful the
  * kill_lguest() routine we met in the Launcher can be: we return a random
  * value (all zeroes) instead of needing to return an error. */
-void __lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
+void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
 {
-	if (!lguest_address_ok(lg, addr, bytes)
-	    || copy_from_user(b, lg->mem_base + addr, bytes) != 0) {
+	if (!lguest_address_ok(cpu->lg, addr, bytes)
+	    || copy_from_user(b, cpu->lg->mem_base + addr, bytes) != 0) {
 		/* copy_from_user should do this, but as we rely on it... */
 		memset(b, 0, bytes);
-		kill_guest(lg, "bad read address %#lx len %u", addr, bytes);
+		kill_guest(cpu, "bad read address %#lx len %u", addr, bytes);
 	}
 }
 
 /* This is the write (copy into guest) version. */
-void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
+void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
 	       unsigned bytes)
 {
-	if (!lguest_address_ok(lg, addr, bytes)
-	    || copy_to_user(lg->mem_base + addr, b, bytes) != 0)
-		kill_guest(lg, "bad write address %#lx len %u", addr, bytes);
+	if (!lguest_address_ok(cpu->lg, addr, bytes)
+	    || copy_to_user(cpu->lg->mem_base + addr, b, bytes) != 0)
+		kill_guest(cpu, "bad write address %#lx len %u", addr, bytes);
 }
 /*:*/
 
 /*H:030 Let's jump straight to the the main loop which runs the Guest.
  * Remember, this is called by the Launcher reading /dev/lguest, and we keep
  * going around and around until something interesting happens. */
-int run_guest(struct lguest *lg, unsigned long __user *user)
+int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 {
 	/* We stop running once the Guest is dead. */
-	while (!lg->dead) {
+	while (!cpu->lg->dead) {
 		/* First we run any hypercalls the Guest wants done. */
-		if (lg->hcall)
-			do_hypercalls(lg);
+		if (cpu->hcall)
+			do_hypercalls(cpu);
 
 		/* It's possible the Guest did a NOTIFY hypercall to the
 		 * Launcher, in which case we return from the read() now. */
-		if (lg->pending_notify) {
-			if (put_user(lg->pending_notify, user))
+		if (cpu->pending_notify) {
+			if (put_user(cpu->pending_notify, user))
 				return -EFAULT;
-			return sizeof(lg->pending_notify);
+			return sizeof(cpu->pending_notify);
 		}
 
 		/* Check for signals */
@@ -195,13 +195,13 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
 			return -ERESTARTSYS;
 
 		/* If Waker set break_out, return to Launcher. */
-		if (lg->break_out)
+		if (cpu->break_out)
 			return -EAGAIN;
 
 		/* Check if there are any interrupts which can be delivered
 		 * now: if so, this sets up the hander to be executed when we
 		 * next run the Guest. */
-		maybe_do_interrupt(lg);
+		maybe_do_interrupt(cpu);
 
 		/* All long-lived kernel loops need to check with this horrible
 		 * thing called the freezer.  If the Host is trying to suspend,
@@ -210,12 +210,12 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
 
 		/* Just make absolutely sure the Guest is still alive.  One of
 		 * those hypercalls could have been fatal, for example. */
-		if (lg->dead)
+		if (cpu->lg->dead)
 			break;
 
 		/* If the Guest asked to be stopped, we sleep.  The Guest's
 		 * clock timer or LHCALL_BREAK from the Waker will wake us. */
-		if (lg->halted) {
+		if (cpu->halted) {
 			set_current_state(TASK_INTERRUPTIBLE);
 			schedule();
 			continue;
@@ -226,15 +226,17 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
 		local_irq_disable();
 
 		/* Actually run the Guest until something happens. */
-		lguest_arch_run_guest(lg);
+		lguest_arch_run_guest(cpu);
 
 		/* Now we're ready to be interrupted or moved to other CPUs */
 		local_irq_enable();
 
 		/* Now we deal with whatever happened to the Guest. */
-		lguest_arch_handle_trap(lg);
+		lguest_arch_handle_trap(cpu);
 	}
 
+	if (cpu->lg->dead == ERR_PTR(-ERESTART))
+		return -ERESTART;
 	/* The Guest is dead => "No such file or directory" */
 	return -ENOENT;
 }
@@ -253,7 +255,7 @@ static int __init init(void)
 
 	/* Lguest can't run under Xen, VMI or itself.  It does Tricky Stuff. */
 	if (paravirt_enabled()) {
-		printk("lguest is afraid of %s\n", pv_info.name);
+		printk("lguest is afraid of being a guest\n");
 		return -EPERM;
 	}
 
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index b478aff..0f2cb4f 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -23,13 +23,14 @@
 #include <linux/uaccess.h>
 #include <linux/syscalls.h>
 #include <linux/mm.h>
+#include <linux/ktime.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include "lg.h"
 
 /*H:120 This is the core hypercall routine: where the Guest gets what it wants.
  * Or gets killed.  Or, in the case of LHCALL_CRASH, both. */
-static void do_hcall(struct lguest *lg, struct hcall_args *args)
+static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
 	switch (args->arg0) {
 	case LHCALL_FLUSH_ASYNC:
@@ -39,60 +40,62 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
 	case LHCALL_LGUEST_INIT:
 		/* You can't get here unless you're already initialized.  Don't
 		 * do that. */
-		kill_guest(lg, "already have lguest_data");
+		kill_guest(cpu, "already have lguest_data");
 		break;
-	case LHCALL_CRASH: {
-		/* Crash is such a trivial hypercall that we do it in four
+	case LHCALL_SHUTDOWN: {
+		/* Shutdown is such a trivial hypercall that we do it in four
 		 * lines right here. */
 		char msg[128];
 		/* If the lgread fails, it will call kill_guest() itself; the
 		 * kill_guest() with the message will be ignored. */
-		__lgread(lg, msg, args->arg1, sizeof(msg));
+		__lgread(cpu, msg, args->arg1, sizeof(msg));
 		msg[sizeof(msg)-1] = '\0';
-		kill_guest(lg, "CRASH: %s", msg);
+		kill_guest(cpu, "CRASH: %s", msg);
+		if (args->arg2 == LGUEST_SHUTDOWN_RESTART)
+			cpu->lg->dead = ERR_PTR(-ERESTART);
 		break;
 	}
 	case LHCALL_FLUSH_TLB:
 		/* FLUSH_TLB comes in two flavors, depending on the
 		 * argument: */
 		if (args->arg1)
-			guest_pagetable_clear_all(lg);
+			guest_pagetable_clear_all(cpu);
 		else
-			guest_pagetable_flush_user(lg);
+			guest_pagetable_flush_user(cpu);
 		break;
 
 	/* All these calls simply pass the arguments through to the right
 	 * routines. */
 	case LHCALL_NEW_PGTABLE:
-		guest_new_pagetable(lg, args->arg1);
+		guest_new_pagetable(cpu, args->arg1);
 		break;
 	case LHCALL_SET_STACK:
-		guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
+		guest_set_stack(cpu, args->arg1, args->arg2, args->arg3);
 		break;
 	case LHCALL_SET_PTE:
-		guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
+		guest_set_pte(cpu, args->arg1, args->arg2, __pte(args->arg3));
 		break;
 	case LHCALL_SET_PMD:
-		guest_set_pmd(lg, args->arg1, args->arg2);
+		guest_set_pmd(cpu->lg, args->arg1, args->arg2);
 		break;
 	case LHCALL_SET_CLOCKEVENT:
-		guest_set_clockevent(lg, args->arg1);
+		guest_set_clockevent(cpu, args->arg1);
 		break;
 	case LHCALL_TS:
 		/* This sets the TS flag, as we saw used in run_guest(). */
-		lg->ts = args->arg1;
+		cpu->ts = args->arg1;
 		break;
 	case LHCALL_HALT:
 		/* Similarly, this sets the halted flag for run_guest(). */
-		lg->halted = 1;
+		cpu->halted = 1;
 		break;
 	case LHCALL_NOTIFY:
-		lg->pending_notify = args->arg1;
+		cpu->pending_notify = args->arg1;
 		break;
 	default:
 		/* It should be an architecture-specific hypercall. */
-		if (lguest_arch_do_hcall(lg, args))
-			kill_guest(lg, "Bad hypercall %li\n", args->arg0);
+		if (lguest_arch_do_hcall(cpu, args))
+			kill_guest(cpu, "Bad hypercall %li\n", args->arg0);
 	}
 }
 /*:*/
@@ -104,13 +107,13 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
  * Guest put them in the ring, but we also promise the Guest that they will
  * happen before any normal hypercall (which is why we check this before
  * checking for a normal hcall). */
-static void do_async_hcalls(struct lguest *lg)
+static void do_async_hcalls(struct lg_cpu *cpu)
 {
 	unsigned int i;
 	u8 st[LHCALL_RING_SIZE];
 
 	/* For simplicity, we copy the entire call status array in at once. */
-	if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
+	if (copy_from_user(&st, &cpu->lg->lguest_data->hcall_status, sizeof(st)))
 		return;
 
 	/* We process "struct lguest_data"s hcalls[] ring once. */
@@ -119,7 +122,7 @@ static void do_async_hcalls(struct lguest *lg)
 		/* We remember where we were up to from last time.  This makes
 		 * sure that the hypercalls are done in the order the Guest
 		 * places them in the ring. */
-		unsigned int n = lg->next_hcall;
+		unsigned int n = cpu->next_hcall;
 
 		/* 0xFF means there's no call here (yet). */
 		if (st[n] == 0xFF)
@@ -127,65 +130,65 @@ static void do_async_hcalls(struct lguest *lg)
 
 		/* OK, we have hypercall.  Increment the "next_hcall" cursor,
 		 * and wrap back to 0 if we reach the end. */
-		if (++lg->next_hcall == LHCALL_RING_SIZE)
-			lg->next_hcall = 0;
+		if (++cpu->next_hcall == LHCALL_RING_SIZE)
+			cpu->next_hcall = 0;
 
 		/* Copy the hypercall arguments into a local copy of
 		 * the hcall_args struct. */
-		if (copy_from_user(&args, &lg->lguest_data->hcalls[n],
+		if (copy_from_user(&args, &cpu->lg->lguest_data->hcalls[n],
 				   sizeof(struct hcall_args))) {
-			kill_guest(lg, "Fetching async hypercalls");
+			kill_guest(cpu, "Fetching async hypercalls");
 			break;
 		}
 
 		/* Do the hypercall, same as a normal one. */
-		do_hcall(lg, &args);
+		do_hcall(cpu, &args);
 
 		/* Mark the hypercall done. */
-		if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
-			kill_guest(lg, "Writing result for async hypercall");
+		if (put_user(0xFF, &cpu->lg->lguest_data->hcall_status[n])) {
+			kill_guest(cpu, "Writing result for async hypercall");
 			break;
 		}
 
 		/* Stop doing hypercalls if they want to notify the Launcher:
 		 * it needs to service this first. */
-		if (lg->pending_notify)
+		if (cpu->pending_notify)
 			break;
 	}
 }
 
 /* Last of all, we look at what happens first of all.  The very first time the
  * Guest makes a hypercall, we end up here to set things up: */
-static void initialize(struct lguest *lg)
+static void initialize(struct lg_cpu *cpu)
 {
 	/* You can't do anything until you're initialized.  The Guest knows the
 	 * rules, so we're unforgiving here. */
-	if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) {
-		kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0);
+	if (cpu->hcall->arg0 != LHCALL_LGUEST_INIT) {
+		kill_guest(cpu, "hypercall %li before INIT", cpu->hcall->arg0);
 		return;
 	}
 
-	if (lguest_arch_init_hypercalls(lg))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	if (lguest_arch_init_hypercalls(cpu))
+		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
 	/* The Guest tells us where we're not to deliver interrupts by putting
 	 * the range of addresses into "struct lguest_data". */
-	if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
-	    || get_user(lg->noirq_end, &lg->lguest_data->noirq_end))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	if (get_user(cpu->lg->noirq_start, &cpu->lg->lguest_data->noirq_start)
+	    || get_user(cpu->lg->noirq_end, &cpu->lg->lguest_data->noirq_end))
+		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
 	/* We write the current time into the Guest's data page once so it can
 	 * set its clock. */
-	write_timestamp(lg);
+	write_timestamp(cpu);
 
 	/* page_tables.c will also do some setup. */
-	page_table_guest_data_init(lg);
+	page_table_guest_data_init(cpu);
 
 	/* This is the one case where the above accesses might have been the
 	 * first write to a Guest page.  This may have caused a copy-on-write
 	 * fault, but the old page might be (read-only) in the Guest
 	 * pagetable. */
-	guest_pagetable_clear_all(lg);
+	guest_pagetable_clear_all(cpu);
 }
 
 /*H:100
@@ -194,27 +197,27 @@ static void initialize(struct lguest *lg)
  * Remember from the Guest, hypercalls come in two flavors: normal and
  * asynchronous.  This file handles both of types.
  */
-void do_hypercalls(struct lguest *lg)
+void do_hypercalls(struct lg_cpu *cpu)
 {
 	/* Not initialized yet?  This hypercall must do it. */
-	if (unlikely(!lg->lguest_data)) {
+	if (unlikely(!cpu->lg->lguest_data)) {
 		/* Set up the "struct lguest_data" */
-		initialize(lg);
+		initialize(cpu);
 		/* Hcall is done. */
-		lg->hcall = NULL;
+		cpu->hcall = NULL;
 		return;
 	}
 
 	/* The Guest has initialized.
 	 *
 	 * Look in the hypercall ring for the async hypercalls: */
-	do_async_hcalls(lg);
+	do_async_hcalls(cpu);
 
 	/* If we stopped reading the hypercall ring because the Guest did a
 	 * NOTIFY to the Launcher, we want to return now.  Otherwise we do
 	 * the hypercall. */
-	if (!lg->pending_notify) {
-		do_hcall(lg, lg->hcall);
+	if (!cpu->pending_notify) {
+		do_hcall(cpu, cpu->hcall);
 		/* Tricky point: we reset the hcall pointer to mark the
 		 * hypercall as "done".  We use the hcall pointer rather than
 		 * the trap number to indicate a hypercall is pending.
@@ -225,16 +228,17 @@ void do_hypercalls(struct lguest *lg)
 		 * Launcher, the run_guest() loop will exit without running the
 		 * Guest.  When it comes back it would try to re-run the
 		 * hypercall. */
-		lg->hcall = NULL;
+		cpu->hcall = NULL;
 	}
 }
 
 /* This routine supplies the Guest with time: it's used for wallclock time at
  * initial boot and as a rough time source if the TSC isn't available. */
-void write_timestamp(struct lguest *lg)
+void write_timestamp(struct lg_cpu *cpu)
 {
 	struct timespec now;
 	ktime_get_real_ts(&now);
-	if (copy_to_user(&lg->lguest_data->time, &now, sizeof(struct timespec)))
-		kill_guest(lg, "Writing timestamp");
+	if (copy_to_user(&cpu->lg->lguest_data->time,
+			 &now, sizeof(struct timespec)))
+		kill_guest(cpu, "Writing timestamp");
 }
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 2b66f79..32e97c1 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -41,11 +41,11 @@ static int idt_present(u32 lo, u32 hi)
 
 /* We need a helper to "push" a value onto the Guest's stack, since that's a
  * big part of what delivering an interrupt does. */
-static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
+static void push_guest_stack(struct lg_cpu *cpu, unsigned long *gstack, u32 val)
 {
 	/* Stack grows upwards: move stack then write value. */
 	*gstack -= 4;
-	lgwrite(lg, *gstack, u32, val);
+	lgwrite(cpu, *gstack, u32, val);
 }
 
 /*H:210 The set_guest_interrupt() routine actually delivers the interrupt or
@@ -60,7 +60,7 @@ static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
  * We set up the stack just like the CPU does for a real interrupt, so it's
  * identical for the Guest (and the standard "iret" instruction will undo
  * it). */
-static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
+static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
 {
 	unsigned long gstack, origstack;
 	u32 eflags, ss, irq_enable;
@@ -69,59 +69,59 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
 	/* There are two cases for interrupts: one where the Guest is already
 	 * in the kernel, and a more complex one where the Guest is in
 	 * userspace.  We check the privilege level to find out. */
-	if ((lg->regs->ss&0x3) != GUEST_PL) {
+	if ((cpu->regs->ss&0x3) != GUEST_PL) {
 		/* The Guest told us their kernel stack with the SET_STACK
 		 * hypercall: both the virtual address and the segment */
-		virtstack = lg->esp1;
-		ss = lg->ss1;
+		virtstack = cpu->esp1;
+		ss = cpu->ss1;
 
-		origstack = gstack = guest_pa(lg, virtstack);
+		origstack = gstack = guest_pa(cpu, virtstack);
 		/* We push the old stack segment and pointer onto the new
 		 * stack: when the Guest does an "iret" back from the interrupt
 		 * handler the CPU will notice they're dropping privilege
 		 * levels and expect these here. */
-		push_guest_stack(lg, &gstack, lg->regs->ss);
-		push_guest_stack(lg, &gstack, lg->regs->esp);
+		push_guest_stack(cpu, &gstack, cpu->regs->ss);
+		push_guest_stack(cpu, &gstack, cpu->regs->esp);
 	} else {
 		/* We're staying on the same Guest (kernel) stack. */
-		virtstack = lg->regs->esp;
-		ss = lg->regs->ss;
+		virtstack = cpu->regs->esp;
+		ss = cpu->regs->ss;
 
-		origstack = gstack = guest_pa(lg, virtstack);
+		origstack = gstack = guest_pa(cpu, virtstack);
 	}
 
 	/* Remember that we never let the Guest actually disable interrupts, so
 	 * the "Interrupt Flag" bit is always set.  We copy that bit from the
 	 * Guest's "irq_enabled" field into the eflags word: we saw the Guest
 	 * copy it back in "lguest_iret". */
-	eflags = lg->regs->eflags;
-	if (get_user(irq_enable, &lg->lguest_data->irq_enabled) == 0
+	eflags = cpu->regs->eflags;
+	if (get_user(irq_enable, &cpu->lg->lguest_data->irq_enabled) == 0
 	    && !(irq_enable & X86_EFLAGS_IF))
 		eflags &= ~X86_EFLAGS_IF;
 
 	/* An interrupt is expected to push three things on the stack: the old
 	 * "eflags" word, the old code segment, and the old instruction
 	 * pointer. */
-	push_guest_stack(lg, &gstack, eflags);
-	push_guest_stack(lg, &gstack, lg->regs->cs);
-	push_guest_stack(lg, &gstack, lg->regs->eip);
+	push_guest_stack(cpu, &gstack, eflags);
+	push_guest_stack(cpu, &gstack, cpu->regs->cs);
+	push_guest_stack(cpu, &gstack, cpu->regs->eip);
 
 	/* For the six traps which supply an error code, we push that, too. */
 	if (has_err)
-		push_guest_stack(lg, &gstack, lg->regs->errcode);
+		push_guest_stack(cpu, &gstack, cpu->regs->errcode);
 
 	/* Now we've pushed all the old state, we change the stack, the code
 	 * segment and the address to execute. */
-	lg->regs->ss = ss;
-	lg->regs->esp = virtstack + (gstack - origstack);
-	lg->regs->cs = (__KERNEL_CS|GUEST_PL);
-	lg->regs->eip = idt_address(lo, hi);
+	cpu->regs->ss = ss;
+	cpu->regs->esp = virtstack + (gstack - origstack);
+	cpu->regs->cs = (__KERNEL_CS|GUEST_PL);
+	cpu->regs->eip = idt_address(lo, hi);
 
 	/* There are two kinds of interrupt handlers: 0xE is an "interrupt
 	 * gate" which expects interrupts to be disabled on entry. */
 	if (idt_type(lo, hi) == 0xE)
-		if (put_user(0, &lg->lguest_data->irq_enabled))
-			kill_guest(lg, "Disabling interrupts");
+		if (put_user(0, &cpu->lg->lguest_data->irq_enabled))
+			kill_guest(cpu, "Disabling interrupts");
 }
 
 /*H:205
@@ -129,23 +129,23 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
  *
  * maybe_do_interrupt() gets called before every entry to the Guest, to see if
  * we should divert the Guest to running an interrupt handler. */
-void maybe_do_interrupt(struct lguest *lg)
+void maybe_do_interrupt(struct lg_cpu *cpu)
 {
 	unsigned int irq;
 	DECLARE_BITMAP(blk, LGUEST_IRQS);
 	struct desc_struct *idt;
 
 	/* If the Guest hasn't even initialized yet, we can do nothing. */
-	if (!lg->lguest_data)
+	if (!cpu->lg->lguest_data)
 		return;
 
 	/* Take our "irqs_pending" array and remove any interrupts the Guest
 	 * wants blocked: the result ends up in "blk". */
-	if (copy_from_user(&blk, lg->lguest_data->blocked_interrupts,
+	if (copy_from_user(&blk, cpu->lg->lguest_data->blocked_interrupts,
 			   sizeof(blk)))
 		return;
 
-	bitmap_andnot(blk, lg->irqs_pending, blk, LGUEST_IRQS);
+	bitmap_andnot(blk, cpu->irqs_pending, blk, LGUEST_IRQS);
 
 	/* Find the first interrupt. */
 	irq = find_first_bit(blk, LGUEST_IRQS);
@@ -155,19 +155,20 @@ void maybe_do_interrupt(struct lguest *lg)
 
 	/* They may be in the middle of an iret, where they asked us never to
 	 * deliver interrupts. */
-	if (lg->regs->eip >= lg->noirq_start && lg->regs->eip < lg->noirq_end)
+	if (cpu->regs->eip >= cpu->lg->noirq_start &&
+	   (cpu->regs->eip < cpu->lg->noirq_end))
 		return;
 
 	/* If they're halted, interrupts restart them. */
-	if (lg->halted) {
+	if (cpu->halted) {
 		/* Re-enable interrupts. */
-		if (put_user(X86_EFLAGS_IF, &lg->lguest_data->irq_enabled))
-			kill_guest(lg, "Re-enabling interrupts");
-		lg->halted = 0;
+		if (put_user(X86_EFLAGS_IF, &cpu->lg->lguest_data->irq_enabled))
+			kill_guest(cpu, "Re-enabling interrupts");
+		cpu->halted = 0;
 	} else {
 		/* Otherwise we check if they have interrupts disabled. */
 		u32 irq_enabled;
-		if (get_user(irq_enabled, &lg->lguest_data->irq_enabled))
+		if (get_user(irq_enabled, &cpu->lg->lguest_data->irq_enabled))
 			irq_enabled = 0;
 		if (!irq_enabled)
 			return;
@@ -176,15 +177,15 @@ void maybe_do_interrupt(struct lguest *lg)
 	/* Look at the IDT entry the Guest gave us for this interrupt.  The
 	 * first 32 (FIRST_EXTERNAL_VECTOR) entries are for traps, so we skip
 	 * over them. */
-	idt = &lg->arch.idt[FIRST_EXTERNAL_VECTOR+irq];
+	idt = &cpu->arch.idt[FIRST_EXTERNAL_VECTOR+irq];
 	/* If they don't have a handler (yet?), we just ignore it */
 	if (idt_present(idt->a, idt->b)) {
 		/* OK, mark it no longer pending and deliver it. */
-		clear_bit(irq, lg->irqs_pending);
+		clear_bit(irq, cpu->irqs_pending);
 		/* set_guest_interrupt() takes the interrupt descriptor and a
 		 * flag to say whether this interrupt pushes an error code onto
 		 * the stack as well: virtual interrupts never do. */
-		set_guest_interrupt(lg, idt->a, idt->b, 0);
+		set_guest_interrupt(cpu, idt->a, idt->b, 0);
 	}
 
 	/* Every time we deliver an interrupt, we update the timestamp in the
@@ -192,7 +193,7 @@ void maybe_do_interrupt(struct lguest *lg)
 	 * did this more often, but it can actually be quite slow: doing it
 	 * here is a compromise which means at least it gets updated every
 	 * timer interrupt. */
-	write_timestamp(lg);
+	write_timestamp(cpu);
 }
 /*:*/
 
@@ -245,19 +246,19 @@ static int has_err(unsigned int trap)
 }
 
 /* deliver_trap() returns true if it could deliver the trap. */
-int deliver_trap(struct lguest *lg, unsigned int num)
+int deliver_trap(struct lg_cpu *cpu, unsigned int num)
 {
 	/* Trap numbers are always 8 bit, but we set an impossible trap number
 	 * for traps inside the Switcher, so check that here. */
-	if (num >= ARRAY_SIZE(lg->arch.idt))
+	if (num >= ARRAY_SIZE(cpu->arch.idt))
 		return 0;
 
 	/* Early on the Guest hasn't set the IDT entries (or maybe it put a
 	 * bogus one in): if we fail here, the Guest will be killed. */
-	if (!idt_present(lg->arch.idt[num].a, lg->arch.idt[num].b))
+	if (!idt_present(cpu->arch.idt[num].a, cpu->arch.idt[num].b))
 		return 0;
-	set_guest_interrupt(lg, lg->arch.idt[num].a, lg->arch.idt[num].b,
-			    has_err(num));
+	set_guest_interrupt(cpu, cpu->arch.idt[num].a,
+			    cpu->arch.idt[num].b, has_err(num));
 	return 1;
 }
 
@@ -309,18 +310,18 @@ static int direct_trap(unsigned int num)
  * the Guest.
  *
  * Which is deeply unfair, because (literally!) it wasn't the Guests' fault. */
-void pin_stack_pages(struct lguest *lg)
+void pin_stack_pages(struct lg_cpu *cpu)
 {
 	unsigned int i;
 
 	/* Depending on the CONFIG_4KSTACKS option, the Guest can have one or
 	 * two pages of stack space. */
-	for (i = 0; i < lg->stack_pages; i++)
+	for (i = 0; i < cpu->lg->stack_pages; i++)
 		/* The stack grows *upwards*, so the address we're given is the
 		 * start of the page after the kernel stack.  Subtract one to
 		 * get back onto the first stack page, and keep subtracting to
 		 * get to the rest of the stack pages. */
-		pin_page(lg, lg->esp1 - 1 - i * PAGE_SIZE);
+		pin_page(cpu, cpu->esp1 - 1 - i * PAGE_SIZE);
 }
 
 /* Direct traps also mean that we need to know whenever the Guest wants to use
@@ -331,21 +332,21 @@ void pin_stack_pages(struct lguest *lg)
  *
  * In Linux each process has its own kernel stack, so this happens a lot: we
  * change stacks on each context switch. */
-void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages)
+void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages)
 {
 	/* You are not allowed have a stack segment with privilege level 0: bad
 	 * Guest! */
 	if ((seg & 0x3) != GUEST_PL)
-		kill_guest(lg, "bad stack segment %i", seg);
+		kill_guest(cpu, "bad stack segment %i", seg);
 	/* We only expect one or two stack pages. */
 	if (pages > 2)
-		kill_guest(lg, "bad stack pages %u", pages);
+		kill_guest(cpu, "bad stack pages %u", pages);
 	/* Save where the stack is, and how many pages */
-	lg->ss1 = seg;
-	lg->esp1 = esp;
-	lg->stack_pages = pages;
+	cpu->ss1 = seg;
+	cpu->esp1 = esp;
+	cpu->lg->stack_pages = pages;
 	/* Make sure the new stack pages are mapped */
-	pin_stack_pages(lg);
+	pin_stack_pages(cpu);
 }
 
 /* All this reference to mapping stacks leads us neatly into the other complex
@@ -353,7 +354,7 @@ void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages)
 
 /*H:235 This is the routine which actually checks the Guest's IDT entry and
  * transfers it into the entry in "struct lguest": */
-static void set_trap(struct lguest *lg, struct desc_struct *trap,
+static void set_trap(struct lg_cpu *cpu, struct desc_struct *trap,
 		     unsigned int num, u32 lo, u32 hi)
 {
 	u8 type = idt_type(lo, hi);
@@ -366,7 +367,7 @@ static void set_trap(struct lguest *lg, struct desc_struct *trap,
 
 	/* We only support interrupt and trap gates. */
 	if (type != 0xE && type != 0xF)
-		kill_guest(lg, "bad IDT type %i", type);
+		kill_guest(cpu, "bad IDT type %i", type);
 
 	/* We only copy the handler address, present bit, privilege level and
 	 * type.  The privilege level controls where the trap can be triggered
@@ -383,7 +384,7 @@ static void set_trap(struct lguest *lg, struct desc_struct *trap,
  *
  * We saw the Guest setting Interrupt Descriptor Table (IDT) entries with the
  * LHCALL_LOAD_IDT_ENTRY hypercall before: that comes here. */
-void load_guest_idt_entry(struct lguest *lg, unsigned int num, u32 lo, u32 hi)
+void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int num, u32 lo, u32 hi)
 {
 	/* Guest never handles: NMI, doublefault, spurious interrupt or
 	 * hypercall.  We ignore when it tries to set them. */
@@ -392,13 +393,13 @@ void load_guest_idt_entry(struct lguest *lg, unsigned int num, u32 lo, u32 hi)
 
 	/* Mark the IDT as changed: next time the Guest runs we'll know we have
 	 * to copy this again. */
-	lg->changed |= CHANGED_IDT;
+	cpu->changed |= CHANGED_IDT;
 
 	/* Check that the Guest doesn't try to step outside the bounds. */
-	if (num >= ARRAY_SIZE(lg->arch.idt))
-		kill_guest(lg, "Setting idt entry %u", num);
+	if (num >= ARRAY_SIZE(cpu->arch.idt))
+		kill_guest(cpu, "Setting idt entry %u", num);
 	else
-		set_trap(lg, &lg->arch.idt[num], num, lo, hi);
+		set_trap(cpu, &cpu->arch.idt[num], num, lo, hi);
 }
 
 /* The default entry for each interrupt points into the Switcher routines which
@@ -434,14 +435,14 @@ void setup_default_idt_entries(struct lguest_ro_state *state,
 /*H:240 We don't use the IDT entries in the "struct lguest" directly, instead
  * we copy them into the IDT which we've set up for Guests on this CPU, just
  * before we run the Guest.  This routine does that copy. */
-void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
 		const unsigned long *def)
 {
 	unsigned int i;
 
 	/* We can simply copy the direct traps, otherwise we use the default
 	 * ones in the Switcher: they will return to the Host. */
-	for (i = 0; i < ARRAY_SIZE(lg->arch.idt); i++) {
+	for (i = 0; i < ARRAY_SIZE(cpu->arch.idt); i++) {
 		/* If no Guest can ever override this trap, leave it alone. */
 		if (!direct_trap(i))
 			continue;
@@ -450,8 +451,8 @@ void copy_traps(const struct lguest *lg, struct desc_struct *idt,
 		 * Interrupt gates (type 14) disable interrupts as they are
 		 * entered, which we never let the Guest do.  Not present
 		 * entries (type 0x0) also can't go direct, of course. */
-		if (idt_type(lg->arch.idt[i].a, lg->arch.idt[i].b) == 0xF)
-			idt[i] = lg->arch.idt[i];
+		if (idt_type(cpu->arch.idt[i].a, cpu->arch.idt[i].b) == 0xF)
+			idt[i] = cpu->arch.idt[i];
 		else
 			/* Reset it to the default. */
 			default_idt_entry(&idt[i], i, def[i]);
@@ -470,13 +471,13 @@ void copy_traps(const struct lguest *lg, struct desc_struct *idt,
  * infrastructure to set a callback at that time.
  *
  * 0 means "turn off the clock". */
-void guest_set_clockevent(struct lguest *lg, unsigned long delta)
+void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta)
 {
 	ktime_t expires;
 
 	if (unlikely(delta == 0)) {
 		/* Clock event device is shutting down. */
-		hrtimer_cancel(&lg->hrt);
+		hrtimer_cancel(&cpu->hrt);
 		return;
 	}
 
@@ -484,25 +485,25 @@ void guest_set_clockevent(struct lguest *lg, unsigned long delta)
 	 * all the time between now and the timer interrupt it asked for.  This
 	 * is almost always the right thing to do. */
 	expires = ktime_add_ns(ktime_get_real(), delta);
-	hrtimer_start(&lg->hrt, expires, HRTIMER_MODE_ABS);
+	hrtimer_start(&cpu->hrt, expires, HRTIMER_MODE_ABS);
 }
 
 /* This is the function called when the Guest's timer expires. */
 static enum hrtimer_restart clockdev_fn(struct hrtimer *timer)
 {
-	struct lguest *lg = container_of(timer, struct lguest, hrt);
+	struct lg_cpu *cpu = container_of(timer, struct lg_cpu, hrt);
 
 	/* Remember the first interrupt is the timer interrupt. */
-	set_bit(0, lg->irqs_pending);
+	set_bit(0, cpu->irqs_pending);
 	/* If the Guest is actually stopped, we need to wake it up. */
-	if (lg->halted)
-		wake_up_process(lg->tsk);
+	if (cpu->halted)
+		wake_up_process(cpu->tsk);
 	return HRTIMER_NORESTART;
 }
 
 /* This sets up the timer for this Guest. */
-void init_clockdev(struct lguest *lg)
+void init_clockdev(struct lg_cpu *cpu)
 {
-	hrtimer_init(&lg->hrt, CLOCK_REALTIME, HRTIMER_MODE_ABS);
-	lg->hrt.function = clockdev_fn;
+	hrtimer_init(&cpu->hrt, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+	cpu->hrt.function = clockdev_fn;
 }
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 8692489..2337e1a 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -8,6 +8,7 @@
 #include <linux/lguest.h>
 #include <linux/lguest_launcher.h>
 #include <linux/wait.h>
+#include <linux/hrtimer.h>
 #include <linux/err.h>
 #include <asm/semaphore.h>
 
@@ -38,58 +39,72 @@ struct lguest_pages
 #define CHANGED_GDT_TLS		4 /* Actually a subset of CHANGED_GDT */
 #define CHANGED_ALL	        3
 
-/* The private info the thread maintains about the guest. */
-struct lguest
-{
-	/* At end of a page shared mapped over lguest_pages in guest.  */
-	unsigned long regs_page;
-	struct lguest_regs *regs;
-	struct lguest_data __user *lguest_data;
+struct lguest;
+
+struct lg_cpu {
+	unsigned int id;
+	struct lguest *lg;
 	struct task_struct *tsk;
 	struct mm_struct *mm; 	/* == tsk->mm, but that becomes NULL on exit */
-	u32 pfn_limit;
-	/* This provides the offset to the base of guest-physical
-	 * memory in the Launcher. */
-	void __user *mem_base;
-	unsigned long kernel_address;
+
 	u32 cr2;
-	int halted;
 	int ts;
-	u32 next_hcall;
 	u32 esp1;
 	u8 ss1;
 
+	/* Bitmap of what has changed: see CHANGED_* above. */
+	int changed;
+
+	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
+
+	/* At end of a page shared mapped over lguest_pages in guest.  */
+	unsigned long regs_page;
+	struct lguest_regs *regs;
+
+	struct lguest_pages *last_pages;
+
+	int cpu_pgd; /* which pgd this cpu is currently using */
+
 	/* If a hypercall was asked for, this points to the arguments. */
 	struct hcall_args *hcall;
+	u32 next_hcall;
+
+	/* Virtual clock device */
+	struct hrtimer hrt;
 
 	/* Do we need to stop what we're doing and return to userspace? */
 	int break_out;
 	wait_queue_head_t break_wq;
+	int halted;
 
-	/* Bitmap of what has changed: see CHANGED_* above. */
-	int changed;
-	struct lguest_pages *last_pages;
+	/* Pending virtual interrupts */
+	DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
+
+	struct lg_cpu_arch arch;
+};
+
+/* The private info the thread maintains about the guest. */
+struct lguest
+{
+	struct lguest_data __user *lguest_data;
+	struct lg_cpu cpus[NR_CPUS];
+	unsigned int nr_cpus;
+
+	u32 pfn_limit;
+	/* This provides the offset to the base of guest-physical
+	 * memory in the Launcher. */
+	void __user *mem_base;
+	unsigned long kernel_address;
 
-	/* We keep a small number of these. */
-	u32 pgdidx;
 	struct pgdir pgdirs[4];
 
 	unsigned long noirq_start, noirq_end;
-	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
 
 	unsigned int stack_pages;
 	u32 tsc_khz;
 
 	/* Dead? */
 	const char *dead;
-
-	struct lguest_arch arch;
-
-	/* Virtual clock device */
-	struct hrtimer hrt;
-
-	/* Pending virtual interrupts */
-	DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
 };
 
 extern struct mutex lguest_lock;
@@ -97,26 +112,26 @@ extern struct mutex lguest_lock;
 /* core.c: */
 int lguest_address_ok(const struct lguest *lg,
 		      unsigned long addr, unsigned long len);
-void __lgread(struct lguest *, void *, unsigned long, unsigned);
-void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
+void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
+void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
 
 /*H:035 Using memory-copy operations like that is usually inconvient, so we
  * have the following helper macros which read and write a specific type (often
  * an unsigned long).
  *
  * This reads into a variable of the given type then returns that. */
-#define lgread(lg, addr, type)						\
-	({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
+#define lgread(cpu, addr, type)						\
+	({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
 
 /* This checks that the variable is of the given type, then writes it out. */
-#define lgwrite(lg, addr, type, val)				\
+#define lgwrite(cpu, addr, type, val)				\
 	do {							\
 		typecheck(type, val);				\
-		__lgwrite((lg), (addr), &(val), sizeof(val));	\
+		__lgwrite((cpu), (addr), &(val), sizeof(val));	\
 	} while(0)
 /* (end of memory access helper routines) :*/
 
-int run_guest(struct lguest *lg, unsigned long __user *user);
+int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
 
 /* Helper macros to obtain the first 12 or the last 20 bits, this is only the
  * first step in the migration to the kernel types.  pte_pfn is already defined
@@ -126,52 +141,53 @@ int run_guest(struct lguest *lg, unsigned long __user *user);
 #define pgd_pfn(x)	(pgd_val(x) >> PAGE_SHIFT)
 
 /* interrupts_and_traps.c: */
-void maybe_do_interrupt(struct lguest *lg);
-int deliver_trap(struct lguest *lg, unsigned int num);
-void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
-void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
-void pin_stack_pages(struct lguest *lg);
+void maybe_do_interrupt(struct lg_cpu *cpu);
+int deliver_trap(struct lg_cpu *cpu, unsigned int num);
+void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
+			  u32 low, u32 hi);
+void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
+void pin_stack_pages(struct lg_cpu *cpu);
 void setup_default_idt_entries(struct lguest_ro_state *state,
 			       const unsigned long *def);
-void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
 		const unsigned long *def);
-void guest_set_clockevent(struct lguest *lg, unsigned long delta);
-void init_clockdev(struct lguest *lg);
+void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
+void init_clockdev(struct lg_cpu *cpu);
 bool check_syscall_vector(struct lguest *lg);
 int init_interrupts(void);
 void free_interrupts(void);
 
 /* segments.c: */
 void setup_default_gdt_entries(struct lguest_ro_state *state);
-void setup_guest_gdt(struct lguest *lg);
-void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
-void guest_load_tls(struct lguest *lg, unsigned long tls_array);
-void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
-void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
+void setup_guest_gdt(struct lg_cpu *cpu);
+void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
+void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
+void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
+void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
 
 /* page_tables.c: */
 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
 void free_guest_pagetable(struct lguest *lg);
-void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
+void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
-void guest_pagetable_clear_all(struct lguest *lg);
-void guest_pagetable_flush_user(struct lguest *lg);
-void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
+void guest_pagetable_clear_all(struct lg_cpu *cpu);
+void guest_pagetable_flush_user(struct lg_cpu *cpu);
+void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
 		   unsigned long vaddr, pte_t val);
-void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
-int demand_page(struct lguest *info, unsigned long cr2, int errcode);
-void pin_page(struct lguest *lg, unsigned long vaddr);
-unsigned long guest_pa(struct lguest *lg, unsigned long vaddr);
-void page_table_guest_data_init(struct lguest *lg);
+void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
+int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
+void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
+unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
+void page_table_guest_data_init(struct lg_cpu *cpu);
 
 /* <arch>/core.c: */
 void lguest_arch_host_init(void);
 void lguest_arch_host_fini(void);
-void lguest_arch_run_guest(struct lguest *lg);
-void lguest_arch_handle_trap(struct lguest *lg);
-int lguest_arch_init_hypercalls(struct lguest *lg);
-int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
-void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
+void lguest_arch_run_guest(struct lg_cpu *cpu);
+void lguest_arch_handle_trap(struct lg_cpu *cpu);
+int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
+int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
+void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start);
 
 /* <arch>/switcher.S: */
 extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
@@ -181,8 +197,8 @@ int lguest_device_init(void);
 void lguest_device_remove(void);
 
 /* hypercalls.c: */
-void do_hypercalls(struct lguest *lg);
-void write_timestamp(struct lguest *lg);
+void do_hypercalls(struct lg_cpu *cpu);
+void write_timestamp(struct lg_cpu *cpu);
 
 /*L:035
  * Let's step aside for the moment, to study one important routine that's used
@@ -208,12 +224,12 @@ void write_timestamp(struct lguest *lg);
  * Like any macro which uses an "if", it is safely wrapped in a run-once "do {
  * } while(0)".
  */
-#define kill_guest(lg, fmt...)					\
+#define kill_guest(cpu, fmt...)					\
 do {								\
-	if (!(lg)->dead) {					\
-		(lg)->dead = kasprintf(GFP_ATOMIC, fmt);	\
-		if (!(lg)->dead)				\
-			(lg)->dead = ERR_PTR(-ENOMEM);		\
+	if (!(cpu)->lg->dead) {					\
+		(cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt);	\
+		if (!(cpu)->lg->dead)				\
+			(cpu)->lg->dead = ERR_PTR(-ENOMEM);	\
 	}							\
 } while(0)
 /* (End of aside) :*/
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index 3b92a61..85d42d3 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -6,6 +6,7 @@
 #include <linux/uaccess.h>
 #include <linux/miscdevice.h>
 #include <linux/fs.h>
+#include <linux/sched.h>
 #include "lg.h"
 
 /*L:055 When something happens, the Waker process needs a way to stop the
@@ -13,7 +14,7 @@
  * LHREQ_BREAK and the value "1" to /dev/lguest to do this.  Once the Launcher
  * has done whatever needs attention, it writes LHREQ_BREAK and "0" to release
  * the Waker. */
-static int break_guest_out(struct lguest *lg, const unsigned long __user *input)
+static int break_guest_out(struct lg_cpu *cpu, const unsigned long __user*input)
 {
 	unsigned long on;
 
@@ -22,21 +23,21 @@ static int break_guest_out(struct lguest *lg, const unsigned long __user *input)
 		return -EFAULT;
 
 	if (on) {
-		lg->break_out = 1;
+		cpu->break_out = 1;
 		/* Pop it out of the Guest (may be running on different CPU) */
-		wake_up_process(lg->tsk);
+		wake_up_process(cpu->tsk);
 		/* Wait for them to reset it */
-		return wait_event_interruptible(lg->break_wq, !lg->break_out);
+		return wait_event_interruptible(cpu->break_wq, !cpu->break_out);
 	} else {
-		lg->break_out = 0;
-		wake_up(&lg->break_wq);
+		cpu->break_out = 0;
+		wake_up(&cpu->break_wq);
 		return 0;
 	}
 }
 
 /*L:050 Sending an interrupt is done by writing LHREQ_IRQ and an interrupt
  * number to /dev/lguest. */
-static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
+static int user_send_irq(struct lg_cpu *cpu, const unsigned long __user *input)
 {
 	unsigned long irq;
 
@@ -46,7 +47,7 @@ static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
 		return -EINVAL;
 	/* Next time the Guest runs, the core code will see if it can deliver
 	 * this interrupt. */
-	set_bit(irq, lg->irqs_pending);
+	set_bit(irq, cpu->irqs_pending);
 	return 0;
 }
 
@@ -55,13 +56,21 @@ static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
 static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
 {
 	struct lguest *lg = file->private_data;
+	struct lg_cpu *cpu;
+	unsigned int cpu_id = *o;
 
 	/* You must write LHREQ_INITIALIZE first! */
 	if (!lg)
 		return -EINVAL;
 
+	/* Watch out for arbitrary vcpu indexes! */
+	if (cpu_id >= lg->nr_cpus)
+		return -EINVAL;
+
+	cpu = &lg->cpus[cpu_id];
+
 	/* If you're not the task which owns the Guest, go away. */
-	if (current != lg->tsk)
+	if (current != cpu->tsk)
 		return -EPERM;
 
 	/* If the guest is already dead, we indicate why */
@@ -81,11 +90,53 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
 
 	/* If we returned from read() last time because the Guest notified,
 	 * clear the flag. */
-	if (lg->pending_notify)
-		lg->pending_notify = 0;
+	if (cpu->pending_notify)
+		cpu->pending_notify = 0;
 
 	/* Run the Guest until something interesting happens. */
-	return run_guest(lg, (unsigned long __user *)user);
+	return run_guest(cpu, (unsigned long __user *)user);
+}
+
+static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip)
+{
+	if (id >= NR_CPUS)
+		return -EINVAL;
+
+	cpu->id = id;
+	cpu->lg = container_of((cpu - id), struct lguest, cpus[0]);
+	cpu->lg->nr_cpus++;
+	init_clockdev(cpu);
+
+	/* We need a complete page for the Guest registers: they are accessible
+	 * to the Guest and we can only grant it access to whole pages. */
+	cpu->regs_page = get_zeroed_page(GFP_KERNEL);
+	if (!cpu->regs_page)
+		return -ENOMEM;
+
+	/* We actually put the registers at the bottom of the page. */
+	cpu->regs = (void *)cpu->regs_page + PAGE_SIZE - sizeof(*cpu->regs);
+
+	/* Now we initialize the Guest's registers, handing it the start
+	 * address. */
+	lguest_arch_setup_regs(cpu, start_ip);
+
+	/* Initialize the queue for the waker to wait on */
+	init_waitqueue_head(&cpu->break_wq);
+
+	/* We keep a pointer to the Launcher task (ie. current task) for when
+	 * other Guests want to wake this one (inter-Guest I/O). */
+	cpu->tsk = current;
+
+	/* We need to keep a pointer to the Launcher's memory map, because if
+	 * the Launcher dies we need to clean it up.  If we don't keep a
+	 * reference, it is destroyed before close() is called. */
+	cpu->mm = get_task_mm(cpu->tsk);
+
+	/* We remember which CPU's pages this Guest used last, for optimization
+	 * when the same Guest runs on the same CPU twice. */
+	cpu->last_pages = NULL;
+
+	return 0;
 }
 
 /*L:020 The initialization write supplies 4 pointer sized (32 or 64 bit)
@@ -134,15 +185,10 @@ static int initialize(struct file *file, const unsigned long __user *input)
 	lg->mem_base = (void __user *)(long)args[0];
 	lg->pfn_limit = args[1];
 
-	/* We need a complete page for the Guest registers: they are accessible
-	 * to the Guest and we can only grant it access to whole pages. */
-	lg->regs_page = get_zeroed_page(GFP_KERNEL);
-	if (!lg->regs_page) {
-		err = -ENOMEM;
+	/* This is the first cpu */
+	err = lg_cpu_start(&lg->cpus[0], 0, args[3]);
+	if (err)
 		goto release_guest;
-	}
-	/* We actually put the registers at the bottom of the page. */
-	lg->regs = (void *)lg->regs_page + PAGE_SIZE - sizeof(*lg->regs);
 
 	/* Initialize the Guest's shadow page tables, using the toplevel
 	 * address the Launcher gave us.  This allocates memory, so can
@@ -151,28 +197,6 @@ static int initialize(struct file *file, const unsigned long __user *input)
 	if (err)
 		goto free_regs;
 
-	/* Now we initialize the Guest's registers, handing it the start
-	 * address. */
-	lguest_arch_setup_regs(lg, args[3]);
-
-	/* The timer for lguest's clock needs initialization. */
-	init_clockdev(lg);
-
-	/* We keep a pointer to the Launcher task (ie. current task) for when
-	 * other Guests want to wake this one (inter-Guest I/O). */
-	lg->tsk = current;
-	/* We need to keep a pointer to the Launcher's memory map, because if
-	 * the Launcher dies we need to clean it up.  If we don't keep a
-	 * reference, it is destroyed before close() is called. */
-	lg->mm = get_task_mm(lg->tsk);
-
-	/* Initialize the queue for the waker to wait on */
-	init_waitqueue_head(&lg->break_wq);
-
-	/* We remember which CPU's pages this Guest used last, for optimization
-	 * when the same Guest runs on the same CPU twice. */
-	lg->last_pages = NULL;
-
 	/* We keep our "struct lguest" in the file's private_data. */
 	file->private_data = lg;
 
@@ -182,7 +206,8 @@ static int initialize(struct file *file, const unsigned long __user *input)
 	return sizeof(args);
 
 free_regs:
-	free_page(lg->regs_page);
+	/* FIXME: This should be in free_vcpu */
+	free_page(lg->cpus[0].regs_page);
 release_guest:
 	kfree(lg);
 unlock:
@@ -202,30 +227,37 @@ static ssize_t write(struct file *file, const char __user *in,
 	struct lguest *lg = file->private_data;
 	const unsigned long __user *input = (const unsigned long __user *)in;
 	unsigned long req;
+	struct lg_cpu *uninitialized_var(cpu);
+	unsigned int cpu_id = *off;
 
 	if (get_user(req, input) != 0)
 		return -EFAULT;
 	input++;
 
 	/* If you haven't initialized, you must do that first. */
-	if (req != LHREQ_INITIALIZE && !lg)
-		return -EINVAL;
+	if (req != LHREQ_INITIALIZE) {
+		if (!lg || (cpu_id >= lg->nr_cpus))
+			return -EINVAL;
+		cpu = &lg->cpus[cpu_id];
+		if (!cpu)
+			return -EINVAL;
+	}
 
 	/* Once the Guest is dead, all you can do is read() why it died. */
 	if (lg && lg->dead)
 		return -ENOENT;
 
 	/* If you're not the task which owns the Guest, you can only break */
-	if (lg && current != lg->tsk && req != LHREQ_BREAK)
+	if (lg && current != cpu->tsk && req != LHREQ_BREAK)
 		return -EPERM;
 
 	switch (req) {
 	case LHREQ_INITIALIZE:
 		return initialize(file, input);
 	case LHREQ_IRQ:
-		return user_send_irq(lg, input);
+		return user_send_irq(cpu, input);
 	case LHREQ_BREAK:
-		return break_guest_out(lg, input);
+		return break_guest_out(cpu, input);
 	default:
 		return -EINVAL;
 	}
@@ -241,6 +273,7 @@ static ssize_t write(struct file *file, const char __user *in,
 static int close(struct inode *inode, struct file *file)
 {
 	struct lguest *lg = file->private_data;
+	unsigned int i;
 
 	/* If we never successfully initialized, there's nothing to clean up */
 	if (!lg)
@@ -249,19 +282,23 @@ static int close(struct inode *inode, struct file *file)
 	/* We need the big lock, to protect from inter-guest I/O and other
 	 * Launchers initializing guests. */
 	mutex_lock(&lguest_lock);
-	/* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
-	hrtimer_cancel(&lg->hrt);
+
 	/* Free up the shadow page tables for the Guest. */
 	free_guest_pagetable(lg);
-	/* Now all the memory cleanups are done, it's safe to release the
-	 * Launcher's memory management structure. */
-	mmput(lg->mm);
+
+	for (i = 0; i < lg->nr_cpus; i++) {
+		/* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
+		hrtimer_cancel(&lg->cpus[i].hrt);
+		/* We can free up the register page we allocated. */
+		free_page(lg->cpus[i].regs_page);
+		/* Now all the memory cleanups are done, it's safe to release
+		 * the Launcher's memory management structure. */
+		mmput(lg->cpus[i].mm);
+	}
 	/* If lg->dead doesn't contain an error code it will be NULL or a
 	 * kmalloc()ed string, either of which is ok to hand to kfree(). */
 	if (!IS_ERR(lg->dead))
 		kfree(lg->dead);
-	/* We can free up the register page we allocated. */
-	free_page(lg->regs_page);
 	/* We clear the entire structure, which also marks it as free for the
 	 * next user. */
 	memset(lg, 0, sizeof(*lg));
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index fffabb3..74b4cf2 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -68,23 +68,23 @@ static DEFINE_PER_CPU(pte_t *, switcher_pte_pages);
  * page directory entry (PGD) for that address.  Since we keep track of several
  * page tables, the "i" argument tells us which one we're interested in (it's
  * usually the current one). */
-static pgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
+static pgd_t *spgd_addr(struct lg_cpu *cpu, u32 i, unsigned long vaddr)
 {
 	unsigned int index = pgd_index(vaddr);
 
 	/* We kill any Guest trying to touch the Switcher addresses. */
 	if (index >= SWITCHER_PGD_INDEX) {
-		kill_guest(lg, "attempt to access switcher pages");
+		kill_guest(cpu, "attempt to access switcher pages");
 		index = 0;
 	}
 	/* Return a pointer index'th pgd entry for the i'th page table. */
-	return &lg->pgdirs[i].pgdir[index];
+	return &cpu->lg->pgdirs[i].pgdir[index];
 }
 
 /* This routine then takes the page directory entry returned above, which
  * contains the address of the page table entry (PTE) page.  It then returns a
  * pointer to the PTE entry for the given address. */
-static pte_t *spte_addr(struct lguest *lg, pgd_t spgd, unsigned long vaddr)
+static pte_t *spte_addr(pgd_t spgd, unsigned long vaddr)
 {
 	pte_t *page = __va(pgd_pfn(spgd) << PAGE_SHIFT);
 	/* You should never call this if the PGD entry wasn't valid */
@@ -94,14 +94,13 @@ static pte_t *spte_addr(struct lguest *lg, pgd_t spgd, unsigned long vaddr)
 
 /* These two functions just like the above two, except they access the Guest
  * page tables.  Hence they return a Guest address. */
-static unsigned long gpgd_addr(struct lguest *lg, unsigned long vaddr)
+static unsigned long gpgd_addr(struct lg_cpu *cpu, unsigned long vaddr)
 {
 	unsigned int index = vaddr >> (PGDIR_SHIFT);
-	return lg->pgdirs[lg->pgdidx].gpgdir + index * sizeof(pgd_t);
+	return cpu->lg->pgdirs[cpu->cpu_pgd].gpgdir + index * sizeof(pgd_t);
 }
 
-static unsigned long gpte_addr(struct lguest *lg,
-			       pgd_t gpgd, unsigned long vaddr)
+static unsigned long gpte_addr(pgd_t gpgd, unsigned long vaddr)
 {
 	unsigned long gpage = pgd_pfn(gpgd) << PAGE_SHIFT;
 	BUG_ON(!(pgd_flags(gpgd) & _PAGE_PRESENT));
@@ -138,7 +137,7 @@ static unsigned long get_pfn(unsigned long virtpfn, int write)
  * entry can be a little tricky.  The flags are (almost) the same, but the
  * Guest PTE contains a virtual page number: the CPU needs the real page
  * number. */
-static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
+static pte_t gpte_to_spte(struct lg_cpu *cpu, pte_t gpte, int write)
 {
 	unsigned long pfn, base, flags;
 
@@ -149,7 +148,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
 	flags = (pte_flags(gpte) & ~_PAGE_GLOBAL);
 
 	/* The Guest's pages are offset inside the Launcher. */
-	base = (unsigned long)lg->mem_base / PAGE_SIZE;
+	base = (unsigned long)cpu->lg->mem_base / PAGE_SIZE;
 
 	/* We need a temporary "unsigned long" variable to hold the answer from
 	 * get_pfn(), because it returns 0xFFFFFFFF on failure, which wouldn't
@@ -157,7 +156,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
 	 * page, given the virtual number. */
 	pfn = get_pfn(base + pte_pfn(gpte), write);
 	if (pfn == -1UL) {
-		kill_guest(lg, "failed to get page %lu", pte_pfn(gpte));
+		kill_guest(cpu, "failed to get page %lu", pte_pfn(gpte));
 		/* When we destroy the Guest, we'll go through the shadow page
 		 * tables and release_pte() them.  Make sure we don't think
 		 * this one is valid! */
@@ -177,17 +176,18 @@ static void release_pte(pte_t pte)
 }
 /*:*/
 
-static void check_gpte(struct lguest *lg, pte_t gpte)
+static void check_gpte(struct lg_cpu *cpu, pte_t gpte)
 {
 	if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE))
-	    || pte_pfn(gpte) >= lg->pfn_limit)
-		kill_guest(lg, "bad page table entry");
+	    || pte_pfn(gpte) >= cpu->lg->pfn_limit)
+		kill_guest(cpu, "bad page table entry");
 }
 
-static void check_gpgd(struct lguest *lg, pgd_t gpgd)
+static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd)
 {
-	if ((pgd_flags(gpgd) & ~_PAGE_TABLE) || pgd_pfn(gpgd) >= lg->pfn_limit)
-		kill_guest(lg, "bad page directory entry");
+	if ((pgd_flags(gpgd) & ~_PAGE_TABLE) ||
+	   (pgd_pfn(gpgd) >= cpu->lg->pfn_limit))
+		kill_guest(cpu, "bad page directory entry");
 }
 
 /*H:330
@@ -200,7 +200,7 @@ static void check_gpgd(struct lguest *lg, pgd_t gpgd)
  *
  * If we fixed up the fault (ie. we mapped the address), this routine returns
  * true.  Otherwise, it was a real fault and we need to tell the Guest. */
-int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
+int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
 {
 	pgd_t gpgd;
 	pgd_t *spgd;
@@ -209,24 +209,24 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
 	pte_t *spte;
 
 	/* First step: get the top-level Guest page table entry. */
-	gpgd = lgread(lg, gpgd_addr(lg, vaddr), pgd_t);
+	gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
 	/* Toplevel not present?  We can't map it in. */
 	if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
 		return 0;
 
 	/* Now look at the matching shadow entry. */
-	spgd = spgd_addr(lg, lg->pgdidx, vaddr);
+	spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
 	if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) {
 		/* No shadow entry: allocate a new shadow PTE page. */
 		unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
 		/* This is not really the Guest's fault, but killing it is
 		 * simple for this corner case. */
 		if (!ptepage) {
-			kill_guest(lg, "out of memory allocating pte page");
+			kill_guest(cpu, "out of memory allocating pte page");
 			return 0;
 		}
 		/* We check that the Guest pgd is OK. */
-		check_gpgd(lg, gpgd);
+		check_gpgd(cpu, gpgd);
 		/* And we copy the flags to the shadow PGD entry.  The page
 		 * number in the shadow PGD is the page we just allocated. */
 		*spgd = __pgd(__pa(ptepage) | pgd_flags(gpgd));
@@ -234,8 +234,8 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
 
 	/* OK, now we look at the lower level in the Guest page table: keep its
 	 * address, because we might update it later. */
-	gpte_ptr = gpte_addr(lg, gpgd, vaddr);
-	gpte = lgread(lg, gpte_ptr, pte_t);
+	gpte_ptr = gpte_addr(gpgd, vaddr);
+	gpte = lgread(cpu, gpte_ptr, pte_t);
 
 	/* If this page isn't in the Guest page tables, we can't page it in. */
 	if (!(pte_flags(gpte) & _PAGE_PRESENT))
@@ -252,7 +252,7 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
 
 	/* Check that the Guest PTE flags are OK, and the page number is below
 	 * the pfn_limit (ie. not mapping the Launcher binary). */
-	check_gpte(lg, gpte);
+	check_gpte(cpu, gpte);
 
 	/* Add the _PAGE_ACCESSED and (for a write) _PAGE_DIRTY flag */
 	gpte = pte_mkyoung(gpte);
@@ -260,7 +260,7 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
 		gpte = pte_mkdirty(gpte);
 
 	/* Get the pointer to the shadow PTE entry we're going to set. */
-	spte = spte_addr(lg, *spgd, vaddr);
+	spte = spte_addr(*spgd, vaddr);
 	/* If there was a valid shadow PTE entry here before, we release it.
 	 * This can happen with a write to a previously read-only entry. */
 	release_pte(*spte);
@@ -268,17 +268,17 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
 	/* If this is a write, we insist that the Guest page is writable (the
 	 * final arg to gpte_to_spte()). */
 	if (pte_dirty(gpte))
-		*spte = gpte_to_spte(lg, gpte, 1);
+		*spte = gpte_to_spte(cpu, gpte, 1);
 	else
 		/* If this is a read, don't set the "writable" bit in the page
 		 * table entry, even if the Guest says it's writable.  That way
 		 * we will come back here when a write does actually occur, so
 		 * we can update the Guest's _PAGE_DIRTY flag. */
-		*spte = gpte_to_spte(lg, pte_wrprotect(gpte), 0);
+		*spte = gpte_to_spte(cpu, pte_wrprotect(gpte), 0);
 
 	/* Finally, we write the Guest PTE entry back: we've set the
 	 * _PAGE_ACCESSED and maybe the _PAGE_DIRTY flags. */
-	lgwrite(lg, gpte_ptr, pte_t, gpte);
+	lgwrite(cpu, gpte_ptr, pte_t, gpte);
 
 	/* The fault is fixed, the page table is populated, the mapping
 	 * manipulated, the result returned and the code complete.  A small
@@ -297,19 +297,19 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
  *
  * This is a quick version which answers the question: is this virtual address
  * mapped by the shadow page tables, and is it writable? */
-static int page_writable(struct lguest *lg, unsigned long vaddr)
+static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
 {
 	pgd_t *spgd;
 	unsigned long flags;
 
 	/* Look at the current top level entry: is it present? */
-	spgd = spgd_addr(lg, lg->pgdidx, vaddr);
+	spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
 	if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
 		return 0;
 
 	/* Check the flags on the pte entry itself: it must be present and
 	 * writable. */
-	flags = pte_flags(*(spte_addr(lg, *spgd, vaddr)));
+	flags = pte_flags(*(spte_addr(*spgd, vaddr)));
 
 	return (flags & (_PAGE_PRESENT|_PAGE_RW)) == (_PAGE_PRESENT|_PAGE_RW);
 }
@@ -317,10 +317,10 @@ static int page_writable(struct lguest *lg, unsigned long vaddr)
 /* So, when pin_stack_pages() asks us to pin a page, we check if it's already
  * in the page tables, and if not, we call demand_page() with error code 2
  * (meaning "write"). */
-void pin_page(struct lguest *lg, unsigned long vaddr)
+void pin_page(struct lg_cpu *cpu, unsigned long vaddr)
 {
-	if (!page_writable(lg, vaddr) && !demand_page(lg, vaddr, 2))
-		kill_guest(lg, "bad stack page %#lx", vaddr);
+	if (!page_writable(cpu, vaddr) && !demand_page(cpu, vaddr, 2))
+		kill_guest(cpu, "bad stack page %#lx", vaddr);
 }
 
 /*H:450 If we chase down the release_pgd() code, it looks like this: */
@@ -358,28 +358,28 @@ static void flush_user_mappings(struct lguest *lg, int idx)
  *
  * The Guest has a hypercall to throw away the page tables: it's used when a
  * large number of mappings have been changed. */
-void guest_pagetable_flush_user(struct lguest *lg)
+void guest_pagetable_flush_user(struct lg_cpu *cpu)
 {
 	/* Drop the userspace part of the current page table. */
-	flush_user_mappings(lg, lg->pgdidx);
+	flush_user_mappings(cpu->lg, cpu->cpu_pgd);
 }
 /*:*/
 
 /* We walk down the guest page tables to get a guest-physical address */
-unsigned long guest_pa(struct lguest *lg, unsigned long vaddr)
+unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr)
 {
 	pgd_t gpgd;
 	pte_t gpte;
 
 	/* First step: get the top-level Guest page table entry. */
-	gpgd = lgread(lg, gpgd_addr(lg, vaddr), pgd_t);
+	gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
 	/* Toplevel not present?  We can't map it in. */
 	if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
-		kill_guest(lg, "Bad address %#lx", vaddr);
+		kill_guest(cpu, "Bad address %#lx", vaddr);
 
-	gpte = lgread(lg, gpte_addr(lg, gpgd, vaddr), pte_t);
+	gpte = lgread(cpu, gpte_addr(gpgd, vaddr), pte_t);
 	if (!(pte_flags(gpte) & _PAGE_PRESENT))
-		kill_guest(lg, "Bad address %#lx", vaddr);
+		kill_guest(cpu, "Bad address %#lx", vaddr);
 
 	return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK);
 }
@@ -399,7 +399,7 @@ static unsigned int find_pgdir(struct lguest *lg, unsigned long pgtable)
 /*H:435 And this is us, creating the new page directory.  If we really do
  * allocate a new one (and so the kernel parts are not there), we set
  * blank_pgdir. */
-static unsigned int new_pgdir(struct lguest *lg,
+static unsigned int new_pgdir(struct lg_cpu *cpu,
 			      unsigned long gpgdir,
 			      int *blank_pgdir)
 {
@@ -407,22 +407,23 @@ static unsigned int new_pgdir(struct lguest *lg,
 
 	/* We pick one entry at random to throw out.  Choosing the Least
 	 * Recently Used might be better, but this is easy. */
-	next = random32() % ARRAY_SIZE(lg->pgdirs);
+	next = random32() % ARRAY_SIZE(cpu->lg->pgdirs);
 	/* If it's never been allocated at all before, try now. */
-	if (!lg->pgdirs[next].pgdir) {
-		lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
+	if (!cpu->lg->pgdirs[next].pgdir) {
+		cpu->lg->pgdirs[next].pgdir =
+					(pgd_t *)get_zeroed_page(GFP_KERNEL);
 		/* If the allocation fails, just keep using the one we have */
-		if (!lg->pgdirs[next].pgdir)
-			next = lg->pgdidx;
+		if (!cpu->lg->pgdirs[next].pgdir)
+			next = cpu->cpu_pgd;
 		else
 			/* This is a blank page, so there are no kernel
 			 * mappings: caller must map the stack! */
 			*blank_pgdir = 1;
 	}
 	/* Record which Guest toplevel this shadows. */
-	lg->pgdirs[next].gpgdir = gpgdir;
+	cpu->lg->pgdirs[next].gpgdir = gpgdir;
 	/* Release all the non-kernel mappings. */
-	flush_user_mappings(lg, next);
+	flush_user_mappings(cpu->lg, next);
 
 	return next;
 }
@@ -432,21 +433,21 @@ static unsigned int new_pgdir(struct lguest *lg,
  * Now we've seen all the page table setting and manipulation, let's see what
  * what happens when the Guest changes page tables (ie. changes the top-level
  * pgdir).  This occurs on almost every context switch. */
-void guest_new_pagetable(struct lguest *lg, unsigned long pgtable)
+void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable)
 {
 	int newpgdir, repin = 0;
 
 	/* Look to see if we have this one already. */
-	newpgdir = find_pgdir(lg, pgtable);
+	newpgdir = find_pgdir(cpu->lg, pgtable);
 	/* If not, we allocate or mug an existing one: if it's a fresh one,
 	 * repin gets set to 1. */
-	if (newpgdir == ARRAY_SIZE(lg->pgdirs))
-		newpgdir = new_pgdir(lg, pgtable, &repin);
+	if (newpgdir == ARRAY_SIZE(cpu->lg->pgdirs))
+		newpgdir = new_pgdir(cpu, pgtable, &repin);
 	/* Change the current pgd index to the new one. */
-	lg->pgdidx = newpgdir;
+	cpu->cpu_pgd = newpgdir;
 	/* If it was completely blank, we map in the Guest kernel stack */
 	if (repin)
-		pin_stack_pages(lg);
+		pin_stack_pages(cpu);
 }
 
 /*H:470 Finally, a routine which throws away everything: all PGD entries in all
@@ -468,11 +469,11 @@ static void release_all_pagetables(struct lguest *lg)
  * mapping.  Since kernel mappings are in every page table, it's easiest to
  * throw them all away.  This traps the Guest in amber for a while as
  * everything faults back in, but it's rare. */
-void guest_pagetable_clear_all(struct lguest *lg)
+void guest_pagetable_clear_all(struct lg_cpu *cpu)
 {
-	release_all_pagetables(lg);
+	release_all_pagetables(cpu->lg);
 	/* We need the Guest kernel stack mapped again. */
-	pin_stack_pages(lg);
+	pin_stack_pages(cpu);
 }
 /*:*/
 /*M:009 Since we throw away all mappings when a kernel mapping changes, our
@@ -497,24 +498,24 @@ void guest_pagetable_clear_all(struct lguest *lg)
  * _PAGE_ACCESSED then we can put a read-only PTE entry in immediately, and if
  * they set _PAGE_DIRTY then we can put a writable PTE entry in immediately.
  */
-static void do_set_pte(struct lguest *lg, int idx,
+static void do_set_pte(struct lg_cpu *cpu, int idx,
 		       unsigned long vaddr, pte_t gpte)
 {
 	/* Look up the matching shadow page directory entry. */
-	pgd_t *spgd = spgd_addr(lg, idx, vaddr);
+	pgd_t *spgd = spgd_addr(cpu, idx, vaddr);
 
 	/* If the top level isn't present, there's no entry to update. */
 	if (pgd_flags(*spgd) & _PAGE_PRESENT) {
 		/* Otherwise, we start by releasing the existing entry. */
-		pte_t *spte = spte_addr(lg, *spgd, vaddr);
+		pte_t *spte = spte_addr(*spgd, vaddr);
 		release_pte(*spte);
 
 		/* If they're setting this entry as dirty or accessed, we might
 		 * as well put that entry they've given us in now.  This shaves
 		 * 10% off a copy-on-write micro-benchmark. */
 		if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
-			check_gpte(lg, gpte);
-			*spte = gpte_to_spte(lg, gpte,
+			check_gpte(cpu, gpte);
+			*spte = gpte_to_spte(cpu, gpte,
 					     pte_flags(gpte) & _PAGE_DIRTY);
 		} else
 			/* Otherwise kill it and we can demand_page() it in
@@ -533,22 +534,22 @@ static void do_set_pte(struct lguest *lg, int idx,
  *
  * The benefit is that when we have to track a new page table, we can copy keep
  * all the kernel mappings.  This speeds up context switch immensely. */
-void guest_set_pte(struct lguest *lg,
+void guest_set_pte(struct lg_cpu *cpu,
 		   unsigned long gpgdir, unsigned long vaddr, pte_t gpte)
 {
 	/* Kernel mappings must be changed on all top levels.  Slow, but
 	 * doesn't happen often. */
-	if (vaddr >= lg->kernel_address) {
+	if (vaddr >= cpu->lg->kernel_address) {
 		unsigned int i;
-		for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
-			if (lg->pgdirs[i].pgdir)
-				do_set_pte(lg, i, vaddr, gpte);
+		for (i = 0; i < ARRAY_SIZE(cpu->lg->pgdirs); i++)
+			if (cpu->lg->pgdirs[i].pgdir)
+				do_set_pte(cpu, i, vaddr, gpte);
 	} else {
 		/* Is this page table one we have a shadow for? */
-		int pgdir = find_pgdir(lg, gpgdir);
-		if (pgdir != ARRAY_SIZE(lg->pgdirs))
+		int pgdir = find_pgdir(cpu->lg, gpgdir);
+		if (pgdir != ARRAY_SIZE(cpu->lg->pgdirs))
 			/* If so, do the update. */
-			do_set_pte(lg, pgdir, vaddr, gpte);
+			do_set_pte(cpu, pgdir, vaddr, gpte);
 	}
 }
 
@@ -590,30 +591,32 @@ int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
 {
 	/* We start on the first shadow page table, and give it a blank PGD
 	 * page. */
-	lg->pgdidx = 0;
-	lg->pgdirs[lg->pgdidx].gpgdir = pgtable;
-	lg->pgdirs[lg->pgdidx].pgdir = (pgd_t*)get_zeroed_page(GFP_KERNEL);
-	if (!lg->pgdirs[lg->pgdidx].pgdir)
+	lg->pgdirs[0].gpgdir = pgtable;
+	lg->pgdirs[0].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
+	if (!lg->pgdirs[0].pgdir)
 		return -ENOMEM;
+	lg->cpus[0].cpu_pgd = 0;
 	return 0;
 }
 
 /* When the Guest calls LHCALL_LGUEST_INIT we do more setup. */
-void page_table_guest_data_init(struct lguest *lg)
+void page_table_guest_data_init(struct lg_cpu *cpu)
 {
 	/* We get the kernel address: above this is all kernel memory. */
-	if (get_user(lg->kernel_address, &lg->lguest_data->kernel_address)
+	if (get_user(cpu->lg->kernel_address,
+		     &cpu->lg->lguest_data->kernel_address)
 	    /* We tell the Guest that it can't use the top 4MB of virtual
 	     * addresses used by the Switcher. */
-	    || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
-	    || put_user(lg->pgdirs[lg->pgdidx].gpgdir,&lg->lguest_data->pgdir))
-		kill_guest(lg, "bad guest page %p", lg->lguest_data);
+	    || put_user(4U*1024*1024, &cpu->lg->lguest_data->reserve_mem)
+	    || put_user(cpu->lg->pgdirs[0].gpgdir, &cpu->lg->lguest_data->pgdir))
+		kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
 
 	/* In flush_user_mappings() we loop from 0 to
 	 * "pgd_index(lg->kernel_address)".  This assumes it won't hit the
 	 * Switcher mappings, so check that now. */
-	if (pgd_index(lg->kernel_address) >= SWITCHER_PGD_INDEX)
-		kill_guest(lg, "bad kernel address %#lx", lg->kernel_address);
+	if (pgd_index(cpu->lg->kernel_address) >= SWITCHER_PGD_INDEX)
+		kill_guest(cpu, "bad kernel address %#lx",
+				 cpu->lg->kernel_address);
 }
 
 /* When a Guest dies, our cleanup is fairly simple. */
@@ -634,17 +637,18 @@ void free_guest_pagetable(struct lguest *lg)
  * Guest (and not the pages for other CPUs).  We have the appropriate PTE pages
  * for each CPU already set up, we just need to hook them in now we know which
  * Guest is about to run on this CPU. */
-void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
+void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
 {
 	pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
 	pgd_t switcher_pgd;
 	pte_t regs_pte;
+	unsigned long pfn;
 
 	/* Make the last PGD entry for this Guest point to the Switcher's PTE
 	 * page for this CPU (with appropriate flags). */
-	switcher_pgd = __pgd(__pa(switcher_pte_page) | _PAGE_KERNEL);
+	switcher_pgd = __pgd(__pa(switcher_pte_page) | __PAGE_KERNEL);
 
-	lg->pgdirs[lg->pgdidx].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd;
+	cpu->lg->pgdirs[cpu->cpu_pgd].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd;
 
 	/* We also change the Switcher PTE page.  When we're running the Guest,
 	 * we want the Guest's "regs" page to appear where the first Switcher
@@ -653,7 +657,8 @@ void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
 	 * CPU's "struct lguest_pages": if we make sure the Guest's register
 	 * page is already mapped there, we don't have to copy them out
 	 * again. */
-	regs_pte = pfn_pte (__pa(lg->regs_page) >> PAGE_SHIFT, __pgprot(_PAGE_KERNEL));
+	pfn = __pa(cpu->regs_page) >> PAGE_SHIFT;
+	regs_pte = pfn_pte(pfn, __pgprot(__PAGE_KERNEL));
 	switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTRS_PER_PTE] = regs_pte;
 }
 /*:*/
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c
index 9e189cb..ec6aa3f 100644
--- a/drivers/lguest/segments.c
+++ b/drivers/lguest/segments.c
@@ -58,7 +58,7 @@ static int ignored_gdt(unsigned int num)
  * Protection Fault in the Switcher when it restores a Guest segment register
  * which tries to use that entry.  Then we kill the Guest for causing such a
  * mess: the message will be "unhandled trap 256". */
-static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
+static void fixup_gdt_table(struct lg_cpu *cpu, unsigned start, unsigned end)
 {
 	unsigned int i;
 
@@ -71,14 +71,14 @@ static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
 		/* Segment descriptors contain a privilege level: the Guest is
 		 * sometimes careless and leaves this as 0, even though it's
 		 * running at privilege level 1.  If so, we fix it here. */
-		if ((lg->arch.gdt[i].b & 0x00006000) == 0)
-			lg->arch.gdt[i].b |= (GUEST_PL << 13);
+		if ((cpu->arch.gdt[i].b & 0x00006000) == 0)
+			cpu->arch.gdt[i].b |= (GUEST_PL << 13);
 
 		/* Each descriptor has an "accessed" bit.  If we don't set it
 		 * now, the CPU will try to set it when the Guest first loads
 		 * that entry into a segment register.  But the GDT isn't
 		 * writable by the Guest, so bad things can happen. */
-		lg->arch.gdt[i].b |= 0x00000100;
+		cpu->arch.gdt[i].b |= 0x00000100;
 	}
 }
 
@@ -109,31 +109,31 @@ void setup_default_gdt_entries(struct lguest_ro_state *state)
 
 /* This routine sets up the initial Guest GDT for booting.  All entries start
  * as 0 (unusable). */
-void setup_guest_gdt(struct lguest *lg)
+void setup_guest_gdt(struct lg_cpu *cpu)
 {
 	/* Start with full 0-4G segments... */
-	lg->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
-	lg->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
 	/* ...except the Guest is allowed to use them, so set the privilege
 	 * level appropriately in the flags. */
-	lg->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
-	lg->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
+	cpu->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
 }
 
 /*H:650 An optimization of copy_gdt(), for just the three "thead-local storage"
  * entries. */
-void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt)
+void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt)
 {
 	unsigned int i;
 
 	for (i = GDT_ENTRY_TLS_MIN; i <= GDT_ENTRY_TLS_MAX; i++)
-		gdt[i] = lg->arch.gdt[i];
+		gdt[i] = cpu->arch.gdt[i];
 }
 
 /*H:640 When the Guest is run on a different CPU, or the GDT entries have
  * changed, copy_gdt() is called to copy the Guest's GDT entries across to this
  * CPU's GDT. */
-void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
+void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
 {
 	unsigned int i;
 
@@ -141,38 +141,38 @@ void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
 	 * replaced.  See ignored_gdt() above. */
 	for (i = 0; i < GDT_ENTRIES; i++)
 		if (!ignored_gdt(i))
-			gdt[i] = lg->arch.gdt[i];
+			gdt[i] = cpu->arch.gdt[i];
 }
 
 /*H:620 This is where the Guest asks us to load a new GDT (LHCALL_LOAD_GDT).
  * We copy it from the Guest and tweak the entries. */
-void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
+void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
 {
 	/* We assume the Guest has the same number of GDT entries as the
 	 * Host, otherwise we'd have to dynamically allocate the Guest GDT. */
-	if (num > ARRAY_SIZE(lg->arch.gdt))
-		kill_guest(lg, "too many gdt entries %i", num);
+	if (num > ARRAY_SIZE(cpu->arch.gdt))
+		kill_guest(cpu, "too many gdt entries %i", num);
 
 	/* We read the whole thing in, then fix it up. */
-	__lgread(lg, lg->arch.gdt, table, num * sizeof(lg->arch.gdt[0]));
-	fixup_gdt_table(lg, 0, ARRAY_SIZE(lg->arch.gdt));
+	__lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
+	fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
 	/* Mark that the GDT changed so the core knows it has to copy it again,
 	 * even if the Guest is run on the same CPU. */
-	lg->changed |= CHANGED_GDT;
+	cpu->changed |= CHANGED_GDT;
 }
 
 /* This is the fast-track version for just changing the three TLS entries.
  * Remember that this happens on every context switch, so it's worth
  * optimizing.  But wouldn't it be neater to have a single hypercall to cover
  * both cases? */
-void guest_load_tls(struct lguest *lg, unsigned long gtls)
+void guest_load_tls(struct lg_cpu *cpu, unsigned long gtls)
 {
-	struct desc_struct *tls = &lg->arch.gdt[GDT_ENTRY_TLS_MIN];
+	struct desc_struct *tls = &cpu->arch.gdt[GDT_ENTRY_TLS_MIN];
 
-	__lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
-	fixup_gdt_table(lg, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
+	__lgread(cpu, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
+	fixup_gdt_table(cpu, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
 	/* Note that just the TLS entries have changed. */
-	lg->changed |= CHANGED_GDT_TLS;
+	cpu->changed |= CHANGED_GDT_TLS;
 }
 /*:*/
 
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 44adb00..61f2f8e 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -60,7 +60,7 @@ static struct lguest_pages *lguest_pages(unsigned int cpu)
 		  (SWITCHER_ADDR + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]);
 }
 
-static DEFINE_PER_CPU(struct lguest *, last_guest);
+static DEFINE_PER_CPU(struct lg_cpu *, last_cpu);
 
 /*S:010
  * We approach the Switcher.
@@ -73,16 +73,16 @@ static DEFINE_PER_CPU(struct lguest *, last_guest);
  * since it last ran.  We saw this set in interrupts_and_traps.c and
  * segments.c.
  */
-static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
+static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages)
 {
 	/* Copying all this data can be quite expensive.  We usually run the
 	 * same Guest we ran last time (and that Guest hasn't run anywhere else
 	 * meanwhile).  If that's not the case, we pretend everything in the
 	 * Guest has changed. */
-	if (__get_cpu_var(last_guest) != lg || lg->last_pages != pages) {
-		__get_cpu_var(last_guest) = lg;
-		lg->last_pages = pages;
-		lg->changed = CHANGED_ALL;
+	if (__get_cpu_var(last_cpu) != cpu || cpu->last_pages != pages) {
+		__get_cpu_var(last_cpu) = cpu;
+		cpu->last_pages = pages;
+		cpu->changed = CHANGED_ALL;
 	}
 
 	/* These copies are pretty cheap, so we do them unconditionally: */
@@ -90,42 +90,42 @@ static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
 	pages->state.host_cr3 = __pa(current->mm->pgd);
 	/* Set up the Guest's page tables to see this CPU's pages (and no
 	 * other CPU's pages). */
-	map_switcher_in_guest(lg, pages);
+	map_switcher_in_guest(cpu, pages);
 	/* Set up the two "TSS" members which tell the CPU what stack to use
 	 * for traps which do directly into the Guest (ie. traps at privilege
 	 * level 1). */
-	pages->state.guest_tss.sp1 = lg->esp1;
-	pages->state.guest_tss.ss1 = lg->ss1;
+	pages->state.guest_tss.esp1 = cpu->esp1;
+	pages->state.guest_tss.ss1 = cpu->ss1;
 
 	/* Copy direct-to-Guest trap entries. */
-	if (lg->changed & CHANGED_IDT)
-		copy_traps(lg, pages->state.guest_idt, default_idt_entries);
+	if (cpu->changed & CHANGED_IDT)
+		copy_traps(cpu, pages->state.guest_idt, default_idt_entries);
 
 	/* Copy all GDT entries which the Guest can change. */
-	if (lg->changed & CHANGED_GDT)
-		copy_gdt(lg, pages->state.guest_gdt);
+	if (cpu->changed & CHANGED_GDT)
+		copy_gdt(cpu, pages->state.guest_gdt);
 	/* If only the TLS entries have changed, copy them. */
-	else if (lg->changed & CHANGED_GDT_TLS)
-		copy_gdt_tls(lg, pages->state.guest_gdt);
+	else if (cpu->changed & CHANGED_GDT_TLS)
+		copy_gdt_tls(cpu, pages->state.guest_gdt);
 
 	/* Mark the Guest as unchanged for next time. */
-	lg->changed = 0;
+	cpu->changed = 0;
 }
 
 /* Finally: the code to actually call into the Switcher to run the Guest. */
-static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
+static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
 {
 	/* This is a dummy value we need for GCC's sake. */
 	unsigned int clobber;
 
 	/* Copy the guest-specific information into this CPU's "struct
 	 * lguest_pages". */
-	copy_in_guest_info(lg, pages);
+	copy_in_guest_info(cpu, pages);
 
 	/* Set the trap number to 256 (impossible value).  If we fault while
 	 * switching to the Guest (bad segment registers or bug), this will
 	 * cause us to abort the Guest. */
-	lg->regs->trapnum = 256;
+	cpu->regs->trapnum = 256;
 
 	/* Now: we push the "eflags" register on the stack, then do an "lcall".
 	 * This is how we change from using the kernel code segment to using
@@ -143,7 +143,7 @@ static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
 		      * 0-th argument above, ie "a").  %ebx contains the
 		      * physical address of the Guest's top-level page
 		      * directory. */
-		     : "0"(pages), "1"(__pa(lg->pgdirs[lg->pgdidx].pgdir))
+		     : "0"(pages), "1"(__pa(cpu->lg->pgdirs[cpu->cpu_pgd].pgdir))
 		     /* We tell gcc that all these registers could change,
 		      * which means we don't have to save and restore them in
 		      * the Switcher. */
@@ -161,12 +161,12 @@ static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
 
 /*H:040 This is the i386-specific code to setup and run the Guest.  Interrupts
  * are disabled: we own the CPU. */
-void lguest_arch_run_guest(struct lguest *lg)
+void lguest_arch_run_guest(struct lg_cpu *cpu)
 {
 	/* Remember the awfully-named TS bit?  If the Guest has asked to set it
 	 * we set it now, so we can trap and pass that trap to the Guest if it
 	 * uses the FPU. */
-	if (lg->ts)
+	if (cpu->ts)
 		lguest_set_ts();
 
 	/* SYSENTER is an optimized way of doing system calls.  We can't allow
@@ -180,7 +180,7 @@ void lguest_arch_run_guest(struct lguest *lg)
 	/* Now we actually run the Guest.  It will return when something
 	 * interesting happens, and we can examine its registers to see what it
 	 * was doing. */
-	run_guest_once(lg, lguest_pages(raw_smp_processor_id()));
+	run_guest_once(cpu, lguest_pages(raw_smp_processor_id()));
 
 	/* Note that the "regs" pointer contains two extra entries which are
 	 * not really registers: a trap number which says what interrupt or
@@ -191,11 +191,11 @@ void lguest_arch_run_guest(struct lguest *lg)
 	 * bad virtual address.  We have to grab this now, because once we
 	 * re-enable interrupts an interrupt could fault and thus overwrite
 	 * cr2, or we could even move off to a different CPU. */
-	if (lg->regs->trapnum == 14)
-		lg->arch.last_pagefault = read_cr2();
+	if (cpu->regs->trapnum == 14)
+		cpu->arch.last_pagefault = read_cr2();
 	/* Similarly, if we took a trap because the Guest used the FPU,
 	 * we have to restore the FPU it expects to see. */
-	else if (lg->regs->trapnum == 7)
+	else if (cpu->regs->trapnum == 7)
 		math_state_restore();
 
 	/* Restore SYSENTER if it's supposed to be on. */
@@ -214,22 +214,22 @@ void lguest_arch_run_guest(struct lguest *lg)
  * When the Guest uses one of these instructions, we get a trap (General
  * Protection Fault) and come here.  We see if it's one of those troublesome
  * instructions and skip over it.  We return true if we did. */
-static int emulate_insn(struct lguest *lg)
+static int emulate_insn(struct lg_cpu *cpu)
 {
 	u8 insn;
 	unsigned int insnlen = 0, in = 0, shift = 0;
 	/* The eip contains the *virtual* address of the Guest's instruction:
 	 * guest_pa just subtracts the Guest's page_offset. */
-	unsigned long physaddr = guest_pa(lg, lg->regs->eip);
+	unsigned long physaddr = guest_pa(cpu, cpu->regs->eip);
 
 	/* This must be the Guest kernel trying to do something, not userspace!
 	 * The bottom two bits of the CS segment register are the privilege
 	 * level. */
-	if ((lg->regs->cs & 3) != GUEST_PL)
+	if ((cpu->regs->cs & 3) != GUEST_PL)
 		return 0;
 
 	/* Decoding x86 instructions is icky. */
-	insn = lgread(lg, physaddr, u8);
+	insn = lgread(cpu, physaddr, u8);
 
 	/* 0x66 is an "operand prefix".  It means it's using the upper 16 bits
 	   of the eax register. */
@@ -237,7 +237,7 @@ static int emulate_insn(struct lguest *lg)
 		shift = 16;
 		/* The instruction is 1 byte so far, read the next byte. */
 		insnlen = 1;
-		insn = lgread(lg, physaddr + insnlen, u8);
+		insn = lgread(cpu, physaddr + insnlen, u8);
 	}
 
 	/* We can ignore the lower bit for the moment and decode the 4 opcodes
@@ -268,26 +268,26 @@ static int emulate_insn(struct lguest *lg)
 	if (in) {
 		/* Lower bit tells is whether it's a 16 or 32 bit access */
 		if (insn & 0x1)
-			lg->regs->eax = 0xFFFFFFFF;
+			cpu->regs->eax = 0xFFFFFFFF;
 		else
-			lg->regs->eax |= (0xFFFF << shift);
+			cpu->regs->eax |= (0xFFFF << shift);
 	}
 	/* Finally, we've "done" the instruction, so move past it. */
-	lg->regs->eip += insnlen;
+	cpu->regs->eip += insnlen;
 	/* Success! */
 	return 1;
 }
 
 /*H:050 Once we've re-enabled interrupts, we look at why the Guest exited. */
-void lguest_arch_handle_trap(struct lguest *lg)
+void lguest_arch_handle_trap(struct lg_cpu *cpu)
 {
-	switch (lg->regs->trapnum) {
+	switch (cpu->regs->trapnum) {
 	case 13: /* We've intercepted a General Protection Fault. */
 		/* Check if this was one of those annoying IN or OUT
 		 * instructions which we need to emulate.  If so, we just go
 		 * back into the Guest after we've done it. */
-		if (lg->regs->errcode == 0) {
-			if (emulate_insn(lg))
+		if (cpu->regs->errcode == 0) {
+			if (emulate_insn(cpu))
 				return;
 		}
 		break;
@@ -301,7 +301,8 @@ void lguest_arch_handle_trap(struct lguest *lg)
 		 *
 		 * The errcode tells whether this was a read or a write, and
 		 * whether kernel or userspace code. */
-		if (demand_page(lg, lg->arch.last_pagefault, lg->regs->errcode))
+		if (demand_page(cpu, cpu->arch.last_pagefault,
+				cpu->regs->errcode))
 			return;
 
 		/* OK, it's really not there (or not OK): the Guest needs to
@@ -311,15 +312,16 @@ void lguest_arch_handle_trap(struct lguest *lg)
 		 * Note that if the Guest were really messed up, this could
 		 * happen before it's done the LHCALL_LGUEST_INIT hypercall, so
 		 * lg->lguest_data could be NULL */
-		if (lg->lguest_data &&
-		    put_user(lg->arch.last_pagefault, &lg->lguest_data->cr2))
-			kill_guest(lg, "Writing cr2");
+		if (cpu->lg->lguest_data &&
+		    put_user(cpu->arch.last_pagefault,
+			     &cpu->lg->lguest_data->cr2))
+			kill_guest(cpu, "Writing cr2");
 		break;
 	case 7: /* We've intercepted a Device Not Available fault. */
 		/* If the Guest doesn't want to know, we already restored the
 		 * Floating Point Unit, so we just continue without telling
 		 * it. */
-		if (!lg->ts)
+		if (!cpu->ts)
 			return;
 		break;
 	case 32 ... 255:
@@ -332,19 +334,19 @@ void lguest_arch_handle_trap(struct lguest *lg)
 	case LGUEST_TRAP_ENTRY:
 		/* Our 'struct hcall_args' maps directly over our regs: we set
 		 * up the pointer now to indicate a hypercall is pending. */
-		lg->hcall = (struct hcall_args *)lg->regs;
+		cpu->hcall = (struct hcall_args *)cpu->regs;
 		return;
 	}
 
 	/* We didn't handle the trap, so it needs to go to the Guest. */
-	if (!deliver_trap(lg, lg->regs->trapnum))
+	if (!deliver_trap(cpu, cpu->regs->trapnum))
 		/* If the Guest doesn't have a handler (either it hasn't
 		 * registered any yet, or it's one of the faults we don't let
 		 * it handle), it dies with a cryptic error message. */
-		kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
-			   lg->regs->trapnum, lg->regs->eip,
-			   lg->regs->trapnum == 14 ? lg->arch.last_pagefault
-			   : lg->regs->errcode);
+		kill_guest(cpu, "unhandled trap %li at %#lx (%#lx)",
+			   cpu->regs->trapnum, cpu->regs->eip,
+			   cpu->regs->trapnum == 14 ? cpu->arch.last_pagefault
+			   : cpu->regs->errcode);
 }
 
 /* Now we can look at each of the routines this calls, in increasing order of
@@ -487,17 +489,17 @@ void __exit lguest_arch_host_fini(void)
 
 
 /*H:122 The i386-specific hypercalls simply farm out to the right functions. */
-int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args)
+int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
 	switch (args->arg0) {
 	case LHCALL_LOAD_GDT:
-		load_guest_gdt(lg, args->arg1, args->arg2);
+		load_guest_gdt(cpu, args->arg1, args->arg2);
 		break;
 	case LHCALL_LOAD_IDT_ENTRY:
-		load_guest_idt_entry(lg, args->arg1, args->arg2, args->arg3);
+		load_guest_idt_entry(cpu, args->arg1, args->arg2, args->arg3);
 		break;
 	case LHCALL_LOAD_TLS:
-		guest_load_tls(lg, args->arg1);
+		guest_load_tls(cpu, args->arg1);
 		break;
 	default:
 		/* Bad Guest.  Bad! */
@@ -507,13 +509,14 @@ int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args)
 }
 
 /*H:126 i386-specific hypercall initialization: */
-int lguest_arch_init_hypercalls(struct lguest *lg)
+int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
 {
 	u32 tsc_speed;
 
 	/* The pointer to the Guest's "struct lguest_data" is the only
 	 * argument.  We check that address now. */
-	if (!lguest_address_ok(lg, lg->hcall->arg1, sizeof(*lg->lguest_data)))
+	if (!lguest_address_ok(cpu->lg, cpu->hcall->arg1,
+			       sizeof(*cpu->lg->lguest_data)))
 		return -EFAULT;
 
 	/* Having checked it, we simply set lg->lguest_data to point straight
@@ -521,7 +524,7 @@ int lguest_arch_init_hypercalls(struct lguest *lg)
 	 * copy_to_user/from_user from now on, instead of lgread/write.  I put
 	 * this in to show that I'm not immune to writing stupid
 	 * optimizations. */
-	lg->lguest_data = lg->mem_base + lg->hcall->arg1;
+	cpu->lg->lguest_data = cpu->lg->mem_base + cpu->hcall->arg1;
 
 	/* We insist that the Time Stamp Counter exist and doesn't change with
 	 * cpu frequency.  Some devious chip manufacturers decided that TSC
@@ -534,12 +537,12 @@ int lguest_arch_init_hypercalls(struct lguest *lg)
 		tsc_speed = tsc_khz;
 	else
 		tsc_speed = 0;
-	if (put_user(tsc_speed, &lg->lguest_data->tsc_khz))
+	if (put_user(tsc_speed, &cpu->lg->lguest_data->tsc_khz))
 		return -EFAULT;
 
 	/* The interrupt code might not like the system call vector. */
-	if (!check_syscall_vector(lg))
-		kill_guest(lg, "bad syscall vector");
+	if (!check_syscall_vector(cpu->lg))
+		kill_guest(cpu, "bad syscall vector");
 
 	return 0;
 }
@@ -548,9 +551,9 @@ int lguest_arch_init_hypercalls(struct lguest *lg)
  *
  * Most of the Guest's registers are left alone: we used get_zeroed_page() to
  * allocate the structure, so they will be 0. */
-void lguest_arch_setup_regs(struct lguest *lg, unsigned long start)
+void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start)
 {
-	struct lguest_regs *regs = lg->regs;
+	struct lguest_regs *regs = cpu->regs;
 
 	/* There are four "segment" registers which the Guest needs to boot:
 	 * The "code segment" register (cs) refers to the kernel code segment
@@ -577,5 +580,5 @@ void lguest_arch_setup_regs(struct lguest *lg, unsigned long start)
 
 	/* There are a couple of GDT entries the Guest expects when first
 	 * booting. */
-	setup_guest_gdt(lg);
+	setup_guest_gdt(cpu);
 }