diff mbox series

[v2,09/11] KVM: SEV: define VM types for SEV and SEV-ES

Message ID 20240223104009.632194-10-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 
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20240209183743.22030-9-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Documentation/virt/kvm/api.rst  |  2 ++
 arch/x86/include/uapi/asm/kvm.h |  2 ++
 arch/x86/kvm/svm/sev.c          | 21 ++++++++++++++++++++-
 arch/x86/kvm/svm/svm.c          | 11 +++++++++++
 arch/x86/kvm/svm/svm.h          |  2 ++
 arch/x86/kvm/x86.c              |  4 ++++
 6 files changed, 41 insertions(+), 1 deletion(-)

Comments

Sean Christopherson Feb. 23, 2024, 4:55 p.m. UTC | #1 
On Fri, Feb 23, 2024, Paolo Bonzini wrote:

Changelog...

> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 392b9c2e2ce1..87541c84d07e 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -4087,6 +4087,11 @@ static void svm_cancel_injection(struct kvm_vcpu *vcpu)
>  
>  static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu)
>  {
> +	struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;

Ugh, we really should have

static inline struct kvm_sev_info *to_kvm_sev(struct kvm *kvm)
{
	return &to_kvm_svm(vcpu->kvm)->sev_info;
}

> +
> +	if (sev->need_init)

And then this can be:

	if (to_kvm_sev(vcpu->kvm)->need_init)

> +		return -EINVAL;
> +
>  	return 1;
>  }
>  
> @@ -4888,6 +4893,11 @@ static void svm_vm_destroy(struct kvm *kvm)
>  
>  static int svm_vm_init(struct kvm *kvm)
>  {
> +	if (kvm->arch.vm_type) {
> +		struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> +		sev->need_init = true;

And

	if (kvm->arch.vm_type)
		to_kvm_sev(vcpu->kvm)->need_init = true;
Sean Christopherson Feb. 23, 2024, 5:22 p.m. UTC | #2 
On Fri, Feb 23, 2024, Paolo Bonzini wrote:
> @@ -3193,3 +3199,16 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
>  
>  	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);
>  }
> +
> +bool sev_is_vm_type_supported(unsigned long type)
> +{
> +	if (type == KVM_X86_SEV_VM)
> +		return sev_enabled;

Oh, I almost forgot!  This is the perfect way to solve the mess where sev_enabled
is true, but all ASIDs are binned to SEV-ES[1], which sefltests doesn't currently
handle because the info isn't surfaced to userspace[2].

So it'll end up like this?

	if (sev_enabled && min_sev_asid <= max_sev_asid)
		kvm_caps.supported_vm_types |= BIT(KVM_X86_SEV_VM);

[1] https://lore.kernel.org/all/20240131235609.4161407-1-seanjc@google.com
[2] https://lore.kernel.org/all/ZdfQ4jI8yT-bvbV4@google.com

> +	if (type == KVM_X86_SEV_ES_VM)
> +		return sev_es_enabled;
diff mbox series

Patch

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 3ec0b7a455a0..bf957bb70e4b 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8790,6 +8790,8 @@  means the VM type with value @n is supported.  Possible values of @n are::
 
   #define KVM_X86_DEFAULT_VM	0
   #define KVM_X86_SW_PROTECTED_VM	1
+  #define KVM_X86_SEV_VM	8
+  #define KVM_X86_SEV_ES_VM	10
 
 9. Known KVM API problems
 =========================
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index cccaa5ff6d01..12cf6f3b367e 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -850,5 +850,7 @@  struct kvm_hyperv_eventfd {
 
 #define KVM_X86_DEFAULT_VM	0
 #define KVM_X86_SW_PROTECTED_VM	1
+#define KVM_X86_SEV_VM		8
+#define KVM_X86_SEV_ES_VM	10
 
 #endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 06e03a6fe7e4..f859ea270fcc 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -261,6 +261,9 @@  static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (kvm->created_vcpus)
 		return -EINVAL;
 
+	if (kvm->arch.vm_type != KVM_X86_DEFAULT_VM)
+		return -EINVAL;
+
 	ret = -EBUSY;
 	if (unlikely(sev->active))
 		return ret;
@@ -280,6 +283,7 @@  static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 
 	INIT_LIST_HEAD(&sev->regions_list);
 	INIT_LIST_HEAD(&sev->mirror_vms);
+	sev->need_init = false;
 
 	kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_SEV);
 
@@ -1815,7 +1819,8 @@  int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 	if (ret)
 		goto out_fput;
 
-	if (sev_guest(kvm) || !sev_guest(source_kvm)) {
+	if (kvm->arch.vm_type != source_kvm->arch.vm_type ||
+	    sev_guest(kvm) || !sev_guest(source_kvm)) {
 		ret = -EINVAL;
 		goto out_unlock;
 	}
@@ -2136,6 +2141,7 @@  int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 	mirror_sev->asid = source_sev->asid;
 	mirror_sev->fd = source_sev->fd;
 	mirror_sev->es_active = source_sev->es_active;
+	mirror_sev->need_init = false;
 	mirror_sev->handle = source_sev->handle;
 	INIT_LIST_HEAD(&mirror_sev->regions_list);
 	INIT_LIST_HEAD(&mirror_sev->mirror_vms);
@@ -3193,3 +3199,16 @@  void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
 
 	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);
 }
+
+bool sev_is_vm_type_supported(unsigned long type)
+{
+	if (type == KVM_X86_SEV_VM)
+		return sev_enabled;
+	if (type == KVM_X86_SEV_ES_VM)
+		return sev_es_enabled;
+
+	return false;
+}
+
+static_assert((KVM_X86_SEV_VM & __KVM_X86_VM_TYPE_FEATURES) == 0);
+static_assert((KVM_X86_SEV_ES_VM & __KVM_X86_VM_TYPE_FEATURES) == __KVM_X86_PROTECTED_STATE_TYPE);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 392b9c2e2ce1..87541c84d07e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4087,6 +4087,11 @@  static void svm_cancel_injection(struct kvm_vcpu *vcpu)
 
 static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu)
 {
+	struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
+
+	if (sev->need_init)
+		return -EINVAL;
+
 	return 1;
 }
 
@@ -4888,6 +4893,11 @@  static void svm_vm_destroy(struct kvm *kvm)
 
 static int svm_vm_init(struct kvm *kvm)
 {
+	if (kvm->arch.vm_type) {
+		struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+		sev->need_init = true;
+	}
+
 	if (!pause_filter_count || !pause_filter_thresh)
 		kvm->arch.pause_in_guest = true;
 
@@ -4914,6 +4924,7 @@  static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.vcpu_free = svm_vcpu_free,
 	.vcpu_reset = svm_vcpu_reset,
 
+	.is_vm_type_supported = sev_is_vm_type_supported,
 	.vm_size = sizeof(struct kvm_svm),
 	.vm_init = svm_vm_init,
 	.vm_destroy = svm_vm_destroy,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 864c782eaa58..63be26d4a024 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -79,6 +79,7 @@  enum {
 struct kvm_sev_info {
 	bool active;		/* SEV enabled guest */
 	bool es_active;		/* SEV-ES enabled guest */
+	bool need_init;		/* waiting for SEV_INIT2 */
 	unsigned int asid;	/* ASID used for this guest */
 	unsigned int handle;	/* SEV firmware handle */
 	int fd;			/* SEV device fd */
@@ -696,6 +697,7 @@  void sev_es_vcpu_reset(struct vcpu_svm *svm);
 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
 void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa);
 void sev_es_unmap_ghcb(struct vcpu_svm *svm);
+bool sev_is_vm_type_supported(unsigned long type);
 
 /* vmenter.S */
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d4029053b6d8..4b26d84bc836 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4794,6 +4794,10 @@  int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		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);
 		break;
 	default:
 		break;