Re: [PATCH v2 28/30] vfio-pci/zdev: add DTSM to clp group capability

Pierre Morel
2022-01-19T13:47:07Z

On 1/14/22 21:31, Matthew Rosato wrote:
> The DTSM, or designation type supported mask, indicates what IOAT formats
> are available to the guest. For an interpreted device, userspace will not
> know what format(s) the IOAT assist supports, so pass it via the
> capability chain. Since the value belongs to the Query PCI Function Group
> clp, let's extend the existing capability with a new version.
>
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>

> ---
> drivers/vfio/pci/vfio_pci_zdev.c | 9 ++++++---
> include/uapi/linux/vfio_zdev.h | 3 +++
> 2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
> index 2b169d688937..aa2ef9067c7d 100644
> --- a/drivers/vfio/pci/vfio_pci_zdev.c
> +++ b/drivers/vfio/pci/vfio_pci_zdev.c
> @@ -45,19 +45,22 @@ static int zpci_group_cap(struct zpci_dev *zdev, struct vfio_info_cap *caps)
> {
> struct vfio_device_info_cap_zpci_group cap = {
> .header.id = VFIO_DEVICE_INFO_CAP_ZPCI_GROUP,
> - .header.version = 1,
> + .header.version = 2,
> .dasm = zdev->dma_mask,
> .msi_addr = zdev->msi_addr,
> .flags = VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH,
> .mui = zdev->fmb_update,
> .noi = zdev->max_msi,
> .maxstbl = ZPCI_MAX_WRITE_SIZE,
> - .version = zdev->version
> + .version = zdev->version,
> + .dtsm = 0
> };
>
> /* Some values are different for interpreted devices */
> - if (zdev->kzdev && zdev->kzdev->interp)
> + if (zdev->kzdev && zdev->kzdev->interp) {
> cap.maxstbl = zdev->maxstbl;
> + cap.dtsm = kvm_s390_pci_get_dtsm(zdev);
> + }
>
> return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
> }
> diff --git a/include/uapi/linux/vfio_zdev.h b/include/uapi/linux/vfio_zdev.h
> index 1a5229b7bb18..b4c2ba8e71f0 100644
> --- a/include/uapi/linux/vfio_zdev.h
> +++ b/include/uapi/linux/vfio_zdev.h
> @@ -47,6 +47,9 @@ struct vfio_device_info_cap_zpci_group {
> __u16 noi; /* Maximum number of MSIs */
> __u16 maxstbl; /* Maximum Store Block Length */
> __u8 version; /* Supported PCI Version */
> + /* End of version 1 */
> + __u8 dtsm; /* Supported IOAT Designations */
> + /* End of version 2 */
> };
>
> /**
>

--
Pierre Morel
IBM Lab Boeblingen