Merge tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "PPC and ARM do not have much going on this time.  Most of the cool
  stuff, instead, is in s390 and (after a few releases) x86.

  ARM has some caching fixes and PPC has transactional memory support in
  guests.  MIPS has some fixes, with more probably coming in 3.16 as
  QEMU will soon get support for MIPS KVM.

  For x86 there are optimizations for debug registers, which trigger on
  some Windows games, and other important fixes for Windows guests.  We
  now expose to the guest Broadwell instruction set extensions and also
  Intel MPX.  There's also a fix/workaround for OS X guests, nested
  virtualization features (preemption timer), and a couple kvmclock
  refinements.

  For s390, the main news is asynchronous page faults, together with
  improvements to IRQs (floating irqs and adapter irqs) that speed up
  virtio devices"

* tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (96 commits)
  KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8
  KVM: PPC: Book3S HV: Fix decrementer timeouts with non-zero TB offset
  KVM: PPC: Book3S HV: Don't use kvm_memslots() in real mode
  KVM: PPC: Book3S HV: Return ENODEV error rather than EIO
  KVM: PPC: Book3S: Trim top 4 bits of physical address in RTAS code
  KVM: PPC: Book3S HV: Add get/set_one_reg for new TM state
  KVM: PPC: Book3S HV: Add transactional memory support
  KVM: Specify byte order for KVM_EXIT_MMIO
  KVM: vmx: fix MPX detection
  KVM: PPC: Book3S HV: Fix KVM hang with CONFIG_KVM_XICS=n
  KVM: PPC: Book3S: Introduce hypervisor call H_GET_TCE
  KVM: PPC: Book3S HV: Fix incorrect userspace exit on ioeventfd write
  KVM: s390: clear local interrupts at cpu initial reset
  KVM: s390: Fix possible memory leak in SIGP functions
  KVM: s390: fix calculation of idle_mask array size
  KVM: s390: randomize sca address
  KVM: ioapic: reinject pending interrupts on KVM_SET_IRQCHIP
  KVM: Bump KVM_MAX_IRQ_ROUTES for s390
  KVM: s390: irq routing for adapter interrupts.
  KVM: s390: adapter interrupt sources
  ...

1 files changed, 22 insertions, 4 deletions

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index d95265b2..88cef50 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -50,6 +50,7 @@
 #define VM_FAULT_BADMAP		0x020000
 #define VM_FAULT_BADACCESS	0x040000
 #define VM_FAULT_SIGNAL		0x080000
+#define VM_FAULT_PFAULT		0x100000
 
 static unsigned long store_indication __read_mostly;
 
@@ -227,6 +228,7 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault)
 			return;
 		}
 	case VM_FAULT_BADCONTEXT:
+	case VM_FAULT_PFAULT:
 		do_no_context(regs);
 		break;
 	case VM_FAULT_SIGNAL:
@@ -264,6 +266,9 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault)
  */
 static inline int do_exception(struct pt_regs *regs, int access)
 {
+#ifdef CONFIG_PGSTE
+	struct gmap *gmap;
+#endif
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	struct vm_area_struct *vma;
@@ -304,9 +309,10 @@ static inline int do_exception(struct pt_regs *regs, int access)
 	down_read(&mm->mmap_sem);
 
 #ifdef CONFIG_PGSTE
-	if ((current->flags & PF_VCPU) && S390_lowcore.gmap) {
-		address = __gmap_fault(address,
-				     (struct gmap *) S390_lowcore.gmap);
+	gmap = (struct gmap *)
+		((current->flags & PF_VCPU) ? S390_lowcore.gmap : 0);
+	if (gmap) {
+		address = __gmap_fault(address, gmap);
 		if (address == -EFAULT) {
 			fault = VM_FAULT_BADMAP;
 			goto out_up;
@@ -315,6 +321,8 @@ static inline int do_exception(struct pt_regs *regs, int access)
 			fault = VM_FAULT_OOM;
 			goto out_up;
 		}
+		if (gmap->pfault_enabled)
+			flags |= FAULT_FLAG_RETRY_NOWAIT;
 	}
 #endif
 
@@ -371,9 +379,19 @@ retry:
 				      regs, address);
 		}
 		if (fault & VM_FAULT_RETRY) {
+#ifdef CONFIG_PGSTE
+			if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) {
+				/* FAULT_FLAG_RETRY_NOWAIT has been set,
+				 * mmap_sem has not been released */
+				current->thread.gmap_pfault = 1;
+				fault = VM_FAULT_PFAULT;
+				goto out_up;
+			}
+#endif
 			/* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
 			 * of starvation. */
-			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+			flags &= ~(FAULT_FLAG_ALLOW_RETRY |
+				   FAULT_FLAG_RETRY_NOWAIT);
 			flags |= FAULT_FLAG_TRIED;
 			down_read(&mm->mmap_sem);
 			goto retry;