[PATCH RFC 09/11] KVM: nVMX: hyper-v: Introduce nested_vmx_evmcs() accessor

From: Vitaly Kuznetsov
Date: Tue Oct 10 2023 - 12:04:15 EST


There's a number of 'vmx->nested.hv_evmcs' accesses in nested.c, introduce
'nested_vmx_evmcs()' accessor to hide them all in !CONFIG_KVM_HYPERV case.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
arch/x86/kvm/vmx/hyperv.h | 8 ++++++++
arch/x86/kvm/vmx/nested.c | 33 ++++++++++++++++++---------------
2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/vmx/hyperv.h b/arch/x86/kvm/vmx/hyperv.h
index 6ca5c8c5be9c..b07131a23250 100644
--- a/arch/x86/kvm/vmx/hyperv.h
+++ b/arch/x86/kvm/vmx/hyperv.h
@@ -25,6 +25,10 @@ struct vcpu_vmx;

#ifdef CONFIG_KVM_HYPERV
static inline gpa_t nested_vmx_evmptr(struct vcpu_vmx *vmx) { return vmx->nested.hv_evmcs_vmptr; }
+static inline struct hv_enlightened_vmcs *nested_vmx_evmcs(struct vcpu_vmx *vmx)
+{
+ return vmx->nested.hv_evmcs;
+}
u64 nested_get_evmptr(struct kvm_vcpu *vcpu);
uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu);
int nested_enable_evmcs(struct kvm_vcpu *vcpu,
@@ -35,6 +39,10 @@ bool nested_evmcs_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu);
void vmx_hv_inject_synthetic_vmexit_post_tlb_flush(struct kvm_vcpu *vcpu);
#else
static inline gpa_t nested_vmx_evmptr(struct vcpu_vmx *vmx) { return EVMPTR_INVALID; };
+static inline struct hv_enlightened_vmcs *nested_vmx_evmcs(struct vcpu_vmx *vmx)
+{
+ return NULL;
+}
static inline u64 nested_get_evmptr(struct kvm_vcpu *vcpu) { return EVMPTR_INVALID; }
static inline void nested_evmcs_filter_control_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) {}
static inline bool nested_evmcs_l2_tlb_flush_enabled(struct kvm_vcpu *vcpu) { return false; }
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index e6476f8e2ccd..d539904d8f1e 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -574,7 +574,6 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
int msr;
unsigned long *msr_bitmap_l1;
unsigned long *msr_bitmap_l0 = vmx->nested.vmcs02.msr_bitmap;
- struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;
struct kvm_host_map *map = &vmx->nested.msr_bitmap_map;

/* Nothing to do if the MSR bitmap is not in use. */
@@ -590,10 +589,13 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
* - Nested hypervisor (L1) has enabled 'Enlightened MSR Bitmap' feature
* and tells KVM (L0) there were no changes in MSR bitmap for L2.
*/
- if (!vmx->nested.force_msr_bitmap_recalc && evmcs &&
- evmcs->hv_enlightenments_control.msr_bitmap &&
- evmcs->hv_clean_fields & HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP)
- return true;
+ if (!vmx->nested.force_msr_bitmap_recalc) {
+ struct hv_enlightened_vmcs *evmcs = nested_vmx_evmcs(vmx);
+
+ if (evmcs && evmcs->hv_enlightenments_control.msr_bitmap &&
+ evmcs->hv_clean_fields & HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP)
+ return true;
+ }

if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->msr_bitmap), map))
return false;
@@ -1584,7 +1586,7 @@ static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
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 hv_enlightened_vmcs *evmcs = nested_vmx_evmcs(vmx);
struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(&vmx->vcpu);

/* HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE */
@@ -1828,7 +1830,7 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields
static void copy_vmcs12_to_enlightened(struct vcpu_vmx *vmx)
{
struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
- struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;
+ struct hv_enlightened_vmcs *evmcs = nested_vmx_evmcs(vmx);

/*
* Should not be changed by KVM:
@@ -2412,7 +2414,7 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0

static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
{
- struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;
+ struct hv_enlightened_vmcs *hv_evmcs = nested_vmx_evmcs(vmx);

if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {
@@ -2544,6 +2546,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
enum vm_entry_failure_code *entry_failure_code)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ struct hv_enlightened_vmcs *evmcs = nested_vmx_evmcs(vmx);
bool load_guest_pdptrs_vmcs12 = false;

if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(nested_vmx_evmptr(vmx))) {
@@ -2551,8 +2554,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
vmx->nested.dirty_vmcs12 = false;

load_guest_pdptrs_vmcs12 = !evmptr_is_valid(nested_vmx_evmptr(vmx)) ||
- !(vmx->nested.hv_evmcs->hv_clean_fields &
- HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1);
+ !(evmcs->hv_clean_fields & HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1);
}

if (vmx->nested.nested_run_pending &&
@@ -2674,8 +2676,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
* here.
*/
if (evmptr_is_valid(nested_vmx_evmptr(vmx)))
- vmx->nested.hv_evmcs->hv_clean_fields |=
- HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;
+ evmcs->hv_clean_fields |= HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;

return 0;
}
@@ -3600,7 +3601,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
return nested_vmx_failInvalid(vcpu);

if (evmptr_is_valid(nested_vmx_evmptr(vmx))) {
- copy_enlightened_to_vmcs12(vmx, vmx->nested.hv_evmcs->hv_clean_fields);
+ struct hv_enlightened_vmcs *evmcs = nested_vmx_evmcs(vmx);
+
+ copy_enlightened_to_vmcs12(vmx, evmcs->hv_clean_fields);
/* Enlightened VMCS doesn't have launch state */
vmcs12->launch_state = !launch;
} else if (enable_shadow_vmcs) {
@@ -5335,7 +5338,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
vmptr + offsetof(struct vmcs12,
launch_state),
&zero, sizeof(zero));
- } else if (vmx->nested.hv_evmcs && vmptr == nested_vmx_evmptr(vmx)) {
+ } else if (nested_vmx_evmcs(vmx) && vmptr == nested_vmx_evmptr(vmx)) {
nested_release_evmcs(vcpu);
}

@@ -5413,7 +5416,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
return nested_vmx_fail(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);

/* Read the field, zero-extended to a u64 value */
- value = evmcs_read_any(vmx->nested.hv_evmcs, field, offset);
+ value = evmcs_read_any(nested_vmx_evmcs(vmx), field, offset);
}

/*
--
2.41.0