From: Jacob Pan <jacob.jun.pan@linux.intel.com> To: Christoph Hellwig <hch@infradead.org> Cc: Lu Baolu <baolu.lu@linux.intel.com>, iommu@lists.linux-foundation.org, LKML <linux-kernel@vger.kernel.org>, Joerg Roedel <joro@8bytes.org>, David Woodhouse <dwmw2@infradead.org>, Jean-Philippe Brucker <jean-philippe@linaro.com>, Eric Auger <eric.auger@redhat.com>, Yi Liu <yi.l.liu@intel.com>, "Tian, Kevin" <kevin.tian@intel.com>, Raj Ashok <ashok.raj@intel.com>, Alex Williamson <alex.williamson@redhat.com>, Jonathan Cameron <jic23@kernel.org>, jacob.jun.pan@linux.intel.com Subject: Re: [PATCH v13 4/8] iommu/vt-d: Add bind guest PASID support Date: Thu, 14 May 2020 08:57:45 -0700 [thread overview] Message-ID: <20200514085745.105af4fb@jacob-builder> (raw) In-Reply-To: <20200514055930.GD22388@infradead.org> Hi Christoph, Thanks a lot for the reviews, comments below. Jacob On Wed, 13 May 2020 22:59:30 -0700 Christoph Hellwig <hch@infradead.org> wrote: > > + if (dev_is_pci(dev)) { > > + /* VT-d supports devices with full 20 bit PASIDs > > only */ > > + if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX) > > + return -EINVAL; > > + } else { > > + return -ENOTSUPP; > > + } > > This looks strange. Why not: > > if (!dev_is_pci(dev)) { > return -ENOTSUPP; > > /* VT-d supports devices with full 20 bit PASIDs only */ > if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX) > return -EINVAL; > That is better, will do. > > + for_each_svm_dev(sdev, svm, dev) { > > + /* > > + * For devices with aux domains, we should > > allow multiple > > + * bind calls with the same PASID and pdev. > > + */ > > + if (iommu_dev_feature_enabled(dev, > > IOMMU_DEV_FEAT_AUX)) { > > + sdev->users++; > > + } else { > > + dev_warn_ratelimited(dev, "Already > > bound with PASID %u\n", > > + svm->pasid); > > + ret = -EBUSY; > > + } > > + goto out; > > Is this intentionally a for loop that jumps out of the loop after > the first device? > The name is confusing, it is not a loop. I will change it to find_svm_dev() and comments like this? /* * Find the matching device in a given SVM. The bind code ensures that * each device can only be added to the SVM list once. */ #define find_svm_dev(sdev, svm, d) \ list_for_each_entry((sdev), &(svm)->devs, list) \ if ((d) != (sdev)->dev) {} else > > + /* > > + * PASID table is per device for better security. > > Therefore, for > > + * each bind of a new device even with an existing PASID, > > we need to > > + * call the nested mode setup function here. > > + */ > > + spin_lock(&iommu->lock); > > + ret = intel_pasid_setup_nested(iommu, > > + dev, > > + (pgd_t *)data->gpgd, > > + data->hpasid, > > + &data->vtd, > > + dmar_domain, > > + data->addr_width); > > Why not: > > et = intel_pasid_setup_nested(iommu, dev, (pgd_t *)data->gpgd, > data->hpasid, &data->vtd, dmar_domain, > data->addr_width); > > ? > I thought we want to align the parentheses? Either way is fine. Baolu? > > + for_each_svm_dev(sdev, svm, dev) { > > + ret = 0; > > ... > > > + break; > > + } > > Same only looks at the first device style. Why dos it only care about > the first device? That needs at least a comment, and probably a > first_svm_dev or so heper to make it explicit. Yes, same as above. change to find_svm_dev() since there should be at most one matching device in the svm list.
WARNING: multiple messages have this Message-ID (diff)
From: Jacob Pan <jacob.jun.pan@linux.intel.com> To: Christoph Hellwig <hch@infradead.org> Cc: "Tian, Kevin" <kevin.tian@intel.com>, Alex Williamson <alex.williamson@redhat.com>, Raj Ashok <ashok.raj@intel.com>, David Woodhouse <dwmw2@infradead.org>, LKML <linux-kernel@vger.kernel.org>, iommu@lists.linux-foundation.org, Jean-Philippe Brucker <jean-philippe@linaro.com>, Jonathan Cameron <jic23@kernel.org> Subject: Re: [PATCH v13 4/8] iommu/vt-d: Add bind guest PASID support Date: Thu, 14 May 2020 08:57:45 -0700 [thread overview] Message-ID: <20200514085745.105af4fb@jacob-builder> (raw) In-Reply-To: <20200514055930.GD22388@infradead.org> Hi Christoph, Thanks a lot for the reviews, comments below. Jacob On Wed, 13 May 2020 22:59:30 -0700 Christoph Hellwig <hch@infradead.org> wrote: > > + if (dev_is_pci(dev)) { > > + /* VT-d supports devices with full 20 bit PASIDs > > only */ > > + if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX) > > + return -EINVAL; > > + } else { > > + return -ENOTSUPP; > > + } > > This looks strange. Why not: > > if (!dev_is_pci(dev)) { > return -ENOTSUPP; > > /* VT-d supports devices with full 20 bit PASIDs only */ > if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX) > return -EINVAL; > That is better, will do. > > + for_each_svm_dev(sdev, svm, dev) { > > + /* > > + * For devices with aux domains, we should > > allow multiple > > + * bind calls with the same PASID and pdev. > > + */ > > + if (iommu_dev_feature_enabled(dev, > > IOMMU_DEV_FEAT_AUX)) { > > + sdev->users++; > > + } else { > > + dev_warn_ratelimited(dev, "Already > > bound with PASID %u\n", > > + svm->pasid); > > + ret = -EBUSY; > > + } > > + goto out; > > Is this intentionally a for loop that jumps out of the loop after > the first device? > The name is confusing, it is not a loop. I will change it to find_svm_dev() and comments like this? /* * Find the matching device in a given SVM. The bind code ensures that * each device can only be added to the SVM list once. */ #define find_svm_dev(sdev, svm, d) \ list_for_each_entry((sdev), &(svm)->devs, list) \ if ((d) != (sdev)->dev) {} else > > + /* > > + * PASID table is per device for better security. > > Therefore, for > > + * each bind of a new device even with an existing PASID, > > we need to > > + * call the nested mode setup function here. > > + */ > > + spin_lock(&iommu->lock); > > + ret = intel_pasid_setup_nested(iommu, > > + dev, > > + (pgd_t *)data->gpgd, > > + data->hpasid, > > + &data->vtd, > > + dmar_domain, > > + data->addr_width); > > Why not: > > et = intel_pasid_setup_nested(iommu, dev, (pgd_t *)data->gpgd, > data->hpasid, &data->vtd, dmar_domain, > data->addr_width); > > ? > I thought we want to align the parentheses? Either way is fine. Baolu? > > + for_each_svm_dev(sdev, svm, dev) { > > + ret = 0; > > ... > > > + break; > > + } > > Same only looks at the first device style. Why dos it only care about > the first device? That needs at least a comment, and probably a > first_svm_dev or so heper to make it explicit. Yes, same as above. change to find_svm_dev() since there should be at most one matching device in the svm list. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-05-14 15:51 UTC|newest] Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-13 23:01 [PATCH v13 0/8] Nested Shared Virtual Address (SVA) VT-d support Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 1/8] iommu/vt-d: Move domain helper to header Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 2/8] iommu/vt-d: Use a helper function to skip agaw for SL Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-14 5:51 ` Christoph Hellwig 2020-05-14 5:51 ` Christoph Hellwig 2020-05-14 15:20 ` Jacob Pan 2020-05-14 15:20 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 3/8] iommu/vt-d: Add nested translation helper function Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-14 5:54 ` Christoph Hellwig 2020-05-14 5:54 ` Christoph Hellwig 2020-05-14 15:31 ` Jacob Pan 2020-05-14 15:31 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 4/8] iommu/vt-d: Add bind guest PASID support Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-14 5:59 ` Christoph Hellwig 2020-05-14 5:59 ` Christoph Hellwig 2020-05-14 15:57 ` Jacob Pan [this message] 2020-05-14 15:57 ` Jacob Pan 2020-05-15 1:01 ` Lu Baolu 2020-05-15 1:01 ` Lu Baolu 2020-05-16 6:02 ` Lu Baolu 2020-05-16 6:02 ` Lu Baolu 2020-05-13 23:01 ` [PATCH v13 5/8] iommu/vt-d: Support flushing more translation cache types Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 6/8] iommu/vt-d: Add svm/sva invalidate function Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 7/8] iommu/vt-d: Enlightened PASID allocation Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-13 23:01 ` [PATCH v13 8/8] iommu/vt-d: Add custom allocator for IOASID Jacob Pan 2020-05-13 23:01 ` Jacob Pan 2020-05-16 6:31 ` [PATCH v13 0/8] Nested Shared Virtual Address (SVA) VT-d support Lu Baolu 2020-05-16 6:31 ` Lu Baolu 2020-05-16 4:59 [PATCH v13 4/8] iommu/vt-d: Add bind guest PASID support kbuild test robot
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