diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-01-25 07:40:58 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-02-12 13:12:19 +0100 |
| commit | f1727b4954772a778df0b73a93c4b646fd3c21f6 (patch) | |
| tree | c168e8cc8b0ed6f100f9f2d2ad9a32fda965ee0e | |
| parent | 6c1e7e5b40f23b9e754a47852924115febba35df (diff) | |
KVM: nVMX: Capture VM-Fail to a local var in nested_vmx_check_vmentry_hw()
Unlike the primary vCPU-run flow, the nested early checks code doesn't
actually want to propagate VM-Fail back to 'vmx'. Yay copy+paste.
In additional to eliminating the need to clear vmx->fail before
returning, using a local boolean also drops a reference to 'vmx' in the
asm blob. Dropping the reference to 'vmx' will save a register in the
long run as future patches will shift all pointer references from 'vmx'
to 'vmx->loaded_vmcs'.
Fixes: 52017608da33 ("KVM: nVMX: add option to perform early consistency checks via H/W")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index a562ecabc118..bfacf9029466 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2718,6 +2718,7 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long cr3, cr4; + bool vm_fail; if (!nested_early_check) return 0; @@ -2763,14 +2764,18 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) /* Check if vmlaunch or vmresume is needed */ "cmpb $0, %c[launched](%% " _ASM_CX")\n\t" + /* + * VMLAUNCH and VMRESUME clear RFLAGS.{CF,ZF} on VM-Exit, set + * RFLAGS.CF on VM-Fail Invalid and set RFLAGS.ZF on VM-Fail + * Valid. vmx_vmenter() directly "returns" RFLAGS, and so the + * results of VM-Enter is captured via SETBE to vm_fail. + */ "call vmx_vmenter\n\t" - /* Set vmx->fail accordingly */ - "setbe %c[fail](%% " _ASM_CX")\n\t" - : ASM_CALL_CONSTRAINT + "setbe %[fail]\n\t" + : ASM_CALL_CONSTRAINT, [fail]"=qm"(vm_fail) : "c"(vmx), "d"((unsigned long)HOST_RSP), [launched]"i"(offsetof(struct vcpu_vmx, __launched)), - [fail]"i"(offsetof(struct vcpu_vmx, fail)), [host_rsp]"i"(offsetof(struct vcpu_vmx, host_rsp)), [wordsize]"i"(sizeof(ulong)) : "cc", "memory" @@ -2783,10 +2788,9 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) if (vmx->msr_autoload.guest.nr) vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr); - if (vmx->fail) { + if (vm_fail) { WARN_ON_ONCE(vmcs_read32(VM_INSTRUCTION_ERROR) != VMXERR_ENTRY_INVALID_CONTROL_FIELD); - vmx->fail = 0; return 1; } |