PCI: Unify domain emulation and misc documentation update

[PATCH 0/3] PCI: Unify domain emulation and misc documentation update

Posted by Dan Williams 2 months, 3 weeks ago

Bjorn,

This is a small collection of miscellaneous updates that originated in
the PCI/TSM work, but are suitable to go ahead in v6.17. It is a
documentation update and a new pci_bus_find_emul_domain_nr() helper.

First, the PCI/TSM work (Trusted Execution Environment Security Manager
(PCI device assignment for confidential guests)) wants to add some
additional PCI host bridge sysfs attributes. In preparation for that,
document what is already there.

Next, the PCI/TSM effort proposes samples/devsec/ as a reference and
test implementation of all the TSM infrastructure. It is implemented via
host bridge emulation and aims to be cross-architecture compatible. It
stumbled over the current state of PCI domain number emulation being
arch and driver specific. Remove some of that differentiation and unify
the existing x86 host bridge emulators (hyper-v and vmd) on a common
pci_bus_find_emul_domain_nr() helper.

Dan Williams (3):
  PCI: Establish document for PCI host bridge sysfs attributes
  PCI: Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms
  PCI: vmd: Switch to pci_bus_find_emul_domain_nr()

 .../ABI/testing/sysfs-devices-pci-host-bridge | 19 +++++++
 MAINTAINERS                                   |  1 +
 drivers/pci/controller/pci-hyperv.c           | 53 ++-----------------
 drivers/pci/controller/vmd.c                  | 33 ++++--------
 drivers/pci/pci.c                             | 43 ++++++++++++++-
 drivers/pci/probe.c                           |  8 ++-
 include/linux/pci.h                           |  4 ++
 7 files changed, 86 insertions(+), 75 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-devices-pci-host-bridge


base-commit: e04c78d86a9699d136910cfc0bdcf01087e3267e
-- 
2.50.1

Re: [PATCH 0/3] PCI: Unify domain emulation and misc documentation update

Posted by dan.j.williams@intel.com 2 months, 2 weeks ago

[ add Syzmon for extra eyes on the VMD change ]

Syzmon see the proposed fixup in the discussion with Michael:

http://lore.kernel.org/687993e03bb4c_14c3561008c@dwillia2-xfh.jf.intel.com.notmuch

Dan Williams wrote:
> Bjorn,
> 
> This is a small collection of miscellaneous updates that originated in
> the PCI/TSM work, but are suitable to go ahead in v6.17. It is a
> documentation update and a new pci_bus_find_emul_domain_nr() helper.
> 
> First, the PCI/TSM work (Trusted Execution Environment Security Manager
> (PCI device assignment for confidential guests)) wants to add some
> additional PCI host bridge sysfs attributes. In preparation for that,
> document what is already there.
> 
> Next, the PCI/TSM effort proposes samples/devsec/ as a reference and
> test implementation of all the TSM infrastructure. It is implemented via
> host bridge emulation and aims to be cross-architecture compatible. It
> stumbled over the current state of PCI domain number emulation being
> arch and driver specific. Remove some of that differentiation and unify
> the existing x86 host bridge emulators (hyper-v and vmd) on a common
> pci_bus_find_emul_domain_nr() helper.
> 
> Dan Williams (3):
>   PCI: Establish document for PCI host bridge sysfs attributes
>   PCI: Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms
>   PCI: vmd: Switch to pci_bus_find_emul_domain_nr()
> 
>  .../ABI/testing/sysfs-devices-pci-host-bridge | 19 +++++++
>  MAINTAINERS                                   |  1 +
>  drivers/pci/controller/pci-hyperv.c           | 53 ++-----------------
>  drivers/pci/controller/vmd.c                  | 33 ++++--------
>  drivers/pci/pci.c                             | 43 ++++++++++++++-
>  drivers/pci/probe.c                           |  8 ++-
>  include/linux/pci.h                           |  4 ++
>  7 files changed, 86 insertions(+), 75 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-devices-pci-host-bridge
> 
> 
> base-commit: e04c78d86a9699d136910cfc0bdcf01087e3267e
> -- 
> 2.50.1
>

Re: [PATCH 0/3] PCI: Unify domain emulation and misc documentation update

Posted by Bjorn Helgaas 2 months, 2 weeks ago

On Wed, Jul 16, 2025 at 09:08:32AM -0700, Dan Williams wrote:
> Bjorn,
> 
> This is a small collection of miscellaneous updates that originated in
> the PCI/TSM work, but are suitable to go ahead in v6.17. It is a
> documentation update and a new pci_bus_find_emul_domain_nr() helper.
> 
> First, the PCI/TSM work (Trusted Execution Environment Security Manager
> (PCI device assignment for confidential guests)) wants to add some
> additional PCI host bridge sysfs attributes. In preparation for that,
> document what is already there.
> 
> Next, the PCI/TSM effort proposes samples/devsec/ as a reference and
> test implementation of all the TSM infrastructure. It is implemented via
> host bridge emulation and aims to be cross-architecture compatible. It
> stumbled over the current state of PCI domain number emulation being
> arch and driver specific. Remove some of that differentiation and unify
> the existing x86 host bridge emulators (hyper-v and vmd) on a common
> pci_bus_find_emul_domain_nr() helper.
> 
> Dan Williams (3):
>   PCI: Establish document for PCI host bridge sysfs attributes
>   PCI: Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms
>   PCI: vmd: Switch to pci_bus_find_emul_domain_nr()
> 
>  .../ABI/testing/sysfs-devices-pci-host-bridge | 19 +++++++
>  MAINTAINERS                                   |  1 +
>  drivers/pci/controller/pci-hyperv.c           | 53 ++-----------------
>  drivers/pci/controller/vmd.c                  | 33 ++++--------
>  drivers/pci/pci.c                             | 43 ++++++++++++++-
>  drivers/pci/probe.c                           |  8 ++-
>  include/linux/pci.h                           |  4 ++
>  7 files changed, 86 insertions(+), 75 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-devices-pci-host-bridge

Seems OK to me, modulo the conversation with Michael.  Would like a
Reviewed-by from the owners of pci-hyperv.c and vmd.c, of course.

Bjorn