On Thu, Jul 30, 2015 at 08:22:18AM +0200, Igor Mammedov wrote: > On Wed, 29 Jul 2015 18:03:36 +0300 > "Michael S. Tsirkin" <m...@redhat.com> wrote: > > > On Wed, Jul 29, 2015 at 01:49:47PM +0200, Igor Mammedov wrote: > > > v1->v2: > > > * replace probbing with checking for > > > /sys/module/vhost/parameters/max_mem_regions and > > > if it's missing has non wrong value return > > > hardcoded legacy limit (64 slots). > > > > > > it's defensive patchset which helps to avoid QEMU crashing > > > at memory hotplug time by checking that vhost has free capacity > > > for an additional memory slot. > > > > What if vhost is added after memory hotplug? Don't you need > > to check that as well? > vhost device can be hotplugged after memory hotplug as far as > current slots count doesn't exceed its limit, > if limit is exceeded device_add would fail or virtio device > would fallback to non vhost mode at its start-up (depends on > how particular device treats vhost_start failure).
Where exactly does it fail? memory_listener_register returns void so clearly it's not that ... > > > > > > > > > > Igor Mammedov (2): > > > vhost: add vhost_has_free_slot() interface > > > pc-dimm: add vhost slots limit check before commiting to hotplug > > > > > > hw/mem/pc-dimm.c | 7 +++++++ > > > hw/virtio/vhost-backend.c | 21 ++++++++++++++++++++- > > > hw/virtio/vhost-user.c | 8 +++++++- > > > hw/virtio/vhost.c | 21 +++++++++++++++++++++ > > > include/hw/virtio/vhost-backend.h | 2 ++ > > > include/hw/virtio/vhost.h | 1 + > > > stubs/Makefile.objs | 1 + > > > stubs/vhost.c | 6 ++++++ > > > 8 files changed, 65 insertions(+), 2 deletions(-) > > > create mode 100644 stubs/vhost.c > > > > > > -- > > > 1.8.3.1
