On 27.09.23 15:18, Linux regression tracking #adding (Thorsten Leemhuis) wrote: > On 26.09.23 15:04, Michael Roth wrote: >> On Sun, Sep 03, 2023 at 06:13:38PM -0400, Michael S. Tsirkin wrote: >>> virtio_net: merge dma operations when filling mergeable buffers >> >> This ^ patch (upstream commit 295525e29a) seems to cause a >> network-related regression when using SWIOTLB in the guest. I noticed >> this initially testing SEV guests, which use SWIOTLB by default, but >> it can also be seen with normal guests when forcing SWIOTLB via >> swiotlb=force kernel cmdline option. I see it with both 6.6-rc1 and >> 6.6-rc2 (haven't tried rc3 yet, but don't see any related changes >> there), and reverting 714073495f seems to avoid the issue. >> >> Steps to reproduce: >>> [...] > > Thanks for the report. To be sure the issue doesn't fall through the > cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression > tracking bot: > > #regzbot ^introduced 295525e29a > #regzbot title virtio: network-related regression when using SWIOTLB in > the guest > #regzbot ignore-activity Regzbot missed the fix due to a fluke: #regzbot monitor: https://lore.kernel.org/all/20230927055246.121544-1-xuanzhuo@xxxxxxxxxxxxxxxxx/ #regzbot fix: virtio_net: fix the missing of the dma cpu sync #regzbot ignore-activity Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr That page also explains what to do if mails like this annoy you.
