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authorSean Christopherson <sean.j.christopherson@intel.com>2019-01-25 07:40:58 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2019-02-12 13:12:19 +0100
commitf1727b4954772a778df0b73a93c4b646fd3c21f6 (patch)
treec168e8cc8b0ed6f100f9f2d2ad9a32fda965ee0e
parent6c1e7e5b40f23b9e754a47852924115febba35df (diff)
downloadlinux-stericsson-f1727b4954772a778df0b73a93c4b646fd3c21f6.tar.gz
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.c16
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;
}