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SubjectRe: [PATCH v2 05/15] s390: vfio-ap: base implementation of VFIO AP device driver
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On 27/02/2018 15:28, Tony Krowiak wrote:
> 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. 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 /sys/devices/vfio-ap/matrix device to hold
> the APQNs of the AP devices bound to the VFIO
> AP device driver and serves as the parent of the
> mediated devices created for each guest.
>
> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
> ---
> MAINTAINERS | 2 +
> arch/s390/Kconfig | 8 ++
> arch/s390/configs/default_defconfig | 3 +
> arch/s390/configs/gcov_defconfig | 3 +
> arch/s390/configs/performance_defconfig | 3 +
> arch/s390/defconfig | 3 +
> drivers/s390/crypto/Makefile | 4 +
> drivers/s390/crypto/vfio_ap_drv.c | 134 +++++++++++++++++++++++++++++++
> drivers/s390/crypto/vfio_ap_private.h | 20 +++++
> include/uapi/linux/vfio.h | 2 +
> 10 files changed, 182 insertions(+), 0 deletions(-)
> create mode 100644 drivers/s390/crypto/vfio_ap_drv.c
> create mode 100644 drivers/s390/crypto/vfio_ap_private.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4acf7c2..a2f232d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11884,6 +11884,8 @@ W: http://www.ibm.com/developerworks/linux/linux390/
> S: Supported
> F: arch/s390/include/asm/kvm/kvm-ap.h
> F: arch/s390/kvm/kvm-ap.c
> +F: drivers/s390/crypto/vfio_ap_drv.c
> +F: drivers/s390/crypto/vfio_ap_private.h
>
> S390 ZFCP DRIVER
> M: Steffen Maier <maier@linux.vnet.ibm.com>
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index cbe1d97..9f23caf 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -771,6 +771,14 @@ config VFIO_CCW
> To compile this driver as a module, choose M here: the
> module will be called vfio_ccw.
>
> +config VFIO_AP
> + def_tristate m
> + prompt "Support for virtual Adjunct Processor device interface"

The VFIO AP devices are not virtual.
What about
    "VFIO support for AP devices"

> + depends on ZCRYPT && VFIO_MDEV_DEVICE
> + help
> + driver grants access to Adjunct Processor (AP) devices
> + via the VFIO mediated device interface.
> +
> endmenu
>
> menu "Dump support"
> diff --git a/arch/s390/configs/default_defconfig b/arch/s390/configs/default_defconfig
> index 5af8458..40fa3f6 100644
> --- a/arch/s390/configs/default_defconfig
> +++ b/arch/s390/configs/default_defconfig

Not sure that this file belongs to this patch

> @@ -719,3 +719,6 @@ CONFIG_APPLDATA_BASE=y
> CONFIG_KVM=m
> CONFIG_KVM_S390_UCONTROL=y
> CONFIG_VHOST_NET=m
> +VFIO_MDEV=m
> +VFIO_MDEV_DEVICE=m
> +CONFIG_VFIO_AP=m

What is your goal when modifying this three files?
Could you add a comment in the commit message?


> diff --git a/arch/s390/configs/gcov_defconfig b/arch/s390/configs/gcov_defconfig
> index d52eafe..377d40f 100644
> --- a/arch/s390/configs/gcov_defconfig
> +++ b/arch/s390/configs/gcov_defconfig
> @@ -659,3 +659,6 @@ CONFIG_APPLDATA_BASE=y
> CONFIG_KVM=m
> CONFIG_KVM_S390_UCONTROL=y
> CONFIG_VHOST_NET=m
> +VFIO_MDEV=m
> +VFIO_MDEV_DEVICE=m
> +CONFIG_VFIO_AP=m
> diff --git a/arch/s390/configs/performance_defconfig b/arch/s390/configs/performance_defconfig
> index 20ed149..f0c52df 100644
> --- a/arch/s390/configs/performance_defconfig
> +++ b/arch/s390/configs/performance_defconfig
> @@ -657,3 +657,6 @@ CONFIG_APPLDATA_BASE=y
> CONFIG_KVM=m
> CONFIG_KVM_S390_UCONTROL=y
> CONFIG_VHOST_NET=m
> +VFIO_MDEV=m
> +VFIO_MDEV_DEVICE=m
> +CONFIG_VFIO_AP=m
> diff --git a/arch/s390/defconfig b/arch/s390/defconfig
> index 46a3178..0996eb7 100644
> --- a/arch/s390/defconfig
> +++ b/arch/s390/defconfig
> @@ -239,3 +239,6 @@ CONFIG_CRC7=m
> # CONFIG_XZ_DEC_ARMTHUMB is not set
> # CONFIG_XZ_DEC_SPARC is not set
> CONFIG_CMM=m
> +VFIO_MDEV=m
> +VFIO_MDEV_DEVICE=m
> +CONFIG_VFIO_AP=m
> diff --git a/drivers/s390/crypto/Makefile b/drivers/s390/crypto/Makefile
> index b59af54..48e466e 100644
> --- a/drivers/s390/crypto/Makefile
> +++ b/drivers/s390/crypto/Makefile
> @@ -15,3 +15,7 @@ obj-$(CONFIG_ZCRYPT) += zcrypt_pcixcc.o zcrypt_cex2a.o zcrypt_cex4.o
> # pkey kernel module
> pkey-objs := pkey_api.o
> obj-$(CONFIG_PKEY) += pkey.o
> +
> +# adjunct processor matrix
> +vfio_ap-objs := vfio_ap_drv.o
> +obj-$(CONFIG_VFIO_AP) += vfio_ap.o
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> new file mode 100644
> index 0000000..8bb72af
> --- /dev/null
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -0,0 +1,134 @@
> +/*
> + * VFIO based AP device driver
> + *
> + * Copyright IBM Corp. 2017
> + *
> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/slab.h>
> +
> +#include "ap_bus.h"

Since you do it in a later patch, may be put this include of ap_bus.h in
ap_private.h now.

> +#include "vfio_ap_private.h"
> +
> +#define VFIO_AP_ROOT_NAME "vfio_ap"
> +#define VFIO_AP_DEV_TYPE_NAME "ap_matrix"
> +#define VFIO_AP_DEV_NAME "matrix"
> +
> +MODULE_AUTHOR("IBM Corporation");
> +MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2017");
> +MODULE_LICENSE("GPL v2");
> +
> +static struct device *vfio_ap_root_device;
> +
> +static struct ap_driver vfio_ap_drv;
> +
> +static struct ap_matrix *ap_matrix;
> +
> +static struct device_type vfio_ap_dev_type = {
> + .name = VFIO_AP_DEV_TYPE_NAME,
> +};
> +
> +/* Only type 10 adapters (CEX4 and later) are supported
> + * by the AP matrix device driver
> + */
> +static struct ap_device_id ap_queue_ids[] = {
> + { .dev_type = AP_DEVICE_TYPE_CEX4,
> + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
> + { .dev_type = AP_DEVICE_TYPE_CEX5,
> + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
> + { .dev_type = AP_DEVICE_TYPE_CEX6,
> + .match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
> + { /* end of sibling */ },
> +};
> +
> +MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
> +
> +static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
> +{
> + return 0;
> +}
> +
> +static void vfio_ap_matrix_dev_release(struct device *dev)
> +{
> + struct ap_matrix *ap_matrix = dev_get_drvdata(dev);
> +
> + kfree(ap_matrix);
> +}
> +
> +static int vfio_ap_matrix_dev_create(void)
> +{
> + int ret;
> +
> + vfio_ap_root_device = root_device_register(VFIO_AP_ROOT_NAME);
> +
> + ret = PTR_ERR_OR_ZERO(vfio_ap_root_device);

IS_ERR() is enough, root_device_register() never return NULL.

> + if (ret)
> + goto done;
> +
> + ap_matrix = kzalloc(sizeof(*ap_matrix), GFP_KERNEL);
> + if (!ap_matrix) {
> + ret = -ENOMEM;
> + goto matrix_alloc_err;
> + }
> +
> + ap_matrix->device.type = &vfio_ap_dev_type;
> + dev_set_name(&ap_matrix->device, "%s", VFIO_AP_DEV_NAME);
> + ap_matrix->device.parent = vfio_ap_root_device;
> + ap_matrix->device.release = vfio_ap_matrix_dev_release;
> + ap_matrix->device.driver = &vfio_ap_drv.driver;
> +
> + ret = device_register(&ap_matrix->device);
> + if (ret)
> + goto matrix_reg_err;
> +
> + goto done;
> +
> +matrix_reg_err:
> + put_device(&ap_matrix->device);
> + kfree(ap_matrix);
> +
> +matrix_alloc_err:
> + root_device_unregister(vfio_ap_root_device);
> +
> +done:
> + return ret;
> +}
> +
> +static void vfio_ap_matrix_dev_destroy(struct ap_matrix *ap_matrix)
> +{
> + device_unregister(&ap_matrix->device);
> + root_device_unregister(vfio_ap_root_device);
> +}
> +
> +int __init vfio_ap_init(void)
> +{
> + int ret;
> +
> + ret = vfio_ap_matrix_dev_create();
> + if (ret)
> + return ret;
> +
> + memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
> + vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
> + vfio_ap_drv.ids = ap_queue_ids;
> +
> + ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
> + if (ret) {
> + vfio_ap_matrix_dev_destroy(ap_matrix);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +void __exit vfio_ap_exit(void)
> +{
> + ap_driver_unregister(&vfio_ap_drv);
> + vfio_ap_matrix_dev_destroy(ap_matrix);
> +}
> +
> +module_init(vfio_ap_init);
> +module_exit(vfio_ap_exit);
> diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
> new file mode 100644
> index 0000000..3505947
> --- /dev/null
> +++ b/drivers/s390/crypto/vfio_ap_private.h
> @@ -0,0 +1,20 @@
> +/*
> + * Private data and functions for adjunct processor VFIO matrix driver.
> + *
> + * Copyright IBM Corp. 2017
> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
> + */
> +
> +#ifndef _VFIO_AP_PRIVATE_H_
> +#define _VFIO_AP_PRIVATE_H_
> +
> +#include <linux/types.h>
> +
> +#define VFIO_AP_MODULE_NAME "vfio_ap"
> +#define VFIO_AP_DRV_NAME "vfio_ap"
> +
> +struct ap_matrix {
> + struct device device;
> +};
> +
> +#endif /* _VFIO_AP_PRIVATE_H_ */
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index e3301db..cf2a5e9 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,


--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany

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