On Thu, Apr 13, 2023 at 2:24 PM Viktor Prutyanov <vik...@daynix.com> wrote: > > On Thu, Mar 30, 2023 at 7:49 PM Viktor Prutyanov <vik...@daynix.com> wrote: > > > > Even if Device-TLB and PCI ATS is enabled, the guest can reject to use > > it. For example, this situation appears when Windows Server 2022 is > > running with intel-iommu with device-iotlb=on and virtio-net-pci with > > vhost=on. The guest implies that no address translation info cached in > > device IOTLB and doesn't send device IOTLB invalidation commands. So, > > it leads to irrelevant address translations in vhost-net in the host > > kernel. Therefore network frames from the guest in host tap interface > > contains wrong payload data. > > > > This patch enables IOTLB unmap events (IOMMU_NOTIFIER_UNMAP) along with > > Device-TLB unmap events (IOMMU_NOTIFIER_DEVIOTLB_UNMAP) handling for > > proper vhost IOTLB unmapping when the guest isn't aware of Device-TLB. > > > > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2001312 > > Signed-off-by: Viktor Prutyanov <vik...@daynix.com> > > --- > > > > Tested on Windows Server 2022 and Fedora guests with > > -device virtio-net-pci,bus=pci.3,netdev=nd0,iommu_platform=on,ats=on > > -netdev tap,id=nd0,ifname=tap1,script=no,downscript=no,vhost=on > > -device intel-iommu,intremap=on,eim=on,device-iotlb=on/off > > > > hw/virtio/vhost.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > > index a266396576..968ca18fce 100644 > > --- a/hw/virtio/vhost.c > > +++ b/hw/virtio/vhost.c > > @@ -796,7 +796,7 @@ static void vhost_iommu_region_add(MemoryListener > > *listener, > > iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr, > > MEMTXATTRS_UNSPECIFIED); > > iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, > > - IOMMU_NOTIFIER_DEVIOTLB_UNMAP, > > + IOMMU_NOTIFIER_DEVIOTLB_UNMAP | > > IOMMU_NOTIFIER_UNMAP, > > section->offset_within_region, > > int128_get64(end), > > iommu_idx);
This looks kind of tricky. E.g when ATS is enabled, there could be unnecessary flues. Or at least it requires some comment to explain. I think the correct fix is: 1) introduce a transport specific method for querying if it supports device IOTLB 2) in the pci implementation hook it to some like pice_ats_enabled() 3) so we can decide if device IOTLB is enabled, go for DEVIOTLB_UNMAP otherwise a simple UNMAP. Thanks > > -- > > 2.35.1 > > > > ping >
