[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [RFC PATCH] vhost: enable IOMMU_NOTIFIER_UNMAP events handling when
From: |
Viktor Prutyanov |
Subject: |
Re: [RFC PATCH] vhost: enable IOMMU_NOTIFIER_UNMAP events handling when device-iotlb=on |
Date: |
Thu, 13 Apr 2023 09:23:57 +0300 |
On Thu, Mar 30, 2023 at 7:49 PM Viktor Prutyanov <viktor@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 <viktor@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);
> --
> 2.35.1
>
ping
- Re: [RFC PATCH] vhost: enable IOMMU_NOTIFIER_UNMAP events handling when device-iotlb=on,
Viktor Prutyanov <=