Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH 1/1] iommu/vt-d: Make context clearing consistent with context mapping | Date | Tue, 14 Nov 2023 04:46:23 +0000 |
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> From: Baolu Lu <baolu.lu@linux.intel.com> > Sent: Tuesday, November 14, 2023 11:22 AM > > On 11/14/23 11:20 AM, Tian, Kevin wrote: > >> From: Lu Baolu <baolu.lu@linux.intel.com> > >> Sent: Tuesday, November 14, 2023 9:11 AM > >> > >> In the iommu probe_device path, domain_context_mapping() allows > setting > >> up the context entry for a non-PCI device. However, in the iommu > >> release_device path, domain_context_clear() only clears context entries > >> for PCI devices. > >> > >> Make domain_context_clear() behave consistently with > >> domain_context_mapping() by clearing context entries for both PCI and > >> non-PCI devices. > >> > >> Fixes: 579305f75d34 ("iommu/vt-d: Update to use PCI DMA aliases") > >> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > > > > The code before the fix tag also has the same problem. If we really want > > backport then let's find out the very first commit which exhibits this > > problem. > > Commit 579305f75d34 allows non-PCI devices. > > + if (!dev_is_pci(dev)) > + return domain_context_mapping_one(domain, iommu, bus, devfn, > translation); > + > + data.domain = domain; > + data.iommu = iommu; > + data.translation = translation; > + > + return pci_for_each_dma_alias(to_pci_dev(dev), > + &domain_context_mapping_cb, &data); > > But it forgot to update the domain_context_clear() helper. So this is > actually a fix for that commit.
thanks. I didn't note that side effect from commit msg.
> > > > > But I wonder the actual impact w/o such fix. If there is no hot-remove > > possible for those non-PCI devices the context entry will be leaved > > enabled until the machine is off. Then this fix is nice-to-have then > > probably no need to backport? > > It doesn't cause real issues as far as I can see. So there's no need to > back port it to stable kernels. That's the reason I didn't add cc-stable > tag. But we still need a fix tag as it's actually a fix. >
make sense.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
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