Messages in this thread | | | Date | Thu, 17 Aug 2023 13:49:06 +0200 | Subject | Re: [PATCH v4 3/4] KVM: s390: Add UV feature negotiation | From | Michael Mueller <> |
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On 15.08.23 17:14, Steffen Eiden wrote: > Add a uv_feature list for pv-guests to the KVM cpu-model. > The feature bits 'AP-interpretation for secure guests' and > 'AP-interrupt for secure guests' are available. > > Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> > Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Michael Mueller <mimu@linux.ibm.com>
but a minor comment, see below.
> --- > arch/s390/include/asm/kvm_host.h | 2 + > arch/s390/include/uapi/asm/kvm.h | 16 +++++++ > arch/s390/kvm/kvm-s390.c | 73 ++++++++++++++++++++++++++++++++ > 3 files changed, 91 insertions(+) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index 91bfecb91321..427f9528a7b6 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -817,6 +817,8 @@ struct kvm_s390_cpu_model { > __u64 *fac_list; > u64 cpuid; > unsigned short ibc; > + /* subset of available UV-features for pv-guests enabled by user space */ > + struct kvm_s390_vm_cpu_uv_feat uv_feat_guest; > }; > > typedef int (*crypto_hook)(struct kvm_vcpu *vcpu); > diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h > index a73cf01a1606..abe926d43cbe 100644 > --- a/arch/s390/include/uapi/asm/kvm.h > +++ b/arch/s390/include/uapi/asm/kvm.h > @@ -159,6 +159,22 @@ struct kvm_s390_vm_cpu_subfunc { > __u8 reserved[1728]; > }; > > +#define KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST 6 > +#define KVM_S390_VM_CPU_MACHINE_UV_FEAT_GUEST 7 > + > +#define KVM_S390_VM_CPU_UV_FEAT_NR_BITS 64 > +struct kvm_s390_vm_cpu_uv_feat { > + union { > + struct { > + __u64 : 4; > + __u64 ap : 1; /* bit 4 */ > + __u64 ap_intr : 1; /* bit 5 */ > + __u64 : 58; > + }; > + __u64 feat; > + }; > +}; > + > /* kvm attributes for crypto */ > #define KVM_S390_VM_CRYPTO_ENABLE_AES_KW 0 > #define KVM_S390_VM_CRYPTO_ENABLE_DEA_KW 1 > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 813cc3d59c90..b3f17e014cab 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -1531,6 +1531,39 @@ static int kvm_s390_set_processor_subfunc(struct kvm *kvm, > return 0; > } > > +#define KVM_S390_VM_CPU_UV_FEAT_GUEST_MASK \ > +( \ > + ((struct kvm_s390_vm_cpu_uv_feat){ \ > + .ap = 1, \ > + .ap_intr = 1, \ > + }) \ > + .feat \ > +) > + > +static int kvm_s390_set_uv_feat(struct kvm *kvm, struct kvm_device_attr *attr) > +{ > + struct kvm_s390_vm_cpu_uv_feat __user *ptr = (void __user *)attr->addr; > + unsigned long data, filter; > + > + filter = uv_info.uv_feature_indications & KVM_S390_VM_CPU_UV_FEAT_GUEST_MASK;
if get_user() fails the uv feature bits in "filter" are calculated in vain
> + if (get_user(data, &ptr->feat)) > + return -EFAULT;
could be done here, but that's really minor to me
> + if (!bitmap_subset(&data, &filter, KVM_S390_VM_CPU_UV_FEAT_NR_BITS)) > + return -EINVAL; > + > + mutex_lock(&kvm->lock); > + if (kvm->created_vcpus) { > + mutex_unlock(&kvm->lock); > + return -EBUSY; > + } > + kvm->arch.model.uv_feat_guest.feat = data; > + mutex_unlock(&kvm->lock); > + > + VM_EVENT(kvm, 3, "SET: guest UV-feat: 0x%16.16lx", data); > + > + return 0; > +} > + > static int kvm_s390_set_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) > { > int ret = -ENXIO; > @@ -1545,6 +1578,9 @@ static int kvm_s390_set_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) > case KVM_S390_VM_CPU_PROCESSOR_SUBFUNC: > ret = kvm_s390_set_processor_subfunc(kvm, attr); > break; > + case KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST: > + ret = kvm_s390_set_uv_feat(kvm, attr); > + break; > } > return ret; > } > @@ -1777,6 +1813,33 @@ static int kvm_s390_get_machine_subfunc(struct kvm *kvm, > return 0; > } > > +static int kvm_s390_get_processor_uv_feat(struct kvm *kvm, struct kvm_device_attr *attr) > +{ > + struct kvm_s390_vm_cpu_uv_feat __user *dst = (void __user *)attr->addr; > + unsigned long feat = kvm->arch.model.uv_feat_guest.feat; > + > + if (put_user(feat, &dst->feat)) > + return -EFAULT; > + VM_EVENT(kvm, 3, "GET: guest UV-feat: 0x%16.16lx", feat); > + > + return 0; > +} > + > +static int kvm_s390_get_machine_uv_feat(struct kvm *kvm, struct kvm_device_attr *attr) > +{ > + struct kvm_s390_vm_cpu_uv_feat __user *dst = (void __user *)attr->addr; > + unsigned long feat; > + > + BUILD_BUG_ON(sizeof(*dst) != sizeof(uv_info.uv_feature_indications)); > + > + feat = uv_info.uv_feature_indications & KVM_S390_VM_CPU_UV_FEAT_GUEST_MASK; > + if (put_user(feat, &dst->feat)) > + return -EFAULT; > + VM_EVENT(kvm, 3, "GET: guest UV-feat: 0x%16.16lx", feat); > + > + return 0; > +} > + > static int kvm_s390_get_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) > { > int ret = -ENXIO; > @@ -1800,6 +1863,12 @@ static int kvm_s390_get_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) > case KVM_S390_VM_CPU_MACHINE_SUBFUNC: > ret = kvm_s390_get_machine_subfunc(kvm, attr); > break; > + case KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST: > + ret = kvm_s390_get_processor_uv_feat(kvm, attr); > + break; > + case KVM_S390_VM_CPU_MACHINE_UV_FEAT_GUEST: > + ret = kvm_s390_get_machine_uv_feat(kvm, attr); > + break; > } > return ret; > } > @@ -1952,6 +2021,8 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) > case KVM_S390_VM_CPU_MACHINE_FEAT: > case KVM_S390_VM_CPU_MACHINE_SUBFUNC: > case KVM_S390_VM_CPU_PROCESSOR_SUBFUNC: > + case KVM_S390_VM_CPU_MACHINE_UV_FEAT_GUEST: > + case KVM_S390_VM_CPU_PROCESSOR_UV_FEAT_GUEST: > ret = 0; > break; > default: > @@ -3296,6 +3367,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) > kvm->arch.model.cpuid = kvm_s390_get_initial_cpuid(); > kvm->arch.model.ibc = sclp.ibc & 0x0fff; > > + kvm->arch.model.uv_feat_guest.feat = 0; > + > kvm_s390_crypto_init(kvm); > > if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) {
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