Messages in this thread | | | Date | Tue, 17 Oct 2023 15:44:14 +0200 | From | Stefano Garzarella <> | Subject | Re: [RFC PATCH] vdpa_sim: implement .reset_map support |
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On Fri, Oct 13, 2023 at 10:29:26AM -0700, Si-Wei Liu wrote: >Hi Stefano, > >On 10/13/2023 2:22 AM, Stefano Garzarella wrote: >>Hi Si-Wei, >> >>On Fri, Oct 13, 2023 at 01:23:40AM -0700, Si-Wei Liu wrote: >>>RFC only. Not tested on vdpa-sim-blk with user virtual address. >> >>I can test it, but what I should stress? >Great, thank you! As you see, my patch moved vhost_iotlb_reset out of >vdpasim_reset for the sake of decoupling mapping from vdpa device >reset. For hardware devices this decoupling makes sense as platform >IOMMU already did it. But I'm not sure if there's something in the >software device (esp. with vdpa-blk and the userspace library stack) >that may have to rely on the current .reset behavior that clears the >vhost_iotlb. So perhaps you can try to exercise every possible case >involving blk device reset, and see if anything (related to mapping) >breaks?
I just tried these steps without using a VM and the host kernel hangs after adding the device:
[root@f38-vm-build ~]# modprobe virtio-vdpa [root@f38-vm-build ~]# modprobe vdpa-sim-blk [root@f38-vm-build ~]# vdpa dev add mgmtdev vdpasim_blk name blk0 [ 35.284575][ T563] virtio_blk virtio6: 1/0/0 default/read/poll queues [ 35.286372][ T563] virtio_blk virtio6: [vdb] 262144 512-byte logical blocks (134 MB/128 MiB) [ 35.295271][ T564] vringh:
Reverting this patch (so building "vdpa/mlx5: implement .reset_map driver op") worked here.
> >> >>>Works fine with vdpa-sim-net which uses physical address to map. >> >>Can you share your tests? so I'll try to do the same with blk. >Basically everything involving virtio device reset in the guest, e.g. >reboot the VM, remove/unbind then reprobe/bind the virtio-net >module/driver, then see if device I/O (which needs mapping properly) is >still flowing as expected. And then everything else that could trigger >QEMU's vhost_dev_start/stop paths ending up as passive vhos-vdpa >backend reset, for e.g. link status change, suspend/hibernate, SVQ >switch and live migration. I am not sure if vdpa-blk supports live >migration through SVQ or not, if not you don't need to worry about. > >> >>> >>>This patch is based on top of [1]. >>> >>>[1] https://lore.kernel.org/virtualization/1696928580-7520-1-git-send-email-si-wei.liu@oracle.com/ >> >>The series does not apply well on master or vhost tree. >>Where should I apply it? >Sent the link through another email offline.
Received thanks!
Stefano
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