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| author |  Nipun Gupta <nipun.gupta@amd.com>
| 2023-09-15 10:24:22 +0530 |
|---|---|---|
| committer |  Alex Williamson <alex.williamson@redhat.com>
| 2023-09-28 12:12:07 -0600 |
| commit | f59a7b6af012619199c55f587a6c4ed681639b32 (patch) | |
| tree | f2c3e4e32661fdf856a6a4517007a4229a8414ac | |
| parent | cdx: add support for bus mastering (diff) | |
| download | linux-f59a7b6af012619199c55f587a6c4ed681639b32.tar.gz linux-f59a7b6af012619199c55f587a6c4ed681639b32.tar.bz2 linux-f59a7b6af012619199c55f587a6c4ed681639b32.zip | |
vfio: add bus master feature to device feature ioctl
add bus mastering control to VFIO_DEVICE_FEATURE IOCTL. The VFIO user
can use this feature to enable or disable the Bus Mastering of a
device bound to VFIO.
Co-developed-by: Shubham Rohila <shubham.rohila@amd.com>
Signed-off-by: Shubham Rohila <shubham.rohila@amd.com>
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Link: https://lore.kernel.org/r/20230915045423.31630-2-nipun.gupta@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| -rw-r--r-- | include/uapi/linux/vfio.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index afc1369216d9..b177424149f4 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1434,6 +1434,27 @@ struct vfio_device_feature_mig_data_size { #define VFIO_DEVICE_FEATURE_MIG_DATA_SIZE 9 +/** + * Upon VFIO_DEVICE_FEATURE_SET, set or clear the BUS mastering for the device + * based on the operation specified in op flag. + * + * The functionality is incorporated for devices that needs bus master control, + * but the in-band device interface lacks the support. Consequently, it is not + * applicable to PCI devices, as bus master control for PCI devices is managed + * in-band through the configuration space. At present, this feature is supported + * only for CDX devices. + * When the device's BUS MASTER setting is configured as CLEAR, it will result in + * blocking all incoming DMA requests from the device. On the other hand, configuring + * the device's BUS MASTER setting as SET (enable) will grant the device the + * capability to perform DMA to the host memory. + */ +struct vfio_device_feature_bus_master { + __u32 op; +#define VFIO_DEVICE_FEATURE_CLEAR_MASTER 0 /* Clear Bus Master */ +#define VFIO_DEVICE_FEATURE_SET_MASTER 1 /* Set Bus Master */ +}; +#define VFIO_DEVICE_FEATURE_BUS_MASTER 10 + /* -------- API for Type1 VFIO IOMMU -------- */ /** |