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db0da029a1
qemu/hw/vfio/platform.c
Alex Williamson db0da029a1 vfio: Generalize region support 
Both platform and PCI vfio drivers create a "slow", I/O memory region
with one or more mmap memory regions overlayed when supported by the
device. Generalize this to a set of common helpers in the core that
pulls the region info from vfio, fills the region data, configures
slow mapping, and adds helpers for comleting the mmap, enable/disable,
and teardown.  This can be immediately used by the PCI MSI-X code,
which needs to mmap around the MSI-X vector table.

This also changes VFIORegion.mem to be dynamically allocated because
otherwise we don't know how the caller has allocated VFIORegion and
therefore don't know whether to unreference it to destroy the
MemoryRegion or not.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-03-10 20:03:16 -07:00

705 lines
21 KiB
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/*
* vfio based device assignment support - platform devices
*
* Copyright Linaro Limited, 2014
*
* Authors:
* Kim Phillips <kim.phillips@linaro.org>
* Eric Auger <eric.auger@linaro.org>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Based on vfio based PCI device assignment support:
* Copyright Red Hat, Inc. 2012
*/
#include "qemu/osdep.h"
#include <sys/ioctl.h>
#include <linux/vfio.h>
#include "hw/vfio/vfio-platform.h"
#include "qemu/error-report.h"
#include "qemu/range.h"
#include "sysemu/sysemu.h"
#include "exec/memory.h"
#include "qemu/queue.h"
#include "hw/sysbus.h"
#include "trace.h"
#include "hw/platform-bus.h"
#include "sysemu/kvm.h"
/*
* Functions used whatever the injection method
*/
static inline bool vfio_irq_is_automasked(VFIOINTp *intp)
{
return intp->flags & VFIO_IRQ_INFO_AUTOMASKED;
}
/**
* vfio_init_intp - allocate, initialize the IRQ struct pointer
* and add it into the list of IRQs
* @vbasedev: the VFIO device handle
* @info: irq info struct retrieved from VFIO driver
*/
static VFIOINTp *vfio_init_intp(VFIODevice *vbasedev,
struct vfio_irq_info info)
{
int ret;
VFIOPlatformDevice *vdev =
container_of(vbasedev, VFIOPlatformDevice, vbasedev);
SysBusDevice *sbdev = SYS_BUS_DEVICE(vdev);
VFIOINTp *intp;
intp = g_malloc0(sizeof(*intp));
intp->vdev = vdev;
intp->pin = info.index;
intp->flags = info.flags;
intp->state = VFIO_IRQ_INACTIVE;
intp->kvm_accel = false;
sysbus_init_irq(sbdev, &intp->qemuirq);
/* Get an eventfd for trigger */
intp->interrupt = g_malloc0(sizeof(EventNotifier));
ret = event_notifier_init(intp->interrupt, 0);
if (ret) {
g_free(intp->interrupt);
g_free(intp);
error_report("vfio: Error: trigger event_notifier_init failed ");
return NULL;
}
if (vfio_irq_is_automasked(intp)) {
/* Get an eventfd for resample/unmask */
intp->unmask = g_malloc0(sizeof(EventNotifier));
ret = event_notifier_init(intp->unmask, 0);
if (ret) {
g_free(intp->interrupt);
g_free(intp->unmask);
g_free(intp);
error_report("vfio: Error: resamplefd event_notifier_init failed");
return NULL;
}
}
QLIST_INSERT_HEAD(&vdev->intp_list, intp, next);
return intp;
}
/**
* vfio_set_trigger_eventfd - set VFIO eventfd handling
*
* @intp: IRQ struct handle
* @handler: handler to be called on eventfd signaling
*
* Setup VFIO signaling and attach an optional user-side handler
* to the eventfd
*/
static int vfio_set_trigger_eventfd(VFIOINTp *intp,
eventfd_user_side_handler_t handler)
{
VFIODevice *vbasedev = &intp->vdev->vbasedev;
struct vfio_irq_set *irq_set;
int argsz, ret;
int32_t *pfd;
argsz = sizeof(*irq_set) + sizeof(*pfd);
irq_set = g_malloc0(argsz);
irq_set->argsz = argsz;
irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
irq_set->index = intp->pin;
irq_set->start = 0;
irq_set->count = 1;
pfd = (int32_t *)&irq_set->data;
*pfd = event_notifier_get_fd(intp->interrupt);
qemu_set_fd_handler(*pfd, (IOHandler *)handler, NULL, intp);
ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
g_free(irq_set);
if (ret < 0) {
error_report("vfio: Failed to set trigger eventfd: %m");
qemu_set_fd_handler(*pfd, NULL, NULL, NULL);
}
return ret;
}
/*
* Functions only used when eventfds are handled on user-side
* ie. without irqfd
*/
/**
* vfio_mmap_set_enabled - enable/disable the fast path mode
* @vdev: the VFIO platform device
* @enabled: the target mmap state
*
* enabled = true ~ fast path = MMIO region is mmaped (no KVM TRAP);
* enabled = false ~ slow path = MMIO region is trapped and region callbacks
* are called; slow path enables to trap the device IRQ status register reset
*/
static void vfio_mmap_set_enabled(VFIOPlatformDevice *vdev, bool enabled)
{
int i;
for (i = 0; i < vdev->vbasedev.num_regions; i++) {
vfio_region_mmaps_set_enabled(vdev->regions[i], enabled);
}
}
/**
* vfio_intp_mmap_enable - timer function, restores the fast path
* if there is no more active IRQ
* @opaque: actually points to the VFIO platform device
*
* Called on mmap timer timout, this function checks whether the
* IRQ is still active and if not, restores the fast path.
* by construction a single eventfd is handled at a time.
* if the IRQ is still active, the timer is re-programmed.
*/
static void vfio_intp_mmap_enable(void *opaque)
{
VFIOINTp *tmp;
VFIOPlatformDevice *vdev = (VFIOPlatformDevice *)opaque;
qemu_mutex_lock(&vdev->intp_mutex);
QLIST_FOREACH(tmp, &vdev->intp_list, next) {
if (tmp->state == VFIO_IRQ_ACTIVE) {
trace_vfio_platform_intp_mmap_enable(tmp->pin);
/* re-program the timer to check active status later */
timer_mod(vdev->mmap_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
vdev->mmap_timeout);
qemu_mutex_unlock(&vdev->intp_mutex);
return;
}
}
vfio_mmap_set_enabled(vdev, true);
qemu_mutex_unlock(&vdev->intp_mutex);
}
/**
* vfio_intp_inject_pending_lockheld - Injects a pending IRQ
* @opaque: opaque pointer, in practice the VFIOINTp handle
*
* The function is called on a previous IRQ completion, from
* vfio_platform_eoi, while the intp_mutex is locked.
* Also in such situation, the slow path already is set and
* the mmap timer was already programmed.
*/
static void vfio_intp_inject_pending_lockheld(VFIOINTp *intp)
{
trace_vfio_platform_intp_inject_pending_lockheld(intp->pin,
event_notifier_get_fd(intp->interrupt));
intp->state = VFIO_IRQ_ACTIVE;
/* trigger the virtual IRQ */
qemu_set_irq(intp->qemuirq, 1);
}
/**
* vfio_intp_interrupt - The user-side eventfd handler
* @opaque: opaque pointer which in practice is the VFIOINTp handle
*
* the function is entered in event handler context:
* the vIRQ is injected into the guest if there is no other active
* or pending IRQ.
*/
static void vfio_intp_interrupt(VFIOINTp *intp)
{
int ret;
VFIOINTp *tmp;
VFIOPlatformDevice *vdev = intp->vdev;
bool delay_handling = false;
qemu_mutex_lock(&vdev->intp_mutex);
if (intp->state == VFIO_IRQ_INACTIVE) {
QLIST_FOREACH(tmp, &vdev->intp_list, next) {
if (tmp->state == VFIO_IRQ_ACTIVE ||
tmp->state == VFIO_IRQ_PENDING) {
delay_handling = true;
break;
}
}
}
if (delay_handling) {
/*
* the new IRQ gets a pending status and is pushed in
* the pending queue
*/
intp->state = VFIO_IRQ_PENDING;
trace_vfio_intp_interrupt_set_pending(intp->pin);
QSIMPLEQ_INSERT_TAIL(&vdev->pending_intp_queue,
intp, pqnext);
ret = event_notifier_test_and_clear(intp->interrupt);
qemu_mutex_unlock(&vdev->intp_mutex);
return;
}
trace_vfio_platform_intp_interrupt(intp->pin,
event_notifier_get_fd(intp->interrupt));
ret = event_notifier_test_and_clear(intp->interrupt);
if (!ret) {
error_report("Error when clearing fd=%d (ret = %d)",
event_notifier_get_fd(intp->interrupt), ret);
}
intp->state = VFIO_IRQ_ACTIVE;
/* sets slow path */
vfio_mmap_set_enabled(vdev, false);
/* trigger the virtual IRQ */
qemu_set_irq(intp->qemuirq, 1);
/*
* Schedule the mmap timer which will restore fastpath when no IRQ
* is active anymore
*/
if (vdev->mmap_timeout) {
timer_mod(vdev->mmap_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
vdev->mmap_timeout);
}
qemu_mutex_unlock(&vdev->intp_mutex);
}
/**
* vfio_platform_eoi - IRQ completion routine
* @vbasedev: the VFIO device handle
*
* De-asserts the active virtual IRQ and unmasks the physical IRQ
* (effective for level sensitive IRQ auto-masked by the VFIO driver).
* Then it handles next pending IRQ if any.
* eoi function is called on the first access to any MMIO region
* after an IRQ was triggered, trapped since slow path was set.
* It is assumed this access corresponds to the IRQ status
* register reset. With such a mechanism, a single IRQ can be
* handled at a time since there is no way to know which IRQ
* was completed by the guest (we would need additional details
* about the IRQ status register mask).
*/
static void vfio_platform_eoi(VFIODevice *vbasedev)
{
VFIOINTp *intp;
VFIOPlatformDevice *vdev =
container_of(vbasedev, VFIOPlatformDevice, vbasedev);
qemu_mutex_lock(&vdev->intp_mutex);
QLIST_FOREACH(intp, &vdev->intp_list, next) {
if (intp->state == VFIO_IRQ_ACTIVE) {
trace_vfio_platform_eoi(intp->pin,
event_notifier_get_fd(intp->interrupt));
intp->state = VFIO_IRQ_INACTIVE;
/* deassert the virtual IRQ */
qemu_set_irq(intp->qemuirq, 0);
if (vfio_irq_is_automasked(intp)) {
/* unmasks the physical level-sensitive IRQ */
vfio_unmask_single_irqindex(vbasedev, intp->pin);
}
/* a single IRQ can be active at a time */
break;
}
}
/* in case there are pending IRQs, handle the first one */
if (!QSIMPLEQ_EMPTY(&vdev->pending_intp_queue)) {
intp = QSIMPLEQ_FIRST(&vdev->pending_intp_queue);
vfio_intp_inject_pending_lockheld(intp);
QSIMPLEQ_REMOVE_HEAD(&vdev->pending_intp_queue, pqnext);
}
qemu_mutex_unlock(&vdev->intp_mutex);
}
/**
* vfio_start_eventfd_injection - starts the virtual IRQ injection using
* user-side handled eventfds
* @sbdev: the sysbus device handle
* @irq: the qemu irq handle
*/
static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
{
int ret;
VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
VFIOINTp *intp;
QLIST_FOREACH(intp, &vdev->intp_list, next) {
if (intp->qemuirq == irq) {
break;
}
}
assert(intp);
ret = vfio_set_trigger_eventfd(intp, vfio_intp_interrupt);
if (ret) {
error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
intp->pin);
abort();
}
}
/*
* Functions used for irqfd
*/
/**
* vfio_set_resample_eventfd - sets the resamplefd for an IRQ
* @intp: the IRQ struct handle
* programs the VFIO driver to unmask this IRQ when the
* intp->unmask eventfd is triggered
*/
static int vfio_set_resample_eventfd(VFIOINTp *intp)
{
VFIODevice *vbasedev = &intp->vdev->vbasedev;
struct vfio_irq_set *irq_set;
int argsz, ret;
int32_t *pfd;
argsz = sizeof(*irq_set) + sizeof(*pfd);
irq_set = g_malloc0(argsz);
irq_set->argsz = argsz;
irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_UNMASK;
irq_set->index = intp->pin;
irq_set->start = 0;
irq_set->count = 1;
pfd = (int32_t *)&irq_set->data;
*pfd = event_notifier_get_fd(intp->unmask);
qemu_set_fd_handler(*pfd, NULL, NULL, NULL);
ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
g_free(irq_set);
if (ret < 0) {
error_report("vfio: Failed to set resample eventfd: %m");
}
return ret;
}
/**
* vfio_start_irqfd_injection - starts the virtual IRQ injection using
* irqfd
*
* @sbdev: the sysbus device handle
* @irq: the qemu irq handle
*
* In case the irqfd setup fails, we fallback to userspace handled eventfd
*/
static void vfio_start_irqfd_injection(SysBusDevice *sbdev, qemu_irq irq)
{
VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
VFIOINTp *intp;
if (!kvm_irqfds_enabled() || !kvm_resamplefds_enabled() ||
!vdev->irqfd_allowed) {
goto fail_irqfd;
}
QLIST_FOREACH(intp, &vdev->intp_list, next) {
if (intp->qemuirq == irq) {
break;
}
}
assert(intp);
if (kvm_irqchip_add_irqfd_notifier(kvm_state, intp->interrupt,
intp->unmask, irq) < 0) {
goto fail_irqfd;
}
if (vfio_set_trigger_eventfd(intp, NULL) < 0) {
goto fail_vfio;
}
if (vfio_irq_is_automasked(intp)) {
if (vfio_set_resample_eventfd(intp) < 0) {
goto fail_vfio;
}
trace_vfio_platform_start_level_irqfd_injection(intp->pin,
event_notifier_get_fd(intp->interrupt),
event_notifier_get_fd(intp->unmask));
} else {
trace_vfio_platform_start_edge_irqfd_injection(intp->pin,
event_notifier_get_fd(intp->interrupt));
}
intp->kvm_accel = true;
return;
fail_vfio:
kvm_irqchip_remove_irqfd_notifier(kvm_state, intp->interrupt, irq);
error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
intp->pin);
abort();
fail_irqfd:
vfio_start_eventfd_injection(sbdev, irq);
return;
}
/* VFIO skeleton */
static void vfio_platform_compute_needs_reset(VFIODevice *vbasedev)
{
vbasedev->needs_reset = true;
}
/* not implemented yet */
static int vfio_platform_hot_reset_multi(VFIODevice *vbasedev)
{
return -1;
}
/**
* vfio_populate_device - Allocate and populate MMIO region
* and IRQ structs according to driver returned information
* @vbasedev: the VFIO device handle
*
*/
static int vfio_populate_device(VFIODevice *vbasedev)
{
VFIOINTp *intp, *tmp;
int i, ret = -1;
VFIOPlatformDevice *vdev =
container_of(vbasedev, VFIOPlatformDevice, vbasedev);
if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PLATFORM)) {
error_report("vfio: Um, this isn't a platform device");
return ret;
}
vdev->regions = g_new0(VFIORegion *, vbasedev->num_regions);
for (i = 0; i < vbasedev->num_regions; i++) {
char *name = g_strdup_printf("VFIO %s region %d\n", vbasedev->name, i);
vdev->regions[i] = g_new0(VFIORegion, 1);
ret = vfio_region_setup(OBJECT(vdev), vbasedev,
vdev->regions[i], i, name);
g_free(name);
if (ret) {
error_report("vfio: Error getting region %d info: %m", i);
goto reg_error;
}
}
vdev->mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
vfio_intp_mmap_enable, vdev);
QSIMPLEQ_INIT(&vdev->pending_intp_queue);
for (i = 0; i < vbasedev->num_irqs; i++) {
struct vfio_irq_info irq = { .argsz = sizeof(irq) };
irq.index = i;
ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq);
if (ret) {
error_printf("vfio: error getting device %s irq info",
vbasedev->name);
goto irq_err;
} else {
trace_vfio_platform_populate_interrupts(irq.index,
irq.count,
irq.flags);
intp = vfio_init_intp(vbasedev, irq);
if (!intp) {
error_report("vfio: Error installing IRQ %d up", i);
goto irq_err;
}
}
}
return 0;
irq_err:
timer_del(vdev->mmap_timer);
QLIST_FOREACH_SAFE(intp, &vdev->intp_list, next, tmp) {
QLIST_REMOVE(intp, next);
g_free(intp);
}
reg_error:
for (i = 0; i < vbasedev->num_regions; i++) {
if (vdev->regions[i]) {
vfio_region_finalize(vdev->regions[i]);
}
g_free(vdev->regions[i]);
}
g_free(vdev->regions);
return ret;
}
/* specialized functions for VFIO Platform devices */
static VFIODeviceOps vfio_platform_ops = {
.vfio_compute_needs_reset = vfio_platform_compute_needs_reset,
.vfio_hot_reset_multi = vfio_platform_hot_reset_multi,
.vfio_eoi = vfio_platform_eoi,
};
/**
* vfio_base_device_init - perform preliminary VFIO setup
* @vbasedev: the VFIO device handle
*
* Implement the VFIO command sequence that allows to discover
* assigned device resources: group extraction, device
* fd retrieval, resource query.
* Precondition: the device name must be initialized
*/
static int vfio_base_device_init(VFIODevice *vbasedev)
{
VFIOGroup *group;
VFIODevice *vbasedev_iter;
char *tmp, group_path[PATH_MAX], *group_name;
ssize_t len;
struct stat st;
int groupid;
int ret;
/* @sysfsdev takes precedence over @host */
if (vbasedev->sysfsdev) {
g_free(vbasedev->name);
vbasedev->name = g_strdup(basename(vbasedev->sysfsdev));
} else {
if (!vbasedev->name || strchr(vbasedev->name, '/')) {
return -EINVAL;
}
vbasedev->sysfsdev = g_strdup_printf("/sys/bus/platform/devices/%s",
vbasedev->name);
}
if (stat(vbasedev->sysfsdev, &st) < 0) {
error_report("vfio: error: no such host device: %s",
vbasedev->sysfsdev);
return -errno;
}
tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
len = readlink(tmp, group_path, sizeof(group_path));
g_free(tmp);
if (len < 0 || len >= sizeof(group_path)) {
error_report("vfio: error no iommu_group for device");
return len < 0 ? -errno : -ENAMETOOLONG;
}
group_path[len] = 0;
group_name = basename(group_path);
if (sscanf(group_name, "%d", &groupid) != 1) {
error_report("vfio: error reading %s: %m", group_path);
return -errno;
}
trace_vfio_platform_base_device_init(vbasedev->name, groupid);
group = vfio_get_group(groupid, &address_space_memory);
if (!group) {
error_report("vfio: failed to get group %d", groupid);
return -ENOENT;
}
QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
error_report("vfio: error: device %s is already attached",
vbasedev->name);
vfio_put_group(group);
return -EBUSY;
}
}
ret = vfio_get_device(group, vbasedev->name, vbasedev);
if (ret) {
error_report("vfio: failed to get device %s", vbasedev->name);
vfio_put_group(group);
return ret;
}
ret = vfio_populate_device(vbasedev);
if (ret) {
error_report("vfio: failed to populate device %s", vbasedev->name);
vfio_put_group(group);
}
return ret;
}
/**
* vfio_platform_realize - the device realize function
* @dev: device state pointer
* @errp: error
*
* initialize the device, its memory regions and IRQ structures
* IRQ are started separately
*/
static void vfio_platform_realize(DeviceState *dev, Error **errp)
{
VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(dev);
SysBusDevice *sbdev = SYS_BUS_DEVICE(dev);
VFIODevice *vbasedev = &vdev->vbasedev;
int i, ret;
vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
vbasedev->ops = &vfio_platform_ops;
trace_vfio_platform_realize(vbasedev->sysfsdev ?
vbasedev->sysfsdev : vbasedev->name,
vdev->compat);
ret = vfio_base_device_init(vbasedev);
if (ret) {
error_setg(errp, "vfio: vfio_base_device_init failed for %s",
vbasedev->name);
return;
}
for (i = 0; i < vbasedev->num_regions; i++) {
if (vfio_region_mmap(vdev->regions[i])) {
error_report("%s mmap unsupported. Performance may be slow",
memory_region_name(vdev->regions[i]->mem));
}
sysbus_init_mmio(sbdev, vdev->regions[i]->mem);
}
}
static const VMStateDescription vfio_platform_vmstate = {
.name = TYPE_VFIO_PLATFORM,
.unmigratable = 1,
};
static Property vfio_platform_dev_properties[] = {
DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
DEFINE_PROP_STRING("sysfsdev", VFIOPlatformDevice, vbasedev.sysfsdev),
DEFINE_PROP_BOOL("x-no-mmap", VFIOPlatformDevice, vbasedev.no_mmap, false),
DEFINE_PROP_UINT32("mmap-timeout-ms", VFIOPlatformDevice,
mmap_timeout, 1100),
DEFINE_PROP_BOOL("x-irqfd", VFIOPlatformDevice, irqfd_allowed, true),
DEFINE_PROP_END_OF_LIST(),
};
static void vfio_platform_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
dc->realize = vfio_platform_realize;
dc->props = vfio_platform_dev_properties;
dc->vmsd = &vfio_platform_vmstate;
dc->desc = "VFIO-based platform device assignment";
sbc->connect_irq_notifier = vfio_start_irqfd_injection;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
}
static const TypeInfo vfio_platform_dev_info = {
.name = TYPE_VFIO_PLATFORM,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(VFIOPlatformDevice),
.class_init = vfio_platform_class_init,
.class_size = sizeof(VFIOPlatformDeviceClass),
.abstract = true,
};
static void register_vfio_platform_dev_type(void)
{
type_register_static(&vfio_platform_dev_info);
}
type_init(register_vfio_platform_dev_type)
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