On 22/11/2018 17:54, Cornelia Huck wrote:
Add a region to the vfio-ccw device that can be used to submit
asynchronous I/O instructions. ssch continues to be handled by the
existing I/O region; the new region handles hsch and csch.
Interrupt status continues to be reported through the same channels
as for ssch.
Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx>
---
drivers/s390/cio/Makefile | 3 +-
drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++++++
drivers/s390/cio/vfio_ccw_drv.c | 48 ++++++---
drivers/s390/cio/vfio_ccw_fsm.c | 158 +++++++++++++++++++++++++++-
drivers/s390/cio/vfio_ccw_ops.c | 13 ++-
drivers/s390/cio/vfio_ccw_private.h | 6 ++
include/uapi/linux/vfio.h | 4 +
include/uapi/linux/vfio_ccw.h | 12 +++
8 files changed, 313 insertions(+), 19 deletions(-)
create mode 100644 drivers/s390/cio/vfio_ccw_async.c
diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile
index f230516abb96..f6a8db04177c 100644
--- a/drivers/s390/cio/Makefile
+++ b/drivers/s390/cio/Makefile
@@ -20,5 +20,6 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o
qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o
obj-$(CONFIG_QDIO) += qdio.o
-vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o
+vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o \
+ vfio_ccw_async.o
obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o
diff --git a/drivers/s390/cio/vfio_ccw_async.c b/drivers/s390/cio/vfio_ccw_async.c
new file mode 100644
index 000000000000..8c7f51d17d70
--- /dev/null
+++ b/drivers/s390/cio/vfio_ccw_async.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
...snip...
static void __exit vfio_ccw_sch_exit(void)
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index f94aa01f9c36..0caf77e8f377 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -3,8 +3,10 @@
* Finite state machine for vfio-ccw device handling
*
* Copyright IBM Corp. 2017
+ * Copyright Red Hat, Inc. 2018
*
* Author(s): Dong Jia Shi <bjsdjshi@xxxxxxxxxxxxxxxxxx>
+ * Cornelia Huck <cohuck@xxxxxxxxxx>
*/
#include <linux/vfio.h>
@@ -68,6 +70,81 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
return ret;
}
+static int fsm_do_halt(struct vfio_ccw_private *private)
+{
+ struct subchannel *sch;
+ unsigned long flags;
+ int ccode;
+ int ret;
+
+ sch = private->sch;
+
+ spin_lock_irqsave(sch->lock, flags);
+ private->state = VFIO_CCW_STATE_BUSY;
+
+ /* Issue "Halt Subchannel" */
+ ccode = hsch(sch->schid);
+
+ switch (ccode) {
+ case 0:
+ /*
+ * Initialize device status information
+ */
+ sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND;
+ ret = 0;
+ break;
+ case 1: /* Status pending */
+ case 2: /* Busy */
+ ret = -EBUSY;
+ break;
+ case 3: /* Device not operational */
+ {
+ ret = -ENODEV;
+ break;
+ }
+ default:
+ ret = ccode;
+ }
Shouldn't you set the state back here?
+ spin_unlock_irqrestore(sch->lock, flags);
+ return ret;
+}
+
+static int fsm_do_clear(struct vfio_ccw_private *private)
+{
+ struct subchannel *sch;
+ unsigned long flags;
+ int ccode;
+ int ret;
+
+ sch = private->sch;
+
+ spin_lock_irqsave(sch->lock, flags);
+ private->state = VFIO_CCW_STATE_BUSY;
+
+ /* Issue "Clear Subchannel" */
+ ccode = csch(sch->schid);
+
+ switch (ccode) {
+ case 0:
+ /*
+ * Initialize device status information
+ */
+ sch->schib.scsw.cmd.actl = SCSW_ACTL_CLEAR_PEND;
+ /* TODO: check what else we might need to clear */
+ ret = 0;
+ break;
+ case 3: /* Device not operational */
+ {
+ ret = -ENODEV;
+ break;
+ }
+ default:
+ ret = ccode;
+ }
+ spin_unlock_irqrestore(sch->lock, flags);
+ return ret;
+}
+
static void fsm_notoper(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
@@ -102,6 +179,20 @@ static void fsm_io_busy(struct vfio_ccw_private *private,
private->io_region->ret_code = -EBUSY;
}
+static void fsm_async_error(struct vfio_ccw_private *private,
+ enum vfio_ccw_event event)
+{
+ pr_err("vfio-ccw: FSM: halt/clear request from state:%d\n",
+ private->state);
+ private->cmd_region->ret_code = -EIO;
+}
+
+static void fsm_async_busy(struct vfio_ccw_private *private,
+ enum vfio_ccw_event event)
+{
+ private->cmd_region->ret_code = -EBUSY;
+}
+
static void fsm_disabled_irq(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
@@ -166,11 +257,11 @@ static void fsm_io_request(struct vfio_ccw_private *private,
}
return;
} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
- /* XXX: Handle halt. */
+ /* halt is handled via the async cmd region */
io_region->ret_code = -EOPNOTSUPP;
goto err_out;
} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
- /* XXX: Handle clear. */
+ /* clear is handled via the async cmd region */
io_region->ret_code = -EOPNOTSUPP;
goto err_out;
What about filtering inside the vfio_ccw_mdev_write_io_region() before
the call to the FSM?
}
@@ -181,6 +272,59 @@ static void fsm_io_request(struct vfio_ccw_private *private,
io_region->ret_code, errstr);
}
+/*
+ * Deal with a halt request from userspace.
+ */
+static void fsm_halt_request(struct vfio_ccw_private *private,
+ enum vfio_ccw_event event)
+{
+ struct ccw_cmd_region *cmd_region = private->cmd_region;
+ int state = private->state;
+
+ private->state = VFIO_CCW_STATE_BOXED;
+
+ if (cmd_region->command != VFIO_CCW_ASYNC_CMD_HSCH) {
+ /* should not happen? */
I think we should make sure it does not happen before we get here.
Like serializing HALT and CLEAR before the FSM.
+ cmd_region->ret_code = -EINVAL;
+ goto err_out;
+ }
+
+ cmd_region->ret_code = fsm_do_halt(private);
fsm_do_halt() set the state to BUSY.
Do we need a state change here and in fsm_do_halt ?
Why not only the BUSY state?
+ if (cmd_region->ret_code)
+ goto err_out;
+
+ return;
+
+err_out:
+ private->state = state;
+}
+
...snip...
Regards,
Pierre
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
