On 9/19/20 11:28 AM, Matthew Rosato wrote:
This patchset provides a means by which hardware information about the underlying PCI device can be passed up to userspace (ie, QEMU) so that this hardware information can be used rather than previously hard-coded assumptions. A new VFIO region type is defined which holds this information. A form of these patches saw some rounds last year but has been back- tabled for a while. The original work for this feature was done by Pierre Morel. I'd like to refresh the discussion on this and get this finished up so that we can move forward with better-supporting additional types of PCI-attached devices. The proposal here presents a completely different region mapping vs the prior approach, taking inspiration from vfio info capability chains to provide device CLP information in a way that allows for future expansion (new CLP features). This feature is toggled via the CONFIG_VFIO_PCI_ZDEV configuration entry.
QEMU patchset that exploits the new region: https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg07076.html
Matthew Rosato (4): s390/pci: stash version in the zpci_dev s390/pci: track whether util_str is valid in the zpci_dev vfio-pci/zdev: define the vfio_zdev header vfio-pci/zdev: use a device region to retrieve zPCI information arch/s390/include/asm/pci.h | 4 +- arch/s390/pci/pci_clp.c | 2 + drivers/vfio/pci/Kconfig | 13 ++ drivers/vfio/pci/Makefile | 1 + drivers/vfio/pci/vfio_pci.c | 8 ++ drivers/vfio/pci/vfio_pci_private.h | 10 ++ drivers/vfio/pci/vfio_pci_zdev.c | 242 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/vfio.h | 5 + include/uapi/linux/vfio_zdev.h | 116 +++++++++++++++++ 9 files changed, 400 insertions(+), 1 deletion(-) create mode 100644 drivers/vfio/pci/vfio_pci_zdev.c create mode 100644 include/uapi/linux/vfio_zdev.h
