diff options
| -rw-r--r-- | Documentation/s390/vfio-ccw.rst | 31 | ||||
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 28 | ||||
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_drv.c | 2 |
3 files changed, 46 insertions, 15 deletions
diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst index 1e210c6afa88..fca9c4f5bd9c 100644 --- a/Documentation/s390/vfio-ccw.rst +++ b/Documentation/s390/vfio-ccw.rst @@ -180,6 +180,13 @@ The process of how these work together. add it to an iommu_group and a vfio_group. Then we could pass through the mdev to a guest. + +VFIO-CCW Regions +---------------- + +The vfio-ccw driver exposes MMIO regions to accept requests from and return +results to userspace. + vfio-ccw I/O region ------------------- @@ -205,6 +212,25 @@ irb_area stores the I/O result. ret_code stores a return code for each access of the region. +This region is always available. + +vfio-ccw cmd region +------------------- + +The vfio-ccw cmd region is used to accept asynchronous instructions +from userspace:: + + #define VFIO_CCW_ASYNC_CMD_HSCH (1 << 0) + #define VFIO_CCW_ASYNC_CMD_CSCH (1 << 1) + struct ccw_cmd_region { + __u32 command; + __u32 ret_code; + } __packed; + +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. + +Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region. + vfio-ccw operation details -------------------------- @@ -306,9 +332,8 @@ Together with the corresponding work in QEMU, we can bring the passed through DASD/ECKD device online in a guest now and use it as a block device. -While the current code allows the guest to start channel programs via -START SUBCHANNEL, support for HALT SUBCHANNEL or CLEAR SUBCHANNEL is -not yet implemented. +The current code allows the guest to start channel programs via +START SUBCHANNEL, and to issue HALT SUBCHANNEL and CLEAR SUBCHANNEL. vfio-ccw supports classic (command mode) channel I/O only. Transport mode (HPF) is not supported. diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 1d4c893ead23..3645d1720c4b 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -72,8 +72,10 @@ static int pfn_array_alloc(struct pfn_array *pa, u64 iova, unsigned int len) sizeof(*pa->pa_iova_pfn) + sizeof(*pa->pa_pfn), GFP_KERNEL); - if (unlikely(!pa->pa_iova_pfn)) + if (unlikely(!pa->pa_iova_pfn)) { + pa->pa_nr = 0; return -ENOMEM; + } pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr; pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT; @@ -421,7 +423,7 @@ static int ccwchain_loop_tic(struct ccwchain *chain, static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) { struct ccwchain *chain; - int len; + int len, ret; /* Copy 2K (the most we support today) of possible CCWs */ len = copy_from_iova(cp->mdev, cp->guest_cp, cda, @@ -448,7 +450,12 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) memcpy(chain->ch_ccw, cp->guest_cp, len * sizeof(struct ccw1)); /* Loop for tics on this new chain. */ - return ccwchain_loop_tic(chain, cp); + ret = ccwchain_loop_tic(chain, cp); + + if (ret) + ccwchain_free(chain); + + return ret; } /* Loop for TICs. */ @@ -642,17 +649,16 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb) /* Build a ccwchain for the first CCW segment */ ret = ccwchain_handle_ccw(orb->cmd.cpa, cp); - if (ret) - cp_free(cp); - - /* It is safe to force: if not set but idals used - * ccwchain_calc_length returns an error. - */ - cp->orb.cmd.c64 = 1; - if (!ret) + if (!ret) { cp->initialized = true; + /* It is safe to force: if it was not set but idals used + * ccwchain_calc_length would have returned an error. + */ + cp->orb.cmd.c64 = 1; + } + return ret; } diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 2b90a5ecaeb9..9208c0e56c33 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -88,7 +88,7 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)); if (scsw_is_solicited(&irb->scsw)) { cp_update_scsw(&private->cp, &irb->scsw); - if (is_final) + if (is_final && private->state == VFIO_CCW_STATE_CP_PENDING) cp_free(&private->cp); } mutex_lock(&private->io_mutex); |