[PATCH 3/5] KVM: nVMX: Enable nested apic register virtualization.

[Wincy Van]

We can reduce apic register virtualization cost with this feature,
it is also a requirement for virtual interrupt delivery and posted
interrupt processing.

Signed-off-by: Wincy Van <fanwenyi0529@xxxxxxxxx>
---
 arch/x86/kvm/vmx.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 10183ee..99e19bb 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1139,6 +1139,11 @@ static inline bool
nested_cpu_has_virt_x2apic_mode(struct vmcs12 *vmcs12)
        return nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE);
 }

+static inline bool nested_cpu_has_apic_reg_virt(struct vmcs12 *vmcs12)
+{
+       return nested_cpu_has2(vmcs12, SECONDARY_EXEC_APIC_REGISTER_VIRT);
+}
+
 static inline bool is_exception(u32 intr_info)
 {
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
@@ -2432,6 +2437,7 @@ static void nested_vmx_setup_ctls_msrs(struct
vcpu_vmx *vmx)
        vmx->nested.nested_vmx_secondary_ctls_high &=
                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
+               SECONDARY_EXEC_APIC_REGISTER_VIRT |
                SECONDARY_EXEC_WBINVD_EXITING |
                SECONDARY_EXEC_XSAVES;

@@ -8378,10 +8384,12 @@ static int
nested_vmx_check_apicv_controls(struct kvm_vcpu *vcpu,
 {
        int r;

-       if (!nested_cpu_has_virt_x2apic_mode(vmcs12))
+       if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
+           !nested_cpu_has_apic_reg_virt(vmcs12))
                return 0;

-       r = nested_vmx_check_virt_x2apic(vcpu, vmcs12);
+       if (nested_cpu_has_virt_x2apic_mode(vmcs12))
+               r = nested_vmx_check_virt_x2apic(vcpu, vmcs12);
        if (r)
                goto fail;

--
1.7.1
--
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