Xen project Mailing List

On Mon, Jun 19, 2023 at 7:22 AM Roger Pau Monné <roger.pau@xxxxxxxxxx> wrote:

On Sun, Jun 18, 2023 at 06:22:01PM -0400, Joel Upham wrote:
> Q35 support using Qemu's device emulation. I based the patches from 2017
> found on the mailing list here:
> https://lists.xenproject.org/archives/html/xen-devel/2018-03/msg01176.html
>
> I have been using a version of these patches on Xen 4.16 with Qemu
> version 4.1 for over 6 months. The guest VMs are very stable, and PCIe
> PT is working as was designed (all of the PCIe devices are on the root
> PCIe device). I have successfully passed through GPUs, NICs, etc. I was
> asked by those in the community to attempt to once again upstream the
> patches. I have them working with Seabios and OVMF (patches are needed
> to OVMF which I will be sending to the mailing list). I will be sending
> my Qemu patches to their mailing list in hopes of getting everything
> upstreamed. The Qemu patches allow for the xenvbd to properly unplug the
> AHCI SATA device, and all xen pv windows drivers work as intended.
>
> I used the original author of the patches to get a majority of this to work:
> Alexey Gerasimenko. I fixed the patches to be in line with the upstream
> Qemu and Xen versions. Any original issues may still exist; however, I
> am sure in time they can be improved. If the code doesn't exist then they
> can't be actively looked at by the community.
>
> I am not an expert on the Q35 chipset or PCIe technology. This is my
> first patch to this mailing list.
>
> Recap of changes to Qemu, only here for reference:
> pc/xen: Xen Q35 support: provide IRQ handling for PCI devices
> pc/q35: Apply PCI bus BSEL property for Xen PCI device hotplug
> acpi/ich9: Multiple fixes for S3 support
> acpi/pcihp: Allow for machines to hotplug when using Xen
> isa/lpc_ich9: Write lpc configuration for xen IRQs
> q35/acpi/xen: Provide ACPI PCI hotplug interface for Xen on Q35
> q35/xen: Add Xen platform device support for Q35
> q35: Fix incorrect values for PCIEXBAR masks
> xen/pt: XenHostPCIDevice: provide functions for PCI Capabilities and
> PCIe Extended Capabilities enumeration
> xen/pt: avoid reading PCIe device type and cap version multiple times
> xen/pt: determine the legacy/PCIe mode for a passed through device
> xen/pt: Xen PCIe passthrough support for Q35: bypass PCIe topology
> check
> xen/pt: add support for PCIe Extended Capabilities and larger config
> space
> xen/pt: handle PCIe Extended Capabilities Next register
> xen/pt: allow to hide PCIe Extended Capabilities
> xen/pt: add Vendor-specific PCIe Extended Capability descriptor and
> sizing
> xen/pt: add fixed-size PCIe Extended Capabilities descriptors
> xen/pt: add AER PCIe Extended Capability descriptor and sizing
> xen/pt: add descriptors and size calculation for
> RCLD/ACS/PMUX/DPA/MCAST/TPH/DPC PCIe Extended Capabilities
> xen/pt: add Resizable BAR PCIe Extended Capability descriptor and
> sizing
> xen/pt: add VC/VC9/MFVC PCIe Extended Capabilities descriptors and
> sizing
>
> Changes that would be going to upstream Qemu:
> hw/acpi/ich9.c | 22 +-
> hw/acpi/pcihp.c | 6 +-
> hw/core/machine.c | 19 +
> hw/i386/pc_piix.c | 3 +-
> hw/i386/pc_q35.c | 39 +-
> hw/i386/xen/xen-hvm.c | 7 +-
> hw/i386/xen/xen_platform.c | 19 +-
> hw/ide/ahci.c | 2 +-
> hw/isa/lpc_ich9.c | 53 +-
> hw/isa/piix3.c | 2 +-
> hw/pci-host/q35.c | 28 +-
> hw/pci/pci.c | 17 +
> hw/xen/xen-host-pci-device.c | 106 +++-
> hw/xen/xen-host-pci-device.h | 6 +-
> hw/xen/xen_pt.c | 49 +-
> hw/xen/xen_pt.h | 19 +-
> hw/xen/xen_pt_config_init.c | 1103 ++++++++++++++++++++++++++++++---
> include/hw/acpi/ich9.h | 1 +
> include/hw/acpi/pcihp.h | 2 +
> include/hw/boards.h | 1 +
> include/hw/i386/pc.h | 3 +
> include/hw/pci-host/q35.h | 4 +-
> include/hw/pci/pci.h | 3 +
> include/hw/southbridge/ich9.h | 1 +
> include/hw/xen/xen.h | 4 +-
> qemu-options.hx | 1 +
> softmmu/datadir.c | 1 -
> softmmu/qdev-monitor.c | 3 +-
> stubs/xen-hw-stub.c | 4 +-
> 29 files changed, 1396 insertions(+), 132 deletions(-)
> *** These patches are not found in this series, if they are supposed to
> be I will send them here as well. ***

It's unclear, do the QEMU patches depend on the Xen side? I have a
suspicion you likely want to post them mostly at the same time, but
using two different patch series (one for Xen and one for QEMU).

> Recap of changes to Xen:
> libacpi: new DSDT ACPI table for Q35
> Makefile: build and use new DSDT table for Q35
> hvmloader: add function to query an emulated machine type (i440/Q35)
> hvmloader: add ACPI enabling for Q35
> hvmloader: add Q35 DSDT table loading
> hvmloader: add basic Q35 support
> hvmloader: allocate MMCONFIG area in the MMIO hole + minor code
> refactoring
> hvmloader: seabios dsdt set to load correct config
> hvmloader: ovmf dsdt set to load correct config
> libxl: Q35 support (new option device_model_machine)
> libxl: Xen Platform device support for Q35
> libacpi: build ACPI MCFG table if requested
> hvmloader: use libacpi to build MCFG table
> docs: provide description for device_model_machine option
>
> Joel Upham (1):
> Q35 support

I'm afraid this needs to be split into a patch series, with proper
commit messages in order to be considered for review. The current
huge patch is impossible to review at all.

Also you need to keep the Signed-off-by of the original author in the
patches.

Thanks, Roger.

Re: [PATCH v1 0/1] Q35 Support