Commit 8fadea24 authored by Cornelia Huck's avatar Cornelia Huck
Browse files

vfio-ccw: support async command subregion 



A vfio-ccw device may provide an async command subregion for
issuing halt/clear subchannel requests. If it is present, use
it for sending halt/clear request to the device; if not, fall
back to emulation (as done today).

Reviewed-by: default avatarFarhan Ali <alifm@linux.ibm.com>
Message-Id: <20190613092542.2834-1-cohuck@redhat.com>
Reviewed-by: default avatarEric Farman <farman@linux.ibm.com>
Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
parent b5e89f04

hw/s390x/css.c

+23 −4
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include "trace.h"

#include "hw/s390x/s390_flic.h"

#include "hw/s390x/s390-virtio-ccw.h"

#include "hw/s390x/s390-ccw.h"



typedef struct CrwContainer {

    CRW crw;
@@ -1205,6 +1206,26 @@ static void sch_handle_start_func_virtual(SubchDev *sch) 


}



static void sch_handle_halt_func_passthrough(SubchDev *sch)

{

    int ret;



    ret = s390_ccw_halt(sch);

    if (ret == -ENOSYS) {

        sch_handle_halt_func(sch);

    }

}



static void sch_handle_clear_func_passthrough(SubchDev *sch)

{

    int ret;



    ret = s390_ccw_clear(sch);

    if (ret == -ENOSYS) {

        sch_handle_clear_func(sch);

    }

}



static IOInstEnding sch_handle_start_func_passthrough(SubchDev *sch)

{

    SCHIB *schib = &sch->curr_status;
@@ -1244,11 +1265,9 @@ IOInstEnding do_subchannel_work_passthrough(SubchDev *sch) 
    SCHIB *schib = &sch->curr_status;



    if (schib->scsw.ctrl & SCSW_FCTL_CLEAR_FUNC) {

        /* TODO: Clear handling */

        sch_handle_clear_func(sch);

        sch_handle_clear_func_passthrough(sch);

    } else if (schib->scsw.ctrl & SCSW_FCTL_HALT_FUNC) {

        /* TODO: Halt handling */

        sch_handle_halt_func(sch);

        sch_handle_halt_func_passthrough(sch);

    } else if (schib->scsw.ctrl & SCSW_FCTL_START_FUNC) {

        return sch_handle_start_func_passthrough(sch);

    }

hw/s390x/s390-ccw.c

+20 −0
Original line number Diff line number Diff line
@@ -30,6 +30,26 @@ IOInstEnding s390_ccw_cmd_request(SubchDev *sch) 
    return cdc->handle_request(sch);

}



int s390_ccw_halt(SubchDev *sch)

{

    S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(sch->driver_data);



    if (!cdc->handle_halt) {

        return -ENOSYS;

    }

    return cdc->handle_halt(sch);

}



int s390_ccw_clear(SubchDev *sch)

{

    S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(sch->driver_data);



    if (!cdc->handle_clear) {

        return -ENOSYS;

    }

    return cdc->handle_clear(sch);

}



static void s390_ccw_get_dev_info(S390CCWDevice *cdev,

                                  char *sysfsdev,

                                  Error **errp)

hw/vfio/ccw.c

+111 −2
Original line number Diff line number Diff line
@@ -2,9 +2,12 @@ 
 * vfio based subchannel assignment support

 *

 * Copyright 2017 IBM Corp.

 * Copyright 2019 Red Hat, Inc.

 *

 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>

 *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>

 *            Pierre Morel <pmorel@linux.vnet.ibm.com>

 *            Cornelia Huck <cohuck@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or (at

 * your option) any later version. See the COPYING file in the top-level
@@ -33,6 +36,9 @@ struct VFIOCCWDevice { 
    uint64_t io_region_size;

    uint64_t io_region_offset;

    struct ccw_io_region *io_region;

    uint64_t async_cmd_region_size;

    uint64_t async_cmd_region_offset;

    struct ccw_cmd_region *async_cmd_region;

    EventNotifier io_notifier;

    bool force_orb_pfch;

    bool warned_orb_pfch;
@@ -115,6 +121,87 @@ again: 
    }

}



static int vfio_ccw_handle_clear(SubchDev *sch)

{

    S390CCWDevice *cdev = sch->driver_data;

    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);

    struct ccw_cmd_region *region = vcdev->async_cmd_region;

    int ret;



    if (!vcdev->async_cmd_region) {

        /* Async command region not available, fall back to emulation */

        return -ENOSYS;

    }



    memset(region, 0, sizeof(*region));

    region->command = VFIO_CCW_ASYNC_CMD_CSCH;



again:

    ret = pwrite(vcdev->vdev.fd, region,

                 vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);

    if (ret != vcdev->async_cmd_region_size) {

        if (errno == EAGAIN) {

            goto again;

        }

        error_report("vfio-ccw: write cmd region failed with errno=%d", errno);

        ret = -errno;

    } else {

        ret = region->ret_code;

    }

    switch (ret) {

    case 0:

    case -ENODEV:

    case -EACCES:

        return 0;

    case -EFAULT:

    default:

        sch_gen_unit_exception(sch);

        css_inject_io_interrupt(sch);

        return 0;

    }

}



static int vfio_ccw_handle_halt(SubchDev *sch)

{

    S390CCWDevice *cdev = sch->driver_data;

    VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);

    struct ccw_cmd_region *region = vcdev->async_cmd_region;

    int ret;



    if (!vcdev->async_cmd_region) {

        /* Async command region not available, fall back to emulation */

        return -ENOSYS;

    }



    memset(region, 0, sizeof(*region));

    region->command = VFIO_CCW_ASYNC_CMD_HSCH;



again:

    ret = pwrite(vcdev->vdev.fd, region,

                 vcdev->async_cmd_region_size, vcdev->async_cmd_region_offset);

    if (ret != vcdev->async_cmd_region_size) {

        if (errno == EAGAIN) {

            goto again;

        }

        error_report("vfio-ccw: write cmd region failed with errno=%d", errno);

        ret = -errno;

    } else {

        ret = region->ret_code;

    }

    switch (ret) {

    case 0:

    case -EBUSY:

    case -ENODEV:

    case -EACCES:

        return 0;

    case -EFAULT:

    default:

        sch_gen_unit_exception(sch);

        css_inject_io_interrupt(sch);

        return 0;

    }

}



static void vfio_ccw_reset(DeviceState *dev)

{

    CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
@@ -263,9 +350,13 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp) 
        return;

    }



    /*

     * We always expect at least the I/O region to be present. We also

     * may have a variable number of regions governed by capabilities.

     */

    if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {

        error_setg(errp, "vfio: Unexpected number of the I/O region %u",

                   vdev->num_regions);

        error_setg(errp, "vfio: too few regions (%u), expected at least %u",

                   vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1);

        return;

    }
@@ -285,11 +376,27 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp) 
    vcdev->io_region_offset = info->offset;

    vcdev->io_region = g_malloc0(info->size);



    /* check for the optional async command region */

    ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,

                                   VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info);

    if (!ret) {

        vcdev->async_cmd_region_size = info->size;

        if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) {

            error_setg(errp, "vfio: Unexpected size of the async cmd region");

            g_free(vcdev->io_region);

            g_free(info);

            return;

        }

        vcdev->async_cmd_region_offset = info->offset;

        vcdev->async_cmd_region = g_malloc0(info->size);

    }



    g_free(info);

}



static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)

{

    g_free(vcdev->async_cmd_region);

    g_free(vcdev->io_region);

}
@@ -462,6 +569,8 @@ static void vfio_ccw_class_init(ObjectClass *klass, void *data) 
    dc->reset = vfio_ccw_reset;



    cdc->handle_request = vfio_ccw_handle_request;

    cdc->handle_halt = vfio_ccw_handle_halt;

    cdc->handle_clear = vfio_ccw_handle_clear;

}



static const TypeInfo vfio_ccw_info = {

include/hw/s390x/css.h

+3 −0
Original line number Diff line number Diff line
@@ -215,6 +215,9 @@ IOInstEnding s390_ccw_cmd_request(SubchDev *sch); 
IOInstEnding do_subchannel_work_virtual(SubchDev *sub);

IOInstEnding do_subchannel_work_passthrough(SubchDev *sub);



int s390_ccw_halt(SubchDev *sch);

int s390_ccw_clear(SubchDev *sch);



typedef enum {

    CSS_IO_ADAPTER_VIRTIO = 0,

    CSS_IO_ADAPTER_PCI = 1,

include/hw/s390x/s390-ccw.h

+2 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ typedef struct S390CCWDeviceClass { 
    void (*realize)(S390CCWDevice *dev, char *sysfsdev, Error **errp);

    void (*unrealize)(S390CCWDevice *dev, Error **errp);

    IOInstEnding (*handle_request) (SubchDev *sch);

    int (*handle_halt) (SubchDev *sch);

    int (*handle_clear) (SubchDev *sch);

} S390CCWDeviceClass;



#endif