[v2,08/11] KVM: x86: Add is_vm_type_supported callback
Commit Message
Allow the backend to specify which VM types are supported.
Based on a patch by Isaku Yamahata <isaku.yamahata@intel.com>.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/x86.c | 8 +++++++-
3 files changed, 9 insertions(+), 1 deletion(-)
Comments
On Fri, Feb 23, 2024, Paolo Bonzini wrote:
> Allow the backend to specify which VM types are supported.
Hmm, rather than another kvm_x86_ops hook, I vote to add kvm_caps.supported_vm_types,
and use the existing harware_setup() hook to fill in the vendor specific types.
As a very incomplete stub:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3bc69b0c9822..bb7d979db2df 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4576,17 +4576,9 @@ static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
}
#endif
-static inline 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);
-}
-
static bool kvm_is_vm_type_supported(unsigned long type)
{
- return __kvm_is_vm_type_supported(type) ||
- static_call(kvm_x86_is_vm_type_supported)(type);
+ return kvm_caps.supported_vm_types & BIT(type);
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
@@ -4787,13 +4779,7 @@ 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);
- if (kvm_is_vm_type_supported(KVM_X86_SEV_VM))
- r |= BIT(KVM_X86_SEV_VM);
- if (kvm_is_vm_type_supported(KVM_X86_SEV_ES_VM))
- r |= BIT(KVM_X86_SEV_ES_VM);
+ r = kvm_caps.supported_vm_types;
break;
default:
break;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 2f7e19166658..802ac1ead055 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -29,6 +29,8 @@ struct kvm_caps {
u64 supported_xcr0;
u64 supported_xss;
u64 supported_perf_cap;
+
+ u32 supported_vm_types;
};
void kvm_spurious_fault(void);
@@ -20,6 +20,7 @@ KVM_X86_OP(hardware_disable)
KVM_X86_OP(hardware_unsetup)
KVM_X86_OP(has_emulated_msr)
KVM_X86_OP(vcpu_after_set_cpuid)
+KVM_X86_OP_OPTIONAL_RET0(is_vm_type_supported)
KVM_X86_OP(vm_init)
KVM_X86_OP_OPTIONAL(vm_destroy)
KVM_X86_OP_OPTIONAL_RET0(vcpu_precreate)
@@ -1601,6 +1601,7 @@ struct kvm_x86_ops {
bool (*has_emulated_msr)(struct kvm *kvm, u32 index);
void (*vcpu_after_set_cpuid)(struct kvm_vcpu *vcpu);
+ bool (*is_vm_type_supported)(unsigned long vm_type);
unsigned int vm_size;
int (*vm_init)(struct kvm *kvm);
void (*vm_destroy)(struct kvm *kvm);
@@ -4581,13 +4581,19 @@ static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
}
#endif
-static bool kvm_is_vm_type_supported(unsigned long type)
+static inline 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_enabled);
}
+static bool kvm_is_vm_type_supported(unsigned long type)
+{
+ return __kvm_is_vm_type_supported(type) ||
+ static_call(kvm_x86_is_vm_type_supported)(type);
+}
+
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r = 0;