[PATCH v6 13/38] KVM: nVMX: Keep track of hv_vm_id/hv_vp_id when eVMCS is in use

From: Vitaly Kuznetsov
Date: Mon Jun 06 2022 - 04:39:26 EST


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@xxxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 6 ++++++
arch/x86/kvm/vmx/nested.c | 15 +++++++++++++++
2 files changed, 21 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 278d8d3ee994..02bef551dafb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -648,6 +648,12 @@ 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 */
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 7d8cd0ebcc75..6e264a7f205b 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/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,
@@ -1591,11 +1598,19 @@ 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;
--
2.35.3