linux_dsm_epyc7002/arch/x86/kvm
Igor Mammedov ebae871a50 kvm: svm: reset mmu on VCPU reset
When INIT/SIPI sequence is sent to VCPU which before that
was in use by OS, VMRUN might fail with:

 KVM: entry failed, hardware error 0xffffffff
 EAX=00000000 EBX=00000000 ECX=00000000 EDX=000006d3
 ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
 EIP=00000000 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
 ES =0000 00000000 0000ffff 00009300
 CS =9a00 0009a000 0000ffff 00009a00
 [...]
 CR0=60000010 CR2=b6f3e000 CR3=01942000 CR4=000007e0
 [...]
 EFER=0000000000000000

with corresponding SVM error:
 KVM: FAILED VMRUN WITH VMCB:
 [...]
 cpl:            0                efer:         0000000000001000
 cr0:            0000000080010010 cr2:          00007fd7fe85bf90
 cr3:            0000000187d0c000 cr4:          0000000000000020
 [...]

What happens is that VCPU state right after offlinig:
CR0: 0x80050033  EFER: 0xd01  CR4: 0x7e0
  -> long mode with CR3 pointing to longmode page tables

and when VCPU gets INIT/SIPI following transition happens
CR0: 0 -> 0x60000010 EFER: 0x0  CR4: 0x7e0
  -> paging disabled with stale CR3

However SVM under the hood puts VCPU in Paged Real Mode*
which effectively translates CR0 0x60000010 -> 80010010 after

   svm_vcpu_reset()
       -> init_vmcb()
           -> kvm_set_cr0()
               -> svm_set_cr0()

but from  kvm_set_cr0() perspective CR0: 0 -> 0x60000010
only caching bits are changed and
commit d81135a57a
 ("KVM: x86: do not reset mmu if CR0.CD and CR0.NW are changed")'
regressed svm_vcpu_reset() which relied on MMU being reset.

As result VMRUN after svm_vcpu_reset() tries to run
VCPU in Paged Real Mode with stale MMU context (longmode page tables),
which causes some AMD CPUs** to bail out with VMEXIT_INVALID.

Fix issue by unconditionally resetting MMU context
at init_vmcb() time.

	* AMD64 Architecture Programmer’s Manual,
	    Volume 2: System Programming, rev: 3.25
	      15.19 Paged Real Mode
	** Opteron 1216

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Fixes: d81135a57a
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-18 16:49:02 +02:00
..
assigned-dev.c VFS: assorted d_backing_inode() annotations 2015-04-15 15:06:59 -04:00
assigned-dev.h KVM: x86: move device assignment out of kvm_host.h 2014-11-24 16:53:50 +01:00
cpuid.c KVM: VMX: fix vmwrite to invalid VMCS 2015-07-10 13:25:25 +02:00
cpuid.h KVM: x86: save/load state on SMM switch 2015-06-04 16:17:46 +02:00
emulate.c Silence compiler warning in arch/x86/kvm/emulate.c 2015-09-06 16:26:23 +02:00
hyperv.c kvm/x86: added hyper-v crash msrs into kvm hyperv context 2015-07-23 08:27:06 +02:00
hyperv.h kvm/x86: added hyper-v crash msrs into kvm hyperv context 2015-07-23 08:27:06 +02:00
i8254.c KVM: x86: make vapics_in_nmi_mode atomic 2015-07-03 18:55:17 +02:00
i8254.h KVM: move iodev.h from virt/kvm/ to include/kvm 2015-03-26 21:43:12 +00:00
i8259.c KVM: x86: clean/fix memory barriers in irqchip_in_kernel 2015-07-30 16:02:56 +02:00
ioapic.c KVM: x86: drop unneeded null test 2015-05-07 11:29:47 +02:00
ioapic.h KVM/ARM changes for v4.1: 2015-04-07 18:09:20 +02:00
iommu.c KVM: count number of assigned devices 2015-07-10 13:25:26 +02:00
irq_comm.c kvm: x86: Deliver MSI IRQ to only lowest prio cpu if msi_redir_hint is true 2015-05-07 11:29:45 +02:00
irq.c
irq.h KVM: x86: clean/fix memory barriers in irqchip_in_kernel 2015-07-30 16:02:56 +02:00
Kconfig KVM: x86: mark legacy PCI device assignment as deprecated 2015-06-05 17:26:39 +02:00
kvm_cache_regs.h KVM: x86: API changes for SMM support 2015-06-04 16:01:11 +02:00
lapic.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 08:40:25 -07:00
lapic.h kvm/x86: move Hyper-V MSR's/hypercall code into hyperv.c file 2015-07-23 08:27:06 +02:00
Makefile kvm/x86: move Hyper-V MSR's/hypercall code into hyperv.c file 2015-07-23 08:27:06 +02:00
mmu_audit.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
mmu.c KVM: x86: avoid uninitialized variable warning 2015-09-06 16:26:21 +02:00
mmu.h KVM: VMX: drop ept misconfig check 2015-08-05 12:47:26 +02:00
mmutrace.h tracing: Rename ftrace_event.h to trace_events.h 2015-05-13 14:05:12 -04:00
mtrr.c KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON 2015-08-05 12:47:21 +02:00
paging_tmpl.h KVM: MMU: move FNAME(is_rsvd_bits_set) to mmu.c 2015-08-05 12:47:22 +02:00
pmu_amd.c KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn 2015-08-11 15:19:41 +02:00
pmu_intel.c KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch 2015-06-23 14:12:14 +02:00
pmu.c KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch 2015-06-23 14:12:14 +02:00
pmu.h KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch 2015-06-23 14:12:14 +02:00
svm.c kvm: svm: reset mmu on VCPU reset 2015-09-18 16:49:02 +02:00
trace.h KVM: x86: save/load state on SMM switch 2015-06-04 16:17:46 +02:00
tss.h
vmx.c KVM: vmx: fix VPID is 0000H in non-root operation 2015-09-16 15:17:27 +02:00
x86.c KVM: add halt_attempted_poll to VCPU stats 2015-09-16 12:17:00 +02:00
x86.h kvm/x86: move Hyper-V MSR's/hypercall code into hyperv.c file 2015-07-23 08:27:06 +02:00