[PATCH v10 057/108] KVM: x86/VMX: introduce vmx tlb_remote_flush and tlb_remote_flush_with_range

isaku.yamahata
2022-10-30T06:28:46Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

This is preparation for TDX to define its own tlb_remote_flush and
tlb_remote_flush_with_range. Currently vmx code defines tlb_remote_flush
and tlb_remote_flush_with_range defined as NULL by default and only when
nested hyper-v guest case, they are defined to non-NULL methods.

To make TDX code to override those two methods consistently with other
methods, define vmx_tlb_remote_flush and vmx_tlb_remote_flush_with_range
as nop and call hyper-v code only when nested hyper-v guest case.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/kvm_onhyperv.c | 5 ++++-
arch/x86/kvm/kvm_onhyperv.h | 1 +
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/svm/svm_onhyperv.h | 1 +
arch/x86/kvm/vmx/main.c | 2 ++
arch/x86/kvm/vmx/vmx.c | 34 ++++++++++++++++++++++++++++-----
arch/x86/kvm/vmx/x86_ops.h | 3 +++
7 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/kvm_onhyperv.c b/arch/x86/kvm/kvm_onhyperv.c
index ee4f696a0782..d43518da1c0e 100644
--- a/arch/x86/kvm/kvm_onhyperv.c
+++ b/arch/x86/kvm/kvm_onhyperv.c
@@ -93,11 +93,14 @@ int hv_remote_flush_tlb(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(hv_remote_flush_tlb);

+bool hv_use_remote_flush_tlb __ro_after_init;
+EXPORT_SYMBOL_GPL(hv_use_remote_flush_tlb);
+
void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
{
struct kvm_arch *kvm_arch = &vcpu->kvm->arch;

- if (kvm_x86_ops.tlb_remote_flush == hv_remote_flush_tlb) {
+ if (hv_use_remote_flush_tlb) {
spin_lock(&kvm_arch->hv_root_tdp_lock);
vcpu->arch.hv_root_tdp = root_tdp;
if (root_tdp != kvm_arch->hv_root_tdp)
diff --git a/arch/x86/kvm/kvm_onhyperv.h b/arch/x86/kvm/kvm_onhyperv.h
index 287e98ef9df3..9a07a34666fb 100644
--- a/arch/x86/kvm/kvm_onhyperv.h
+++ b/arch/x86/kvm/kvm_onhyperv.h
@@ -10,6 +10,7 @@
int hv_remote_flush_tlb_with_range(struct kvm *kvm,
struct kvm_tlb_range *range);
int hv_remote_flush_tlb(struct kvm *kvm);
+extern bool hv_use_remote_flush_tlb __ro_after_init;
void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp);
#else /* !CONFIG_HYPERV */
static inline void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index efc3b3f2dd12..08923b64dcc8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -242,7 +242,7 @@ static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm,
{
int ret = -ENOTSUPP;

- if (range && kvm_x86_ops.tlb_remote_flush_with_range)
+ if (range && kvm_available_flush_tlb_with_range())
ret = static_call(kvm_x86_tlb_remote_flush_with_range)(kvm, range);

if (ret)
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index e2fc59380465..b3cd61c62305 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -36,6 +36,7 @@ static inline void svm_hv_hardware_setup(void)
svm_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
svm_x86_ops.tlb_remote_flush_with_range =
hv_remote_flush_tlb_with_range;
+ hv_use_remote_flush_tlb = true;
}

if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH) {
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 974e00fd3260..fe9583b640fb 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -178,6 +178,8 @@ struct kvm_x86_ops vt_x86_ops __initdata = {

.flush_tlb_all = vmx_flush_tlb_all,
.flush_tlb_current = vmx_flush_tlb_current,
+ .tlb_remote_flush = vmx_tlb_remote_flush,
+ .tlb_remote_flush_with_range = vmx_tlb_remote_flush_with_range,
.flush_tlb_gva = vmx_flush_tlb_gva,
.flush_tlb_guest = vmx_flush_tlb_guest,

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b5c3652c3cc4..f2887dbde700 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3126,6 +3126,33 @@ void vmx_flush_tlb_current(struct kvm_vcpu *vcpu)
vpid_sync_context(vmx_get_current_vpid(vcpu));
}

+int vmx_tlb_remote_flush(struct kvm *kvm)
+{
+#if IS_ENABLED(CONFIG_HYPERV)
+ if (hv_use_remote_flush_tlb)
+ return hv_remote_flush_tlb(kvm);
+#endif
+ /*
+ * fallback to KVM_REQ_TLB_FLUSH.
+ * See kvm_arch_flush_remote_tlb() and kvm_flush_remote_tlbs().
+ */
+ return -EOPNOTSUPP;
+}
+
+int vmx_tlb_remote_flush_with_range(struct kvm *kvm,
+ struct kvm_tlb_range *range)
+{
+#if IS_ENABLED(CONFIG_HYPERV)
+ if (hv_use_remote_flush_tlb)
+ return hv_remote_flush_tlb_with_range(kvm, range);
+#endif
+ /*
+ * fallback to tlb_remote_flush. See
+ * kvm_flush_remote_tlbs_with_range()
+ */
+ return -EOPNOTSUPP;
+}
+
void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
{
/*
@@ -8223,11 +8250,8 @@ __init int vmx_hardware_setup(void)

#if IS_ENABLED(CONFIG_HYPERV)
if (ms_hyperv.nested_features & HV_X64_NESTED_GUEST_MAPPING_FLUSH
- && enable_ept) {
- vt_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
- vt_x86_ops.tlb_remote_flush_with_range =
- hv_remote_flush_tlb_with_range;
- }
+ && enable_ept)
+ hv_use_remote_flush_tlb = true;
#endif

if (!cpu_has_vmx_ple()) {
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index dd05991afbad..cf7e0c6c65ac 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -92,6 +92,9 @@ void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
bool vmx_get_if_flag(struct kvm_vcpu *vcpu);
void vmx_flush_tlb_all(struct kvm_vcpu *vcpu);
void vmx_flush_tlb_current(struct kvm_vcpu *vcpu);
+int vmx_tlb_remote_flush(struct kvm *kvm);
+int vmx_tlb_remote_flush_with_range(struct kvm *kvm,
+ struct kvm_tlb_range *range);
void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr);
void vmx_flush_tlb_guest(struct kvm_vcpu *vcpu);
void vmx_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask);
--
2.25.1