Re: kern/60144: virtio(4) cache coherence issue

[Tetsuya Isaki <isaki%pastel-flower.jp@localhost>]

At Mon, 18 May 2026 23:29:58 +0000,
Taylor R Campbell wrote:
> OK, here is a candidate patch to address this issue.  Most of what
> needs review is the commit message, but it would be good to test
> whether it empirically addresses the problem too.  (Note that alone it
> is probably _not_ enough to fix PR 60182, but it is probably needed
> _in addition_ to the patch I already posted there.)
> 
> Isaki-san: Can you verify that this patch works?

It worked with these three patches applied.  Thank you!
- sys/arch/virt68k/virt68k/bus_dma.c,v 1.5 (I tested it on -11)
- sys/dev/pci/ld_virtio.c (from kern/60182)
- sys/dev/pci/virtio.c (this patch)

By the way, one spurious interrupt has still occurred.

...
virtio1: allocated 24576 byte for virtqueue 0 for I/O request, size 32
virtio1: using 16384 byte (1024 entries) indirect descriptors
virtio1: interrupting at gfpic4 irq 2 (IPL 5)
ld1: 8192 MB, 4161 cyl, 64 head, 63 sec, 512 bytes/sect x 16777216 sectors (0 bytes/physsect)
Spurious interrupt on CPU ipl 5
No statclock; using hardclock.
Initialzing hardclock: freq=100 Hz, interval=10000 usec
timecounter: Timecounter "clockinterrupt" frequency 100 Hz quality 0
swwdog0: software watchdog initialized
root on ld0a dumps on ld0b
root file system type: ffs
---
Tetsuya Isaki <isaki%pastel-flower.jp@localhost / isaki%NetBSD.org@localhost>