On Wed, 24 Jan 2018 10:14:57 +0100 Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > On 24/01/2018 10:05, Greg Kurz wrote: > > On Wed, 24 Jan 2018 09:46:21 +0100 > > Greg Kurz <groug@xxxxxxxx> wrote: > > > >> Please note that Peter usually doesn't work on Wednesdays. The master branch > >> might remain broken for everyone until tomorrow... :-\ > >> > >> And I don't think this is the right fix anyway. See below. > >> > >> On Wed, 24 Jan 2018 00:44:14 +0200 > >> "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > >> > >>> From: Jose Ricardo Ziviani <joserz@xxxxxxxxxxxxxxxxxx> > >>> > >>> This commit partially reverts the commit 4fe6d78b2e because of issues > >>> reported in the virtio. > >>> > >>> Examples: > >>> > >>> $ qemu-system-ppc64 -cpu POWER8 -nographic -vga none -m 4G \ > >>> -M pseries,accel=kvm -netdev type=user,id=net0 \ > >>> -device virtio-net-pci,netdev=net0 -drive file=../disk.qcow2,if=virtio > >>> > >>> Populating /vdevice/nvram@71000001 > >>> Populating /vdevice/v-scsi@71000002 > >>> SCSI: Looking for devices > >>> 8200000000000000 CD-ROM : "QEMU QEMU CD-ROM 2.5+" > >>> Populating /pci@800000020000000 > >>> 00 0000 (D) : 1af4 1000 virtio [ net ] > >>> Aborted > >>> > >>> $ qemu-system-x86_64 -m 4G -enable-kvm -drive file=util.qcow2,if=virtio > >>> > >>> Running QEMU with GTK 2.x is deprecated, and will be removed > >>> in a future release. Please switch to GTK 3.x instead > >>> [1] 5282 abort > >>> > >>> Reference http://lists.nongnu.org/archive/html/qemu-devel/2018-01/msg05457.html > >>> > >>> Reported-by: Anton Blanchard <anton@xxxxxxxxx> > >>> Signed-off-by: Jose Ricardo Ziviani <joserz@xxxxxxxxxxxxxxxxxx> > >>> Reviewed-by: Daniel Henrique Barboza <danielhb@xxxxxxxxxxxxxxxxxx> > >>> Tested-by: Daniel Henrique Barboza <danielhb@xxxxxxxxxxxxxxxxxx> > >>> Reviewed-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > >>> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > >>> --- > >>> accel/kvm/kvm-all.c | 4 ---- > >>> 1 file changed, 4 deletions(-) > >>> > >>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > >>> index 071f4f5..f290f48 100644 > >>> --- a/accel/kvm/kvm-all.c > >>> +++ b/accel/kvm/kvm-all.c > >>> @@ -812,10 +812,6 @@ static void kvm_mem_ioeventfd_del(MemoryListener *listener, > >>> if (r < 0) { > >>> abort(); > >>> } > >>> - > >>> - if (e->cleanup) { > >>> - e->cleanup(e); > >>> - } > >> > >> This looks wrong as the cleanup is expected to do things like closing fds: > >> > >> static void virtio_bus_cleanup_event_notifier(EventNotifier *notifier) > >> { > >> /* Test and clear notifier after disabling event, > >> * in case poll callback didn't have time to run. > >> */ > >> virtio_queue_host_notifier_read(notifier); > >> event_notifier_cleanup(notifier); > >> } > >> > >> void event_notifier_cleanup(EventNotifier *e) > >> { > >> if (e->rfd != e->wfd) { > >> close(e->rfd); > >> } > >> close(e->wfd); > >> e->rfd = -1; > >> e->wfd = -1; > >> e->cleanup = NULL; > >> } > >> > >> And indeed, with this patch applied, QEMU leaks eventfds on every machine > >> reset. > >> > > > > Reverting 4fe6d78b2e entirely isn't even enough and QEMU aborts at the > > next machine reset. The following commit must be reverted as well: > > > > commit 6f0bb230722931d17fb284eee8efd40b9d653822 > > Author: Gal Hammer <ghammer@xxxxxxxxxx> > > Date: Sun Jan 14 12:06:56 2018 +0200 > > > > virtio: improve virtio devices initialization time > > I'm a bit confused by this patch. The basic idea of wrapping with > transaction_begin/commit is clear (without it you have quadratic > behavior from removing one ioeventfd at a time), but I don't understand > why the new ->cleanup member is needed. > I don't understand either... the cover letter of the series says: "The patch wraps all the changes made to the Memory Regions during the eventfd registrations in a memory regions transaction. I had to add a cleanup callback function to the EventNotifier struct, so it will be possible to use a transaction in the shutdown code path as well." Until this is sorted out, maybe best to revert both commits or even the full series (ie, f87d72f5c5bf as well), no ? > Paolo
