On 20.01.20 07:27, Michael S. Tsirkin wrote:

On Tue, Jan 07, 2020 at 01:16:50PM +0100, Christian Borntraeger wrote:

quoted

On 07.01.20 12:55, Michael S. Tsirkin wrote:

quoted

I pushed batched-v3 - same head but bisect should work now.

With 
commit 38ced0208491103b50f1056f0d1c8f28e2e13d08 (HEAD)
Author:     Michael S. Tsirkin [off-list ref]
AuthorDate: Wed Dec 11 12:19:26 2019 -0500
Commit:     Michael S. Tsirkin [off-list ref]
CommitDate: Tue Jan 7 06:52:42 2020 -0500

    vhost: use batched version by default


I have exactly one successful ping and then the network inside the guest is broken (no packet
anymore).

Does anything appear in host's dmesg when this happens?

I think there was nothing, but I am not sure. I would need to redo the test if this is important to know.

quoted

So you could consider this commit broken (but in a different way and also without any
guest reboot necessary).


bisect log:
git bisect start
# bad: [d2f6175f52062ee51ee69754a6925608213475d2] vhost: use vhost_desc instead of vhost_log
git bisect bad d2f6175f52062ee51ee69754a6925608213475d2
# good: [d1281e3a562ec6a08f944a876481dd043ba739b9] virtio-blk: remove VIRTIO_BLK_F_SCSI support
git bisect good d1281e3a562ec6a08f944a876481dd043ba739b9
# good: [fac7c0f46996e32d996f5c46121df24a6b95ec3b] vhost: option to fetch descriptors through an independent struct
git bisect good fac7c0f46996e32d996f5c46121df24a6b95ec3b
# bad: [539eb9d738f048cd7be61f404e8f9c7d9d2ff3cc] vhost: batching fetches
git bisect bad 539eb9d738f048cd7be61f404e8f9c7d9d2ff3cc