diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-01-25 07:41:06 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-02-12 13:12:25 +0100 |
| commit | 217aaff53c25f03b1d2fc23eff9dc2bae34f690e (patch) | |
| tree | d00cf0b9fb832403cb21ed88b0464e0e7351b63f | |
| parent | c9afc58cc368623aaa34a62e321eea2a59240f6f (diff) | |
KVM: VMX: Invert the ordering of saving guest/host scratch reg at VM-Enter
Switching the ordering allows for an out-of-line path for VM-Fail
that elides saving guest state but still shares the register clearing
with the VM-Exit path.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 996a13ea86cc..79b42197ed7e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6382,7 +6382,6 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx) asm( /* Store host registers */ "push %%" _ASM_BP " \n\t" - "sub $%c[wordsize], %%" _ASM_SP "\n\t" /* placeholder for guest RCX */ "push %%" _ASM_ARG1 " \n\t" /* Adjust RSP to account for the CALL to vmx_vmenter(). */ @@ -6418,11 +6417,11 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx) /* Enter guest mode */ "call vmx_vmenter\n\t" - /* Save guest's RCX to the stack placeholder (see above) */ - "mov %%" _ASM_CX ", %c[wordsize](%%" _ASM_SP ") \n\t" + /* Temporarily save guest's RCX. */ + "push %%" _ASM_CX " \n\t" - /* Load host's RCX, i.e. the vmx_vcpu pointer */ - "pop %%" _ASM_CX " \n\t" + /* Reload the vcpu_vmx pointer to RCX. */ + "mov %c[wordsize](%%" _ASM_SP "), %%" _ASM_CX " \n\t" /* Set vmx->fail based on EFLAGS.{CF,ZF} */ "setbe %c[fail](%%" _ASM_CX ")\n\t" @@ -6469,6 +6468,9 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx) "xor %%esi, %%esi \n\t" "xor %%edi, %%edi \n\t" "xor %%ebp, %%ebp \n\t" + + /* "POP" the vcpu_vmx pointer. */ + "add $%c[wordsize], %%" _ASM_SP " \n\t" "pop %%" _ASM_BP " \n\t" : ASM_CALL_CONSTRAINT, "=b"((int){0}), #ifdef CONFIG_X86_64 |