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. Paolo
