diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-02 13:18:37 +0200 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-03 10:18:54 +0200 |
commit | 5e352519519623a0b62587c606280e534d0cf1d9 (patch) | |
tree | 776ecf76c11f6092c28d2125e7e79cd49a937f9b | |
parent | a0c0feb57992c5caed170feab8a68c51306eb7c3 (diff) |
KVM: nSVM: propagate the NPF EXITINFO to the guest
This is similar to what the EPT code does with the exit qualification.
This allows the guest to see a valid value for bits 33:32.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 12 | ||||
-rw-r--r-- | arch/x86/kvm/svm.c | 24 |
2 files changed, 32 insertions, 4 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 41077652826..df1a044d92d 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -322,8 +322,20 @@ retry_walk: real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn), PFERR_USER_MASK|PFERR_WRITE_MASK); + + /* + * FIXME: This can happen if emulation (for of an INS/OUTS + * instruction) triggers a nested page fault. The exit + * qualification / exit info field will incorrectly have + * "guest page access" as the nested page fault's cause, + * instead of "guest page structure access". To fix this, + * the x86_exception struct should be augmented with enough + * information to fix the exit_qualification or exit_info_1 + * fields. + */ if (unlikely(real_gfn == UNMAPPED_GVA)) goto error; + real_gfn = gpa_to_gfn(real_gfn); host_addr = gfn_to_hva_prot(vcpu->kvm, real_gfn, diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 8ef70403737..d0a61a05a89 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1974,10 +1974,26 @@ static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu, { struct vcpu_svm *svm = to_svm(vcpu); - svm->vmcb->control.exit_code = SVM_EXIT_NPF; - svm->vmcb->control.exit_code_hi = 0; - svm->vmcb->control.exit_info_1 = fault->error_code; - svm->vmcb->control.exit_info_2 = fault->address; + if (svm->vmcb->control.exit_code != SVM_EXIT_NPF) { + /* + * TODO: track the cause of the nested page fault, and + * correctly fill in the high bits of exit_info_1. + */ + svm->vmcb->control.exit_code = SVM_EXIT_NPF; + svm->vmcb->control.exit_code_hi = 0; + svm->vmcb->control.exit_info_1 = (1ULL << 32); + svm->vmcb->control.exit_info_2 = fault->address; + } + + svm->vmcb->control.exit_info_1 &= ~0xffffffffULL; + svm->vmcb->control.exit_info_1 |= fault->error_code; + + /* + * The present bit is always zero for page structure faults on real + * hardware. + */ + if (svm->vmcb->control.exit_info_1 & (2ULL << 32)) + svm->vmcb->control.exit_info_1 &= ~1; nested_svm_vmexit(svm); } |