summaryrefslogtreecommitdiffstats
path: root/arch/x86
AgeCommit message (Collapse)AuthorFilesLines
2013-04-16KVM: VMX: Use posted interrupt to deliver virtual interruptYang Zhang3-12/+21
If posted interrupt is avaliable, then uses it to inject virtual interrupt to guest. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: VMX: Add the deliver posted interrupt algorithmYang Zhang5-1/+85
Only deliver the posted interrupt when target vcpu is running and there is no previous interrupt pending in pir. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: Set TMR when programming ioapic entryYang Zhang3-7/+14
We already know the trigger mode of a given interrupt when programming the ioapice entry. So it's not necessary to set it in each interrupt delivery. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: Call common update function when ioapic entry changed.Yang Zhang3-5/+11
Both TMR and EOI exit bitmap need to be updated when ioapic changed or vcpu's id/ldr/dfr changed. So use common function instead eoi exit bitmap specific function. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: VMX: Check the posted interrupt capabilityYang Zhang2-20/+66
Detect the posted interrupt feature. If it exists, then set it in vmcs_config. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: VMX: Register a new IPI for posted interruptYang Zhang7-0/+44
Posted Interrupt feature requires a special IPI to deliver posted interrupt to guest. And it should has a high priority so the interrupt will not be blocked by others. Normally, the posted interrupt will be consumed by vcpu if target vcpu is running and transparent to OS. But in some cases, the interrupt will arrive when target vcpu is scheduled out. And host will see it. So we need to register a dump handler to handle it. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: VMX: Enable acknowledge interupt on vmexitYang Zhang4-5/+64
The "acknowledge interrupt on exit" feature controls processor behavior for external interrupt acknowledgement. When this control is set, the processor acknowledges the interrupt controller to acquire the interrupt vector on VM exit. After enabling this feature, an interrupt which arrived when target cpu is running in vmx non-root mode will be handled by vmx handler instead of handler in idt. Currently, vmx handler only fakes an interrupt stack and jump to idt table to let real handler to handle it. Further, we will recognize the interrupt and only delivery the interrupt which not belong to current vcpu through idt table. The interrupt which belonged to current vcpu will be handled inside vmx handler. This will reduce the interrupt handle cost of KVM. Also, interrupt enable logic is changed if this feature is turnning on: Before this patch, hypervior call local_irq_enable() to enable it directly. Now IF bit is set on interrupt stack frame, and will be enabled on a return from interrupt handler if exterrupt interrupt exists. If no external interrupt, still call local_irq_enable() to enable it. Refer to Intel SDM volum 3, chapter 33.2. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Let ioapic know the irq line statusYang Zhang2-4/+6
Userspace may deliver RTC interrupt without query the status. So we want to track RTC EOI for this case. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Add reset/restore rtc_status supportYang Zhang2-0/+11
restore rtc_status from migration or save/restore Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Return destination vcpu on interrupt injectionYang Zhang2-11/+19
Add a new parameter to know vcpus who received the interrupt. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Add vcpu info to ioapic_update_eoi()Yang Zhang1-1/+1
Add vcpu info to ioapic_update_eoi, so we can know which vcpu issued this EOI. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-14KVM: nVMX: Avoid reading VM_EXIT_INTR_ERROR_CODE needlessly on nested exitsJan Kiszka1-1/+5
We only need to update vm_exit_intr_error_code if there is a valid exit interruption information and it comes with a valid error code. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: nVMX: Fix conditions for interrupt injectionJan Kiszka1-8/+12
If we are entering guest mode, we do not want L0 to interrupt this vmentry with all its side effects on the vmcs. Therefore, injection shall be disallowed during L1->L2 transitions, as in the previous version. However, this check is conceptually independent of nested_exit_on_intr, so decouple it. If L1 traps external interrupts, we can kick the guest from L2 to L1, also just like the previous code worked. But we no longer need to consider L1's idt_vectoring_info_field. It will always be empty at this point. Instead, if L2 has pending events, those are now found in the architectural queues and will, thus, prevent vmx_interrupt_allowed from being called at all. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: nVMX: Rework event injection and recoveryJan Kiszka1-35/+64
The basic idea is to always transfer the pending event injection on vmexit into the architectural state of the VCPU and then drop it from there if it turns out that we left L2 to enter L1, i.e. if we enter prepare_vmcs12. vmcs12_save_pending_events takes care to transfer pending L0 events into the queue of L1. That is mandatory as L1 may decide to switch the guest state completely, invalidating or preserving the pending events for later injection (including on a different node, once we support migration). This concept is based on the rule that a pending vmlaunch/vmresume is not canceled. Otherwise, we would risk to lose injected events or leak them into the wrong queues. Encode this rule via a WARN_ON_ONCE at the entry of nested_vmx_vmexit. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: nVMX: Fix injection of PENDING_INTERRUPT and NMI_WINDOW exits to L1Jan Kiszka1-7/+2
Check if the interrupt or NMI window exit is for L1 by testing if it has the corresponding controls enabled. This is required when we allow direct injection from L0 to L2 Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: emulator: mark 0xff 0x7d opcode as undefined.Gleb Natapov1-1/+1
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: emulator: Do not fail on emulation of undefined opcodeGleb Natapov1-2/+3
Emulation of undefined opcode should inject #UD instead of causing emulation failure. Do that by moving Undefined flag check to emulation stage and injection #UD there. Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: VMX: do not try to reexecute failed instruction while emulating invalid ↵Gleb Natapov3-5/+11
guest state During invalid guest state emulation vcpu cannot enter guest mode to try to reexecute instruction that emulator failed to emulate, so emulation will happen again and again. Prevent that by telling the emulator that instruction reexecution should not be attempted. Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-14KVM: emulator: fix unimplemented instruction detectionGleb Natapov1-3/+4
Unimplemented instruction detection is broken for group instructions since it relies on "flags" field of opcode to be zero, but all instructions in a group inherit flags from a group encoding. Fix that by having a separate flag for unimplemented instructions. Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-11KVM: x86 emulator: Fix segment loading in VM86Kevin Wolf1-3/+12
This fixes a regression introduced in commit 03ebebeb1 ("KVM: x86 emulator: Leave segment limit and attributs alone in real mode"). The mentioned commit changed the segment descriptors for both real mode and VM86 to only update the segment base instead of creating a completely new descriptor with limit 0xffff so that unreal mode keeps working across a segment register reload. This leads to an invalid segment descriptor in the eyes of VMX, which seems to be okay for real mode because KVM will fix it up before the next VM entry or emulate the state, but it doesn't do this if the guest is in VM86, so we end up with: KVM: entry failed, hardware error 0x80000021 Fix this by effectively reverting commit 03ebebeb1 for VM86 and leaving it only in place for real mode, which is where it's really needed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08KVM: Move kvm_rebooting declaration out of x86Geoff Levand1-1/+0
The variable kvm_rebooting is a common kvm variable, so move its declaration from arch/x86/include/asm/kvm_host.h to include/asm/kvm_host.h. Fixes this sparse warning when building on arm64: virt/kvm/kvm_main.c:warning: symbol 'kvm_rebooting' was not declared. Should it be static? Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08KVM: Move kvm_spurious_fault to x86.cGeoff Levand1-0/+7
The routine kvm_spurious_fault() is an x86 specific routine, so move it from virt/kvm/kvm_main.c to arch/x86/kvm/x86.c. Fixes this sparse warning when building on arm64: virt/kvm/kvm_main.c:warning: symbol 'kvm_spurious_fault' was not declared. Should it be static? Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08KVM: Move vm_list kvm_lock declarations out of x86Geoff Levand1-3/+0
The variables vm_list and kvm_lock are common to all architectures, so move the declarations from arch/x86/include/asm/kvm_host.h to include/linux/kvm_host.h. Fixes sparse warnings like these when building for arm64: virt/kvm/kvm_main.c: warning: symbol 'kvm_lock' was not declared. Should it be static? virt/kvm/kvm_main.c: warning: symbol 'vm_list' was not declared. Should it be static? Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08KVM: VMX: Add missing braces to avoid redundant error checkJan Kiszka1-1/+2
The code was already properly aligned, now also add the braces to avoid that err is checked even if alloc_apic_access_page didn't run and change it. Found via Coccinelle by Fengguang Wu. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08KVM: x86: fix memory leak in vmx_initYang Zhang1-1/+3
Free vmx_msr_bitmap_longmode_x2apic and vmx_msr_bitmap_longmode if kvm_init() fails. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07KVM: nVMX: Check exit control for VM_EXIT_SAVE_IA32_PAT, not entry controlsJan Kiszka1-1/+1
Obviously a copy&paste mistake: prepare_vmcs12 has to check L1's exit controls for VM_EXIT_SAVE_IA32_PAT. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07KVM: Call kvm_apic_match_dest() to check destination vcpuYang Zhang2-51/+0
For a given vcpu, kvm_apic_match_dest() will tell you whether the vcpu in the destination list quickly. Drop kvm_calculate_eoi_exitmap() and use kvm_apic_match_dest() instead. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07Revert "KVM: MMU: Move kvm_mmu_free_some_pages() into kvm_mmu_alloc_page()"Takuya Yoshikawa2-4/+8
With the following commit, shadow pages can be zapped at random during a shadow page talbe walk: KVM: MMU: Move kvm_mmu_free_some_pages() into kvm_mmu_alloc_page() 7ddca7e43c8f28f9419da81a0e7730b66aa60fe9 This patch reverts it and fixes __direct_map() and FNAME(fetch)(). Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-02pmu: prepare for migration supportPaolo Bonzini3-6/+14
In order to migrate the PMU state correctly, we need to restore the values of MSR_CORE_PERF_GLOBAL_STATUS (a read-only register) and MSR_CORE_PERF_GLOBAL_OVF_CTRL (which has side effects when written). We also need to write the full 40-bit value of the performance counter, which would only be possible with a v3 architectural PMU's full-width counter MSRs. To distinguish host-initiated writes from the guest's, pass the full struct msr_data to kvm_pmu_set_msr. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-21KVM: MMU: Rename kvm_mmu_free_some_pages() to make_mmu_pages_available()Takuya Yoshikawa2-8/+7
The current name "kvm_mmu_free_some_pages" should be used for something that actually frees some shadow pages, as we expect from the name, but what the function is doing is to make some, KVM_MIN_FREE_MMU_PAGES, shadow pages available: it does nothing when there are enough. This patch changes the name to reflect this meaning better; while doing this renaming, the code in the wrapper function is inlined into the main body since the whole function will be inlined into the only caller now. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-21KVM: MMU: Move kvm_mmu_free_some_pages() into kvm_mmu_alloc_page()Takuya Yoshikawa2-7/+3
What this function is doing is to ensure that the number of shadow pages does not exceed the maximum limit stored in n_max_mmu_pages: so this is placed at every code path that can reach kvm_mmu_alloc_page(). Although it might have some sense to spread this function in each such code path when it could be called before taking mmu_lock, the rule was changed not to do so. Taking this background into account, this patch moves it into kvm_mmu_alloc_page() and simplifies the code. Note: the unlikely hint in kvm_mmu_free_some_pages() guarantees that the overhead of this function is almost zero except when we actually need to allocate some shadow pages, so we do not need to care about calling it multiple times in one path by doing kvm_mmu_get_page() a few times. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-21Merge remote-tracking branch 'upstream/master' into queueMarcelo Tosatti10-45/+82
Merge reason: From: Alexander Graf <agraf@suse.de> "Just recently this really important patch got pulled into Linus' tree for 3.9: commit 1674400aaee5b466c595a8fc310488263ce888c7 Author: Anton Blanchard <anton <at> samba.org> Date: Tue Mar 12 01:51:51 2013 +0000 Without that commit, I can not boot my G5, thus I can't run automated tests on it against my queue. Could you please merge kvm/next against linus/master, so that I can base my trees against that?" * upstream/master: (653 commits) PCI: Use ROM images from firmware only if no other ROM source available sparc: remove unused "config BITS" sparc: delete "if !ULTRA_HAS_POPULATION_COUNT" KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798) KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions (CVE-2013-1797) KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME (CVE-2013-1796) arm64: Kconfig.debug: Remove unused CONFIG_DEBUG_ERRORS arm64: Do not select GENERIC_HARDIRQS_NO_DEPRECATED inet: limit length of fragment queue hash table bucket lists qeth: Fix scatter-gather regression qeth: Fix invalid router settings handling qeth: delay feature trace sgy-cts1000: Remove __dev* attributes KVM: x86: fix deadlock in clock-in-progress request handling KVM: allow host header to be included even for !CONFIG_KVM hwmon: (lm75) Fix tcn75 prefix hwmon: (lm75.h) Update header inclusion MAINTAINERS: Remove Mark M. Hoffman xfs: ensure we capture IO errors correctly xfs: fix xfs_iomap_eof_prealloc_initial_size type ... Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-20KVM: x86: correctly initialize the CS base on resetPaolo Bonzini2-7/+2
The CS base was initialized to 0 on VMX (wrong, but usually overridden by userspace before starting) or 0xf0000 on SVM. The correct value is 0xffff0000, and VMX is able to emulate it now, so use it. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-19Merge git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-35/+33
Pull kvm fixes from Marcelo Tosatti. * git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798) KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions (CVE-2013-1797) KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME (CVE-2013-1796) KVM: x86: fix deadlock in clock-in-progress request handling KVM: allow host header to be included even for !CONFIG_KVM
2013-03-19KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions ↵Andy Honig2-29/+22
(CVE-2013-1797) There is a potential use after free issue with the handling of MSR_KVM_SYSTEM_TIME. If the guest specifies a GPA in a movable or removable memory such as frame buffers then KVM might continue to write to that address even after it's removed via KVM_SET_USER_MEMORY_REGION. KVM pins the page in memory so it's unlikely to cause an issue, but if the user space component re-purposes the memory previously used for the guest, then the guest will be able to corrupt that memory. Tested: Tested against kvmclock unit test Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-19KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME ↵Andy Honig1-0/+5
(CVE-2013-1796) If the guest sets the GPA of the time_page so that the request to update the time straddles a page then KVM will write onto an incorrect page. The write is done byusing kmap atomic to get a pointer to the page for the time structure and then performing a memcpy to that page starting at an offset that the guest controls. Well behaved guests always provide a 32-byte aligned address, however a malicious guest could use this to corrupt host kernel memory. Tested: Tested against kvmclock unit test. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-18KVM: x86: fix deadlock in clock-in-progress request handlingMarcelo Tosatti1-9/+9
There is a deadlock in pvclock handling: cpu0: cpu1: kvm_gen_update_masterclock() kvm_guest_time_update() spin_lock(pvclock_gtod_sync_lock) local_irq_save(flags) spin_lock(pvclock_gtod_sync_lock) kvm_make_mclock_inprogress_request(kvm) make_all_cpus_request() smp_call_function_many() Now if smp_call_function_many() called by cpu0 tries to call function on cpu1 there will be a deadlock. Fix by moving pvclock_gtod_sync_lock protected section outside irq disabled section. Analyzed by Gleb Natapov <gleb@redhat.com> Acked-by: Gleb Natapov <gleb@redhat.com> Reported-and-Tested-by: Yongjie Ren <yongjie.ren@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-18KVM: VMX: Require KVM_SET_TSS_ADDR being called prior to running a VCPUJan Kiszka1-26/+4
Very old user space (namely qemu-kvm before kvm-49) didn't set the TSS base before running the VCPU. We always warned about this bug, but no reports about users actually seeing this are known. Time to finally remove the workaround that effectively prevented to call vmx_vcpu_reset while already holding the KVM srcu lock. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-17perf,x86: fix wrmsr_on_cpu() warning on suspend/resumeLinus Torvalds1-1/+3
Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after suspend/resume") fixed a crash when doing PEBS performance profiling after resuming, but in using init_debug_store_on_cpu() to restore the DS_AREA mtrr it also resulted in a new WARN_ON() triggering. init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU cross-calls to do the MSR update. Which is not really valid at the early resume stage, and the warning is quite reasonable. Now, it all happens to _work_, for the simple reason that smp_call_function_single() ends up just doing the call directly on the CPU when the CPU number matches, but we really should just do the wrmsr() directly instead. This duplicates the wrmsr() logic, but hopefully we can just remove the wrmsr_on_cpu() version eventually. Reported-and-tested-by: Parag Warudkar <parag.lkml@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-15perf,x86: fix kernel crash with PEBS/BTS after suspend/resumeStephane Eranian2-0/+10
This patch fixes a kernel crash when using precise sampling (PEBS) after a suspend/resume. Turns out the CPU notifier code is not invoked on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly by the kernel and keeps it power-on/resume value of 0 causing any PEBS measurement to crash when running on CPU0. The workaround is to add a hook in the actual resume code to restore the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0, the DS_AREA will be restored twice but this is harmless. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-14KVM: x86: Optimize mmio spte zapping when creating/moving memslotTakuya Yoshikawa3-1/+20
When we create or move a memory slot, we need to zap mmio sptes. Currently, zap_all() is used for this and this is causing two problems: - extra page faults after zapping mmu pages - long mmu_lock hold time during zapping mmu pages For the latter, Marcelo reported a disastrous mmu_lock hold time during hot-plug, which made the guest unresponsive for a long time. This patch takes a simple way to fix these problems: do not zap mmu pages unless they are marked mmio cached. On our test box, this took only 50us for the 4GB guest and we did not see ms of mmu_lock hold time any more. Note that we still need to do zap_all() for other cases. So another work is also needed: Xiao's work may be the one. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-14KVM: MMU: Mark sp mmio cached when creating mmio spteTakuya Yoshikawa2-0/+4
This will be used not to zap unrelated mmu pages when creating/moving a memory slot later. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-14KVM: nVMX: Add preemption timer supportJan Kiszka3-5/+20
Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-14KVM: nVMX: Provide EFER.LMA saving supportJan Kiszka2-1/+14
We will need EFER.LMA saving to provide unrestricted guest mode. All what is missing for this is picking up EFER.LMA from VM_ENTRY_CONTROLS on L2->L1 switches. If the host does not support EFER.LMA saving, no change is performed, otherwise we properly emulate for L1 what the hardware does for L0. Advertise the support, depending on the host feature. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-13KVM: nVMX: Clean up and fix pin-based execution controlsJan Kiszka2-4/+8
Only interrupt and NMI exiting are mandatory for KVM to work, thus can be exposed to the guest unconditionally, virtual NMI exiting is optional. So we must not advertise it unless the host supports it. Introduce the symbolic constant PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR at this chance. Reviewed-by:: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-13KVM: x86: Rework INIT and SIPI handlingJan Kiszka6-45/+93
A VCPU sending INIT or SIPI to some other VCPU races for setting the remote VCPU's mp_state. When we were unlucky, KVM_MP_STATE_INIT_RECEIVED was overwritten by kvm_emulate_halt and, thus, got lost. This introduces APIC events for those two signals, keeping them in kvm_apic until kvm_apic_accept_events is run over the target vcpu context. kvm_apic_has_events reports to kvm_arch_vcpu_runnable if there are pending events, thus if vcpu blocking should end. The patch comes with the side effect of effectively obsoleting KVM_MP_STATE_SIPI_RECEIVED. We still accept it from user space, but immediately translate it to KVM_MP_STATE_INIT_RECEIVED + KVM_APIC_SIPI. The vcpu itself will no longer enter the KVM_MP_STATE_SIPI_RECEIVED state. That also means we no longer exit to user space after receiving a SIPI event. Furthermore, we already reset the VCPU on INIT, only fixing up the code segment later on when SIPI arrives. Moreover, we fix INIT handling for the BSP: it never enter wait-for-SIPI but directly starts over on INIT. Tested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-13KVM: MMU: make kvm_mmu_available_pages robust against n_used_mmu_pages > ↵Marcelo Tosatti1-2/+5
n_max_mmu_pages As noticed by Ulrich Obergfell <uobergfe@redhat.com>, the mmu counters are for beancounting purposes only - so n_used_mmu_pages and n_max_mmu_pages could be relaxed (example: before f0f5933a1626c8df7b), resulting in n_used_mmu_pages > n_max_mmu_pages. Make code robust against n_used_mmu_pages > n_max_mmu_pages. Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-12Select VIRT_TO_BUS directly where neededStephen Rothwell1-1/+1
In commit 887cbce0adea ("arch Kconfig: centralise ARCH_NO_VIRT_TO_BUS") I introduced the config sybmol HAVE_VIRT_TO_BUS and selected that where needed. I am not sure what I was thinking. Instead, just directly select VIRT_TO_BUS where it is needed. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-12KVM: x86: Drop unused return code from VCPU reset callbackJan Kiszka4-19/+9
Neither vmx nor svm nor the common part may generate an error on kvm_vcpu_reset. So drop the return code. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-12VMX: x86: handle host TSC calibration failureMarcelo Tosatti1-11/+18
If the host TSC calibration fails, tsc_khz is zero (see tsc_init.c). Handle such case properly in KVM (instead of dividing by zero). https://bugzilla.redhat.com/show_bug.cgi?id=859282 Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>