On Thu, 9 Nov 2017 10:47:23 +0100 Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote: > The AIS capability was introduced in 4.12, while the interface to > migrate the state was added in 4.13. Unfortunately it is not possible > for userspace to detect the migration capability without creating a flic > kvm device. As in QEMU the the cpu model detection runs on the "none" s/the the/the/ > machine this will result in cpu model issues regarding the "ais" > capability. > > To get the "ais" capability properly let's add a new KVM capability that > tells userspace that AIS states can be migrated. > > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > --- > Documentation/virtual/kvm/api.txt | 8 ++++++++ > Documentation/virtual/kvm/devices/s390_flic.txt | 2 ++ > arch/s390/kvm/kvm-s390.c | 1 + > include/uapi/linux/kvm.h | 1 + > 4 files changed, 12 insertions(+) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index e63a35f..51553ba 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -4347,3 +4347,11 @@ This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its > value is used to denote the target vcpu for a SynIC interrupt. For > compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this > capability is absent, userspace can still query this msr's value. > + > +8.13 KVM_CAP_S390_AIS_MIGRATION > + > +Architectures: s390 > +Parameters: none > + > +This capability indicates if the flic device will be able to get/set the > +AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute. "and allows to discover this without having to create a flic device." > diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt > index 27ad53c..a4e20a0 100644 > --- a/Documentation/virtual/kvm/devices/s390_flic.txt > +++ b/Documentation/virtual/kvm/devices/s390_flic.txt > @@ -151,6 +151,8 @@ struct kvm_s390_ais_all { > to an ISC (MSB0 bit 0 to ISC 0 and so on). The combination of simm bit and > nimm bit presents AIS mode for a ISC. > > + KVM_DEV_FLIC_AISM_ALL is indicated by KVM_CAP_S390_AIS_MIGRATION. > + > Note: The KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR device ioctls executed on > FLIC with an unknown group or attribute gives the error code EINVAL (instead of > ENXIO, as specified in the API documentation). It is not possible to conclude > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index de6a5b7..8f4b655 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -395,6 +395,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_S390_USER_INSTR0: > case KVM_CAP_S390_CMMA_MIGRATION: > case KVM_CAP_S390_AIS: > + case KVM_CAP_S390_AIS_MIGRATION: > r = 1; > break; > case KVM_CAP_S390_MEM_OP: > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 8388875..b605956 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -930,6 +930,7 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_PPC_SMT_POSSIBLE 147 > #define KVM_CAP_HYPERV_SYNIC2 148 > #define KVM_CAP_HYPERV_VP_INDEX 149 > +#define KVM_CAP_S390_AIS_MIGRATION 150 > > #ifdef KVM_CAP_IRQ_ROUTING > With the small addition above, Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html