diff mbox series

[RFC,07/28] arm64: kvm: Allow passing machine type in KVM creation

Message ID 20230127112932.38045-8-steven.price@arm.com
State New
Headers
Series arm64: Support for Arm CCA in KVM |

Commit Message

Steven Price Jan. 27, 2023, 11:29 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     | 13 +++++++++++++
 arch/arm64/kvm/mmu.c     |  3 ---
 arch/arm64/kvm/reset.c   |  3 ---
 include/uapi/linux/kvm.h | 19 +++++++++++++++----
 4 files changed, 28 insertions(+), 10 deletions(-)

Comments

Zhi Wang Feb. 13, 2023, 4:35 p.m. UTC | #1 
On Fri, 27 Jan 2023 11:29:11 +0000
Steven Price <steven.price@arm.com> 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     | 13 +++++++++++++
>  arch/arm64/kvm/mmu.c     |  3 ---
>  arch/arm64/kvm/reset.c   |  3 ---
>  include/uapi/linux/kvm.h | 19 +++++++++++++++----
>  4 files changed, 28 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 50f54a63732a..badd775547b8 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -147,6 +147,19 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
>  {
>  	int ret;
>  
> +	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;

It is better to let this call fail when !kvm_rme_is_available? It is
strange to be able to create a VM with REALM type in a system doesn't
support RME.

> +		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 d0f707767d05..22c00274884a 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -709,9 +709,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
>  	u64 mmfr0, mmfr1;
>  	u32 phys_shift;
>  
> -	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/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index c165df174737..9e71d69e051f 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -405,9 +405,6 @@ int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
>  	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 (phys_shift) {
>  		if (phys_shift > ipa_limit ||
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index fec1909e8b73..bcfc4d58dc19 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -898,14 +898,25 @@ struct kvm_ppc_resize_hpt {
>  #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:
>   */
Steven Price March 1, 2023, 11:55 a.m. UTC | #2 
On 13/02/2023 16:35, Zhi Wang wrote:
> On Fri, 27 Jan 2023 11:29:11 +0000
> Steven Price <steven.price@arm.com> 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     | 13 +++++++++++++
>>  arch/arm64/kvm/mmu.c     |  3 ---
>>  arch/arm64/kvm/reset.c   |  3 ---
>>  include/uapi/linux/kvm.h | 19 +++++++++++++++----
>>  4 files changed, 28 insertions(+), 10 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
>> index 50f54a63732a..badd775547b8 100644
>> --- a/arch/arm64/kvm/arm.c
>> +++ b/arch/arm64/kvm/arm.c
>> @@ -147,6 +147,19 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
>>  {
>>  	int ret;
>>  
>> +	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;
> 
> It is better to let this call fail when !kvm_rme_is_available? It is
> strange to be able to create a VM with REALM type in a system doesn't
> support RME.

Good point - I'll add a check here.

Thanks,

Steve

>> +		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 d0f707767d05..22c00274884a 100644
>> --- a/arch/arm64/kvm/mmu.c
>> +++ b/arch/arm64/kvm/mmu.c
>> @@ -709,9 +709,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
>>  	u64 mmfr0, mmfr1;
>>  	u32 phys_shift;
>>  
>> -	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/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
>> index c165df174737..9e71d69e051f 100644
>> --- a/arch/arm64/kvm/reset.c
>> +++ b/arch/arm64/kvm/reset.c
>> @@ -405,9 +405,6 @@ int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
>>  	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 (phys_shift) {
>>  		if (phys_shift > ipa_limit ||
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index fec1909e8b73..bcfc4d58dc19 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -898,14 +898,25 @@ struct kvm_ppc_resize_hpt {
>>  #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:
>>   */
>
diff mbox series

Patch

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 50f54a63732a..badd775547b8 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -147,6 +147,19 @@  int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	int ret;
 
+	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;
+		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 d0f707767d05..22c00274884a 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -709,9 +709,6 @@  int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 	u64 mmfr0, mmfr1;
 	u32 phys_shift;
 
-	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/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index c165df174737..9e71d69e051f 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -405,9 +405,6 @@  int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
 	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 (phys_shift) {
 		if (phys_shift > ipa_limit ||
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index fec1909e8b73..bcfc4d58dc19 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -898,14 +898,25 @@  struct kvm_ppc_resize_hpt {
 #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:
  */