[PATCH v10 19/39] KVM: nVMX: hyper-v: Cache VP assist page in 'struct kvm_vcpu_hv'

Vitaly Kuznetsov
2022-09-21T15:27:40Z

In preparation to enabling L2 TLB flush, cache VP assist page in
'struct kvm_vcpu_hv'. While on it, rename nested_enlightened_vmentry()
to nested_get_evmptr() and make it return eVMCS GPA directly.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/hyperv.c | 10 ++++++----
arch/x86/kvm/hyperv.h | 3 +--
arch/x86/kvm/vmx/evmcs.c | 21 +++++++--------------
arch/x86/kvm/vmx/evmcs.h | 2 +-
arch/x86/kvm/vmx/nested.c | 6 +++---
6 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b40df51b58d9..bc7d8527578d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -650,6 +650,8 @@ struct kvm_vcpu_hv {
/* Preallocated buffer for handling hypercalls passing sparse vCPU set */
u64 sparse_banks[HV_MAX_SPARSE_VCPU_BANKS];

+ struct hv_vp_assist_page vp_assist_page;
+
struct {
u64 pa_page_gpa;
u64 vm_id;
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 28174a9edf35..8ae32ec87efb 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -900,13 +900,15 @@ bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);

-bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
- struct hv_vp_assist_page *assist_page)
+bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu)
{
- if (!kvm_hv_assist_page_enabled(vcpu))
+ struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
+
+ if (!hv_vcpu || !kvm_hv_assist_page_enabled(vcpu))
return false;
+
return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
- assist_page, sizeof(*assist_page));
+ &hv_vcpu->vp_assist_page, sizeof(struct hv_vp_assist_page));
}
EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);

diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index 3fff3a6f4bb9..990b4fc2e649 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -108,8 +108,7 @@ int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages);
void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu);

bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu);
-bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
- struct hv_vp_assist_page *assist_page);
+bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu);

static inline struct kvm_vcpu_hv_stimer *to_hv_stimer(struct kvm_vcpu *vcpu,
int timer_index)
diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 26bb40933e6d..635a0c81ff1d 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -322,24 +322,17 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = {
};
const unsigned int nr_evmcs_1_fields = ARRAY_SIZE(vmcs_field_to_evmcs_1);

-bool nested_enlightened_vmentry(struct kvm_vcpu *vcpu, u64 *evmcs_gpa)
+u64 nested_get_evmptr(struct kvm_vcpu *vcpu)
{
- struct hv_vp_assist_page assist_page;
-
- *evmcs_gpa = -1ull;
-
- if (unlikely(!kvm_hv_get_assist_page(vcpu, &assist_page)))
- return false;
-
- if (unlikely(!assist_page.enlighten_vmentry))
- return false;
+ struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);

- if (unlikely(!evmptr_is_valid(assist_page.current_nested_vmcs)))
- return false;
+ if (unlikely(!kvm_hv_get_assist_page(vcpu)))
+ return EVMPTR_INVALID;

- *evmcs_gpa = assist_page.current_nested_vmcs;
+ if (unlikely(!hv_vcpu->vp_assist_page.enlighten_vmentry))
+ return EVMPTR_INVALID;

- return true;
+ return hv_vcpu->vp_assist_page.current_nested_vmcs;
}

uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index 492d1c58c734..7ad56fbc4b4d 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -235,7 +235,7 @@ enum nested_evmptrld_status {
EVMPTRLD_ERROR,
};

-bool nested_enlightened_vmentry(struct kvm_vcpu *vcpu, u64 *evmcs_gpa);
+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,
uint16_t *vmcs_version);
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 640680228973..0634518a6719 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1992,7 +1992,8 @@ static enum nested_evmptrld_status nested_vmx_handle_enlightened_vmptrld(
if (likely(!guest_cpuid_has_evmcs(vcpu)))
return EVMPTRLD_DISABLED;

- if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa)) {
+ evmcs_gpa = nested_get_evmptr(vcpu);
+ if (!evmptr_is_valid(evmcs_gpa)) {
nested_release_evmcs(vcpu);
return EVMPTRLD_DISABLED;
}
@@ -5220,7 +5221,6 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 zero = 0;
gpa_t vmptr;
- u64 evmcs_gpa;
int r;

if (!nested_vmx_check_permission(vcpu))
@@ -5246,7 +5246,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
* vmx->nested.hv_evmcs but this shouldn't be a problem.
*/
if (likely(!guest_cpuid_has_evmcs(vcpu) ||
- !nested_enlightened_vmentry(vcpu, &evmcs_gpa))) {
+ !evmptr_is_valid(nested_get_evmptr(vcpu)))) {
if (vmptr == vmx->nested.current_vmptr)
nested_release_vmcs12(vcpu);

--
2.37.3