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2012-03-05KVM: PPC: Allow use of small pages to back Book3S HV guestsPaul Mackerras
This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Only get pages when actually needed, not in prepare_memory_region()Paul Mackerras
This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Make the H_ENTER hcall more reliablePaul Mackerras
At present, our implementation of H_ENTER only makes one try at locking each slot that it looks at, and doesn't even retry the ldarx/stdcx. atomic update sequence that it uses to attempt to lock the slot. Thus it can return the H_PTEG_FULL error unnecessarily, particularly when the H_EXACT flag is set, meaning that the caller wants a specific PTEG slot. This improves the situation by making a second pass when no free HPTE slot is found, where we spin until we succeed in locking each slot in turn and then check whether it is full while we hold the lock. If the second pass fails, then we return H_PTEG_FULL. This also moves lock_hpte to a header file (since later commits in this series will need to use it from other source files) and renames it to try_lock_hpte, which is a somewhat less misleading name. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Add an interface for pinning guest pages in Book3s HV guestsPaul Mackerras
This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Keep page physical addresses in per-slot arraysPaul Mackerras
This allocates an array for each memory slot that is added to store the physical addresses of the pages in the slot. This array is vmalloc'd and accessed in kvmppc_h_enter using real_vmalloc_addr(). This allows us to remove the ram_pginfo field from the kvm_arch struct, and removes the 64GB guest RAM limit that we had. We use the low-order bits of the array entries to store a flag indicating that we have done get_page on the corresponding page, and therefore need to call put_page when we are finished with the page. Currently this is set for all pages except those in our special RMO regions. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Keep a record of HV guest view of hashed page table entriesPaul Mackerras
This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Make wakeups work again for Book3S HV guestsPaul Mackerras
When commit f43fdc15fa ("KVM: PPC: booke: Improve timer register emulation") factored out some code in arch/powerpc/kvm/powerpc.c into a new helper function, kvm_vcpu_kick(), an error crept in which causes Book3s HV guest vcpus to stall. This fixes it. On POWER7 machines, guest vcpus are grouped together into virtual CPU cores that share a single waitqueue, so it's important to use vcpu->arch.wqp rather than &vcpu->wq. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Avoid patching paravirt template codeLiu Yu-B13201
Currently we patch the whole code include paravirt template code. This isn't safe for scratch area and has impact to performance. Signed-off-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: use hardware hint when loading TLB0 entriesScott Wood
The hardware maintains a per-set next victim hint. Using this reduces conflicts, especially on e500v2 where a single guest TLB entry is mapped to two shadow TLB entries (user and kernel). We want those two entries to go to different TLB ways. sesel is now only used for TLB1. Reported-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: Fix TLBnCFG in KVM_CONFIG_TLBScott Wood
The associativity, not just total size, can differ from the host hardware. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Book3S: PR: Fix signal check raceAlexander Graf
As Scott put it: > If we get a signal after the check, we want to be sure that we don't > receive the reschedule IPI until after we're in the guest, so that it > will cause another signal check. we need to have interrupts disabled from the point we do signal_check() all the way until we actually enter the guest. This patch fixes potential signal loss races. Reported-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: align vcpu_kick with x86Alexander Graf
Our vcpu kick implementation differs a bit from x86 which resulted in us not disabling preemption during the kick. Get it a bit closer to what x86 does. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Use get/set for to_svcpu to help preemptionAlexander Graf
When running the 64-bit Book3s PR code without CONFIG_PREEMPT_NONE, we were doing a few things wrong, most notably access to PACA fields without making sure that the pointers stay stable accross the access (preempt_disable()). This patch moves to_svcpu towards a get/put model which allows us to disable preemption while accessing the shadow vcpu fields in the PACA. That way we can run preemptible and everyone's happy! Reported-by: Jörg Sommer <joerg@alea.gnuu.de> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Book3s: PR: No irq_disable in vcpu_runAlexander Graf
Somewhere during merges we ended up from local_irq_enable() foo(); local_irq_disable() to always keeping irqs enabled during that part. However, we now have the following code: foo(); local_irq_disable() which disables interrupts without the surrounding code enabling them again! So let's remove that disable and be happy. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Book3s: PR: Disable preemption in vcpu_runAlexander Graf
When entering the guest, we want to make sure we're not getting preempted away, so let's disable preemption on entry, but enable it again while handling guest exits. Reported-by: Jörg Sommer <joerg@alea.gnuu.de> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: booke: Improve timer register emulationScott Wood
Decrementers are now properly driven by TCR/TSR, and the guest has full read/write access to these registers. The decrementer keeps ticking (and setting the TSR bit) regardless of whether the interrupts are enabled with TCR. The decrementer stops at zero, rather than going negative. Decrementers (and FITs, once implemented) are delivered as level-triggered interrupts -- dequeued when the TSR bit is cleared, not on delivery. Signed-off-by: Liu Yu <yu.liu@freescale.com> [scottwood@freescale.com: significant changes] Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Paravirtualize SPRG4-7, ESR, PIR, MASnScott Wood
This allows additional registers to be accessed by the guest in PR-mode KVM without trapping. SPRG4-7 are readable from userspace. On booke, KVM will sync these registers when it enters the guest, so that accesses from guest userspace will work. The guest kernel, OTOH, must consistently use either the real registers or the shared area between exits. This also applies to the already-paravirted SPRG3. On non-booke, it's not clear to what extent SPRG4-7 are supported (they're not architected for book3s, but exist on at least some classic chips). They are copied in the get/set regs ioctls, but I do not see any non-booke emulation. I also do not see any syncing with real registers (in PR-mode) including the user-readable SPRG3. This patch should not make that situation any worse. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: booke: Paravirtualize wrteeScott Wood
Also fix wrteei 1 paravirt to check for a pending interrupt. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: booke: Fix int_pending calculation for MSR[EE] paravirtScott Wood
int_pending was only being lowered if a bit in pending_exceptions was cleared during exception delivery -- but for interrupts, we clear it during IACK/TSR emulation. This caused paravirt for enabling MSR[EE] to be ineffective. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: booke: Check for MSR[WE] in prepare_to_enterScott Wood
This prevents us from inappropriately blocking in a KVM_SET_REGS ioctl -- the MSR[WE] will take effect when the guest is next entered. It also causes SRR1[WE] to be set when we enter the guest's interrupt handler, which is what e500 hardware is documented to do. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Move prepare_to_enter call site into subarch codeScott Wood
This function should be called with interrupts disabled, to avoid a race where an exception is delivered after we check, but the resched kick is received before we disable interrupts (and thus doesn't actually trigger the exit code that would recheck exceptions). booke already does this properly in the lightweight exit case, but not on initial entry. For now, move the call of prepare_to_enter into subarch-specific code so that booke can do the right thing here. Ideally book3s would do the same thing, but I'm having a hard time seeing where it does any interrupt disabling of this sort (plus it has several additional call sites), so I'm deferring the book3s fix to someone more familiar with that code. book3s behavior should be unchanged by this patch. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Rename deliver_interrupts to prepare_to_enterScott Wood
This function also updates paravirt int_pending, so rename it to be more obvious that this is a collection of checks run prior to (re)entering a guest. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: booke: check for signals in kvmppc_vcpu_runScott Wood
Currently we check prior to returning from a lightweight exit, but not prior to initial entry. book3s already does a similar test. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: booke: Do Not start decrementer when SPRN_DEC set 0Bharat Bhushan
As per specification the decrementer interrupt not happen when DEC is written with 0. Also when DEC is zero, no decrementer running. So we should not start hrtimer for decrementer when DEC = 0. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: Fix DEC truncation for greater than 0xffff_ffff/1000Bharat Bhushan
kvmppc_emulate_dec() uses dec_nsec of type unsigned long and does below calculation: dec_nsec = vcpu->arch.dec; dec_nsec *= 1000; This will truncate if DEC value "vcpu->arch.dec" is greater than 0xffff_ffff/1000. For example : For tb_ticks_per_usec = 4a, we can not set decrementer more than ~58ms. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05PPC: Fix race in mtmsr paravirt implementationBharat Bhushan
The current implementation of mtmsr and mtmsrd are racy in that it does: * check (int_pending == 0) ---> host sets int_pending = 1 <--- * write shared page * done while instead we should check for int_pending after the shared page is written. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: E500: Support hugetlbfsAlexander Graf
With hugetlbfs support emerging on e500, we should also support KVM backing its guest memory by it. This patch adds support for hugetlbfs into the e500 shadow mmu code. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: Don't hardcode PIR=0Scott Wood
The hardcoded behavior prevents proper SMP support. user space shall specify the vcpu's PIR as the vcpu id. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: tlbsx: fix tlb0 eselScott Wood
It should contain the way, not the absolute TLB0 index. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: MMU APIScott Wood
This implements a shared-memory API for giving host userspace access to the guest's TLB. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: clear up confusion between host and guest entriesScott Wood
Split out the portions of tlbe_priv that should be associated with host entries into tlbe_ref. Base victim selection on the number of hardware entries, not guest entries. For TLB1, where one guest entry can be mapped by multiple host entries, we use the host tlbe_ref for tracking page references. For the guest TLB0 entries, we still track it with gtlb_priv, to avoid having to retranslate if the entry is evicted from the host TLB but not the guest TLB. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: Eliminate preempt_disable in local_sid_destroy_allScott Wood
The only place it makes sense to call this function already needs to have preemption disabled. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: PPC: e500: don't translate gfn to pfn with preemption disabledScott Wood
Delay allocation of the shadow pid until we're ready to disable preemption and write the entry. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: provide access guest registers via kvm_runChristian Borntraeger
This patch adds the access registers to the kvm_run structure. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: provide general purpose guest registers via kvm_runChristian Borntraeger
This patch adds the general purpose registers to the kvm_run structure. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: provide the prefix register via kvm_runChristian Borntraeger
Add the prefix register to the synced register field in kvm_run. While we need the prefix register most of the time read-only, this patch also adds handling for guest dirtying of the prefix register. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: provide synchronous registers in kvm_runChristian Borntraeger
On some cpus the overhead for virtualization instructions is in the same range as a system call. Having to call multiple ioctls to get set registers will make certain userspace handled exits more expensive than necessary. Lets provide a section in kvm_run that works as a shared save area for guest registers. We also provide two 64bit flags fields (architecture specific), that will specify 1. which parts of these fields are valid. 2. which registers were modified by userspace Each bit for these flag fields will define a group of registers (like general purpose) or a single register. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: rework code that sets the prefixChristian Borntraeger
There are several places in the kvm module, which set the prefix register. Since we need to flush the cpu, lets combine this operation into a helper function. This helper will also explicitely mask out the unused bits. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: SVM: Add support for AMD's OSVW feature in guestsBoris Ostrovsky
In some cases guests should not provide workarounds for errata even when the physical processor is affected. For example, because of erratum 400 on family 10h processors a Linux guest will read an MSR (resulting in VMEXIT) before going to idle in order to avoid getting stuck in a non-C0 state. This is not necessary: HLT and IO instructions are intercepted and therefore there is no reason for erratum 400 workaround in the guest. This patch allows us to present a guest with certain errata as fixed, regardless of the state of actual hardware. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: MMU: unnecessary NX state assignmentDavidlohr Bueso
We can remove the first ->nx state assignment since it is assigned afterwards anyways. Signed-off-by: Davidlohr Bueso <dave@gnu.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: Fix return code for unknown ioctl numbersCarsten Otte
This patch fixes the return code of kvm_arch_vcpu_ioctl in case of an unkown ioctl number. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: announce capability for user controlled vmsCarsten Otte
This patch announces a new capability KVM_CAP_S390_UCONTROL that indicates that kvm can now support virtual machines that are controlled by userspace. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: fix assumption for KVM_MAX_VCPUSCarsten Otte
This patch fixes definition of the idle_mask and the local_int array in kvm_s390_float_interrupt. Previous definition had 64 cpus max hardcoded instead of using KVM_MAX_VCPUS. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: disable scaCarsten Otte
This patch makes sure user controlled virtual machines do not use a system control area (sca). This is needed in order to create virtual machines with more cpus than the size of the sca [64]. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: interface to inject faults on a vcpu page tableCarsten Otte
This patch allows the user to fault in pages on a virtual cpus address space for user controlled virtual machines. Typically this is superfluous because userspace can just create a mapping and let the kernel's page fault logic take are of it. There is one exception: SIE won't start if the lowcore is not present. Normally the kernel takes care of this [handle_validity() in arch/s390/kvm/intercept.c] but since the kernel does not handle intercepts for user controlled virtual machines, userspace needs to be able to handle this condition. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: disable in-kernel irq stackCarsten Otte
This patch disables the in-kernel interrupt stack for KVM virtual machines that are controlled by user. Userspace has to take care of handling interrupts on its own. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: disable in-kernel handling of SIE interceptsCarsten Otte
This patch disables in-kernel handling of SIE intercepts for user controlled virtual machines. All intercepts are passed to userspace via KVM_EXIT_SIE exit reason just like SIE intercepts that cannot be handled in-kernel for regular KVM guests. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: export SIE control block to userCarsten Otte
This patch exports the s390 SIE hardware control block to userspace via the mapping of the vcpu file descriptor. In order to do so, a new arch callback named kvm_arch_vcpu_fault is introduced for all architectures. It allows to map architecture specific pages. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: export page faults to userCarsten Otte
This patch introduces a new exit reason in the kvm_run structure named KVM_EXIT_S390_UCONTROL. This exit indicates, that a virtual cpu has regognized a fault on the host page table. The idea is that userspace can handle this fault by mapping memory at the fault location into the cpu's address space and then continue to run the virtual cpu. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: s390: ucontrol: per vcpu address spacesCarsten Otte
This patch introduces two ioctls for virtual cpus, that are only valid for kernel virtual machines that are controlled by userspace. Each virtual cpu has its individual address space in this mode of operation, and each address space is backed by the gmap implementation just like the address space for regular KVM guests. KVM_S390_UCAS_MAP allows to map a part of the user's virtual address space to the vcpu. Starting offset and length in both the user and the vcpu address space need to be aligned to 1M. KVM_S390_UCAS_UNMAP can be used to unmap a range of memory from a virtual cpu in a similar way. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>