On Mon, Aug 12, 2019 at 05:49:08AM -0400, Michael S. Tsirkin wrote: > On Mon, Aug 12, 2019 at 10:44:51AM +0800, Jason Wang wrote: > > > > On 2019/8/11 上午1:52, Michael S. Tsirkin wrote: > > > On Fri, Aug 09, 2019 at 01:48:42AM -0400, Jason Wang wrote: > > > > Hi all: > > > > > > > > This series try to fix several issues introduced by meta data > > > > accelreation series. Please review. > > > > > > > > Changes from V4: > > > > - switch to use spinlock synchronize MMU notifier with accessors > > > > > > > > Changes from V3: > > > > - remove the unnecessary patch > > > > > > > > Changes from V2: > > > > - use seqlck helper to synchronize MMU notifier with vhost worker > > > > > > > > Changes from V1: > > > > - try not use RCU to syncrhonize MMU notifier with vhost worker > > > > - set dirty pages after no readers > > > > - return -EAGAIN only when we find the range is overlapped with > > > > metadata > > > > > > > > Jason Wang (9): > > > > vhost: don't set uaddr for invalid address > > > > vhost: validate MMU notifier registration > > > > vhost: fix vhost map leak > > > > vhost: reset invalidate_count in vhost_set_vring_num_addr() > > > > vhost: mark dirty pages during map uninit > > > > vhost: don't do synchronize_rcu() in vhost_uninit_vq_maps() > > > > vhost: do not use RCU to synchronize MMU notifier with worker > > > > vhost: correctly set dirty pages in MMU notifiers callback > > > > vhost: do not return -EAGAIN for non blocking invalidation too early > > > > > > > > drivers/vhost/vhost.c | 202 +++++++++++++++++++++++++----------------- > > > > drivers/vhost/vhost.h | 6 +- > > > > 2 files changed, 122 insertions(+), 86 deletions(-) > > > This generally looks more solid. > > > > > > But this amounts to a significant overhaul of the code. > > > > > > At this point how about we revert 7f466032dc9e5a61217f22ea34b2df932786bbfc > > > for this release, and then re-apply a corrected version > > > for the next one? > > > > > > If possible, consider we've actually disabled the feature. How about just > > queued those patches for next release? > > > > Thanks > > Sorry if I was unclear. My idea is that > 1. I revert the disabled code > 2. You send a patch readding it with all the fixes squashed > 3. Maybe optimizations on top right away? > 4. We queue *that* for next and see what happens. > > And the advantage over the patchy approach is that the current patches > are hard to review. E.g. it's not reasonable to ask RCU guys to review > the whole of vhost for RCU usage but it's much more reasonable to ask > about a specific patch. I think there are other problems here too, I don't like that the use of mmu notifiers is so different from every other driver, or that GUP is called under spinlock. So I favor the revert and try again approach as well. It is hard to get a clear picture with these endless bug fix patches Jason
