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2008-03-04KVM: VMX: Avoid rearranging switched guest msrs while they are loadedAvi Kivity
KVM tries to run as much as possible with the guest msrs loaded instead of host msrs, since switching msrs is very expensive. It also tries to minimize the number of msrs switched according to the guest mode; for example, MSR_LSTAR is needed only by long mode guests. This optimization is done by setup_msrs(). However, we must not change which msrs are switched while we are running with guest msr state: - switch to guest msr state - call setup_msrs(), removing some msrs from the list - switch to host msr state, leaving a few guest msrs loaded An easy way to trigger this is to kexec an x86_64 linux guest. Early during setup, the guest will switch EFER to not include SCE. KVM will stop saving MSR_LSTAR, and on the next msr switch it will leave the guest LSTAR loaded. The next host syscall will end up in a random location in the kernel. Fix by reloading the host msrs before changing the msr list. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04KVM: MMU: Fix race when instantiating a shadow pteAvi Kivity
For improved concurrency, the guest walk is performed concurrently with other vcpus. This means that we need to revalidate the guest ptes once we have write-protected the guest page tables, at which point they can no longer be modified. The current code attempts to avoid this check if the shadow page table is not new, on the assumption that if it has existed before, the guest could not have modified the pte without the shadow lock. However the assumption is incorrect, as the racing vcpu could have modified the pte, then instantiated the shadow page, before our vcpu regains control: vcpu0 vcpu1 fault walk pte modify pte fault in same pagetable instantiate shadow page lookup shadow page conclude it is old instantiate spte based on stale guest pte We could do something clever with generation counters, but a test run by Marcelo suggests this is unnecessary and we can just do the revalidation unconditionally. The pte will be in the processor cache and the check can be quite fast. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04KVM: Avoid infinite-frequency local apic timerAvi Kivity
If the local apic initial count is zero, don't start a an hrtimer with infinite frequency, locking up the host. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04KVM: make MMU_DEBUG compile againMarcelo Tosatti
the cr3 variable is now inside the vcpu->arch structure. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04KVM: move alloc_apic_access_page() outside of non-preemptable regionMarcelo Tosatti
alloc_apic_access_page() can sleep, while vmx_vcpu_setup is called inside a non preemptable region. Move it after put_cpu(). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04KVM: SVM: fix Windows XP 64 bit installation crashJoerg Roedel
While installing Windows XP 64 bit wants to access the DEBUGCTL and the last branch record (LBR) MSRs. Don't allowing this in KVM causes the installation to crash. This patch allow the access to these MSRs and fixes the issue. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-04KVM: remove the usage of the mmap_sem for the protection of the memory slots.Izik Eidus
This patch replaces the mmap_sem lock for the memory slots with a new kvm private lock, it is needed beacuse untill now there were cases where kvm accesses user memory while holding the mmap semaphore. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-03KVM: emulate access to MSR_IA32_MCG_CTLJoerg Roedel
Injecting an GP when accessing this MSR lets Windows crash when running some stress test tools in KVM. So this patch emulates access to this MSR. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-03KVM: Make the supported cpuid list a host property rather than a vm propertyAvi Kivity
One of the use cases for the supported cpuid list is to create a "greatest common denominator" of cpu capabilities in a server farm. As such, it is useful to be able to get the list without creating a virtual machine first. Since the code does not depend on the vm in any way, all that is needed is to move it to the device ioctl handler. The capability identifier is also changed so that binaries made against -rc1 will fail gracefully. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-03KVM: Fix kvm_arch_vcpu_ioctl_set_sregs so that set_cr0 works properlyPaul Knowles
Whilst working on getting a VM to initialize in to IA32e mode I found this issue. set_cr0 relies on comparing the old cr0 to the new one to work correctly. Move the assignment below so the compare can work. Signed-off-by: Paul Knowles <paul@transitive.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-03KVM: SVM: set NM intercept when enabling CR0.TS in the guestJoerg Roedel
Explicitly enable the NM intercept in svm_set_cr0 if we enable TS in the guest copy of CR0 for lazy FPU switching. This fixes guest SMP with Linux under SVM. Without that patch Linux deadlocks or panics right after trying to boot the other CPUs. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-03-03KVM: SVM: Fix lazy FPU switchingJoerg Roedel
If the guest writes to cr0 and leaves the TS flag at 0 while vcpu->fpu_active is also 0, the TS flag in the guest's cr0 gets lost. This leads to corrupt FPU state an causes Windows Vista 64bit to crash very soon after boot. This patch fixes this bug. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-02-05kvm: i386 fixAndrew Morton
arch/x86/kvm/x86.c: In function 'emulator_cmpxchg_emulated': arch/x86/kvm/x86.c:1746: warning: passing argument 2 of 'vcpu->arch.mmu.gva_to_gpa' makes integer from pointer without a cast arch/x86/kvm/x86.c:1746: warning: 'addr' is used uninitialized in this function Is true. Local variable `addr' shadows incoming arg `addr'. Avi is on vacation for a while, so... Cc: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04virtio: Put the virtio under the virtualization menuAnthony Liguori
This patch moves virtio under the virtualization menu and changes virtio devices to not claim to only be for lguest. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30KVM: Move apic timer migration away from critical sectionAvi Kivity
Migrating the apic timer in the critical section is not very nice, and is absolutely horrible with the real-time port. Move migration to the regular vcpu execution path, triggered by a new bitflag. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Fix unbounded preemption latencyAvi Kivity
When preparing to enter the guest, if an interrupt comes in while preemption is disabled but interrupts are still enabled, we miss a preemption point. Fix by explicitly checking whether we need to reschedule. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Initialize the mmu caches only after verifying cpu supportAvi Kivity
Otherwise we re-initialize the mmu caches, which will fail since the caches are already registered, which will cause us to deinitialize said caches. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Fix dirty page setting for pages removed from rmapIzik Eidus
Right now rmap_remove won't set the page as dirty if the shadow pte pointed to this page had write access and then it became readonly. This patches fixes that, by setting the page as dirty for spte changes from write to readonly access. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: x86 emulator: Only allow VMCALL/VMMCALL trapped by #UDSheng Yang
When executing a test program called "crashme", we found the KVM guest cannot survive more than ten seconds, then encounterd kernel panic. The basic concept of "crashme" is generating random assembly code and trying to execute it. After some fixes on emulator insn validity judgment, we found it's hard to get the current emulator handle the invalid instructions correctly, for the #UD trap for hypercall patching caused troubles. The problem is, if the opcode itself was OK, but combination of opcode and modrm_reg was invalid, and one operand of the opcode was memory (SrcMem or DstMem), the emulator will fetch the memory operand first rather than checking the validity, and may encounter an error there. For example, ".byte 0xfe, 0x34, 0xcd" has this problem. In the patch, we simply check that if the invalid opcode wasn't vmcall/vmmcall, then return from emulate_instruction() and inject a #UD to guest. With the patch, the guest had been running for more than 12 hours. Signed-off-by: Feng (Eric) Liu <eric.e.liu@intel.com> Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Merge shadow level check in FNAME(fetch)Dong, Eddie
Remove the redundant level check when fetching shadow pte for present & non-present spte. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Move kvm_free_some_pages() into critical sectionAvi Kivity
If some other cpu steals mmu pages between our check and an attempt to allocate, we can run out of mmu pages. Fix by moving the check into the same critical section as the allocation. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Switch to mmu spinlockMarcelo Tosatti
Convert the synchronization of the shadow handling to a separate mmu_lock spinlock. Also guard fetch() by mmap_sem in read-mode to protect against alias and memslot changes. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Avoid calling gfn_to_page() in mmu_set_spte()Avi Kivity
Since gfn_to_page() is a sleeping function, and we want to make the core mmu spinlocked, we need to pass the page from the walker context (which can sleep) to the shadow context (which cannot). [marcelo: avoid recursive locking of mmap_sem] Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Add kvm_read_guest_atomic()Marcelo Tosatti
In preparation for a mmu spinlock, add kvm_read_guest_atomic() and use it in fetch() and prefetch_page(). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Concurrent guest walkersMarcelo Tosatti
Do not hold kvm->lock mutex across the entire pagefault code, only acquire it in places where it is necessary, such as mmu hash list, active list, rmap and parent pte handling. Allow concurrent guest walkers by switching walk_addr() to use mmap_sem in read-mode. And get rid of the lockless __gfn_to_page. [avi: move kvm_mmu_pte_write() locking inside the function] [avi: add locking for real mode] [avi: fix cmpxchg locking] Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Disable vapic support on Intel machines with FlexPriorityAvi Kivity
FlexPriority accelerates the tpr without any patching. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Accelerated apic supportAvi Kivity
This adds a mechanism for exposing the virtual apic tpr to the guest, and a protocol for letting the guest update the tpr without causing a vmexit if conditions allow (e.g. there is no interrupt pending with a higher priority than the new tpr). Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: local APIC TPR access reporting facilityAvi Kivity
Add a facility to report on accesses to the local apic tpr even if the local apic is emulated in the kernel. This is basically a hack that allows userspace to patch Windows which tends to bang on the tpr a lot. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Print data for unimplemented wrmsrAvi Kivity
This can help diagnosing what the guest is trying to do. In many cases we can get away with partial emulation of msrs. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Add cache miss statisticAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Coalesce remote tlb flushesEddie Dong
Host side TLB flush can be merged together if multiple spte need to be write-protected. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move kvm_vcpu_kick() to x86.cZhang Xiantao
Moving kvm_vcpu_kick() to x86.c. Since it should be common for all archs, put its declarations in <linux/kvm_host.h> Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move ioapic code to common directory.Zhang Xiantao
Move ioapic code to common, since IA64 also needs it. Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move irqchip declarations into new ioapic.h and lapic.hZhang Xiantao
This allows reuse of ioapic in ia64. Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move drivers/kvm/* to virt/kvm/Avi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move arch dependent files to new directory arch/x86/kvm/Avi Kivity
This paves the way for multiple architecture support. Note that while ioapic.c could potentially be shared with ia64, it is also moved. Signed-off-by: Avi Kivity <avi@qumranet.com>