Re: [PATCH v3 1/7] iommu/amd: Warn when found inconsistency EFR mask
On 6/23/2022 3:22 PM, Joerg Roedel wrote: On Wed, Jun 22, 2022 at 12:11:25PM -0500, Suravee Suthikulpanit wrote: #ifdef CONFIG_IRQ_REMAP +/* + * Iterate through all the IOMMUs to verify if the specified + * EFR bitmask of IOMMU feature are set. + * Warn and return false if found inconsistency. + */ static bool check_feature_on_all_iommus(u64 mask) { bool ret = false; struct amd_iommu *iommu; for_each_iommu(iommu) { - ret = iommu_feature(iommu, mask); - if (!ret) + bool tmp = iommu_feature(iommu, mask); + + if ((ret != tmp) && + !list_is_first(>list, _iommu_list)) { + pr_err(FW_BUG "Found inconsistent EFR mask (%#llx) on iommu%d (%04x:%02x:%02x.%01x).\n", + mask, iommu->index, iommu->pci_seg->id, PCI_BUS_NUM(iommu->devid), + PCI_SLOT(iommu->devid), PCI_FUNC(iommu->devid)); return false; + } + ret = tmp; It is better to implement this by introducing a global feature mask, which represents the minial set of features supported by any IOMMU in the system. The warning is then something like: if ((global_feature_mask & iommu_features) != global_feature_mask) pr_warn(...); This also makes the global variable to track SNP support obsolete. Regards, Joerg That's actually better. I'll send out v4 w/ global EFR variable. Thanks, Suravee ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3 1/7] iommu/amd: Warn when found inconsistency EFR mask
On Wed, Jun 22, 2022 at 12:11:25PM -0500, Suravee Suthikulpanit wrote: > #ifdef CONFIG_IRQ_REMAP > +/* > + * Iterate through all the IOMMUs to verify if the specified > + * EFR bitmask of IOMMU feature are set. > + * Warn and return false if found inconsistency. > + */ > static bool check_feature_on_all_iommus(u64 mask) > { > bool ret = false; > struct amd_iommu *iommu; > > for_each_iommu(iommu) { > - ret = iommu_feature(iommu, mask); > - if (!ret) > + bool tmp = iommu_feature(iommu, mask); > + > + if ((ret != tmp) && > + !list_is_first(>list, _iommu_list)) { > + pr_err(FW_BUG "Found inconsistent EFR mask (%#llx) on > iommu%d (%04x:%02x:%02x.%01x).\n", > +mask, iommu->index, iommu->pci_seg->id, > PCI_BUS_NUM(iommu->devid), > +PCI_SLOT(iommu->devid), PCI_FUNC(iommu->devid)); > return false; > + } > + ret = tmp; It is better to implement this by introducing a global feature mask, which represents the minial set of features supported by any IOMMU in the system. The warning is then something like: if ((global_feature_mask & iommu_features) != global_feature_mask) pr_warn(...); This also makes the global variable to track SNP support obsolete. Regards, Joerg ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
[PATCH v3 1/7] iommu/amd: Warn when found inconsistency EFR mask
The function check_feature_on_all_iommus() checks to ensure if an IOMMU feature support bit is set on the Extended Feature Register (EFR). Current logic iterates through all IOMMU, and returns false when it found the first unset bit. To provide more thorough checking, modify the logic to iterate through all IOMMUs even when found that the bit is not set, and also throws a FW_BUG warning if inconsistency is found. Signed-off-by: Suravee Suthikulpanit --- drivers/iommu/amd/init.c | 19 +++ 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 3dd0f26039c7..b3e4551ce9dd 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -261,18 +261,29 @@ int amd_iommu_get_num_iommus(void) } #ifdef CONFIG_IRQ_REMAP +/* + * Iterate through all the IOMMUs to verify if the specified + * EFR bitmask of IOMMU feature are set. + * Warn and return false if found inconsistency. + */ static bool check_feature_on_all_iommus(u64 mask) { bool ret = false; struct amd_iommu *iommu; for_each_iommu(iommu) { - ret = iommu_feature(iommu, mask); - if (!ret) + bool tmp = iommu_feature(iommu, mask); + + if ((ret != tmp) && + !list_is_first(>list, _iommu_list)) { + pr_err(FW_BUG "Found inconsistent EFR mask (%#llx) on iommu%d (%04x:%02x:%02x.%01x).\n", + mask, iommu->index, iommu->pci_seg->id, PCI_BUS_NUM(iommu->devid), + PCI_SLOT(iommu->devid), PCI_FUNC(iommu->devid)); return false; + } + ret = tmp; } - - return true; + return ret; } #endif -- 2.32.0 ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu