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Subject[PART1 V5 11/13] svm: Do not expose x2APIC when enable AVIC
Date
From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

Since AVIC only virtualizes xAPIC hardware for the guest, this patch
disable x2APIC support in guest CPUID.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
arch/x86/kvm/svm.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6c1d558..d35fd61e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4571,14 +4571,26 @@ static u64 svm_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
static void svm_cpuid_update(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
+ struct kvm_cpuid_entry2 *entry;

/* Update nrips enabled cache */
svm->nrips_enabled = !!guest_cpuid_has_nrips(&svm->vcpu);
+
+ if (!kvm_vcpu_apicv_active(vcpu))
+ return;
+
+ entry = kvm_find_cpuid_entry(vcpu, 1, 0);
+ if (entry)
+ entry->ecx &= ~bit(X86_FEATURE_X2APIC);
}

static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
{
switch (func) {
+ case 0x1:
+ if (avic)
+ entry->ecx &= ~bit(X86_FEATURE_X2APIC);
+ break;
case 0x80000001:
if (nested)
entry->ecx |= (1 << 2); /* Set SVM bit */
--
1.9.1
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