KVM: x86: Introduce .hv_inject_synthetic_vmexit_post_tlb_flush() nested hook

Hyper-V supports injecting synthetic L2->L1 exit after performing
L2 TLB flush operation but the procedure is vendor specific. Introduce
.hv_inject_synthetic_vmexit_post_tlb_flush nested hook for it.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-22-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1722,6 +1722,7 @@ struct kvm_x86_nested_ops {
 	int (*enable_evmcs)(struct kvm_vcpu *vcpu,
 			    uint16_t *vmcs_version);
 	uint16_t (*get_evmcs_version)(struct kvm_vcpu *vcpu);
+	void (*hv_inject_synthetic_vmexit_post_tlb_flush)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_x86_init_ops {

arch/x86/kvm/Makefile

@@ -26,7 +26,8 @@ kvm-intel-y		+= vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o \
 			   vmx/hyperv.o vmx/nested.o vmx/posted_intr.o
 kvm-intel-$(CONFIG_X86_SGX_KVM)	+= vmx/sgx.o
 
-kvm-amd-y		+= svm/svm.o svm/vmenter.o svm/pmu.o svm/nested.o svm/avic.o svm/sev.o
+kvm-amd-y		+= svm/svm.o svm/vmenter.o svm/pmu.o svm/nested.o svm/avic.o \
+			   svm/sev.o svm/hyperv.o
 
 ifdef CONFIG_HYPERV
 kvm-amd-y		+= svm/svm_onhyperv.o

arch/x86/kvm/svm/hyperv.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD SVM specific code for Hyper-V on KVM.
+ *
+ * Copyright 2022 Red Hat, Inc. and/or its affiliates.
+ */
+#include "hyperv.h"
+
+void svm_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu)
+{
+}

arch/x86/kvm/svm/hyperv.h

@@ -25,4 +25,6 @@ static inline void nested_svm_hv_update_vm_vp_ids(struct kvm_vcpu *vcpu)
 	hv_vcpu->nested.vp_id = hve->hv_vp_id;
 }
 
+void svm_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu);
+
 #endif /* __ARCH_X86_KVM_SVM_HYPERV_H__ */

arch/x86/kvm/svm/nested.c

@@ -1730,4 +1730,5 @@ struct kvm_x86_nested_ops svm_nested_ops = {
 	.get_nested_state_pages = svm_get_nested_state_pages,
 	.get_state = svm_get_nested_state,
 	.set_state = svm_set_nested_state,
+	.hv_inject_synthetic_vmexit_post_tlb_flush = svm_hv_inject_synthetic_vmexit_post_tlb_flush,
 };

arch/x86/kvm/vmx/hyperv.c

@@ -506,3 +506,7 @@ int nested_enable_evmcs(struct kvm_vcpu *vcpu,
 
 	return 0;
 }
+
+void vmx_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu)
+{
+}

arch/x86/kvm/vmx/hyperv.h

@@ -243,5 +243,6 @@ int nested_enable_evmcs(struct kvm_vcpu *vcpu,
 			uint16_t *vmcs_version);
 void nested_evmcs_filter_control_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
 int nested_evmcs_check_controls(struct vmcs12 *vmcs12);
+void vmx_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu);
 
 #endif /* __KVM_X86_VMX_HYPERV_H */

arch/x86/kvm/vmx/nested.c

@@ -6995,4 +6995,5 @@ struct kvm_x86_nested_ops vmx_nested_ops = {
 	.write_log_dirty = nested_vmx_write_pml_buffer,
 	.enable_evmcs = nested_enable_evmcs,
 	.get_evmcs_version = nested_get_evmcs_version,
+	.hv_inject_synthetic_vmexit_post_tlb_flush = vmx_hv_inject_synthetic_vmexit_post_tlb_flush,
 };