From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Hyper-V provides direct tlb flush function which helps
L1 Hypervisor to handle Hyper-V tlb flush request from
L2 guest. Add the function support for VMX.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
---
Change since v3:
- Update changlog
Change since v2:
- Move hv assist page(hv_pa_pg) from struct kvm to struct kvm_hv.
---
arch/x86/include/asm/hyperv-tlfs.h | 4 ++++
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/vmx/evmcs.h | 2 ++
arch/x86/kvm/vmx/vmx.c | 39 ++++++++++++++++++++++++++++++++++++++
4 files changed, 47 insertions(+)
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index cf0b2a04271d..d53d6e4a6210 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -171,6 +171,7 @@
#define HV_X64_ENLIGHTENED_VMCS_RECOMMENDED BIT(14)
/* Nested features. These are HYPERV_CPUID_NESTED_FEATURES.EAX bits. */
+#define HV_X64_NESTED_DIRECT_FLUSH BIT(17)
#define HV_X64_NESTED_GUEST_MAPPING_FLUSH BIT(18)
#define HV_X64_NESTED_MSR_BITMAP BIT(19)
@@ -882,4 +883,7 @@ struct hv_tlb_flush_ex {
u64 gva_list[];
} __packed;
+struct hv_partition_assist_pg {
+ u32 tlb_lock_count;
+};
#endif
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 667d154e89d4..ad4b5c02db0e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -840,6 +840,8 @@ struct kvm_hv {
/* How many vCPUs have VP index != vCPU index */
atomic_t num_mismatched_vp_indexes;
+
+ struct hv_partition_assist_pg *hv_pa_pg;
};
enum kvm_irqchip_mode {
diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index 39a24eec8884..07ebf6882a45 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -178,6 +178,8 @@ static inline void evmcs_load(u64 phys_addr)
struct hv_vp_assist_page *vp_ap =
hv_get_vp_assist_page(smp_processor_id());
+ if (current_evmcs->hv_enlightenments_control.nested_flush_hypercall)
+ vp_ap->nested_control.features.directhypercall = 1;
vp_ap->current_nested_vmcs = phys_addr;
vp_ap->enlighten_vmentry = 1;
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 84f8d49a2fd2..ed8056049070 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -486,6 +486,35 @@ static int hv_remote_flush_tlb(struct kvm *kvm)
return hv_remote_flush_tlb_with_range(kvm, NULL);
}
+static int hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
+{
+ struct hv_enlightened_vmcs *evmcs;
+ struct hv_partition_assist_pg **p_hv_pa_pg =
+ &vcpu->kvm->arch.hyperv.hv_pa_pg;
+ /*
+ * Synthetic VM-Exit is not enabled in current code and so All
+ * evmcs in singe VM shares same assist page.
+ */
+ if (!*p_hv_pa_pg) {
+ *p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!*p_hv_pa_pg)
+ return -ENOMEM;
+ pr_debug("KVM: Hyper-V: allocated PA_PG for %llx\n",
+ (u64)&vcpu->kvm);
+ }
+
+ evmcs = (struct hv_enlightened_vmcs *)to_vmx(vcpu)->loaded_vmcs->vmcs;
+
+ evmcs->partition_assist_page =
+ __pa(*p_hv_pa_pg);
+ evmcs->hv_vm_id = (u64)vcpu->kvm;
+ evmcs->hv_enlightenments_control.nested_flush_hypercall = 1;
+
+ pr_debug("KVM: Hyper-V: enabled DIRECT flush for %llx\n",
+ (u64)vcpu->kvm);
+ return 0;
+}
+
#endif /* IS_ENABLED(CONFIG_HYPERV) */
/*
@@ -6516,6 +6545,9 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
current_evmcs->hv_clean_fields |=
HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;
+ if (static_branch_unlikely(&enable_evmcs))
+ current_evmcs->hv_vp_id = vcpu->arch.hyperv.vp_index;
+
/* MSR_IA32_DEBUGCTLMSR is zeroed on vmexit. Restore it if needed */
if (vmx->host_debugctlmsr)
update_debugctlmsr(vmx->host_debugctlmsr);
@@ -6583,6 +6615,7 @@ static struct kvm *vmx_vm_alloc(void)
static void vmx_vm_free(struct kvm *kvm)
{
+ kfree(kvm->arch.hyperv.hv_pa_pg);
vfree(to_kvm_vmx(kvm));
}
@@ -7815,6 +7848,7 @@ static void vmx_exit(void)
if (!vp_ap)
continue;
+ vp_ap->nested_control.features.directhypercall = 0;
vp_ap->current_nested_vmcs = 0;
vp_ap->enlighten_vmentry = 0;
}
@@ -7854,6 +7888,11 @@ static int __init vmx_init(void)
pr_info("KVM: vmx: using Hyper-V Enlightened VMCS\n");
static_branch_enable(&enable_evmcs);
}
+
+ if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)
+ vmx_x86_ops.enable_direct_tlbflush
+ = hv_enable_direct_tlbflush;
+
} else {
enlightened_vmcs = false;
}
--
2.14.5
