diff options
| author |   Jim Mattson <jmattson@google.com> | 2018-10-16 14:29:22 -0700 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2018-10-17 19:07:43 +0200 |
| commit | da998b46d244767505e41d050dcac5e4d03ba96f (patch) | |
| tree | 8e719071b6732577b306b04dfb6fe886a244e51f /arch/x86/kvm/vmx.c | |
| parent | kvm: x86: Add payload operands to kvm_multiple_exception (diff) | |
| download | linux-dev-da998b46d244767505e41d050dcac5e4d03ba96f.tar.xz linux-dev-da998b46d244767505e41d050dcac5e4d03ba96f.zip | |
kvm: x86: Defer setting of CR2 until #PF delivery
When exception payloads are enabled by userspace (which is not yet
possible) and a #PF is raised in L2, defer the setting of CR2 until
the #PF is delivered. This allows the L1 hypervisor to intercept the
fault before CR2 is modified.
For backwards compatibility, when exception payloads are not enabled
by userspace, kvm_multiple_exception modifies CR2 when the #PF
exception is raised.
Reported-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8d7c60faaacd..0c7efb1de29d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3292,27 +3292,24 @@ static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned long *exit { struct vmcs12 *vmcs12 = get_vmcs12(vcpu); unsigned int nr = vcpu->arch.exception.nr; + bool has_payload = vcpu->arch.exception.has_payload; + unsigned long payload = vcpu->arch.exception.payload; if (nr == PF_VECTOR) { if (vcpu->arch.exception.nested_apf) { *exit_qual = vcpu->arch.apf.nested_apf_token; return 1; } - /* - * FIXME: we must not write CR2 when L1 intercepts an L2 #PF exception. - * The fix is to add the ancillary datum (CR2 or DR6) to structs - * kvm_queued_exception and kvm_vcpu_events, so that CR2 and DR6 - * can be written only when inject_pending_event runs. This should be - * conditional on a new capability---if the capability is disabled, - * kvm_multiple_exception would write the ancillary information to - * CR2 or DR6, for backwards ABI-compatibility. - */ if (nested_vmx_is_page_fault_vmexit(vmcs12, vcpu->arch.exception.error_code)) { - *exit_qual = vcpu->arch.cr2; + *exit_qual = has_payload ? payload : vcpu->arch.cr2; return 1; } } else { + /* + * FIXME: we must not write DR6 when L1 intercepts an + * L2 #DB exception. + */ if (vmcs12->exception_bitmap & (1u << nr)) { if (nr == DB_VECTOR) { *exit_qual = vcpu->arch.dr6; @@ -3349,6 +3346,8 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu) u32 error_code = vcpu->arch.exception.error_code; u32 intr_info = nr | INTR_INFO_VALID_MASK; + kvm_deliver_exception_payload(vcpu); + if (has_error_code) { vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, error_code); intr_info |= INTR_INFO_DELIVER_CODE_MASK; |