Re: [PATCH qemu v5 0/7] hw/cxl: Support Back-Invalidate (+ PCIe Flit mode)

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Wed, 4 Feb 2026 11:12:02 +0000
Jonathan Cameron via qemu development <qemu-devel@nongnu.org> wrote:

> On Tue, 3 Feb 2026 15:39:22 -0500
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > On Fri, Jan 09, 2026 at 02:45:04PM +0000, Jonathan Cameron wrote:  
> > > Lightly reworked version of Davidlohr's v4.
> > > https://lore.kernel.org/qemu-devel/20251103195209.1319917-1-dave@stgolabs.net/
> > > 
> > > Whilst I have several other series posted for merge this applies fine
> > > to upstream, so no dependencies.
> > > Davidlohr, please check I didn't mess anthing up and perhaps give tags
> > > for the 3 new patches.    
> > 
> > applying this on top does seem to conflict.
> > let me get rest merged then this can be rebased.  
> Hi Michael
> 
> So I assume this is your v01-04-02-2026 branch.
> 
> I tried rebasing on that and ran into some issue.
> 
> Looks like you have a stale version of 
> [PATCH qemu v4 0/5] cxl: r3.2 specification event updates.
> https://lore.kernel.org/all/20260119111542.788389-1-Jonathan.Cameron@huawei.com/
> 
> Markus had some comments that needed a new version.
> Mostly updating a few more version numbers in the comments to keep things consistent.
> 
> Not sure that has anything to do with the merge conflict.

Looks like it was a context change that trips git up.
I'll post a rebased version 6 on top of the 3 series that I think should merge
before this one. (It might be fine to pass with the media operations fixes one as
that is pretty tightly isolated).

Thanks

Jonathan

> 
> >   
> > > v5 changes:
> > > - Rebase much earlier in the CXL queue as Davidlohr had it beind some stuff
> > >   I was carrying that is not ready for upstream just yet.
> > > - Update the CFMWS flags directly as the patch doing restriction control needs
> > >   some more thought.
> > > - Bios tables test data updates.
> > > - Don't provide flit mode control for gen_pcie_root_port as we don't need it
> > >   for the rest of the series which is all about CXL.
> > > 
> > > The following allows support for component basic back invalidation discovery
> > > and config, by exposing the BI routing table and decoder registers. Instead
> > > of going the type2[0] route, this series proposes adding support for type3
> > > hdm-db, which allows a more direct way of supporting BI in qemu.
> > > 
> > > As BI is a dependent on the larger flits introduced in PCIe (and CXL 3.0)
> > > add support for enabling that for CXL components. Negotiation is handled
> > > via an equivalent of what we do for link speed.
> > > 
> > > Davidlohr Bueso (3):
> > >   hw/pcie: Support enabling flit mode
> > >   hw/cxl: Support type3 HDM-DB
> > >   hw/cxl: Remove register special_ops->read()
> > > 
> > > Ira Weiny (1):
> > >   hw/cxl: Refactor component register initialization
> > > 
> > > Jonathan Cameron (3):
> > >   tests/bios-tables-test: Excluded CEDT.cxl for BI restriction
> > >     relaxation.
> > >   hw/cxl: Update CXL Fixed Memory Window ACPI description to include
> > >     Back Invalidate support.
> > >   tests/acpi/cxl: Update CEDT.cxl to allow BI in CFWMS
> > > 
> > >  docs/system/devices/cxl.rst               |  23 +++
> > >  include/hw/cxl/cxl_component.h            |  87 +++++++--
> > >  include/hw/cxl/cxl_device.h               |   4 +
> > >  include/hw/pci-bridge/cxl_upstream_port.h |   1 +
> > >  include/hw/pci/pcie.h                     |   2 +-
> > >  include/hw/pci/pcie_port.h                |   1 +
> > >  hw/acpi/cxl.c                             |   2 +-
> > >  hw/cxl/cxl-component-utils.c              | 211 ++++++++++++++++------
> > >  hw/mem/cxl_type3.c                        |  15 +-
> > >  hw/pci-bridge/cxl_downstream.c            |  10 +-
> > >  hw/pci-bridge/cxl_root_port.c             |  11 +-
> > >  hw/pci-bridge/cxl_upstream.c              |  18 +-
> > >  hw/pci-bridge/pci_expander_bridge.c       |   2 +-
> > >  hw/pci/pcie.c                             |  23 ++-
> > >  tests/data/acpi/x86/q35/CEDT.cxl          | Bin 184 -> 184 bytes
> > >  15 files changed, 313 insertions(+), 97 deletions(-)
> > > 
> > > -- 
> > > 2.48.1    
> > 
> > 
> >   
> 
>