From: Jason Wang <jasowang@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: mst@redhat.com, qemu-devel@nongnu.org, eric.auger@redhat.com,
viktor@daynix.com
Subject: Re: [PATCH 1/3] intel-iommu: fail MAP notifier without caching mode
Date: Wed, 30 Nov 2022 14:23:06 +0800 [thread overview]
Message-ID: <CACGkMEsYCUO+C6ocXryxX9J9E5PrQhS-c3v=ydY601U7Lzp_Jg@mail.gmail.com> (raw)
In-Reply-To: <Y4YmvYzVGwciJUbk@x1n>
On Tue, Nov 29, 2022 at 11:35 PM Peter Xu <peterx@redhat.com> wrote:
>
> On Tue, Nov 29, 2022 at 04:10:35PM +0800, Jason Wang wrote:
> > Without caching mode, MAP notifier won't work correctly since guest
> > won't send IOTLB update event when it establishes new mappings in the
> > I/O page tables. Let's fail the IOMMU notifiers early instead of
> > misbehaving silently.
> >
> > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > ---
> > hw/i386/intel_iommu.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> > index a08ee85edf..9143376677 100644
> > --- a/hw/i386/intel_iommu.c
> > +++ b/hw/i386/intel_iommu.c
> > @@ -3186,6 +3186,13 @@ static int vtd_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu,
> > "Snoop Control with vhost or VFIO is not supported");
> > return -ENOTSUP;
> > }
> > + if (!s->caching_mode && (new & IOMMU_NOTIFIER_MAP)) {
> > + error_setg_errno(errp, ENOTSUP,
> > + "device %02x.%02x.%x requires caching mode",
> > + pci_bus_num(vtd_as->bus), PCI_SLOT(vtd_as->devfn),
> > + PCI_FUNC(vtd_as->devfn));
> > + return -ENOTSUP;
> > + }
>
> We used to have that but got reverted because it's too late to fail, so we
> moved it over even though not as clean..
>
> https://lore.kernel.org/all/20190916080718.3299-5-peterx@redhat.com/
One of the difference is that the patch doesn't do exit() here. I
think it's better to fail instead of misbehving silently, this is what
other vIOMMU did:
E.g in smmu we had:
if (new & IOMMU_NOTIFIER_MAP) {
error_setg(errp,
"device %02x.%02x.%x requires iommu MAP notifier which is "
"not currently supported", pci_bus_num(sdev->bus),
PCI_SLOT(sdev->devfn), PCI_FUNC(sdev->devfn));
return -EINVAL;
}
So did for amd iommu.
Thanks
>
> Thanks,
>
> --
> Peter Xu
>
next prev parent reply other threads:[~2022-11-30 6:24 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-29 8:10 [PATCH 0/3] Fix UNMAP notifier for intel-iommu Jason Wang
2022-11-29 8:10 ` [PATCH 1/3] intel-iommu: fail MAP notifier without caching mode Jason Wang
2022-11-29 15:35 ` Peter Xu
2022-11-30 6:23 ` Jason Wang [this message]
2022-11-30 15:06 ` Peter Xu
2022-12-01 8:46 ` Jason Wang
2022-12-06 13:23 ` Eric Auger
2022-11-29 8:10 ` [PATCH 2/3] intel-iommu: fail DEVIOTLB_UNMAP without dt mode Jason Wang
2022-11-29 15:38 ` Peter Xu
2022-12-01 16:03 ` Peter Xu
2023-02-23 3:19 ` Jason Wang
2022-12-06 13:33 ` Eric Auger
2023-02-03 9:08 ` Laurent Vivier
2023-02-07 16:17 ` Laurent Vivier
2023-02-07 16:35 ` Peter Xu
2022-11-29 8:10 ` [PATCH 3/3] intel-iommu: build iova tree during IOMMU translation Jason Wang
2022-11-29 15:57 ` Peter Xu
2022-11-30 6:33 ` Jason Wang
2022-11-30 15:17 ` Peter Xu
2022-12-01 8:35 ` Jason Wang
2022-12-01 14:58 ` Peter Xu
2022-12-05 4:12 ` Jason Wang
2022-12-05 23:18 ` Peter Xu
2022-12-06 3:18 ` Jason Wang
2022-12-06 13:58 ` Peter Xu
2022-12-23 8:02 ` Jason Wang
2022-12-23 16:22 ` Peter Xu
2022-11-30 16:37 ` [PATCH 0/3] Fix UNMAP notifier for intel-iommu Michael S. Tsirkin
2022-12-01 8:29 ` Jason Wang
2022-12-20 13:53 ` Michael S. Tsirkin
2022-12-21 3:17 ` Jason Wang
2023-01-15 23:30 ` Viktor Prutyanov
2023-01-16 7:06 ` Jason Wang
2023-01-27 13:17 ` Michael S. Tsirkin
2023-01-29 5:43 ` Jason Wang
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