| Message ID | 1579613871-301529-1-git-send-email-jonathan.derrick@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Clean up VMD DMA Map Ops | expand |
On Tue, Jan 21, 2020 at 06:37:44AM -0700, Jon Derrick wrote: > v4 Set: https://lore.kernel.org/linux-pci/20200120110220.GB17267@e121166-lin.cambridge.arm.com/T/#t > v3 Set: https://lore.kernel.org/linux-iommu/20200113181742.GA27623@e121166-lin.cambridge.arm.com/T/#t > v2 Set: https://lore.kernel.org/linux-iommu/1578580256-3483-1-git-send-email-jonathan.derrick@intel.com/T/#t > v1 Set: https://lore.kernel.org/linux-iommu/20200107134125.GD30750@8bytes.org/T/#t > > VMD currently works with VT-d enabled by pointing DMA and IOMMU actions at the > VMD endpoint. The problem with this approach is that the VMD endpoint's > device-specific attributes, such as the DMA Mask Bits, are used instead of the > child device's attributes. > > This set cleans up VMD by removing the override that redirects DMA map > operations to the VMD endpoint. Instead it introduces a new DMA alias mechanism > into the existing DMA alias infrastructure. This new DMA alias mechanism allows > an architecture-specific pci_real_dma_dev() function to provide a pointer from > a pci_dev to its PCI DMA device, where by default it returns the original > pci_dev. > > In addition, this set removes the sanity check that was added to prevent > assigning VMD child devices. By using the DMA alias mechanism, all child > devices are assigned the same IOMMU group as the VMD endpoint. This removes the > need for restricting VMD child devices from assignment, as the whole group > would have to be assigned, requiring unbinding the VMD driver and removing the > child device domain. > > v1 added a pointer in struct pci_dev that pointed to the DMA alias' struct > pci_dev and did the necessary DMA alias and IOMMU modifications. > > v2 introduced a new weak function to reference the 'Direct DMA Alias', and > removed the need to add a pointer in struct device or pci_dev. Weak functions > are generally frowned upon when it's a single architecture implementation, so I > am open to alternatives. > > v3 referenced the pci_dev rather than the struct device for the PCI > 'Direct DMA Alias' (pci_direct_dma_alias()). This revision also allowed > pci_for_each_dma_alias() to call any DMA aliases for the Direct DMA alias > device, though I don't expect the VMD endpoint to need intra-bus DMA aliases. > > v4 changes the 'Direct DMA Alias' to instead refer to the 'Real DMA Dev', which > either returns the PCI device itself or the PCI DMA device. > > v5 Fixes a bad call argument to pci_real_dma_dev that would have broken > bisection. This revision also changes one of the calls to a one-liner, and > assembles the same on my system. > > > Changes from v4: > Fix pci_real_dma_dev() call in 4/7. > Change other pci_real_dma_dev() call in 4/7 to one-liner. > > Changes from v3: > Uses pci_real_dma_dev() instead of pci_direct_dma_alias() > Split IOMMU enabling, IOMMU VMD sanity check and VMD dma_map_ops cleanup into three patches > > Changes from v2: > Uses struct pci_dev for PCI Device 'Direct DMA aliasing' (pci_direct_dma_alias) > Allows pci_for_each_dma_alias to iterate over the alias mask of the 'Direct DMA alias' > > Changes from v1: > Removed 1/5 & 2/5 misc fix patches that were merged > Uses Christoph's staging/cleanup patches > Introduce weak function rather than including pointer in struct device or pci_dev. > > Based on Bjorn's next: > https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git/log/?h=next > > Christoph Hellwig (2): > x86/PCI: Add a to_pci_sysdata helper > x86/PCI: Remove X86_DEV_DMA_OPS > > Jon Derrick (5): > x86/PCI: Expose VMD's PCI Device in pci_sysdata > PCI: Introduce pci_real_dma_dev() > iommu/vt-d: Use pci_real_dma_dev() for mapping > iommu/vt-d: Remove VMD child device sanity check > PCI: vmd: Stop overriding dma_map_ops > > arch/x86/Kconfig | 3 - > arch/x86/include/asm/device.h | 10 --- > arch/x86/include/asm/pci.h | 31 ++++----- > arch/x86/pci/common.c | 48 +++---------- > drivers/iommu/intel-iommu.c | 11 ++- > drivers/pci/controller/Kconfig | 1 - > drivers/pci/controller/vmd.c | 152 +---------------------------------------- > drivers/pci/pci.c | 19 +++++- > drivers/pci/search.c | 6 ++ > include/linux/pci.h | 1 + > 10 files changed, 54 insertions(+), 228 deletions(-) Applied with acks/reviewed-by from Lu, Keith, and Lorenzo to pci/host-vmd for v5.6, thanks!