On 21.10.20 16:18, Christian Borntraeger wrote: > > > On 21.10.20 16:14, David Hildenbrand wrote: >> On 21.10.20 15:43, Janosch Frank wrote: >>> Diag318 fencing needs to be determined on the current VM PV state and >>> not on the state that the VM has when we create the CPU model. >>> >>> Signed-off-by: Janosch Frank <[email protected]> >>> Reported-by: Marc Hartmayer <[email protected]> >>> Reviewed-by: Christian Borntraeger <[email protected]> >>> Fixes: fabdada935 ("s390: guest support for diagnose 0x318") >>> Tested-by: Marc Hartmayer <[email protected]> >>> --- >>> hw/s390x/sclp.c | 10 ++++++++++ >>> target/s390x/kvm.c | 3 +-- >>> 2 files changed, 11 insertions(+), 2 deletions(-) >>> >>> diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c >>> index 0cf2290826..69aba402d3 100644 >>> --- a/hw/s390x/sclp.c >>> +++ b/hw/s390x/sclp.c >>> @@ -22,6 +22,7 @@ >>> #include "hw/s390x/event-facility.h" >>> #include "hw/s390x/s390-pci-bus.h" >>> #include "hw/s390x/ipl.h" >>> +#include "hw/s390x/pv.h" >>> >>> static inline SCLPDevice *get_sclp_device(void) >>> { >>> @@ -142,6 +143,15 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb) >>> if (s390_has_feat(S390_FEAT_EXTENDED_LENGTH_SCCB)) { >>> s390_get_feat_block(S390_FEAT_TYPE_SCLP_FAC134, >>> &read_info->fac134); >>> + /* >>> + * Diag318 is not available in protected mode and will result >>> + * in an operation exception. As we can dynamically move in >>> + * and out of protected mode, we need to fence the feature >>> + * here rather than when creating the CPU model. >>> + */ >>> + if (s390_is_pv()) { >>> + read_info->fac134 &= ~0x80; >>> + } >> >> Hmm, I thought firmware would handle exposing cpu features and similar, >> so we can't temper with it .... > > Only the stfle bits. >> >> Can we move that into s390_get_feat_block instead and check against the >> feature bit instead? > > No because we want to have this active for !pv and disabled for pv but we > switch > this multiple times when doing boot/reboot.
Keeping the s390_is_pv() condition of course. -- Thanks, David / dhildenb
