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| author |   Sean Christopherson <seanjc@google.com> | 2022-01-20 01:07:12 +0000 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2022-01-26 12:14:59 -0500 |
| commit | 31c25585695abdf03d6160aa6d829e855b256329 (patch) | |
| tree | 90f8530f05f5a80529e6d43d7a7f26f6fe4915b9 /arch | |
| parent | KVM: SVM: Never reject emulation due to SMAP errata for !SEV guests (diff) | |
| download | wireguard-linux-31c25585695abdf03d6160aa6d829e855b256329.tar.xz wireguard-linux-31c25585695abdf03d6160aa6d829e855b256329.zip | |
Revert "KVM: SVM: avoid infinite loop on NPF from bad address"
Revert a completely broken check on an "invalid" RIP in SVM's workaround
for the DecodeAssists SMAP errata. kvm_vcpu_gfn_to_memslot() obviously
expects a gfn, i.e. operates in the guest physical address space, whereas
RIP is a virtual (not even linear) address. The "fix" worked for the
problematic KVM selftest because the test identity mapped RIP.
Fully revert the hack instead of trying to translate RIP to a GPA, as the
non-SEV case is now handled earlier, and KVM cannot access guest page
tables to translate RIP.
This reverts commit e72436bc3a5206f95bb384e741154166ddb3202e.
Fixes: e72436bc3a52 ("KVM: SVM: avoid infinite loop on NPF from bad address")
Reported-by: Liam Merwick <liam.merwick@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index a46e1c6abf0e..37eb3168e0ea 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4312,13 +4312,6 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int i if (likely(!insn || insn_len)) return true; - /* - * If RIP is invalid, go ahead with emulation which will cause an - * internal error exit. - */ - if (!kvm_vcpu_gfn_to_memslot(vcpu, kvm_rip_read(vcpu) >> PAGE_SHIFT)) - return true; - cr4 = kvm_read_cr4(vcpu); smep = cr4 & X86_CR4_SMEP; smap = cr4 & X86_CR4_SMAP; |