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| author | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-02 13:24:12 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-03 10:04:11 +0200 |
| commit | a0c0feb57992c5caed170feab8a68c51306eb7c3 (patch) | |
| tree | 03865eccb27cbc1a2604d6e83ae3f8ecff9b355c /arch | |
| parent | d143148383d0395539073dd6c2f25ddf6656bdcc (diff) | |
| download | linux-a0c0feb57992c5caed170feab8a68c51306eb7c3.tar.bz2 | |
KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD
Bit 8 would be the "global" bit, which does not quite make sense for non-leaf
page table entries. Intel ignores it; AMD ignores it in PDEs, but reserves it
in PDPEs and PML4Es. The SVM test is relying on this behavior, so enforce it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 13 |
2 files changed, 19 insertions, 2 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index a5380590ab0e..43b33e301e68 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -88,6 +88,14 @@ static inline bool guest_cpuid_has_x2apic(struct kvm_vcpu *vcpu) return best && (best->ecx & bit(X86_FEATURE_X2APIC)); } +static inline bool guest_cpuid_is_amd(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 0, 0); + return best && best->ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx; +} + static inline bool guest_cpuid_has_gbpages(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 6b6df0c5be3d..5b93a597e0c8 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3512,6 +3512,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int maxphyaddr = cpuid_maxphyaddr(vcpu); u64 exb_bit_rsvd = 0; u64 gbpages_bit_rsvd = 0; + u64 nonleaf_bit8_rsvd = 0; context->bad_mt_xwr = 0; @@ -3519,6 +3520,14 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, exb_bit_rsvd = rsvd_bits(63, 63); if (!guest_cpuid_has_gbpages(vcpu)) gbpages_bit_rsvd = rsvd_bits(7, 7); + + /* + * Non-leaf PML4Es and PDPEs reserve bit 8 (which would be the G bit for + * leaf entries) on AMD CPUs only. + */ + if (guest_cpuid_is_amd(vcpu)) + nonleaf_bit8_rsvd = rsvd_bits(8, 8); + switch (context->root_level) { case PT32_ROOT_LEVEL: /* no rsvd bits for 2 level 4K page table entries */ @@ -3553,9 +3562,9 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, break; case PT64_ROOT_LEVEL: context->rsvd_bits_mask[0][3] = exb_bit_rsvd | - rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7); + nonleaf_bit8_rsvd | rsvd_bits(7, 7) | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][2] = exb_bit_rsvd | - gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51); + nonleaf_bit8_rsvd | gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][1] = exb_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][0] = exb_bit_rsvd | |