diff mbox series

[v2,11/43] arm64: kvm: Allow passing machine type in KVM creation

Message ID 20240412084309.1733783-12-steven.price@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Support for Arm CCA in KVM | expand

Commit Message

Steven Price April 12, 2024, 8:42 a.m. UTC
Previously machine type was used purely for specifying the physical
address size of the guest. Reserve the higher bits to specify an ARM
specific machine type and declare a new type 'KVM_VM_TYPE_ARM_REALM'
used to create a realm guest.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/arm.c     | 17 +++++++++++++++++
 arch/arm64/kvm/mmu.c     |  3 ---
 include/uapi/linux/kvm.h | 19 +++++++++++++++----
 3 files changed, 32 insertions(+), 7 deletions(-)

Comments

Suzuki K Poulose April 17, 2024, 10:20 a.m. UTC | #1
On 12/04/2024 09:42, Steven Price wrote:
> Previously machine type was used purely for specifying the physical
> address size of the guest. Reserve the higher bits to specify an ARM
> specific machine type and declare a new type 'KVM_VM_TYPE_ARM_REALM'
> used to create a realm guest.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
>   arch/arm64/kvm/arm.c     | 17 +++++++++++++++++
>   arch/arm64/kvm/mmu.c     |  3 ---
>   include/uapi/linux/kvm.h | 19 +++++++++++++++----
>   3 files changed, 32 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 22da6493912a..c5a6139d5454 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -173,6 +173,23 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
>   	mutex_unlock(&kvm->lock);
>   #endif
>   
> +	if (type & ~(KVM_VM_TYPE_ARM_MASK | KVM_VM_TYPE_ARM_IPA_SIZE_MASK))
> +		return -EINVAL;
> +
> +	switch (type & KVM_VM_TYPE_ARM_MASK) {
> +	case KVM_VM_TYPE_ARM_NORMAL:
> +		break;
> +	case KVM_VM_TYPE_ARM_REALM:
> +		kvm->arch.is_realm = true;
> +		if (!kvm_is_realm(kvm)) {
> +			/* Realm support unavailable */
> +			return -EINVAL;
> +		}
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
>   	ret = kvm_share_hyp(kvm, kvm + 1);
>   	if (ret)
>   		return ret;
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index aae365647b62..af4564f3add5 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -877,9 +877,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
>   	if (kvm_is_realm(kvm))
>   		ipa_limit = kvm_realm_ipa_limit();
>   
> -	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
> -		return -EINVAL;
> -
>   	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
>   	if (is_protected_kvm_enabled()) {
>   		phys_shift = kvm_ipa_limit;
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index a1147036d1bd..5153c837c8c7 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -635,14 +635,25 @@ struct kvm_enable_cap {
>   #define KVM_S390_SIE_PAGE_OFFSET 1
>   
>   /*
> - * On arm64, machine type can be used to request the physical
> - * address size for the VM. Bits[7-0] are reserved for the guest
> - * PA size shift (i.e, log2(PA_Size)). For backward compatibility,
> - * value 0 implies the default IPA size, 40bits.
> + * On arm64, machine type can be used to request both the machine type and
> + * the physical address size for the VM.
> + *
> + * Bits[11-8] are reserved for the ARM specific machine type.
> + *
> + * Bits[7-0] are reserved for the guest PA size shift (i.e, log2(PA_Size)).
> + * For backward compatibility, value 0 implies the default IPA size, 40bits.
>    */
> +#define KVM_VM_TYPE_ARM_SHIFT		8
> +#define KVM_VM_TYPE_ARM_MASK		(0xfULL << KVM_VM_TYPE_ARM_SHIFT)
> +#define KVM_VM_TYPE_ARM(_type)		\
> +	(((_type) << KVM_VM_TYPE_ARM_SHIFT) & KVM_VM_TYPE_ARM_MASK)
> +#define KVM_VM_TYPE_ARM_NORMAL		KVM_VM_TYPE_ARM(0)
> +#define KVM_VM_TYPE_ARM_REALM		KVM_VM_TYPE_ARM(1)
> +
>   #define KVM_VM_TYPE_ARM_IPA_SIZE_MASK	0xffULL
>   #define KVM_VM_TYPE_ARM_IPA_SIZE(x)		\
>   	((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
> +
>   /*
>    * ioctls for /dev/kvm fds:
>    */


Looks good to me.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
diff mbox series

Patch

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 22da6493912a..c5a6139d5454 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -173,6 +173,23 @@  int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	mutex_unlock(&kvm->lock);
 #endif
 
+	if (type & ~(KVM_VM_TYPE_ARM_MASK | KVM_VM_TYPE_ARM_IPA_SIZE_MASK))
+		return -EINVAL;
+
+	switch (type & KVM_VM_TYPE_ARM_MASK) {
+	case KVM_VM_TYPE_ARM_NORMAL:
+		break;
+	case KVM_VM_TYPE_ARM_REALM:
+		kvm->arch.is_realm = true;
+		if (!kvm_is_realm(kvm)) {
+			/* Realm support unavailable */
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	ret = kvm_share_hyp(kvm, kvm + 1);
 	if (ret)
 		return ret;
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index aae365647b62..af4564f3add5 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -877,9 +877,6 @@  int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 	if (kvm_is_realm(kvm))
 		ipa_limit = kvm_realm_ipa_limit();
 
-	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
-		return -EINVAL;
-
 	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
 	if (is_protected_kvm_enabled()) {
 		phys_shift = kvm_ipa_limit;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a1147036d1bd..5153c837c8c7 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -635,14 +635,25 @@  struct kvm_enable_cap {
 #define KVM_S390_SIE_PAGE_OFFSET 1
 
 /*
- * On arm64, machine type can be used to request the physical
- * address size for the VM. Bits[7-0] are reserved for the guest
- * PA size shift (i.e, log2(PA_Size)). For backward compatibility,
- * value 0 implies the default IPA size, 40bits.
+ * On arm64, machine type can be used to request both the machine type and
+ * the physical address size for the VM.
+ *
+ * Bits[11-8] are reserved for the ARM specific machine type.
+ *
+ * Bits[7-0] are reserved for the guest PA size shift (i.e, log2(PA_Size)).
+ * For backward compatibility, value 0 implies the default IPA size, 40bits.
  */
+#define KVM_VM_TYPE_ARM_SHIFT		8
+#define KVM_VM_TYPE_ARM_MASK		(0xfULL << KVM_VM_TYPE_ARM_SHIFT)
+#define KVM_VM_TYPE_ARM(_type)		\
+	(((_type) << KVM_VM_TYPE_ARM_SHIFT) & KVM_VM_TYPE_ARM_MASK)
+#define KVM_VM_TYPE_ARM_NORMAL		KVM_VM_TYPE_ARM(0)
+#define KVM_VM_TYPE_ARM_REALM		KVM_VM_TYPE_ARM(1)
+
 #define KVM_VM_TYPE_ARM_IPA_SIZE_MASK	0xffULL
 #define KVM_VM_TYPE_ARM_IPA_SIZE(x)		\
 	((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
+
 /*
  * ioctls for /dev/kvm fds:
  */