[PATCH v2 4/8] KVM: VMX: simplify rdtscp handling in vmx_cpuid_update()

From: Xiao Guangrong
Date: Wed Sep 09 2015 - 02:12:37 EST


if vmx_rdtscp_supported() is true SECONDARY_EXEC_RDTSCP must
have already been set in current vmcs by
vmx_secondary_exec_control()

Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 61d44b0..bcc69de 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8678,16 +8678,15 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
vmx->rdtscp_enabled = false;
if (vmx_rdtscp_supported()) {
exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
- if (exec_control & SECONDARY_EXEC_RDTSCP) {
- best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
- if (best && (best->edx & bit(X86_FEATURE_RDTSCP)))
- vmx->rdtscp_enabled = true;
- else {
- exec_control &= ~SECONDARY_EXEC_RDTSCP;
- vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
- exec_control);
- }
+ best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
+ if (best && (best->edx & bit(X86_FEATURE_RDTSCP)))
+ vmx->rdtscp_enabled = true;
+ else {
+ exec_control &= ~SECONDARY_EXEC_RDTSCP;
+ vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
+ exec_control);
}
+
if (nested && !vmx->rdtscp_enabled)
vmx->nested.nested_vmx_secondary_ctls_high &=
~SECONDARY_EXEC_RDTSCP;
--
2.4.3

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