diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-01 13:12:47 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-22 14:49:13 -0700 |
commit | 98eee9987abe51a260ad8b521c33205ce8ea0028 (patch) | |
tree | 181084cdead2edb9c47d3bbe10f2e57ac5d8bc2c /arch/x86 | |
parent | eec2b28cfed52a1154ee6b8577bc1464c03b0838 (diff) |
Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"
commit 606decd67049217684e3cb5a54104d51ddd4ef35 upstream.
This reverts commit fd717f11015f673487ffc826e59b2bad69d20fe5.
It was reported to cause Machine Check Exceptions (bug 104091).
Reported-by: harn-solo@gmx.de
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kvm/svm.c | 7 | ||||
-rw-r--r-- | arch/x86/kvm/vmx.c | 11 |
2 files changed, 13 insertions, 5 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index d2fd1c712b5e..60481b74e202 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1166,11 +1166,14 @@ static u64 svm_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) u8 mtrr; /* - * 1. MMIO: trust guest MTRR, so same as item 3. + * 1. MMIO: always map as UC * 2. No passthrough: always map as WB, and force guest PAT to WB as well * 3. Passthrough: can't guarantee the result, try to trust guest. */ - if (!is_mmio && !kvm_arch_has_assigned_device(vcpu->kvm)) + if (is_mmio) + return _PAGE_NOCACHE; + + if (!kvm_arch_has_assigned_device(vcpu->kvm)) return 0; mtrr = kvm_mtrr_get_guest_memory_type(vcpu, gfn); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e0d2be06a6a3..aa9e8229571d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8634,17 +8634,22 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) u64 ipat = 0; /* For VT-d and EPT combination - * 1. MMIO: guest may want to apply WC, trust it. + * 1. MMIO: always map as UC * 2. EPT with VT-d: * a. VT-d without snooping control feature: can't guarantee the - * result, try to trust guest. So the same as item 1. + * result, try to trust guest. * b. VT-d with snooping control feature: snooping control feature of * VT-d engine can guarantee the cache correctness. Just set it * to WB to keep consistent with host. So the same as item 3. * 3. EPT without VT-d: always map as WB and set IPAT=1 to keep * consistent with host MTRR */ - if (!is_mmio && !kvm_arch_has_noncoherent_dma(vcpu->kvm)) { + if (is_mmio) { + cache = MTRR_TYPE_UNCACHABLE; + goto exit; + } + + if (!kvm_arch_has_noncoherent_dma(vcpu->kvm)) { ipat = VMX_EPT_IPAT_BIT; cache = MTRR_TYPE_WRBACK; goto exit; |