On Fri, 27 Jan 2023 11:29:11 +0000 Steven Price <steven.price@xxxxxxx> 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@xxxxxxx> > --- > 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: > */