qemu-e2k/hw/vfio/ccw.c

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/*
* 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/sysbus.h"
#include "hw/vfio/vfio.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;
EventNotifier io_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)
{
S390CCWDevice *cdev = sch->driver_data;
VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
struct ccw_io_region *region = vcdev->io_region;
int ret;
if (!(sch->orb.ctrl0 & ORB_CTRL0_MASK_PFCH)) {
if (!(vcdev->force_orb_pfch)) {
warn_once_pfch(vcdev, sch, "requires PFCH flag set");
sch_gen_unit_exception(sch);
css_inject_io_interrupt(sch);
return IOINST_CC_EXPECTED;
} else {
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;
} else {
ret = region->ret_code;
}
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 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: write cmd 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;
}
}
static 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: write cmd 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);
S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
}
static void vfio_ccw_io_notifier_handler(void *opaque)
{
VFIOCCWDevice *vcdev = opaque;
struct ccw_io_region *region = vcdev->io_region;
S390CCWDevice *cdev = S390_CCW_DEVICE(vcdev);
CcwDevice *ccw_dev = CCW_DEVICE(cdev);
SubchDev *sch = ccw_dev->sch;
SCHIB *schib = &sch->curr_status;
SCSW s;
IRB irb;
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;
/* 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_io_notifier(VFIOCCWDevice *vcdev, Error **errp)
{
VFIODevice *vdev = &vcdev->vdev;
struct vfio_irq_info *irq_info;
size_t argsz;
int fd;
if (vdev->num_irqs < VFIO_CCW_IO_IRQ_INDEX + 1) {
error_setg(errp, "vfio: unexpected number of io irqs %u",
vdev->num_irqs);
return;
}
argsz = sizeof(*irq_info);
irq_info = g_malloc0(argsz);
irq_info->index = VFIO_CCW_IO_IRQ_INDEX;
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(&vcdev->io_notifier, 0)) {
error_setg_errno(errp, errno,
"vfio: Unable to init event notifier for IO");
goto out_free_info;
}
fd = event_notifier_get_fd(&vcdev->io_notifier);
qemu_set_fd_handler(fd, vfio_ccw_io_notifier_handler, NULL, vcdev);
if (vfio_set_irq_signaling(vdev, VFIO_CCW_IO_IRQ_INDEX, 0,
VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
qemu_set_fd_handler(fd, NULL, NULL, vcdev);
event_notifier_cleanup(&vcdev->io_notifier);
}
out_free_info:
g_free(irq_info);
}
static void vfio_ccw_unregister_io_notifier(VFIOCCWDevice *vcdev)
{
Error *err = NULL;
if (vfio_set_irq_signaling(&vcdev->vdev, VFIO_CCW_IO_IRQ_INDEX, 0,
VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
error_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
}
qemu_set_fd_handler(event_notifier_get_fd(&vcdev->io_notifier),
NULL, NULL, vcdev);
event_notifier_cleanup(&vcdev->io_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");
g_free(info);
return;
}
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(vcdev->io_region);
g_free(info);
return;
}
vcdev->async_cmd_region_offset = info->offset;
vcdev->async_cmd_region = g_malloc0(info->size);
}
g_free(info);
}
static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
{
g_free(vcdev->async_cmd_region);
g_free(vcdev->io_region);
}
static void vfio_ccw_put_device(VFIOCCWDevice *vcdev)
{
g_free(vcdev->vdev.name);
vfio_put_base_device(&vcdev->vdev);
}
static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
Error **errp)
{
char *name = g_strdup_printf("%x.%x.%04x", vcdev->cdev.hostid.cssid,
vcdev->cdev.hostid.ssid,
vcdev->cdev.hostid.devid);
VFIODevice *vbasedev;
QLIST_FOREACH(vbasedev, &group->device_list, next) {
if (strcmp(vbasedev->name, name) == 0) {
error_setg(errp, "vfio: subchannel %s has already been attached",
name);
goto out_err;
}
}
/*
* All vfio-ccw devices are believed to operate in a way compatible with
* memory ballooning, ie. pages pinned in the host are in the current
* working set of the guest driver and therefore never overlap with pages
* available to the guest balloon driver. This needs to be set before
* vfio_get_device() for vfio common to handle the balloon inhibitor.
*/
vcdev->vdev.balloon_allowed = true;
if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) {
goto out_err;
}
vcdev->vdev.ops = &vfio_ccw_ops;
vcdev->vdev.type = VFIO_DEVICE_TYPE_CCW;
vcdev->vdev.name = name;
vcdev->vdev.dev = &vcdev->cdev.parent_obj.parent_obj;
return;
out_err:
g_free(name);
}
static VFIOGroup *vfio_ccw_get_group(S390CCWDevice *cdev, Error **errp)
{
char *tmp, group_path[PATH_MAX];
ssize_t len;
int groupid;
tmp = g_strdup_printf("/sys/bus/css/devices/%x.%x.%04x/%s/iommu_group",
cdev->hostid.cssid, cdev->hostid.ssid,
cdev->hostid.devid, cdev->mdevid);
len = readlink(tmp, group_path, sizeof(group_path));
g_free(tmp);
if (len <= 0 || len >= sizeof(group_path)) {
error_setg(errp, "vfio: no iommu_group found");
return NULL;
}
group_path[len] = 0;
if (sscanf(basename(group_path), "%d", &groupid) != 1) {
error_setg(errp, "vfio: failed to read %s", group_path);
return NULL;
}
return vfio_get_group(groupid, &address_space_memory, errp);
}
static void vfio_ccw_realize(DeviceState *dev, Error **errp)
{
VFIOGroup *group;
CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
Error *err = NULL;
/* Call the class init function for subchannel. */
if (cdc->realize) {
cdc->realize(cdev, vcdev->vdev.sysfsdev, &err);
if (err) {
goto out_err_propagate;
}
}
group = vfio_ccw_get_group(cdev, &err);
if (!group) {
goto out_group_err;
}
vfio_ccw_get_device(group, vcdev, &err);
if (err) {
goto out_device_err;
}
vfio_ccw_get_region(vcdev, &err);
if (err) {
goto out_region_err;
}
vfio_ccw_register_io_notifier(vcdev, &err);
if (err) {
goto out_notifier_err;
}
return;
out_notifier_err:
vfio_ccw_put_region(vcdev);
out_region_err:
vfio_ccw_put_device(vcdev);
out_device_err:
vfio_put_group(group);
out_group_err:
if (cdc->unrealize) {
cdc->unrealize(cdev, NULL);
}
out_err_propagate:
error_propagate(errp, err);
}
static void vfio_ccw_unrealize(DeviceState *dev, Error **errp)
{
CcwDevice *ccw_dev = DO_UPCAST(CcwDevice, parent_obj, dev);
S390CCWDevice *cdev = DO_UPCAST(S390CCWDevice, parent_obj, ccw_dev);
VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
VFIOGroup *group = vcdev->vdev.group;
vfio_ccw_unregister_io_notifier(vcdev);
vfio_ccw_put_region(vcdev);
vfio_ccw_put_device(vcdev);
vfio_put_group(group);
if (cdc->unrealize) {
cdc->unrealize(cdev, errp);
}
}
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);
dc->props = 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;
}
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)