Messages in this thread | | | Date | Thu, 12 May 2022 20:59:28 -0700 | From | Nicolin Chen <> | Subject | Re: [PATCH] iommu/vt-d: Try info->iommu in device_to_iommu() |
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On Fri, May 13, 2022 at 11:32:11AM +0800, Baolu Lu wrote: > External email: Use caution opening links or attachments > > > On 2022/5/13 08:32, Nicolin Chen wrote: > > Local boot test and VFIO sanity test show that info->iommu can be > > used in device_to_iommu() as a fast path. So this patch adds it. > > > > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > > --- > > drivers/iommu/intel/iommu.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > > index 2990f80c5e08..412fca5ab9cd 100644 > > --- a/drivers/iommu/intel/iommu.c > > +++ b/drivers/iommu/intel/iommu.c > > @@ -777,6 +777,7 @@ static bool iommu_is_dummy(struct intel_iommu *iommu, struct device *dev) > > struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn) > > { > > struct dmar_drhd_unit *drhd = NULL; > > + struct device_domain_info *info; > > struct pci_dev *pdev = NULL; > > struct intel_iommu *iommu; > > struct device *tmp; > > @@ -786,6 +787,10 @@ struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn) > > if (!dev) > > return NULL; > > > > + info = dev_iommu_priv_get(dev); > > + if (info) > > + return info->iommu; > > device_to_iommu() also returns device source id (@bus, @devfn). > > Perhaps, we can make device_to_iommu() only for probe_device() where the > per-device info data is not initialized yet. After probe_device(), iommu > and sid are retrieved through other helpers by looking up the device > info directly?
That should work I think. I was just not sure when the priv could be unset. But it seems that you have cleaned up those places other than probe/release_device() in recent version :)
Nic
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