[PATCH v5 08/17] KVM: x86: Add supported_vm_types to kvm_caps

From: Paolo Bonzini
Date: Thu Apr 04 2024 - 08:16:50 EST


This simplifies the implementation of KVM_CHECK_EXTENSION(KVM_CAP_VM_TYPES),
and also allows the vendor module to specify which VM types are supported.

Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 12 ++++++------
arch/x86/kvm/x86.h | 2 ++
2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d4a8d896798f..d584f5739402 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -94,6 +94,7 @@

struct kvm_caps kvm_caps __read_mostly = {
.supported_mce_cap = MCG_CTL_P | MCG_SER_P,
+ .supported_vm_types = BIT(KVM_X86_DEFAULT_VM),
};
EXPORT_SYMBOL_GPL(kvm_caps);

@@ -4629,9 +4630,7 @@ static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,

static bool kvm_is_vm_type_supported(unsigned long type)
{
- return type == KVM_X86_DEFAULT_VM ||
- (type == KVM_X86_SW_PROTECTED_VM &&
- IS_ENABLED(CONFIG_KVM_SW_PROTECTED_VM) && tdp_mmu_enabled);
+ return type < 32 && (kvm_caps.supported_vm_types & BIT(type));
}

int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
@@ -4832,9 +4831,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
r = kvm_caps.has_notify_vmexit;
break;
case KVM_CAP_VM_TYPES:
- r = BIT(KVM_X86_DEFAULT_VM);
- if (kvm_is_vm_type_supported(KVM_X86_SW_PROTECTED_VM))
- r |= BIT(KVM_X86_SW_PROTECTED_VM);
+ r = kvm_caps.supported_vm_types;
break;
default:
break;
@@ -9824,6 +9821,9 @@ int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)

kvm_register_perf_callbacks(ops->handle_intel_pt_intr);

+ if (IS_ENABLED(CONFIG_KVM_SW_PROTECTED_VM) && tdp_mmu_enabled)
+ kvm_caps.supported_vm_types |= BIT(KVM_X86_SW_PROTECTED_VM);
+
if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
kvm_caps.supported_xss = 0;

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index a8b71803777b..d80a4c6b5a38 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -24,6 +24,8 @@ struct kvm_caps {
bool has_bus_lock_exit;
/* notify VM exit supported? */
bool has_notify_vmexit;
+ /* bit mask of VM types */
+ u32 supported_vm_types;

u64 supported_mce_cap;
u64 supported_xcr0;
--
2.43.0