On 5/13/25 2:50 AM, Christian Borntraeger wrote: > Am 29.04.25 um 16:09 schrieb Matthew Rosato: >> On 4/29/25 3:45 AM, Christian Borntraeger wrote: >>> Am 29.04.25 um 09:37 schrieb David Hildenbrand: >>> [...] >>>> The only problem I see is with vfio devices is the new "memory pinned" >>>> mode. [1] >>>> >>>> There, we'd have to check if any such device is around (discarding of ram >>>> is disabled?), and fallback to actual zeroing of memory. >>> >>> CC Matt to double check. >> >> When triggering the "relaxed translation" mode via iommu.passthrough in the >> guest, we now take the default (for other platforms) memory_region_is_ram() >> path in vfio_listener_region_add/del() which handles the pin/unpin from vfio >> common code. As for ram discarding, we then also use the vfio common path >> and only uncoordinated discards are disabled via: >> >> vfio_ram_block_discard_disable() -> ram_block_uncoordinated_discard_disable() > > So this patch is good? >
Worked fine in my testing in combination with iommu.passthrough=1. I traced to verify I was hitting the S390_RESET_REIPL_CLEAR path in s390_machine_reset() and observed the pinned memory of the guest shrink / grow. Device worked fine afterwards.
