On 3/30/2022 10:49 AM, Bjorn Helgaas wrote: > On Tue, Mar 29, 2022 at 03:48:21PM -0700, Patel, Nirmal wrote: >> On 3/16/2022 8:51 AM, Nirmal Patel wrote: >>> This patch removes a placeholder patch 2565e5b69c44 ("PCI: vmd: Do >>> not disable MSI-X remapping if interrupt remapping is enabled by IOMMU.") >>> This patch was added as a workaround to disable MSI remapping if iommu >>> enables interrupt remapping. VMD does not assign proper IRQ domain to >>> child devices when MSIX is disabled. There is no dependency between MSI >>> remapping by VMD and interrupt remapping by iommu. MSI remapping can be >>> enabled or disabled with and without interrupt remap. >>> >>> Signed-off-by: Nirmal Patel <nirmal.patel@xxxxxxxxx> >>> --- >>> drivers/pci/controller/vmd.c | 4 +--- >>> 1 file changed, 1 insertion(+), 3 deletions(-) >>> >>> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c >>> index 3a6570e5b765..91bc1b40d40c 100644 >>> --- a/drivers/pci/controller/vmd.c >>> +++ b/drivers/pci/controller/vmd.c >>> @@ -6,7 +6,6 @@ >>> >>> #include <linux/device.h> >>> #include <linux/interrupt.h> >>> -#include <linux/iommu.h> >>> #include <linux/irq.h> >>> #include <linux/kernel.h> >>> #include <linux/module.h> >>> @@ -813,8 +812,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) >>> * acceptable because the guest is usually CPU-limited and MSI >>> * remapping doesn't become a performance bottleneck. >>> */ >>> - if (iommu_capable(vmd->dev->dev.bus, IOMMU_CAP_INTR_REMAP) || >>> - !(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) || >>> + if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) || >>> offset[0] || offset[1]) { >>> ret = vmd_alloc_irqs(vmd); >>> if (ret) > If/when you repost this, please update the subject and commit log to > use "MSI-X" consistently instead of the current mix of "MSI-X" and > "MSIX". > > Also s/iommu/IOMMU/. > > In subject line, add "PCI: vmd: " prefix and drop trailing period. > > Also rewrite commit log in imperative mood, e.g., "Revert 2565e5b69c44 > ..." instead of "This patch removes ..." It's 100% clear that the > commit log refers to *this* patch, so it's pointless to include that. > > It's further confusing that "This patch was added ..." refers to > *2565e5b69c44*, not this revert. > > This reverts 2565e5b69c44 (but doesn't remove the #include > <linux/iommu.h>" added by 2565e5b69c44). > > 2565e5b69c44 fixed a problem. If that fix is no longer necessary > because of some other change, the commit log should mention that > change. Otherwise somebody will backport this fix too far and > reintroduce the problem solved by 2565e5b69c44. > > Bjorn I will apply these changes. Thank you Nirmal