diff mbox series

[v2,08/11] KVM: x86: Add is_vm_type_supported callback

Message ID 20240223104009.632194-9-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: SEV: allow customizing VMSA features | expand

Commit Message

Paolo Bonzini Feb. 23, 2024, 10:40 a.m. UTC
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

Sean Christopherson Feb. 23, 2024, 4:51 p.m. UTC | #1
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);
diff mbox series

Patch

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index ac8b7614e79d..8694a6e3d012 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -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)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 15db2697863c..9cf588db55e9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e634e5b67516..d4029053b6d8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -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;