From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh

---
 kernel/drivers/s390/cio/vfio_ccw_fsm.c |  201 +++++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 188 insertions(+), 13 deletions(-)

diff --git a/kernel/drivers/s390/cio/vfio_ccw_fsm.c b/kernel/drivers/s390/cio/vfio_ccw_fsm.c
index f94aa01..e435a9c 100644
--- a/kernel/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/kernel/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. 2019
  *
  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
+ *            Cornelia Huck <cohuck@redhat.com>
  */
 
 #include <linux/vfio.h>
@@ -12,9 +14,6 @@
 
 #include "ioasm.h"
 #include "vfio_ccw_private.h"
-
-#define CREATE_TRACE_POINTS
-#include "vfio_ccw_trace.h"
 
 static int fsm_io_helper(struct vfio_ccw_private *private)
 {
@@ -28,12 +27,20 @@
 	sch = private->sch;
 
 	spin_lock_irqsave(sch->lock, flags);
-	private->state = VFIO_CCW_STATE_BUSY;
 
 	orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);
+	if (!orb) {
+		ret = -EIO;
+		goto out;
+	}
+
+	VFIO_CCW_TRACE_EVENT(5, "stIO");
+	VFIO_CCW_TRACE_EVENT(5, dev_name(&sch->dev));
 
 	/* Issue "Start Subchannel" */
 	ccode = ssch(sch->schid, orb);
+
+	VFIO_CCW_HEX_EVENT(5, &ccode, sizeof(ccode));
 
 	switch (ccode) {
 	case 0:
@@ -42,6 +49,7 @@
 		 */
 		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
 		ret = 0;
+		private->state = VFIO_CCW_STATE_CP_PENDING;
 		break;
 	case 1:		/* Status pending */
 	case 2:		/* Busy */
@@ -64,6 +72,86 @@
 	default:
 		ret = ccode;
 	}
+out:
+	spin_unlock_irqrestore(sch->lock, flags);
+	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);
+
+	VFIO_CCW_TRACE_EVENT(2, "haltIO");
+	VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	/* Issue "Halt Subchannel" */
+	ccode = hsch(sch->schid);
+
+	VFIO_CCW_HEX_EVENT(2, &ccode, sizeof(ccode));
+
+	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;
+	}
+	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);
+
+	VFIO_CCW_TRACE_EVENT(2, "clearIO");
+	VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev));
+
+	/* Issue "Clear Subchannel" */
+	ccode = csch(sch->schid);
+
+	VFIO_CCW_HEX_EVENT(2, &ccode, sizeof(ccode));
+
+	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;
 }
@@ -72,6 +160,9 @@
 			enum vfio_ccw_event event)
 {
 	struct subchannel *sch = private->sch;
+
+	VFIO_CCW_TRACE_EVENT(2, "notoper");
+	VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev));
 
 	/*
 	 * TODO:
@@ -102,6 +193,30 @@
 	private->io_region->ret_code = -EBUSY;
 }
 
+static void fsm_io_retry(struct vfio_ccw_private *private,
+			 enum vfio_ccw_event event)
+{
+	private->io_region->ret_code = -EAGAIN;
+}
+
+static void fsm_async_error(struct vfio_ccw_private *private,
+			    enum vfio_ccw_event event)
+{
+	struct ccw_cmd_region *cmd_region = private->cmd_region;
+
+	pr_err("vfio-ccw: FSM: %s request from state:%d\n",
+	       cmd_region->command == VFIO_CCW_ASYNC_CMD_HSCH ? "halt" :
+	       cmd_region->command == VFIO_CCW_ASYNC_CMD_CSCH ? "clear" :
+	       "<unknown>", private->state);
+	cmd_region->ret_code = -EIO;
+}
+
+static void fsm_async_retry(struct vfio_ccw_private *private,
+			    enum vfio_ccw_event event)
+{
+	private->cmd_region->ret_code = -EAGAIN;
+}
+
 static void fsm_disabled_irq(struct vfio_ccw_private *private,
 			     enum vfio_ccw_event event)
 {
@@ -129,9 +244,9 @@
 	struct ccw_io_region *io_region = private->io_region;
 	struct mdev_device *mdev = private->mdev;
 	char *errstr = "request";
+	struct subchannel_id schid = get_schid(private);
 
-	private->state = VFIO_CCW_STATE_BOXED;
-
+	private->state = VFIO_CCW_STATE_CP_PROCESSING;
 	memcpy(scsw, io_region->scsw_area, sizeof(*scsw));
 
 	if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) {
@@ -140,18 +255,32 @@
 		/* Don't try to build a cp if transport mode is specified. */
 		if (orb->tm.b) {
 			io_region->ret_code = -EOPNOTSUPP;
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): transport mode\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no);
 			errstr = "transport mode";
 			goto err_out;
 		}
 		io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
 					      orb);
 		if (io_region->ret_code) {
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): cp_init=%d\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no,
+					   io_region->ret_code);
 			errstr = "cp init";
 			goto err_out;
 		}
 
 		io_region->ret_code = cp_prefetch(&private->cp);
 		if (io_region->ret_code) {
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): cp_prefetch=%d\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no,
+					   io_region->ret_code);
 			errstr = "cp prefetch";
 			cp_free(&private->cp);
 			goto err_out;
@@ -160,25 +289,63 @@
 		/* Start channel program and wait for I/O interrupt. */
 		io_region->ret_code = fsm_io_helper(private);
 		if (io_region->ret_code) {
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): fsm_io_helper=%d\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no,
+					   io_region->ret_code);
 			errstr = "cp fsm_io_helper";
 			cp_free(&private->cp);
 			goto err_out;
 		}
 		return;
 	} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
-		/* XXX: Handle halt. */
+		VFIO_CCW_MSG_EVENT(2,
+				   "%pUl (%x.%x.%04x): halt on io_region\n",
+				   mdev_uuid(mdev), schid.cssid,
+				   schid.ssid, schid.sch_no);
+		/* 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. */
+		VFIO_CCW_MSG_EVENT(2,
+				   "%pUl (%x.%x.%04x): clear on io_region\n",
+				   mdev_uuid(mdev), schid.cssid,
+				   schid.ssid, schid.sch_no);
+		/* clear is handled via the async cmd region */
 		io_region->ret_code = -EOPNOTSUPP;
 		goto err_out;
 	}
 
 err_out:
 	private->state = VFIO_CCW_STATE_IDLE;
-	trace_vfio_ccw_io_fctl(scsw->cmd.fctl, get_schid(private),
-			       io_region->ret_code, errstr);
+	trace_vfio_ccw_fsm_io_request(scsw->cmd.fctl, schid,
+				      io_region->ret_code, errstr);
+}
+
+/*
+ * Deal with an async request from userspace.
+ */
+static void fsm_async_request(struct vfio_ccw_private *private,
+			      enum vfio_ccw_event event)
+{
+	struct ccw_cmd_region *cmd_region = private->cmd_region;
+
+	switch (cmd_region->command) {
+	case VFIO_CCW_ASYNC_CMD_HSCH:
+		cmd_region->ret_code = fsm_do_halt(private);
+		break;
+	case VFIO_CCW_ASYNC_CMD_CSCH:
+		cmd_region->ret_code = fsm_do_clear(private);
+		break;
+	default:
+		/* should not happen? */
+		cmd_region->ret_code = -EINVAL;
+	}
+
+	trace_vfio_ccw_fsm_async_request(get_schid(private),
+					 cmd_region->command,
+					 cmd_region->ret_code);
 }
 
 /*
@@ -188,6 +355,9 @@
 		    enum vfio_ccw_event event)
 {
 	struct irb *irb = this_cpu_ptr(&cio_irb);
+
+	VFIO_CCW_TRACE_EVENT(6, "IRQ");
+	VFIO_CCW_TRACE_EVENT(6, dev_name(&private->sch->dev));
 
 	memcpy(&private->irb, irb, sizeof(*irb));
 
@@ -204,26 +374,31 @@
 	[VFIO_CCW_STATE_NOT_OPER] = {
 		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_nop,
 		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_error,
+		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_error,
 		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_disabled_irq,
 	},
 	[VFIO_CCW_STATE_STANDBY] = {
 		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
 		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_error,
+		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_error,
 		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
 	},
 	[VFIO_CCW_STATE_IDLE] = {
 		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
 		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_request,
+		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_request,
 		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
 	},
-	[VFIO_CCW_STATE_BOXED] = {
+	[VFIO_CCW_STATE_CP_PROCESSING] = {
 		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
-		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_busy,
+		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_retry,
+		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_retry,
 		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
 	},
-	[VFIO_CCW_STATE_BUSY] = {
+	[VFIO_CCW_STATE_CP_PENDING] = {
 		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
 		[VFIO_CCW_EVENT_IO_REQ]		= fsm_io_busy,
+		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_request,
 		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
 	},
 };

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