Re: [PATCH 0/3] Fix UNMAP notifier for intel-iommu

[Jason Wang <jasowang@redhat.com>]

On Mon, Jan 16, 2023 at 7:30 AM Viktor Prutyanov <viktor@daynix.com> wrote:
>
> On Tue, Nov 29, 2022 at 11:10 AM Jason Wang <jasowang@redhat.com> wrote:
> >
> > Hi All:
> >
> > According to ATS, device should work if ATS is disabled. This is not
> > correctly implemented in the current intel-iommu since it doesn't
> > handle the UNMAP notifier correctly. This breaks the vhost-net +
> > vIOMMU without dt.
> >
> > The root casue is that the when there's a device IOTLB miss (note that
> > it's not specific to PCI so it can work without ATS), Qemu doesn't
> > build the IOVA tree, so when guest start an IOTLB invalidation, Qemu
> > won't trigger the UNMAP notifier.
> >
> > Fixing by build IOVA tree during IOMMU translsation.
> >
> > Thanks
> >
> > Jason Wang (3):
> >   intel-iommu: fail MAP notifier without caching mode
> >   intel-iommu: fail DEVIOTLB_UNMAP without dt mode
> >   intel-iommu: build iova tree during IOMMU translation
> >
> >  hw/i386/intel_iommu.c | 58 ++++++++++++++++++++++++-------------------
> >  1 file changed, 33 insertions(+), 25 deletions(-)
> >
> > --
> > 2.25.1
> >
>
> Hi Jason,
>
> I've tried the series with Windows Server 2022 guest with vhost and
> intel-iommu (device-iotlb=off) and now networking on this system has
> become working.
> So, as we discussed, I'm waiting for the series to be accepted in some
> form to continue my work about supporting guests who refuse Device-TLB
> on systems with device-iotlb=on.
>
> Tested-by: Viktor Prutyanov <viktor@daynix.com>

Great, Peter has some comments on this series, so I will probably send
a new version (probably after the chinese new year).

Thanks

>
> Best regards,
> Viktor Prutyanov
>