Introduce a helper to quickly check if KVM needs to handle VMCALL/VMMCALL
from L2 in L0 to process Direct TLB flush requests.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/hyperv.c | 6 ++++++
arch/x86/kvm/hyperv.h | 7 +++++++
3 files changed, 14 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 7c607307a5d4..3be54b51d6bc 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -615,6 +615,7 @@ struct kvm_vcpu_hv {
u32 enlightenments_eax; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EAX */
u32 enlightenments_ebx; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EBX */
u32 syndbg_cap_eax; /* HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX */
+ u32 nested_features_eax; /* HYPERV_CPUID_NESTED_FEATURES.EAX */
} cpuid_cache;
/* Two rings for regular Hyper-V TLB flush and Direct TLB flush */
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 2b12f1b5c992..f08cf295d750 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2256,6 +2256,12 @@ void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
else
hv_vcpu->cpuid_cache.syndbg_cap_eax = 0;
+
+ entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES, 0);
+ if (entry)
+ hv_vcpu->cpuid_cache.nested_features_eax = entry->eax;
+ else
+ hv_vcpu->cpuid_cache.nested_features_eax = 0;
}
int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index 3687e1e61e0d..c4f8064da606 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -169,6 +169,13 @@ static inline void kvm_hv_vcpu_empty_flush_tlb(struct kvm_vcpu *vcpu)
tlb_flush_ring->read_idx = tlb_flush_ring->write_idx;
}
+static inline bool kvm_hv_direct_tlb_flush_exposed(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
+
+ return hv_vcpu && (hv_vcpu->cpuid_cache.nested_features_eax & HV_X64_NESTED_DIRECT_FLUSH);
+}
+
static inline bool kvm_hv_is_tlb_flush_hcall(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
--
2.35.1
