Use an additional bit of the VFIO_DEVICE_INFO_CAP_ZPCI_GROUP flags field to pass whether or not the associated device supports relaxed length and alignment for some I/O operations. Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> Acked-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx> --- drivers/vfio/pci/vfio_pci_zdev.c | 2 ++ include/uapi/linux/vfio_zdev.h | 1 + 2 files changed, 3 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c index 2296856..57e19ff 100644 --- a/drivers/vfio/pci/vfio_pci_zdev.c +++ b/drivers/vfio/pci/vfio_pci_zdev.c @@ -60,6 +60,8 @@ static int zpci_group_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev, .version = zdev->version }; + if (zdev->relaxed_align) + cap.flags |= VFIO_DEVICE_INFO_ZPCI_FLAG_RELAXED; 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 b430939..b0b6596 100644 --- a/include/uapi/linux/vfio_zdev.h +++ b/include/uapi/linux/vfio_zdev.h @@ -43,6 +43,7 @@ struct vfio_device_info_cap_zpci_group { __u64 msi_addr; /* MSI address */ __u64 flags; #define VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH 1 /* Program-specified TLB refresh */ +#define VFIO_DEVICE_INFO_ZPCI_FLAG_RELAXED 2 /* Relaxed Length and Alignment */ __u16 mui; /* Measurement Block Update Interval */ __u16 noi; /* Maximum number of MSIs */ __u16 maxstbl; /* Maximum Store Block Length */ -- 1.8.3.1