Messages in this thread | | | Subject | Re: [PATCH v2 1/2] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs | From | Thomas Huth <> | Date | Wed, 4 Sep 2019 11:21:47 +0200 |
| |
On 04/09/2019 11.15, David Hildenbrand wrote: > On 04.09.19 11:11, Christian Borntraeger wrote: >> >> >> On 04.09.19 11:05, David Hildenbrand wrote: >>> On 04.09.19 10:51, Thomas Huth wrote: >>>> If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this >>>> clearly indicates that something went wrong in the KVM userspace >>>> application. The x86 variant of KVM already contains a check for >>>> bad bits, so let's do the same on s390x now, too. >>>> >>>> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> >>>> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> >>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com> >>>> Signed-off-by: Thomas Huth <thuth@redhat.com> >>>> --- >>>> arch/s390/include/uapi/asm/kvm.h | 6 ++++++ >>>> arch/s390/kvm/kvm-s390.c | 4 ++++ >>>> 2 files changed, 10 insertions(+) >>>> >>>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >>>> index 47104e5b47fd..436ec7636927 100644 >>>> --- a/arch/s390/include/uapi/asm/kvm.h >>>> +++ b/arch/s390/include/uapi/asm/kvm.h >>>> @@ -231,6 +231,12 @@ struct kvm_guest_debug_arch { >>>> #define KVM_SYNC_GSCB (1UL << 9) >>>> #define KVM_SYNC_BPBC (1UL << 10) >>>> #define KVM_SYNC_ETOKEN (1UL << 11) >>>> + >>>> +#define KVM_SYNC_S390_VALID_FIELDS \ >>>> + (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \ >>>> + KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \ >>>> + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN) >>>> + >>> >>> We didn't care about the S390 for the actual flags, why care now? >> >> I think it makes sense to have the interface as defined as possible. If for some >> reason userspace sets a wrong bit this would be undetected. If we at a later point >> in time use that bit this would resultin strange problems. > > Not arguing about the concept of checking for valid bits. Was just > wondering if the "S390" part in the name makes sense at all. But you > guys seem to have a consent here.
Oh, I guess we both got your question wrong... Well, I don't care too much whether we've got an "S390" in there or not ... so unless there is a real good reason to remove it, let's simply keep it this way.
Thomas
| |