similar to: [PATCH v3 0/6] Add virtio-iommu built-in topology

Add topology description to the virtio-iommu driver and enable x86 platforms. Since the RFC [1] I've mostly given up on ACPI tables, since the internal discussions seem to have reached a dead end. The built-in topology description presented here isn't ideal, but it is simple to implement and doesn't impose a dependency on ACPI or device-tree, which can be beneficial to lightweight

To support topology description from ACPI and from the builtin description, add helpers to keep track of I/O topology descriptors. To ease re-use of the helpers by other drivers and future ACPI extensions, use the "virt_" prefix rather than "virtio_" when naming structs and functions. Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org> ---

Hi Jean, On 8/21/20 3:15 PM, Jean-Philippe Brucker wrote: > To support topology description from ACPI and from the builtin > description, add helpers to keep track of I/O topology descriptors. > > To ease re-use of the helpers by other drivers and future ACPI > extensions, use the "virt_" prefix rather than "virtio_" when naming > structs and functions. >

On Fri, Aug 21, 2020 at 03:15:39PM +0200, Jean-Philippe Brucker wrote: > Platforms without device-tree nor ACPI can provide a topology > description embedded into the virtio config space. Parse it. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes place, and the > virtio driver may be loaded much

On Fri, Aug 21, 2020 at 03:15:39PM +0200, Jean-Philippe Brucker wrote: > Platforms without device-tree nor ACPI can provide a topology > description embedded into the virtio config space. Parse it. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes place, and the > virtio driver may be loaded much

> From: Jean-Philippe Brucker > Sent: Saturday, February 29, 2020 1:26 AM > > Platforms without device-tree do not currently have a method for > describing the vIOMMU topology. Provide a topology description embedded > into the virtio device. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes

I'm seeking feedback on multi-platform support for virtio-iommu. At the moment only devicetree (DT) is supported and we don't have a pleasant solution for other platforms. Once we figure out the topology description, x86 support is trivial. Since the IOMMU manages memory accesses from other devices, the guest kernel needs to initialize the IOMMU before endpoints start issuing DMA.

I'm seeking feedback on multi-platform support for virtio-iommu. At the moment only devicetree (DT) is supported and we don't have a pleasant solution for other platforms. Once we figure out the topology description, x86 support is trivial. Since the IOMMU manages memory accesses from other devices, the guest kernel needs to initialize the IOMMU before endpoints start issuing DMA.

Platforms without device-tree nor ACPI can provide a topology description embedded into the virtio config space. Parse it. Use PCI FIXUP to probe the config space early, because we need to discover the topology before any DMA configuration takes place, and the virtio driver may be loaded much later. Since we discover the topology description when probing the PCI hierarchy, the virtual IOMMU

Hi Jean, On 8/21/20 3:15 PM, Jean-Philippe Brucker wrote: > Platforms without device-tree nor ACPI can provide a topology > description embedded into the virtio config space. Parse it. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes place, and the > virtio driver may be loaded much later. Since we

> From: Jean-Philippe Brucker > Sent: Saturday, February 29, 2020 1:26 AM > > Platforms without device-tree do not currently have a method for > describing the vIOMMU topology. Provide a topology description embedded > into the virtio device. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes

> From: Jean-Philippe Brucker > Sent: Saturday, February 29, 2020 1:26 AM > > Platforms without device-tree do not currently have a method for > describing the vIOMMU topology. Provide a topology description embedded > into the virtio device. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes

On Fri, Feb 28, 2020 at 06:25:36PM +0100, Jean-Philippe Brucker wrote: > Platforms without device-tree do not currently have a method for > describing the vIOMMU topology. Provide a topology description embedded > into the virtio device. > > Use PCI FIXUP to probe the config space early, because we need to > discover the topology before any DMA configuration takes place, and the

Following specification review a few things were changed in v8 of the virtio-iommu series [1], but have been omitted when merging the base driver. Add them now: * Remove the EXEC flag. * Add feature bit for the MMIO flag. * Change domain_bits to domain_range. * Add NOMEM status flag. [1] https://lore.kernel.org/linux-iommu/20190530170929.19366-1-jean-philippe.brucker at arm.com/ Fixes:

Following specification review a few things were changed in v8 of the virtio-iommu series [1], but have been omitted when merging the base driver. Add them now: * Remove the EXEC flag. * Add feature bit for the MMIO flag. * Change domain_bits to domain_range. * Add NOMEM status flag. [1] https://lore.kernel.org/linux-iommu/20190530170929.19366-1-jean-philippe.brucker at arm.com/ Fixes:

Implement the virtio-iommu driver, following specification v0.8 [1]. Changes since v3 [2]: * Rebase onto v4.20-rc2. Patch 3 now touches drivers/of/base.c instead of drivers/pci/of.c, since the map_rid() function has moved. * Removed the request timeout, that depended on DEBUG. * Other small fixes addressing comments on v3. You can find Linux driver and kvmtool device on my virtio-iommu/v0.8.1

Implement the virtio-iommu driver following version 0.6 of the specification [1]. Previous version, RFCv2, was sent in November [2]. This version addresses Eric's comments and changes the device number. (Since last week I also tested and fixed the probe/release functions, they now use devm properly.) I did not include ACPI support because the next IORT specifications isn't ready yet (even

Implement the virtio-iommu driver following version 0.6 of the specification [1]. Previous version, RFCv2, was sent in November [2]. This version addresses Eric's comments and changes the device number. (Since last week I also tested and fixed the probe/release functions, they now use devm properly.) I did not include ACPI support because the next IORT specifications isn't ready yet (even

Implement the virtio-iommu driver following version 0.5 of the specification [1]. Previous version of this code was sent back in April [2], implementing the first public RFC. Since then there has been lots of progress and discussion on the specification side, and I think the driver is in a good shape now. The reason patches 1-3 are only RFC is that I'm waiting on feedback from the Virtio TC

Implement the virtio-iommu driver following version 0.5 of the specification [1]. Previous version of this code was sent back in April [2], implementing the first public RFC. Since then there has been lots of progress and discussion on the specification side, and I think the driver is in a good shape now. The reason patches 1-3 are only RFC is that I'm waiting on feedback from the Virtio TC