From: Cornelia Huck <cohuck@redhat.com>
To: Heiko Carstens <heiko.carstens@de.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Farman <farman@linux.ibm.com>,
Halil Pasic <pasic@linux.ibm.com>,
linux-s390@vger.kernel.org, kvm@vger.kernel.org,
Farhan Ali <alifm@linux.ibm.com>,
Cornelia Huck <cohuck@redhat.com>
Subject: [PULL 06/10] vfio-ccw: Introduce a new schib region
Date: Mon, 25 May 2020 11:41:11 +0200 [thread overview]
Message-ID: <20200525094115.222299-7-cohuck@redhat.com> (raw)
In-Reply-To: <20200525094115.222299-1-cohuck@redhat.com>
From: Farhan Ali <alifm@linux.ibm.com>
The schib region can be used by userspace to get the subchannel-
information block (SCHIB) for the passthrough subchannel.
This can be useful to get information such as channel path
information via the SCHIB.PMCW fields.
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-5-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
Documentation/s390/vfio-ccw.rst | 18 ++++++-
drivers/s390/cio/Makefile | 2 +-
drivers/s390/cio/vfio_ccw_chp.c | 76 +++++++++++++++++++++++++++++
drivers/s390/cio/vfio_ccw_drv.c | 20 ++++++++
drivers/s390/cio/vfio_ccw_ops.c | 14 +++++-
drivers/s390/cio/vfio_ccw_private.h | 3 ++
include/uapi/linux/vfio.h | 1 +
include/uapi/linux/vfio_ccw.h | 10 ++++
8 files changed, 140 insertions(+), 4 deletions(-)
create mode 100644 drivers/s390/cio/vfio_ccw_chp.c
diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst
index 3a946fd45562..32310df525ba 100644
--- a/Documentation/s390/vfio-ccw.rst
+++ b/Documentation/s390/vfio-ccw.rst
@@ -282,6 +282,21 @@ for each access of the region. The following values may occur:
``-EBUSY``
The subchannel was status pending or busy while processing a halt request.
+vfio-ccw schib region
+---------------------
+
+The vfio-ccw schib region is used to return Subchannel-Information
+Block (SCHIB) data to userspace::
+
+ struct ccw_schib_region {
+ #define SCHIB_AREA_SIZE 52
+ __u8 schib_area[SCHIB_AREA_SIZE];
+ } __packed;
+
+This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB.
+
+Reading this region triggers a STORE SUBCHANNEL to be issued to the
+associated hardware.
vfio-ccw operation details
--------------------------
@@ -385,7 +400,8 @@ through DASD/ECKD device online in a guest now and use it as a block
device.
The current code allows the guest to start channel programs via
-START SUBCHANNEL, and to issue HALT SUBCHANNEL and CLEAR SUBCHANNEL.
+START SUBCHANNEL, and to issue HALT SUBCHANNEL, CLEAR SUBCHANNEL,
+and STORE SUBCHANNEL.
Currently all channel programs are prefetched, regardless of the
p-bit setting in the ORB. As a result, self modifying channel
diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile
index 23eae4188876..a9235f111e79 100644
--- a/drivers/s390/cio/Makefile
+++ b/drivers/s390/cio/Makefile
@@ -21,5 +21,5 @@ qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o
obj-$(CONFIG_QDIO) += qdio.o
vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o \
- vfio_ccw_async.o vfio_ccw_trace.o
+ vfio_ccw_async.o vfio_ccw_trace.o vfio_ccw_chp.o
obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o
diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c
new file mode 100644
index 000000000000..18f3b3e873a9
--- /dev/null
+++ b/drivers/s390/cio/vfio_ccw_chp.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Channel path related status regions for vfio_ccw
+ *
+ * Copyright IBM Corp. 2020
+ *
+ * Author(s): Farhan Ali <alifm@linux.ibm.com>
+ * Eric Farman <farman@linux.ibm.com>
+ */
+
+#include <linux/vfio.h>
+#include "vfio_ccw_private.h"
+
+static ssize_t vfio_ccw_schib_region_read(struct vfio_ccw_private *private,
+ char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
+ loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
+ struct ccw_schib_region *region;
+ int ret;
+
+ if (pos + count > sizeof(*region))
+ return -EINVAL;
+
+ mutex_lock(&private->io_mutex);
+ region = private->region[i].data;
+
+ if (cio_update_schib(private->sch)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ memcpy(region, &private->sch->schib, sizeof(*region));
+
+ if (copy_to_user(buf, (void *)region + pos, count)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = count;
+
+out:
+ mutex_unlock(&private->io_mutex);
+ return ret;
+}
+
+static ssize_t vfio_ccw_schib_region_write(struct vfio_ccw_private *private,
+ const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ return -EINVAL;
+}
+
+
+static void vfio_ccw_schib_region_release(struct vfio_ccw_private *private,
+ struct vfio_ccw_region *region)
+{
+
+}
+
+const struct vfio_ccw_regops vfio_ccw_schib_region_ops = {
+ .read = vfio_ccw_schib_region_read,
+ .write = vfio_ccw_schib_region_write,
+ .release = vfio_ccw_schib_region_release,
+};
+
+int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private)
+{
+ return vfio_ccw_register_dev_region(private,
+ VFIO_REGION_SUBTYPE_CCW_SCHIB,
+ &vfio_ccw_schib_region_ops,
+ sizeof(struct ccw_schib_region),
+ VFIO_REGION_INFO_FLAG_READ,
+ private->schib_region);
+}
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index fb1275a7d1f5..7aeff42f370d 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -27,6 +27,7 @@
struct workqueue_struct *vfio_ccw_work_q;
static struct kmem_cache *vfio_ccw_io_region;
static struct kmem_cache *vfio_ccw_cmd_region;
+static struct kmem_cache *vfio_ccw_schib_region;
debug_info_t *vfio_ccw_debug_msg_id;
debug_info_t *vfio_ccw_debug_trace_id;
@@ -119,6 +120,8 @@ static void vfio_ccw_sch_irq(struct subchannel *sch)
static void vfio_ccw_free_regions(struct vfio_ccw_private *private)
{
+ if (private->schib_region)
+ kmem_cache_free(vfio_ccw_schib_region, private->schib_region);
if (private->cmd_region)
kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
if (private->io_region)
@@ -156,6 +159,12 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
if (!private->cmd_region)
goto out_free;
+ private->schib_region = kmem_cache_zalloc(vfio_ccw_schib_region,
+ GFP_KERNEL | GFP_DMA);
+
+ if (!private->schib_region)
+ goto out_free;
+
private->sch = sch;
dev_set_drvdata(&sch->dev, private);
mutex_init(&private->io_mutex);
@@ -357,6 +366,7 @@ static void vfio_ccw_debug_exit(void)
static void vfio_ccw_destroy_regions(void)
{
+ kmem_cache_destroy(vfio_ccw_schib_region);
kmem_cache_destroy(vfio_ccw_cmd_region);
kmem_cache_destroy(vfio_ccw_io_region);
}
@@ -393,6 +403,16 @@ static int __init vfio_ccw_sch_init(void)
goto out_err;
}
+ vfio_ccw_schib_region = kmem_cache_create_usercopy("vfio_ccw_schib_region",
+ sizeof(struct ccw_schib_region), 0,
+ SLAB_ACCOUNT, 0,
+ sizeof(struct ccw_schib_region), NULL);
+
+ if (!vfio_ccw_schib_region) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
isc_register(VFIO_CCW_ISC);
ret = css_driver_register(&vfio_ccw_sch_driver);
if (ret) {
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index d4fc84b8867f..22988d67b6bb 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -172,8 +172,18 @@ static int vfio_ccw_mdev_open(struct mdev_device *mdev)
ret = vfio_ccw_register_async_dev_regions(private);
if (ret)
- vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
- &private->nb);
+ goto out_unregister;
+
+ ret = vfio_ccw_register_schib_dev_regions(private);
+ if (ret)
+ goto out_unregister;
+
+ return ret;
+
+out_unregister:
+ vfio_ccw_unregister_dev_regions(private);
+ vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+ &private->nb);
return ret;
}
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index ce3834159d98..d6601a8adf13 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -56,6 +56,7 @@ int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private);
int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
+int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private);
/**
* struct vfio_ccw_private
@@ -69,6 +70,7 @@ int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
* @io_mutex: protect against concurrent update of I/O regions
* @region: additional regions for other subchannel operations
* @cmd_region: MMIO region for asynchronous I/O commands other than START
+ * @schib_region: MMIO region for SCHIB information
* @num_regions: number of additional regions
* @cp: channel program for the current I/O operation
* @irb: irb info received from interrupt
@@ -87,6 +89,7 @@ struct vfio_ccw_private {
struct mutex io_mutex;
struct vfio_ccw_region *region;
struct ccw_cmd_region *cmd_region;
+ struct ccw_schib_region *schib_region;
int num_regions;
struct channel_program cp;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 015516bcfaa3..7a1abbd889bd 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -378,6 +378,7 @@ struct vfio_region_gfx_edid {
/* sub-types for VFIO_REGION_TYPE_CCW */
#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
+#define VFIO_REGION_SUBTYPE_CCW_SCHIB (2)
/*
* The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
diff --git a/include/uapi/linux/vfio_ccw.h b/include/uapi/linux/vfio_ccw.h
index cbecbf0cd54f..758bf214898d 100644
--- a/include/uapi/linux/vfio_ccw.h
+++ b/include/uapi/linux/vfio_ccw.h
@@ -34,4 +34,14 @@ struct ccw_cmd_region {
__u32 ret_code;
} __packed;
+/*
+ * Used for processing commands that read the subchannel-information block
+ * Reading this region triggers a stsch() to hardware
+ * Note: this is controlled by a capability
+ */
+struct ccw_schib_region {
+#define SCHIB_AREA_SIZE 52
+ __u8 schib_area[SCHIB_AREA_SIZE];
+} __packed;
+
#endif
--
2.25.4
next prev parent reply other threads:[~2020-05-25 9:41 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 9:41 [PULL 00/10] vfio-ccw patches for 5.8 Cornelia Huck
2020-05-25 9:41 ` [PULL 01/10] vfio-ccw: Enable transparent CCW IPL from DASD Cornelia Huck
2020-05-25 9:41 ` [PULL 02/10] vfio-ccw: document possible errors Cornelia Huck
2020-05-25 9:41 ` [PULL 03/10] vfio-ccw: Introduce new helper functions to free/destroy regions Cornelia Huck
2020-05-25 9:41 ` [PULL 04/10] vfio-ccw: Register a chp_event callback for vfio-ccw Cornelia Huck
2020-05-25 9:41 ` [PULL 05/10] vfio-ccw: Refactor the unregister of the async regions Cornelia Huck
2020-05-25 9:41 ` Cornelia Huck [this message]
2020-05-25 9:41 ` [PULL 07/10] vfio-ccw: Refactor IRQ handlers Cornelia Huck
2020-05-25 9:41 ` [PULL 08/10] vfio-ccw: Introduce a new CRW region Cornelia Huck
2020-06-02 13:13 ` Cornelia Huck
2020-06-02 14:46 ` Eric Farman
2020-06-02 15:34 ` Cornelia Huck
2020-05-25 9:41 ` [PULL 09/10] vfio-ccw: Wire up the CRW irq and " Cornelia Huck
2020-05-25 9:41 ` [PULL 10/10] vfio-ccw: Add trace for CRW event Cornelia Huck
2020-05-28 12:42 ` [PULL 00/10] vfio-ccw patches for 5.8 Vasily Gorbik
2020-05-28 14:22 ` Cornelia Huck
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200525094115.222299-7-cohuck@redhat.com \
--to=cohuck@redhat.com \
--cc=alifm@linux.ibm.com \
--cc=borntraeger@de.ibm.com \
--cc=farman@linux.ibm.com \
--cc=gor@linux.ibm.com \
--cc=heiko.carstens@de.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=pasic@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.