On Thu, 26 Jul 2018 21:54:15 +0200
Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
> From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
>
> Introduces a new AP device driver. This device driver
> is built on the VFIO mediated device framework. The framework
> provides sysfs interfaces that facilitate passthrough
> access by guests to devices installed on the linux host.
>
> The VFIO AP device driver will serve two purposes:
>
> 1. Provide the interfaces to reserve AP devices for exclusive
> use by KVM guests. This is accomplished by unbinding the
> devices to be reserved for guest usage from the default AP
> device driver and binding them to the VFIO AP device driver.
>
> 2. Implements the functions, callbacks and sysfs attribute
> interfaces required to create one or more VFIO mediated
> devices each of which will be used to configure the AP
> matrix for a guest and serve as a file descriptor
> for facilitating communication between QEMU and the
> VFIO AP device driver.
>
> When the VFIO AP device driver is initialized:
>
> * It registers with the AP bus for control of type 10 (CEX4
> and newer) AP queue devices. This limitation was imposed
> due to:
>
> 1. A desire to keep the code as simple as possible;
>
> 2. Some older models are no longer supported by the kernel
> and others are getting close to end of service.
>
> The probe and remove callbacks will be provided to support
> the binding/unbinding of AP queue devices to/from the VFIO
> AP device driver.
>
> * Creates a virtual misc device, /sys/devices/virtual/misc/vfio_ap,
> device to serve as the parent of the mediated devices created, one
> for each guest, and to hold the APQNs of the AP devices bound to
> the VFIO AP device driver.
>
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
> Tested-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
> Tested-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> MAINTAINERS | 10 +++
> arch/s390/Kconfig | 11 +++
> drivers/s390/crypto/Makefile | 4 +
> drivers/s390/crypto/vfio_ap_drv.c | 112 ++++++++++++++++++++++++++
> drivers/s390/crypto/vfio_ap_private.h | 30 +++++++
> include/uapi/linux/vfio.h | 2 +
> 6 files changed, 169 insertions(+)
> create mode 100644 drivers/s390/crypto/vfio_ap_drv.c
> create mode 100644 drivers/s390/crypto/vfio_ap_private.h
>
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 1aa7b82e8169..f378b9802d8b 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -200,6 +200,7 @@ struct vfio_device_info {
> #define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2) /* vfio-platform device */
> #define VFIO_DEVICE_FLAGS_AMBA (1 << 3) /* vfio-amba device */
> #define VFIO_DEVICE_FLAGS_CCW (1 << 4) /* vfio-ccw device */
> +#define VFIO_DEVICE_FLAGS_AP (1 << 5) /* vfio-ap device */
> __u32 num_regions; /* Max region index + 1 */
> __u32 num_irqs; /* Max IRQ index + 1 */
> };
> @@ -215,6 +216,7 @@ struct vfio_device_info {
> #define VFIO_DEVICE_API_PLATFORM_STRING "vfio-platform"
> #define VFIO_DEVICE_API_AMBA_STRING "vfio-amba"
> #define VFIO_DEVICE_API_CCW_STRING "vfio-ccw"
> +#define VFIO_DEVICE_API_AP_STRING "vfio-ap"
>
> /**
> * VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
Should this hunk go into the next patch?
