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From:   Vitaly Kuznetsov <vkuznets@redhat.com>
To:     kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>
Cc:     Sean Christopherson <seanjc@google.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Michael Kelley <mikelley@microsoft.com>,
        Siddharth Chandrasekaran <sidcha@amazon.de>,
        Yuan Yao <yuan.yao@linux.intel.com>,
        Maxim Levitsky <mlevitsk@redhat.com>,
        linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v10 18/39] KVM: x86: hyper-v: Introduce fast guest_hv_cpuid_has_l2_tlb_flush() check
Date:   Wed, 21 Sep 2022 17:24:15 +0200
Message-Id: <20220921152436.3673454-19-vkuznets@redhat.com>
In-Reply-To: <20220921152436.3673454-1-vkuznets@redhat.com>
References: <20220921152436.3673454-1-vkuznets@redhat.com>
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Introduce a helper to quickly check if KVM needs to handle VMCALL/VMMCALL
from L2 in L0 to process L2 TLB flush requests.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/hyperv.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index 1b53dd4cff4d..3fff3a6f4bb9 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -174,6 +174,13 @@ static inline void kvm_hv_vcpu_empty_flush_tlb(struct kvm_vcpu *vcpu)
 	kfifo_reset_out(&tlb_flush_fifo->entries);
 }
 
+static inline bool guest_hv_cpuid_has_l2_tlb_flush(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
+
+	return hv_vcpu && (hv_vcpu->cpuid_cache.nested_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);
-- 
2.37.3