On 5/7/19 11:47 AM, Cornelia Huck wrote:
> 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).
>
> Signed-off-by: Cornelia Huck <coh...@redhat.com>
This looks fine to me; thanks for the explanations!
Reviewed-by: Eric Farman <far...@linux.ibm.com>
> ---
> hw/s390x/css.c | 27 +++++++--
> hw/vfio/ccw.c | 110 +++++++++++++++++++++++++++++++++++-
> include/hw/s390x/s390-ccw.h | 3 +
> 3 files changed, 134 insertions(+), 6 deletions(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 8fc9e35ba5d3..5b21a74b5c29 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -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;
> @@ -1191,6 +1192,26 @@ static void sch_handle_start_func_virtual(SubchDev
> *sch)
>
> }
>
> +static void sch_handle_halt_func_passthrough(SubchDev *sch)
> +{
> + int ret;
> +
> + ret = vfio_ccw_handle_halt(sch);
> + if (ret == -ENOSYS) {
> + sch_handle_halt_func(sch);
> + }
> +}
> +
> +static void sch_handle_clear_func_passthrough(SubchDev *sch)
> +{
> + int ret;
> +
> + ret = vfio_ccw_handle_clear(sch);
> + if (ret == -ENOSYS) {
> + sch_handle_clear_func(sch);
> + }
> +}
> +
> static IOInstEnding sch_handle_start_func_passthrough(SubchDev *sch)
> {
> SCHIB *schib = &sch->curr_status;
> @@ -1230,11 +1251,9 @@ 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);
> }
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index 31dd3a2a87b6..175a17b1772a 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -2,9 +2,12 @@
> * vfio based subchannel assignment support
> *
> * Copyright 2017 IBM Corp.
> + * Copyright 2019 Red Hat, Inc.
> + *
> * Author(s): Dong Jia Shi <bjsdj...@linux.vnet.ibm.com>
> * Xiao Feng Ren <renxi...@linux.vnet.ibm.com>
> * Pierre Morel <pmo...@linux.vnet.ibm.com>
> + * Cornelia Huck <coh...@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
> @@ -32,6 +35,9 @@ 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;
> @@ -114,6 +120,87 @@ again:
> }
> }
>
> +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;
> + }
> +}
> +
> +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);
> @@ -287,9 +374,13 @@ 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;
> }
>
> @@ -309,11 +400,26 @@ 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(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);
> }
>
> diff --git a/include/hw/s390x/s390-ccw.h b/include/hw/s390x/s390-ccw.h
> index 901d805d79a3..e9c7e1db5761 100644
> --- a/include/hw/s390x/s390-ccw.h
> +++ b/include/hw/s390x/s390-ccw.h
> @@ -37,4 +37,7 @@ typedef struct S390CCWDeviceClass {
> IOInstEnding (*handle_request) (SubchDev *sch);
> } S390CCWDeviceClass;
>
> +int vfio_ccw_handle_clear(SubchDev *sch);
> +int vfio_ccw_handle_halt(SubchDev *sch);
> +
> #endif
>
