blob: d857bb8d0fe4ff71b3cf635d6da43eccbe593d5f [file] [log] [blame]
/*
* vfio based subchannel assignment support
*
* Copyright 2017 IBM Corp.
* Copyright 2019 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
* directory.
*/
#include "qemu/osdep.h"
#include <linux/vfio.h>
#include <linux/vfio_ccw.h>
#include <sys/ioctl.h>
#include "qapi/error.h"
#include "hw/vfio/vfio-common.h"
#include "hw/s390x/s390-ccw.h"
#include "hw/s390x/vfio-ccw.h"
#include "hw/qdev-properties.h"
#include "hw/s390x/ccw-device.h"
#include "exec/address-spaces.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
struct VFIOCCWDevice {
S390CCWDevice cdev;
VFIODevice vdev;
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;
uint64_t schib_region_size;
uint64_t schib_region_offset;
struct ccw_schib_region *schib_region;
uint64_t crw_region_size;
uint64_t crw_region_offset;
struct ccw_crw_region *crw_region;
EventNotifier io_notifier;
EventNotifier crw_notifier;
EventNotifier req_notifier;
bool force_orb_pfch;
bool warned_orb_pfch;
};
static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch,
const char *msg)
{
warn_report_once_cond(&vcdev->warned_orb_pfch,
"vfio-ccw (devno %x.%x.%04x): %s",
sch->cssid, sch->ssid, sch->devno, msg);
}
static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
{
vdev->needs_reset = false;
}
/*
* We don't need vfio_hot_reset_multi and vfio_eoi operations for
* vfio_ccw device now.
*/
struct VFIODeviceOps vfio_ccw_ops = {
.vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
};
static IOInstEnding vfio_ccw_handle_request(SubchDev *sch)
{
VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
struct ccw_io_region *region = vcdev->io_region;
int ret;
if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH) && vcdev->force_orb_pfch) {
sch->orb.ctrl0 |= ORB_CTRL0_MASK_PFCH;
warn_once_pfch(vcdev, sch, "PFCH flag forced");
}
QEMU_BUILD_BUG_ON(sizeof(region->orb_area) != sizeof(ORB));
QEMU_BUILD_BUG_ON(sizeof(region->scsw_area) != sizeof(SCSW));
QEMU_BUILD_BUG_ON(sizeof(region->irb_area) != sizeof(IRB));
memset(region, 0, sizeof(*region));
memcpy(region->orb_area, &sch->orb, sizeof(ORB));
memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW));
again:
ret = pwrite(vcdev->vdev.fd, region,
vcdev->io_region_size, vcdev->io_region_offset);
if (ret != vcdev->io_region_size) {
if (errno == EAGAIN) {
goto again;
}
error_report("vfio-ccw: write I/O region failed with errno=%d", errno);
ret = errno ? -errno : -EFAULT;
} else {
ret = 0;
}
switch (ret) {
case 0:
return IOINST_CC_EXPECTED;
case -EBUSY:
return IOINST_CC_BUSY;
case -ENODEV:
case -EACCES:
return IOINST_CC_NOT_OPERATIONAL;
case -EFAULT:
default:
sch_gen_unit_exception(sch);
css_inject_io_interrupt(sch);
return IOINST_CC_EXPECTED;
}
}
static IOInstEnding vfio_ccw_handle_store(SubchDev *sch)
{
VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
SCHIB *schib = &sch->curr_status;
struct ccw_schib_region *region = vcdev->schib_region;
SCHIB *s;
int ret;
/* schib region not available so nothing else to do */
if (!region) {
return IOINST_CC_EXPECTED;
}
memset(region, 0, sizeof(*region));
ret = pread(vcdev->vdev.fd, region, vcdev->schib_region_size,
vcdev->schib_region_offset);
if (ret == -1) {
/*
* Device is probably damaged, but store subchannel does not
* have a nonzero cc defined for this scenario. Log an error,
* and presume things are otherwise fine.
*/
error_report("vfio-ccw: store region read failed with errno=%d", errno);
return IOINST_CC_EXPECTED;
}
/*
* Selectively copy path-related bits of the SCHIB,
* rather than copying the entire struct.
*/
s = (SCHIB *)region->schib_area;
schib->pmcw.pnom = s->pmcw.pnom;
schib->pmcw.lpum = s->pmcw.lpum;
schib->pmcw.pam = s->pmcw.pam;
schib->pmcw.pom = s->pmcw.pom;
if (s->scsw.flags & SCSW_FLAGS_MASK_PNO) {
schib->scsw.flags |= SCSW_FLAGS_MASK_PNO;
}
return IOINST_CC_EXPECTED;
}
static int vfio_ccw_handle_clear(SubchDev *sch)
{
VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
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: write cmd region failed with errno=%d", errno);
ret = errno ? -errno : -EFAULT;
} else {
ret = 0;
}
switch (ret) {
case 0:
case -ENODEV:
case -EACCES:
return ret;
case -EFAULT:
default:
sch_gen_unit_exception(sch);
css_inject_io_interrupt(sch);
return 0;
}
}
static int vfio_ccw_handle_halt(SubchDev *sch)
{
VFIOCCWDevice *vcdev = VFIO_CCW(sch->driver_data);
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: write cmd region failed with errno=%d", errno);
ret = errno ? -errno : -EFAULT;
} else {
ret = 0;
}
switch (ret) {
case 0:
case -EBUSY:
case -ENODEV:
case -EACCES:
return ret;
case -EFAULT:
default:
sch_gen_unit_exception(sch);
css_inject_io_interrupt(sch);
return 0;
}
}
static void vfio_ccw_reset(DeviceState *dev)
{
VFIOCCWDevice *vcdev = VFIO_CCW(dev);
ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
}
static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev)
{
struct ccw_crw_region *region = vcdev->crw_region;
CRW crw;
int size;
/* Keep reading CRWs as long as data is returned */
do {
memset(region, 0, sizeof(*region));
size = pread(vcdev->vdev.fd, region, vcdev->crw_region_size,
vcdev->crw_region_offset);
if (size == -1) {
error_report("vfio-ccw: Read crw region failed with errno=%d",
errno);
break;
}
if (region->crw == 0) {
/* No more CRWs to queue */
break;
}
memcpy(&crw, &region->crw, sizeof(CRW));
css_crw_add_to_queue(crw);
} while (1);
}
static void vfio_ccw_req_notifier_handler(void *opaque)
{
VFIOCCWDevice *vcdev = opaque;
Error *err = NULL;
if (!event_notifier_test_and_clear(&vcdev->req_notifier)) {
return;
}
qdev_unplug(DEVICE(vcdev), &err);
if (err) {
warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
}
}
static void vfio_ccw_crw_notifier_handler(void *opaque)
{
VFIOCCWDevice *vcdev = opaque;
while (event_notifier_test_and_clear(&vcdev->crw_notifier)) {
vfio_ccw_crw_read(vcdev);
}
}
static void vfio_ccw_io_notifier_handler(void *opaque)
{
VFIOCCWDevice *vcdev = opaque;
struct ccw_io_region *region = vcdev->io_region;
CcwDevice *ccw_dev = CCW_DEVICE(vcdev);
SubchDev *sch = ccw_dev->sch;
SCHIB *schib = &sch->curr_status;
SCSW s;
IRB irb;
ESW esw;
int size;
if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
return;
}
size = pread(vcdev->vdev.fd, region, vcdev->io_region_size,
vcdev->io_region_offset);
if (size == -1) {
switch (errno) {
case ENODEV:
/* Generate a deferred cc 3 condition. */
schib->scsw.flags |= SCSW_FLAGS_MASK_CC;
schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
schib->scsw.ctrl |= (SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND);
goto read_err;
case EFAULT:
/* Memory problem, generate channel data check. */
schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
schib->scsw.cstat = SCSW_CSTAT_DATA_CHECK;
schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
goto read_err;
default:
/* Error, generate channel program check. */
schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
schib->scsw.cstat = SCSW_CSTAT_PROG_CHECK;
schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
goto read_err;
}
} else if (size != vcdev->io_region_size) {
/* Information transfer error, generate channel-control check. */
schib->scsw.ctrl &= ~SCSW_ACTL_START_PEND;
schib->scsw.cstat = SCSW_CSTAT_CHN_CTRL_CHK;
schib->scsw.ctrl &= ~SCSW_CTRL_MASK_STCTL;
schib->scsw.ctrl |= SCSW_STCTL_PRIMARY | SCSW_STCTL_SECONDARY |
SCSW_STCTL_ALERT | SCSW_STCTL_STATUS_PEND;
goto read_err;
}
memcpy(&irb, region->irb_area, sizeof(IRB));
/* Update control block via irb. */
s = schib->scsw;
copy_scsw_to_guest(&s, &irb.scsw);
schib->scsw = s;
copy_esw_to_guest(&esw, &irb.esw);
sch->esw = esw;
/* If a uint check is pending, copy sense data. */
if ((schib->scsw.dstat & SCSW_DSTAT_UNIT_CHECK) &&
(schib->pmcw.chars & PMCW_CHARS_MASK_CSENSE)) {
memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw));
}
read_err:
css_inject_io_interrupt(sch);
}
static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
unsigned int irq,
Error **errp)
{
VFIODevice *vdev = &vcdev->vdev;
struct vfio_irq_info *irq_info;
size_t argsz;
int fd;
EventNotifier *notifier;
IOHandler *fd_read;
switch (irq) {
case VFIO_CCW_IO_IRQ_INDEX:
notifier = &vcdev->io_notifier;
fd_read = vfio_ccw_io_notifier_handler;
break;
case VFIO_CCW_CRW_IRQ_INDEX:
notifier = &vcdev->crw_notifier;
fd_read = vfio_ccw_crw_notifier_handler;
break;
case VFIO_CCW_REQ_IRQ_INDEX:
notifier = &vcdev->req_notifier;
fd_read = vfio_ccw_req_notifier_handler;
break;
default:
error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
return;
}
if (vdev->num_irqs < irq + 1) {
error_setg(errp, "vfio: IRQ %u not available (number of irqs %u)",
irq, vdev->num_irqs);
return;
}
argsz = sizeof(*irq_info);
irq_info = g_malloc0(argsz);
irq_info->index = irq;
irq_info->argsz = argsz;
if (ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO,
irq_info) < 0 || irq_info->count < 1) {
error_setg_errno(errp, errno, "vfio: Error getting irq info");
goto out_free_info;
}
if (event_notifier_init(notifier, 0)) {
error_setg_errno(errp, errno,
"vfio: Unable to init event notifier for irq (%d)",
irq);
goto out_free_info;
}
fd = event_notifier_get_fd(notifier);
qemu_set_fd_handler(fd, fd_read, NULL, vcdev);
if (vfio_set_irq_signaling(vdev, irq, 0,
VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
qemu_set_fd_handler(fd, NULL, NULL, vcdev);
event_notifier_cleanup(notifier);
}
out_free_info:
g_free(irq_info);
}
static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
unsigned int irq)
{
Error *err = NULL;
EventNotifier *notifier;
switch (irq) {
case VFIO_CCW_IO_IRQ_INDEX:
notifier = &vcdev->io_notifier;
break;
case VFIO_CCW_CRW_IRQ_INDEX:
notifier = &vcdev->crw_notifier;
break;
case VFIO_CCW_REQ_IRQ_INDEX:
notifier = &vcdev->req_notifier;
break;
default:
error_report("vfio: Unsupported device irq(%d)", irq);
return;
}
if (vfio_set_irq_signaling(&vcdev->vdev, irq, 0,
VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
}
qemu_set_fd_handler(event_notifier_get_fd(notifier),
NULL, NULL, vcdev);
event_notifier_cleanup(notifier);
}
static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
{
VFIODevice *vdev = &vcdev->vdev;
struct vfio_region_info *info;
int ret;
/* Sanity check device */
if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
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: too few regions (%u), expected at least %u",
vdev->num_regions, VFIO_CCW_CONFIG_REGION_INDEX + 1);
return;
}
ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
if (ret) {
error_setg_errno(errp, -ret, "vfio: Error getting config info");
return;
}
vcdev->io_region_size = info->size;
if (sizeof(*vcdev->io_region) != vcdev->io_region_size) {
error_setg(errp, "vfio: Unexpected size of the I/O region");
goto out_err;
}
vcdev->io_region_offset = info->offset;
vcdev->io_region = g_malloc0(info->size);
g_free(info);
/* 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");
goto out_err;
}
vcdev->async_cmd_region_offset = info->offset;
vcdev->async_cmd_region = g_malloc0(info->size);
g_free(info);
}
ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
VFIO_REGION_SUBTYPE_CCW_SCHIB, &info);
if (!ret) {
vcdev->schib_region_size = info->size;
if (sizeof(*vcdev->schib_region) != vcdev->schib_region_size) {
error_setg(errp, "vfio: Unexpected size of the schib region");
goto out_err;
}
vcdev->schib_region_offset = info->offset;
vcdev->schib_region = g_malloc(info->size);
g_free(info);
}
ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
VFIO_REGION_SUBTYPE_CCW_CRW, &info);
if (!ret) {
vcdev->crw_region_size = info->size;
if (sizeof(*vcdev->crw_region) != vcdev->crw_region_size) {
error_setg(errp, "vfio: Unexpected size of the CRW region");
goto out_err;
}
vcdev->crw_region_offset = info->offset;
vcdev->crw_region = g_malloc(info->size);
g_free(info);
}
return;
out_err:
g_free(vcdev->crw_region);
g_free(vcdev->schib_region);
g_free(vcdev->async_cmd_region);
g_free(vcdev->io_region);
g_free(info);
return;
}
static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
{
g_free(vcdev->crw_region);
g_free(vcdev->schib_region);
g_free(vcdev->async_cmd_region);
g_free(vcdev->io_region);
}
static void vfio_ccw_realize(DeviceState *dev, Error **errp)
{
S390CCWDevice *cdev = S390_CCW_DEVICE(dev);
VFIOCCWDevice *vcdev = VFIO_CCW(cdev);
S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
VFIODevice *vbasedev = &vcdev->vdev;
Error *err = NULL;
int ret;
/* Call the class init function for subchannel. */
if (cdc->realize) {
cdc->realize(cdev, vcdev->vdev.sysfsdev, &err);
if (err) {
goto out_err_propagate;
}
}
vbasedev->ops = &vfio_ccw_ops;
vbasedev->type = VFIO_DEVICE_TYPE_CCW;
vbasedev->name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid,
vcdev->cdev.hostid.ssid,
vcdev->cdev.hostid.devid);
vbasedev->dev = dev;
/*
* All vfio-ccw devices are believed to operate in a way compatible with
* discarding of memory in RAM blocks, ie. pages pinned in the host are
* in the current working set of the guest driver and therefore never
* overlap e.g., with pages available to the guest balloon driver. This
* needs to be set before vfio_get_device() for vfio common to handle
* ram_block_discard_disable().
*/
vbasedev->ram_block_discard_allowed = true;
ret = vfio_attach_device(cdev->mdevid, vbasedev,
&address_space_memory, errp);
if (ret) {
goto out_attach_dev_err;
}
vfio_ccw_get_region(vcdev, &err);
if (err) {
goto out_region_err;
}
vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
if (err) {
goto out_io_notifier_err;
}
if (vcdev->crw_region) {
vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
if (err) {
goto out_irq_notifier_err;
}
}
vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
if (err) {
/*
* Report this error, but do not make it a failing condition.
* Lack of this IRQ in the host does not prevent normal operation.
*/
error_report_err(err);
}
return;
out_irq_notifier_err:
vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
out_io_notifier_err:
vfio_ccw_put_region(vcdev);
out_region_err:
vfio_detach_device(vbasedev);
out_attach_dev_err:
g_free(vbasedev->name);
if (cdc->unrealize) {
cdc->unrealize(cdev);
}
out_err_propagate:
error_propagate(errp, err);
}
static void vfio_ccw_unrealize(DeviceState *dev)
{
S390CCWDevice *cdev = S390_CCW_DEVICE(dev);
VFIOCCWDevice *vcdev = VFIO_CCW(cdev);
S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
vfio_ccw_put_region(vcdev);
vfio_detach_device(&vcdev->vdev);
g_free(vcdev->vdev.name);
if (cdc->unrealize) {
cdc->unrealize(cdev);
}
}
static Property vfio_ccw_properties[] = {
DEFINE_PROP_STRING("sysfsdev", VFIOCCWDevice, vdev.sysfsdev),
DEFINE_PROP_BOOL("force-orb-pfch", VFIOCCWDevice, force_orb_pfch, false),
DEFINE_PROP_END_OF_LIST(),
};
static const VMStateDescription vfio_ccw_vmstate = {
.name = "vfio-ccw",
.unmigratable = 1,
};
static void vfio_ccw_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
S390CCWDeviceClass *cdc = S390_CCW_DEVICE_CLASS(klass);
device_class_set_props(dc, vfio_ccw_properties);
dc->vmsd = &vfio_ccw_vmstate;
dc->desc = "VFIO-based subchannel assignment";
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
dc->realize = vfio_ccw_realize;
dc->unrealize = vfio_ccw_unrealize;
dc->reset = vfio_ccw_reset;
cdc->handle_request = vfio_ccw_handle_request;
cdc->handle_halt = vfio_ccw_handle_halt;
cdc->handle_clear = vfio_ccw_handle_clear;
cdc->handle_store = vfio_ccw_handle_store;
}
static const TypeInfo vfio_ccw_info = {
.name = TYPE_VFIO_CCW,
.parent = TYPE_S390_CCW,
.instance_size = sizeof(VFIOCCWDevice),
.class_init = vfio_ccw_class_init,
};
static void register_vfio_ccw_type(void)
{
type_register_static(&vfio_ccw_info);
}
type_init(register_vfio_ccw_type)