Stefan Hajnoczi
2023-Aug-03 14:37 UTC
Unbinding virtio_pci_modern does not release BAR4 in Linux 6.5.0-rc4
Hi, After running "driverctl --nosave set-override 0000:01:00.0 vfio-pci" on a virtio-blk-pci device, /proc/iomem shows that BAR4 is still owned by virtio_pci_modern even though the vfio-pci driver is now bound to the PCI device. This regression was introduced after 6.4.7 but I don't see the culprit in the git logs. Unfortunately I don't have time to investigate further right now but I've included instructions on how to reproduce this below. Can anyone else reproduce this and can we still fix it for the upcoming Linux 6.5? Thanks, Stefan --- $ qemu-system-x86_64 \ -M q35,accel=kvm,kernel-irqchip=split \ -cpu host \ -m 1G \ -device intel-iommu,intremap=on,device-iotlb=on \ --blockdev file,filename=test.img,cache.direct=on,node-name=drive0 \ --device virtio-blk-pci,drive=drive0 \ -blockdev file,filename=test2.img,cache.direct=on,node-name=drive2 \ --device ioh3420,id=pcie.1,chassis=1 \ --device virtio-blk-pci,disable-legacy=on,disable-modern=off,drive=drive2,iommu_platform=on,ats=on,bus=pcie.1 (guest)# driverctl --nosave set-override 0000:01:00.0 vfio-pci (guest)# cat /proc/iomem -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 488 bytes Desc: not available URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20230803/122976f3/attachment-0001.sig>
Jason Wang
2023-Aug-10 03:08 UTC
Unbinding virtio_pci_modern does not release BAR4 in Linux 6.5.0-rc4
On Thu, Aug 3, 2023 at 10:37?PM Stefan Hajnoczi <stefanha at redhat.com> wrote:> > Hi, > After running "driverctl --nosave set-override 0000:01:00.0 vfio-pci" on > a virtio-blk-pci device, /proc/iomem shows that BAR4 is still owned by > virtio_pci_modern even though the vfio-pci driver is now bound to the > PCI device. > > This regression was introduced after 6.4.7 but I don't see the culprit > in the git logs. > > Unfortunately I don't have time to investigate further right now but > I've included instructions on how to reproduce this below. > > Can anyone else reproduce this and can we still fix it for the upcoming > Linux 6.5?This seems to be fixed by: https://lore.kernel.org/lkml/20230720131423-mutt-send-email-mst at kernel.org/T/ Thanks> > Thanks, > Stefan > --- > $ qemu-system-x86_64 \ > -M q35,accel=kvm,kernel-irqchip=split \ > -cpu host \ > -m 1G \ > -device intel-iommu,intremap=on,device-iotlb=on \ > --blockdev file,filename=test.img,cache.direct=on,node-name=drive0 \ > --device virtio-blk-pci,drive=drive0 \ > -blockdev file,filename=test2.img,cache.direct=on,node-name=drive2 \ > --device ioh3420,id=pcie.1,chassis=1 \ > --device virtio-blk-pci,disable-legacy=on,disable-modern=off,drive=drive2,iommu_platform=on,ats=on,bus=pcie.1 > > (guest)# driverctl --nosave set-override 0000:01:00.0 vfio-pci > (guest)# cat /proc/iomem