KVM: nVMX: Keep track of hv_vm_id/hv_vp_id when eVMCS is in use

To handle L2 TLB flush requests, KVM needs to keep track of L2's VM_ID/
VP_IDs which are set by L1 hypervisor. 'Partition assist page' address is
also needed to handle post-flush exit to L1 upon request.
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: <20221101145426.251680-20-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -668,6 +668,12 @@ struct kvm_vcpu_hv {
 
 	/* Preallocated buffer for handling hypercalls passing sparse vCPU set */
 	u64 sparse_banks[HV_MAX_SPARSE_VCPU_BANKS];
+
+	struct {
+		u64 pa_page_gpa;
+		u64 vm_id;
+		u32 vp_id;
+	} nested;
 };
 
 /* Xen HVM per vcpu emulation context */

arch/x86/kvm/vmx/nested.c

@@ -225,6 +225,7 @@ static void vmx_disable_shadow_vmcs(struct vcpu_vmx *vmx)
 
 static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
 {
+	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
 	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
@@ -233,6 +234,12 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
 	}
 
 	vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID;
+
+	if (hv_vcpu) {
+		hv_vcpu->nested.pa_page_gpa = INVALID_GPA;
+		hv_vcpu->nested.vm_id = 0;
+		hv_vcpu->nested.vp_id = 0;
+	}
 }
 
 static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx,
@@ -1557,11 +1564,19 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields
 {
 	struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
 	struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;
+	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(&vmx->vcpu);
 
 	/* HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE */
 	vmcs12->tpr_threshold = evmcs->tpr_threshold;
 	vmcs12->guest_rip = evmcs->guest_rip;
 
+	if (unlikely(!(hv_clean_fields &
+		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_ENLIGHTENMENTSCONTROL))) {
+		hv_vcpu->nested.pa_page_gpa = evmcs->partition_assist_page;
+		hv_vcpu->nested.vm_id = evmcs->hv_vm_id;
+		hv_vcpu->nested.vp_id = evmcs->hv_vp_id;
+	}
+
 	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_BASIC))) {
 		vmcs12->guest_rsp = evmcs->guest_rsp;