[PATCH v2 5/8] KVM: VMX: simplify invpcid handling in vmx_cpuid_update()

From: Xiao Guangrong
Date: Wed Sep 09 2015 - 02:14:06 EST


If vmx_invpcid_supported() is true, second execution control
filed must be supported and SECONDARY_EXEC_ENABLE_INVPCID
must have already been set in current vmcs by
vmx_secondary_exec_control()

If vmx_invpcid_supported() is false, no need to clear
SECONDARY_EXEC_ENABLE_INVPCID

Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index bcc69de..97e3340 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8695,19 +8695,12 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
/* Exposing INVPCID only when PCID is exposed */
best = kvm_find_cpuid_entry(vcpu, 0x7, 0);
if (vmx_invpcid_supported() &&
- best && (best->ebx & bit(X86_FEATURE_INVPCID)) &&
- guest_cpuid_has_pcid(vcpu)) {
+ (!best || !(best->ebx & bit(X86_FEATURE_INVPCID)) ||
+ !guest_cpuid_has_pcid(vcpu))) {
exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
- exec_control |= SECONDARY_EXEC_ENABLE_INVPCID;
- vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
- exec_control);
- } else {
- if (cpu_has_secondary_exec_ctrls()) {
- exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
- exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
- vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
- exec_control);
- }
+ exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
+ vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
+
if (best)
best->ebx &= ~bit(X86_FEATURE_INVPCID);
}
--
2.4.3

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