* [PATCH 0/2] vfio-ccw: support hsch/csch (QEMU part)
@ 2018-11-22 16:54 ` Cornelia Huck
0 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-22 16:54 UTC (permalink / raw)
To: Halil Pasic, Eric Farman, Farhan Ali, Pierre Morel
Cc: linux-s390, kvm, Cornelia Huck, Alex Williamson, qemu-devel, qemu-s390x
[This is the QEMU part, git tree is available at
https://github.com/cohuck/qemu vfio-ccw-caps
The companion Linux kernel patches are available at
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-caps]
Currently, vfio-ccw only relays START SUBCHANNEL requests to the real
device. This tends to work well for the most common 'good path' scenarios;
however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like
clearing pending requests at the device is currently not supported.
This may be a problem for e.g. error recovery.
This patch series makes use of the newly introduced async command region
to issue hsch/csch; if it is not present, continue to emulate hsch/csch,
as before.
[I'm not quite happy with how this async processing hooks up in css.c;
ideas welcome.]
Very lightly tested (I can interact with a dasd as before; I have not
found a reliable way to trigger hsch/csch in the Linux dasd guest driver.)
Cornelia Huck (2):
vfio-ccw: new capability chain support
vfio-ccw: support async command subregion
hw/s390x/css.c | 27 ++++++--
hw/vfio/ccw.c | 109 ++++++++++++++++++++++++++++++++-
include/hw/s390x/s390-ccw.h | 3 +
linux-headers/linux/vfio.h | 4 ++
linux-headers/linux/vfio_ccw.h | 12 ++++
5 files changed, 149 insertions(+), 6 deletions(-)
--
2.17.2
^ permalink raw reply [flat|nested] 16+ messages in thread
* [Qemu-devel] [PATCH 0/2] vfio-ccw: support hsch/csch (QEMU part)
@ 2018-11-22 16:54 ` Cornelia Huck
0 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-22 16:54 UTC (permalink / raw)
To: Halil Pasic, Eric Farman, Farhan Ali, Pierre Morel
Cc: linux-s390, kvm, qemu-s390x, qemu-devel, Alex Williamson, Cornelia Huck
[This is the QEMU part, git tree is available at
https://github.com/cohuck/qemu vfio-ccw-caps
The companion Linux kernel patches are available at
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-caps]
Currently, vfio-ccw only relays START SUBCHANNEL requests to the real
device. This tends to work well for the most common 'good path' scenarios;
however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like
clearing pending requests at the device is currently not supported.
This may be a problem for e.g. error recovery.
This patch series makes use of the newly introduced async command region
to issue hsch/csch; if it is not present, continue to emulate hsch/csch,
as before.
[I'm not quite happy with how this async processing hooks up in css.c;
ideas welcome.]
Very lightly tested (I can interact with a dasd as before; I have not
found a reliable way to trigger hsch/csch in the Linux dasd guest driver.)
Cornelia Huck (2):
vfio-ccw: new capability chain support
vfio-ccw: support async command subregion
hw/s390x/css.c | 27 ++++++--
hw/vfio/ccw.c | 109 ++++++++++++++++++++++++++++++++-
include/hw/s390x/s390-ccw.h | 3 +
linux-headers/linux/vfio.h | 4 ++
linux-headers/linux/vfio_ccw.h | 12 ++++
5 files changed, 149 insertions(+), 6 deletions(-)
--
2.17.2
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH 1/2] vfio-ccw: new capability chain support
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
@ 2018-11-22 16:54 ` Cornelia Huck
-1 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-22 16:54 UTC (permalink / raw)
To: Halil Pasic, Eric Farman, Farhan Ali, Pierre Morel
Cc: linux-s390, kvm, Cornelia Huck, Alex Williamson, qemu-devel, qemu-s390x
To be replaced with a real linux-headers update.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
| 4 ++++
| 12 ++++++++++++
2 files changed, 16 insertions(+)
--git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index ceb6453394..c9ba8d52a0 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -297,12 +297,16 @@ struct vfio_region_info_cap_type {
#define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
#define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
+#define VFIO_REGION_TYPE_CCW (1 << 30)
/* 8086 Vendor sub-types */
#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
+/* ccw sub-types */
+#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
+
/*
* The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
* which allows direct access to non-MSIX registers which happened to be within
--git a/linux-headers/linux/vfio_ccw.h b/linux-headers/linux/vfio_ccw.h
index 5bf96c3812..fcc3e69ef5 100644
--- a/linux-headers/linux/vfio_ccw.h
+++ b/linux-headers/linux/vfio_ccw.h
@@ -12,6 +12,7 @@
#include <linux/types.h>
+/* used for START SUBCHANNEL, always present */
struct ccw_io_region {
#define ORB_AREA_SIZE 12
__u8 orb_area[ORB_AREA_SIZE];
@@ -22,4 +23,15 @@ struct ccw_io_region {
__u32 ret_code;
} __attribute__((packed));
+/*
+ * used for processing commands that trigger asynchronous actions
+ * Note: this is controlled by a capability
+ */
+#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;
+} __attribute__((packed));
+
#endif
--
2.17.2
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [Qemu-devel] [PATCH 1/2] vfio-ccw: new capability chain support
@ 2018-11-22 16:54 ` Cornelia Huck
0 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-22 16:54 UTC (permalink / raw)
To: Halil Pasic, Eric Farman, Farhan Ali, Pierre Morel
Cc: linux-s390, kvm, qemu-s390x, qemu-devel, Alex Williamson, Cornelia Huck
To be replaced with a real linux-headers update.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
| 4 ++++
| 12 ++++++++++++
2 files changed, 16 insertions(+)
--git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index ceb6453394..c9ba8d52a0 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -297,12 +297,16 @@ struct vfio_region_info_cap_type {
#define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
#define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
+#define VFIO_REGION_TYPE_CCW (1 << 30)
/* 8086 Vendor sub-types */
#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
+/* ccw sub-types */
+#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
+
/*
* The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
* which allows direct access to non-MSIX registers which happened to be within
--git a/linux-headers/linux/vfio_ccw.h b/linux-headers/linux/vfio_ccw.h
index 5bf96c3812..fcc3e69ef5 100644
--- a/linux-headers/linux/vfio_ccw.h
+++ b/linux-headers/linux/vfio_ccw.h
@@ -12,6 +12,7 @@
#include <linux/types.h>
+/* used for START SUBCHANNEL, always present */
struct ccw_io_region {
#define ORB_AREA_SIZE 12
__u8 orb_area[ORB_AREA_SIZE];
@@ -22,4 +23,15 @@ struct ccw_io_region {
__u32 ret_code;
} __attribute__((packed));
+/*
+ * used for processing commands that trigger asynchronous actions
+ * Note: this is controlled by a capability
+ */
+#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;
+} __attribute__((packed));
+
#endif
--
2.17.2
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH 2/2] vfio-ccw: support async command subregion
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
@ 2018-11-22 16:54 ` Cornelia Huck
-1 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-22 16:54 UTC (permalink / raw)
To: Halil Pasic, Eric Farman, Farhan Ali, Pierre Morel
Cc: linux-s390, kvm, Cornelia Huck, Alex Williamson, qemu-devel, qemu-s390x
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 <cohuck@redhat.com>
---
hw/s390x/css.c | 27 +++++++--
hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
include/hw/s390x/s390-ccw.h | 3 +
3 files changed, 133 insertions(+), 6 deletions(-)
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 04ec5cc970..0897c041c5 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;
@@ -1194,6 +1195,26 @@ 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)
{
@@ -1237,11 +1258,9 @@ IOInstEnding do_subchannel_work_passthrough(SubchDev *sch)
SCSW *s = &sch->curr_status.scsw;
if (s->ctrl & SCSW_FCTL_CLEAR_FUNC) {
- /* TODO: Clear handling */
- sch_handle_clear_func(sch);
+ sch_handle_clear_func_passthrough(sch);
} else if (s->ctrl & SCSW_FCTL_HALT_FUNC) {
- /* TODO: Halt handling */
- sch_handle_halt_func(sch);
+ sch_handle_halt_func_passthrough(sch);
} else if (s->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 9246729a75..dd0fecf168 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 2018 Red Hat, Inc.
+ *
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
* Pierre Morel <pmorel@linux.vnet.ibm.com>
+ * Cornelia Huck <cohuck@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 @@ typedef 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: wirte I/O 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: wirte I/O 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);
@@ -285,9 +372,13 @@ 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;
}
@@ -307,6 +398,20 @@ 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);
}
diff --git a/include/hw/s390x/s390-ccw.h b/include/hw/s390x/s390-ccw.h
index 7d15a1a5d4..38d54a7a69 100644
--- a/include/hw/s390x/s390-ccw.h
+++ b/include/hw/s390x/s390-ccw.h
@@ -36,4 +36,7 @@ typedef struct S390CCWDeviceClass {
IOInstEnding (*handle_request) (SubchDev *sch);
} S390CCWDeviceClass;
+int vfio_ccw_handle_clear(SubchDev *sch);
+int vfio_ccw_handle_halt(SubchDev *sch);
+
#endif
--
2.17.2
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [Qemu-devel] [PATCH 2/2] vfio-ccw: support async command subregion
@ 2018-11-22 16:54 ` Cornelia Huck
0 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-22 16:54 UTC (permalink / raw)
To: Halil Pasic, Eric Farman, Farhan Ali, Pierre Morel
Cc: linux-s390, kvm, qemu-s390x, qemu-devel, Alex Williamson, Cornelia Huck
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 <cohuck@redhat.com>
---
hw/s390x/css.c | 27 +++++++--
hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
include/hw/s390x/s390-ccw.h | 3 +
3 files changed, 133 insertions(+), 6 deletions(-)
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 04ec5cc970..0897c041c5 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;
@@ -1194,6 +1195,26 @@ 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)
{
@@ -1237,11 +1258,9 @@ IOInstEnding do_subchannel_work_passthrough(SubchDev *sch)
SCSW *s = &sch->curr_status.scsw;
if (s->ctrl & SCSW_FCTL_CLEAR_FUNC) {
- /* TODO: Clear handling */
- sch_handle_clear_func(sch);
+ sch_handle_clear_func_passthrough(sch);
} else if (s->ctrl & SCSW_FCTL_HALT_FUNC) {
- /* TODO: Halt handling */
- sch_handle_halt_func(sch);
+ sch_handle_halt_func_passthrough(sch);
} else if (s->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 9246729a75..dd0fecf168 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 2018 Red Hat, Inc.
+ *
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
* Pierre Morel <pmorel@linux.vnet.ibm.com>
+ * Cornelia Huck <cohuck@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 @@ typedef 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: wirte I/O 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: wirte I/O 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);
@@ -285,9 +372,13 @@ 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;
}
@@ -307,6 +398,20 @@ 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);
}
diff --git a/include/hw/s390x/s390-ccw.h b/include/hw/s390x/s390-ccw.h
index 7d15a1a5d4..38d54a7a69 100644
--- a/include/hw/s390x/s390-ccw.h
+++ b/include/hw/s390x/s390-ccw.h
@@ -36,4 +36,7 @@ typedef struct S390CCWDeviceClass {
IOInstEnding (*handle_request) (SubchDev *sch);
} S390CCWDeviceClass;
+int vfio_ccw_handle_clear(SubchDev *sch);
+int vfio_ccw_handle_halt(SubchDev *sch);
+
#endif
--
2.17.2
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH 1/2] vfio-ccw: new capability chain support
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
@ 2018-11-23 14:12 ` Pierre Morel
-1 siblings, 0 replies; 16+ messages in thread
From: Pierre Morel @ 2018-11-23 14:12 UTC (permalink / raw)
To: Cornelia Huck, Halil Pasic, Eric Farman, Farhan Ali
Cc: linux-s390, qemu-s390x, Alex Williamson, qemu-devel, kvm
On 22/11/2018 17:54, Cornelia Huck wrote:
> To be replaced with a real linux-headers update.
>
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
> linux-headers/linux/vfio.h | 4 ++++
> linux-headers/linux/vfio_ccw.h | 12 ++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> index ceb6453394..c9ba8d52a0 100644
> --- a/linux-headers/linux/vfio.h
> +++ b/linux-headers/linux/vfio.h
> @@ -297,12 +297,16 @@ struct vfio_region_info_cap_type {
>
> #define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
> #define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
> +#define VFIO_REGION_TYPE_CCW (1 << 30)
>
> /* 8086 Vendor sub-types */
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
>
> +/* ccw sub-types */
> +#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
> +
> /*
> * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
> * which allows direct access to non-MSIX registers which happened to be within
> diff --git a/linux-headers/linux/vfio_ccw.h b/linux-headers/linux/vfio_ccw.h
> index 5bf96c3812..fcc3e69ef5 100644
> --- a/linux-headers/linux/vfio_ccw.h
> +++ b/linux-headers/linux/vfio_ccw.h
> @@ -12,6 +12,7 @@
>
> #include <linux/types.h>
>
> +/* used for START SUBCHANNEL, always present */
> struct ccw_io_region {
> #define ORB_AREA_SIZE 12
> __u8 orb_area[ORB_AREA_SIZE];
> @@ -22,4 +23,15 @@ struct ccw_io_region {
> __u32 ret_code;
> } __attribute__((packed));
>
> +/*
> + * used for processing commands that trigger asynchronous actions
> + * Note: this is controlled by a capability
> + */
> +#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;
> +} __attribute__((packed));
> +
> #endif
>
LGTM
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Qemu-devel] [PATCH 1/2] vfio-ccw: new capability chain support
@ 2018-11-23 14:12 ` Pierre Morel
0 siblings, 0 replies; 16+ messages in thread
From: Pierre Morel @ 2018-11-23 14:12 UTC (permalink / raw)
To: Cornelia Huck, Halil Pasic, Eric Farman, Farhan Ali
Cc: linux-s390, kvm, qemu-s390x, qemu-devel, Alex Williamson
On 22/11/2018 17:54, Cornelia Huck wrote:
> To be replaced with a real linux-headers update.
>
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
> linux-headers/linux/vfio.h | 4 ++++
> linux-headers/linux/vfio_ccw.h | 12 ++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> index ceb6453394..c9ba8d52a0 100644
> --- a/linux-headers/linux/vfio.h
> +++ b/linux-headers/linux/vfio.h
> @@ -297,12 +297,16 @@ struct vfio_region_info_cap_type {
>
> #define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
> #define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
> +#define VFIO_REGION_TYPE_CCW (1 << 30)
>
> /* 8086 Vendor sub-types */
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
> #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
>
> +/* ccw sub-types */
> +#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
> +
> /*
> * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
> * which allows direct access to non-MSIX registers which happened to be within
> diff --git a/linux-headers/linux/vfio_ccw.h b/linux-headers/linux/vfio_ccw.h
> index 5bf96c3812..fcc3e69ef5 100644
> --- a/linux-headers/linux/vfio_ccw.h
> +++ b/linux-headers/linux/vfio_ccw.h
> @@ -12,6 +12,7 @@
>
> #include <linux/types.h>
>
> +/* used for START SUBCHANNEL, always present */
> struct ccw_io_region {
> #define ORB_AREA_SIZE 12
> __u8 orb_area[ORB_AREA_SIZE];
> @@ -22,4 +23,15 @@ struct ccw_io_region {
> __u32 ret_code;
> } __attribute__((packed));
>
> +/*
> + * used for processing commands that trigger asynchronous actions
> + * Note: this is controlled by a capability
> + */
> +#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;
> +} __attribute__((packed));
> +
> #endif
>
LGTM
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] vfio-ccw: support async command subregion
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
@ 2018-11-23 14:13 ` Pierre Morel
-1 siblings, 0 replies; 16+ messages in thread
From: Pierre Morel @ 2018-11-23 14:13 UTC (permalink / raw)
To: Cornelia Huck, Halil Pasic, Eric Farman, Farhan Ali
Cc: linux-s390, qemu-s390x, Alex Williamson, qemu-devel, kvm
On 22/11/2018 17:54, 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 <cohuck@redhat.com>
> ---
> hw/s390x/css.c | 27 +++++++--
> hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
> include/hw/s390x/s390-ccw.h | 3 +
> 3 files changed, 133 insertions(+), 6 deletions(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 04ec5cc970..0897c041c5 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;
> @@ -1194,6 +1195,26 @@ 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)
> {
>
> @@ -1237,11 +1258,9 @@ IOInstEnding do_subchannel_work_passthrough(SubchDev *sch)
> SCSW *s = &sch->curr_status.scsw;
>
> if (s->ctrl & SCSW_FCTL_CLEAR_FUNC) {
> - /* TODO: Clear handling */
> - sch_handle_clear_func(sch);
> + sch_handle_clear_func_passthrough(sch);
> } else if (s->ctrl & SCSW_FCTL_HALT_FUNC) {
> - /* TODO: Halt handling */
> - sch_handle_halt_func(sch);
> + sch_handle_halt_func_passthrough(sch);
> } else if (s->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 9246729a75..dd0fecf168 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 2018 Red Hat, Inc.
> + *
> * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
> * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
> * Pierre Morel <pmorel@linux.vnet.ibm.com>
> + * Cornelia Huck <cohuck@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 @@ typedef 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) {
Where do the EAGAIN come from?
> + goto again;
> + }
> + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
> + ret = -errno;
> + } else {
> + ret = region->ret_code;
> + }
> + switch (ret) {
> + case 0:
> + case -ENODEV:
> + case -EACCES:
should never happen?
> + return 0;
> + case -EFAULT:
> + default:
> + sch_gen_unit_exception(sch);
> + css_inject_io_interrupt(sch);
> + return 0;
> + }
> +}
> +
otherwise LGTM
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Qemu-devel] [PATCH 2/2] vfio-ccw: support async command subregion
@ 2018-11-23 14:13 ` Pierre Morel
0 siblings, 0 replies; 16+ messages in thread
From: Pierre Morel @ 2018-11-23 14:13 UTC (permalink / raw)
To: Cornelia Huck, Halil Pasic, Eric Farman, Farhan Ali
Cc: linux-s390, kvm, qemu-s390x, qemu-devel, Alex Williamson
On 22/11/2018 17:54, 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 <cohuck@redhat.com>
> ---
> hw/s390x/css.c | 27 +++++++--
> hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
> include/hw/s390x/s390-ccw.h | 3 +
> 3 files changed, 133 insertions(+), 6 deletions(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 04ec5cc970..0897c041c5 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;
> @@ -1194,6 +1195,26 @@ 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)
> {
>
> @@ -1237,11 +1258,9 @@ IOInstEnding do_subchannel_work_passthrough(SubchDev *sch)
> SCSW *s = &sch->curr_status.scsw;
>
> if (s->ctrl & SCSW_FCTL_CLEAR_FUNC) {
> - /* TODO: Clear handling */
> - sch_handle_clear_func(sch);
> + sch_handle_clear_func_passthrough(sch);
> } else if (s->ctrl & SCSW_FCTL_HALT_FUNC) {
> - /* TODO: Halt handling */
> - sch_handle_halt_func(sch);
> + sch_handle_halt_func_passthrough(sch);
> } else if (s->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 9246729a75..dd0fecf168 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 2018 Red Hat, Inc.
> + *
> * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
> * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
> * Pierre Morel <pmorel@linux.vnet.ibm.com>
> + * Cornelia Huck <cohuck@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 @@ typedef 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) {
Where do the EAGAIN come from?
> + goto again;
> + }
> + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
> + ret = -errno;
> + } else {
> + ret = region->ret_code;
> + }
> + switch (ret) {
> + case 0:
> + case -ENODEV:
> + case -EACCES:
should never happen?
> + return 0;
> + case -EFAULT:
> + default:
> + sch_gen_unit_exception(sch);
> + css_inject_io_interrupt(sch);
> + return 0;
> + }
> +}
> +
otherwise LGTM
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] vfio-ccw: support async command subregion
2018-11-23 14:13 ` [Qemu-devel] " Pierre Morel
@ 2018-11-26 9:58 ` Cornelia Huck
-1 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-26 9:58 UTC (permalink / raw)
To: Pierre Morel
Cc: linux-s390, Eric Farman, Alex Williamson, kvm, Farhan Ali,
qemu-devel, Halil Pasic, qemu-s390x
On Fri, 23 Nov 2018 15:13:12 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 22/11/2018 17:54, 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 <cohuck@redhat.com>
> > ---
> > hw/s390x/css.c | 27 +++++++--
> > hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
> > include/hw/s390x/s390-ccw.h | 3 +
> > 3 files changed, 133 insertions(+), 6 deletions(-)
> >
> > @@ -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) {
>
>
> Where do the EAGAIN come from?
It might be set by pwrite.
>
>
> > + goto again;
> > + }
> > + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
I should also fix up this message here and for hsch as well :)
> > + ret = -errno;
> > + } else {
> > + ret = region->ret_code;
> > + }
> > + switch (ret) {
> > + case 0:
> > + case -ENODEV:
> > + case -EACCES:
>
> should never happen?
It should not happen; but it can nevertheless be returned, so...
>
> > + return 0;
> > + case -EFAULT:
> > + default:
> > + sch_gen_unit_exception(sch);
> > + css_inject_io_interrupt(sch);
> > + return 0;
> > + }
> > +}
> > +
>
> otherwise LGTM
Thanks!
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Qemu-devel] [PATCH 2/2] vfio-ccw: support async command subregion
@ 2018-11-26 9:58 ` Cornelia Huck
0 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-26 9:58 UTC (permalink / raw)
To: Pierre Morel
Cc: Halil Pasic, Eric Farman, Farhan Ali, linux-s390, kvm,
qemu-s390x, qemu-devel, Alex Williamson
On Fri, 23 Nov 2018 15:13:12 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 22/11/2018 17:54, 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 <cohuck@redhat.com>
> > ---
> > hw/s390x/css.c | 27 +++++++--
> > hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
> > include/hw/s390x/s390-ccw.h | 3 +
> > 3 files changed, 133 insertions(+), 6 deletions(-)
> >
> > @@ -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) {
>
>
> Where do the EAGAIN come from?
It might be set by pwrite.
>
>
> > + goto again;
> > + }
> > + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
I should also fix up this message here and for hsch as well :)
> > + ret = -errno;
> > + } else {
> > + ret = region->ret_code;
> > + }
> > + switch (ret) {
> > + case 0:
> > + case -ENODEV:
> > + case -EACCES:
>
> should never happen?
It should not happen; but it can nevertheless be returned, so...
>
> > + return 0;
> > + case -EFAULT:
> > + default:
> > + sch_gen_unit_exception(sch);
> > + css_inject_io_interrupt(sch);
> > + return 0;
> > + }
> > +}
> > +
>
> otherwise LGTM
Thanks!
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] vfio-ccw: support async command subregion
2018-11-26 9:58 ` [Qemu-devel] " Cornelia Huck
@ 2018-11-26 18:01 ` Pierre Morel
-1 siblings, 0 replies; 16+ messages in thread
From: Pierre Morel @ 2018-11-26 18:01 UTC (permalink / raw)
To: Cornelia Huck
Cc: linux-s390, Eric Farman, Alex Williamson, kvm, Farhan Ali,
qemu-devel, Halil Pasic, qemu-s390x
On 26/11/2018 10:58, Cornelia Huck wrote:
> On Fri, 23 Nov 2018 15:13:12 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
>
>> On 22/11/2018 17:54, 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 <cohuck@redhat.com>
>>> ---
>>> hw/s390x/css.c | 27 +++++++--
>>> hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
>>> include/hw/s390x/s390-ccw.h | 3 +
>>> 3 files changed, 133 insertions(+), 6 deletions(-)
>>>
>
>>> @@ -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) {
>>
>>
>> Where do the EAGAIN come from?
>
> It might be set by pwrite.
I saw that the man indicate this, and so we are legitimate to handle the
fail case, but I did not find EAGAIN in the path of the write for
accessing devices and I did not find it in the access to the CSS.
If we do not set it explicitly from the driver, the concern I have is:
isn't it dangerous to try again and shouldn't we better abort?
>
>>
>>
>>> + goto again;
>>> + }
>>> + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
>
> I should also fix up this message here and for hsch as well :)
>
>>> + ret = -errno;
>>> + } else {
>>> + ret = region->ret_code;
>>> + }
>>> + switch (ret) {
>>> + case 0:
>>> + case -ENODEV:
>>> + case -EACCES:
>>
>> should never happen?
>
> It should not happen; but it can nevertheless be returned, so...
I understand: nothing to clear :)
>
>>
>>> + return 0;
>>> + case -EFAULT:
>>> + default:
>>> + sch_gen_unit_exception(sch);
>>> + css_inject_io_interrupt(sch);
>>> + return 0;
>>> + }
>>> +}
>>> +
>>
>> otherwise LGTM
>
> Thanks!
>
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Qemu-devel] [PATCH 2/2] vfio-ccw: support async command subregion
@ 2018-11-26 18:01 ` Pierre Morel
0 siblings, 0 replies; 16+ messages in thread
From: Pierre Morel @ 2018-11-26 18:01 UTC (permalink / raw)
To: Cornelia Huck
Cc: Halil Pasic, Eric Farman, Farhan Ali, linux-s390, kvm,
qemu-s390x, qemu-devel, Alex Williamson
On 26/11/2018 10:58, Cornelia Huck wrote:
> On Fri, 23 Nov 2018 15:13:12 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
>
>> On 22/11/2018 17:54, 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 <cohuck@redhat.com>
>>> ---
>>> hw/s390x/css.c | 27 +++++++--
>>> hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
>>> include/hw/s390x/s390-ccw.h | 3 +
>>> 3 files changed, 133 insertions(+), 6 deletions(-)
>>>
>
>>> @@ -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) {
>>
>>
>> Where do the EAGAIN come from?
>
> It might be set by pwrite.
I saw that the man indicate this, and so we are legitimate to handle the
fail case, but I did not find EAGAIN in the path of the write for
accessing devices and I did not find it in the access to the CSS.
If we do not set it explicitly from the driver, the concern I have is:
isn't it dangerous to try again and shouldn't we better abort?
>
>>
>>
>>> + goto again;
>>> + }
>>> + error_report("vfio-ccw: wirte I/O region failed with errno=%d", errno);
>
> I should also fix up this message here and for hsch as well :)
>
>>> + ret = -errno;
>>> + } else {
>>> + ret = region->ret_code;
>>> + }
>>> + switch (ret) {
>>> + case 0:
>>> + case -ENODEV:
>>> + case -EACCES:
>>
>> should never happen?
>
> It should not happen; but it can nevertheless be returned, so...
I understand: nothing to clear :)
>
>>
>>> + return 0;
>>> + case -EFAULT:
>>> + default:
>>> + sch_gen_unit_exception(sch);
>>> + css_inject_io_interrupt(sch);
>>> + return 0;
>>> + }
>>> +}
>>> +
>>
>> otherwise LGTM
>
> Thanks!
>
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 2/2] vfio-ccw: support async command subregion
2018-11-26 18:01 ` [Qemu-devel] " Pierre Morel
@ 2018-11-26 18:07 ` Cornelia Huck
-1 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-26 18:07 UTC (permalink / raw)
To: Pierre Morel
Cc: linux-s390, Eric Farman, Alex Williamson, kvm, Farhan Ali,
qemu-devel, Halil Pasic, qemu-s390x
On Mon, 26 Nov 2018 19:01:55 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 26/11/2018 10:58, Cornelia Huck wrote:
> > On Fri, 23 Nov 2018 15:13:12 +0100
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >> On 22/11/2018 17:54, 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 <cohuck@redhat.com>
> >>> ---
> >>> hw/s390x/css.c | 27 +++++++--
> >>> hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
> >>> include/hw/s390x/s390-ccw.h | 3 +
> >>> 3 files changed, 133 insertions(+), 6 deletions(-)
> >>>
> >
> >>> @@ -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) {
> >>
> >>
> >> Where do the EAGAIN come from?
> >
> > It might be set by pwrite.
>
> I saw that the man indicate this, and so we are legitimate to handle the
> fail case, but I did not find EAGAIN in the path of the write for
> accessing devices and I did not find it in the access to the CSS.
>
> If we do not set it explicitly from the driver, the concern I have is:
> isn't it dangerous to try again and shouldn't we better abort?
If it is set by the reason stated in the man page, retry sounds like
the sensible thing, doesn't it? I don't think I've yet seen it in
practice, though.
[I don't think we should need to comb through the whole code path to
find out what might happen or not, at some point we'll just have to
trust the documentation.]
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Qemu-devel] [PATCH 2/2] vfio-ccw: support async command subregion
@ 2018-11-26 18:07 ` Cornelia Huck
0 siblings, 0 replies; 16+ messages in thread
From: Cornelia Huck @ 2018-11-26 18:07 UTC (permalink / raw)
To: Pierre Morel
Cc: Halil Pasic, Eric Farman, Farhan Ali, linux-s390, kvm,
qemu-s390x, qemu-devel, Alex Williamson
On Mon, 26 Nov 2018 19:01:55 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 26/11/2018 10:58, Cornelia Huck wrote:
> > On Fri, 23 Nov 2018 15:13:12 +0100
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >> On 22/11/2018 17:54, 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 <cohuck@redhat.com>
> >>> ---
> >>> hw/s390x/css.c | 27 +++++++--
> >>> hw/vfio/ccw.c | 109 +++++++++++++++++++++++++++++++++++-
> >>> include/hw/s390x/s390-ccw.h | 3 +
> >>> 3 files changed, 133 insertions(+), 6 deletions(-)
> >>>
> >
> >>> @@ -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) {
> >>
> >>
> >> Where do the EAGAIN come from?
> >
> > It might be set by pwrite.
>
> I saw that the man indicate this, and so we are legitimate to handle the
> fail case, but I did not find EAGAIN in the path of the write for
> accessing devices and I did not find it in the access to the CSS.
>
> If we do not set it explicitly from the driver, the concern I have is:
> isn't it dangerous to try again and shouldn't we better abort?
If it is set by the reason stated in the man page, retry sounds like
the sensible thing, doesn't it? I don't think I've yet seen it in
practice, though.
[I don't think we should need to comb through the whole code path to
find out what might happen or not, at some point we'll just have to
trust the documentation.]
^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2018-11-26 18:21 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-11-22 16:54 [PATCH 0/2] vfio-ccw: support hsch/csch (QEMU part) Cornelia Huck
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
2018-11-22 16:54 ` [PATCH 1/2] vfio-ccw: new capability chain support Cornelia Huck
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
2018-11-23 14:12 ` Pierre Morel
2018-11-23 14:12 ` [Qemu-devel] " Pierre Morel
2018-11-22 16:54 ` [PATCH 2/2] vfio-ccw: support async command subregion Cornelia Huck
2018-11-22 16:54 ` [Qemu-devel] " Cornelia Huck
2018-11-23 14:13 ` Pierre Morel
2018-11-23 14:13 ` [Qemu-devel] " Pierre Morel
2018-11-26 9:58 ` Cornelia Huck
2018-11-26 9:58 ` [Qemu-devel] " Cornelia Huck
2018-11-26 18:01 ` Pierre Morel
2018-11-26 18:01 ` [Qemu-devel] " Pierre Morel
2018-11-26 18:07 ` Cornelia Huck
2018-11-26 18:07 ` [Qemu-devel] " Cornelia Huck
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