qemu-patch-raspberry4/hw/vfio/platform.c
Alex Williamson 5e15d79b86 vfio: Change polarity of our no-mmap option
The default should be to allow mmap and new drivers shouldn't need to
expose an option or set it to other than the allocation default in
their initfn.  Take advantage of the experimental flag to change this
option to the correct polarity.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-09-23 13:04:44 -06:00

716 lines
21 KiB
C

/*
* 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 <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
*/
/**
* 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 */
ret = event_notifier_init(&intp->interrupt, 0);
if (ret) {
g_free(intp);
error_report("vfio: Error: trigger event_notifier_init failed ");
return NULL;
}
/* Get an eventfd for resample/unmask */
ret = event_notifier_init(&intp->unmask, 0);
if (ret) {
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;
trace_vfio_platform_mmap_set_enabled(enabled);
for (i = 0; i < vdev->vbasedev.num_regions; i++) {
VFIORegion *region = vdev->regions[i];
memory_region_set_enabled(&region->mmap_mem, 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 (intp->flags & VFIO_IRQ_INFO_AUTOMASKED) {
/* 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
* @intp: the IRQ struct pointer
*/
static int vfio_start_eventfd_injection(VFIOINTp *intp)
{
int ret;
ret = vfio_set_trigger_eventfd(intp, vfio_intp_interrupt);
if (ret) {
error_report("vfio: Error: Failed to pass IRQ fd to the driver: %m");
}
return ret;
}
/*
* 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;
}
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) {
return;
}
QLIST_FOREACH(intp, &vdev->intp_list, next) {
if (intp->qemuirq == irq) {
break;
}
}
assert(intp);
/* Get to a known interrupt state */
qemu_set_fd_handler(event_notifier_get_fd(&intp->interrupt),
NULL, NULL, vdev);
vfio_mask_single_irqindex(&vdev->vbasedev, intp->pin);
qemu_set_irq(intp->qemuirq, 0);
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_set_resample_eventfd(intp) < 0) {
goto fail_vfio;
}
/* Let's resume injection with irqfd setup */
vfio_unmask_single_irqindex(&vdev->vbasedev, intp->pin);
intp->kvm_accel = true;
trace_vfio_platform_start_irqfd_injection(intp->pin,
event_notifier_get_fd(&intp->interrupt),
event_notifier_get_fd(&intp->unmask));
return;
fail_vfio:
kvm_irqchip_remove_irqfd_notifier(kvm_state, &intp->interrupt, irq);
fail_irqfd:
vfio_start_eventfd_injection(intp);
vfio_unmask_single_irqindex(&vdev->vbasedev, intp->pin);
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++) {
struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
VFIORegion *ptr;
vdev->regions[i] = g_malloc0(sizeof(VFIORegion));
ptr = vdev->regions[i];
reg_info.index = i;
ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
if (ret) {
error_report("vfio: Error getting region %d info: %m", i);
goto reg_error;
}
ptr->flags = reg_info.flags;
ptr->size = reg_info.size;
ptr->fd_offset = reg_info.offset;
ptr->nr = i;
ptr->vbasedev = vbasedev;
trace_vfio_platform_populate_regions(ptr->nr,
(unsigned long)ptr->flags,
(unsigned long)ptr->size,
ptr->vbasedev->fd,
(unsigned long)ptr->fd_offset);
}
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++) {
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 path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
ssize_t len;
struct stat st;
int groupid;
int ret;
/* name must be set prior to the call */
if (!vbasedev->name || strchr(vbasedev->name, '/')) {
return -EINVAL;
}
/* Check that the host device exists */
g_snprintf(path, sizeof(path), "/sys/bus/platform/devices/%s/",
vbasedev->name);
if (stat(path, &st) < 0) {
error_report("vfio: error: no such host device: %s", path);
return -errno;
}
g_strlcat(path, "iommu_group", sizeof(path));
len = readlink(path, iommu_group_path, sizeof(iommu_group_path));
if (len < 0 || len >= sizeof(iommu_group_path)) {
error_report("vfio: error no iommu_group for device");
return len < 0 ? -errno : -ENAMETOOLONG;
}
iommu_group_path[len] = 0;
group_name = basename(iommu_group_path);
if (sscanf(group_name, "%d", &groupid) != 1) {
error_report("vfio: error reading %s: %m", 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;
}
g_snprintf(path, sizeof(path), "%s", vbasedev->name);
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", path);
vfio_put_group(group);
return -EBUSY;
}
}
ret = vfio_get_device(group, path, vbasedev);
if (ret) {
error_report("vfio: failed to get device %s", path);
vfio_put_group(group);
return ret;
}
ret = vfio_populate_device(vbasedev);
if (ret) {
error_report("vfio: failed to populate device %s", path);
vfio_put_group(group);
}
return ret;
}
/**
* vfio_map_region - initialize the 2 memory regions for a given
* MMIO region index
* @vdev: the VFIO platform device handle
* @nr: the index of the region
*
* Init the top memory region and the mmapped memory region beneath
* VFIOPlatformDevice is used since VFIODevice is not a QOM Object
* and could not be passed to memory region functions
*/
static void vfio_map_region(VFIOPlatformDevice *vdev, int nr)
{
VFIORegion *region = vdev->regions[nr];
uint64_t size = region->size;
char name[64];
if (!size) {
return;
}
g_snprintf(name, sizeof(name), "VFIO %s region %d",
vdev->vbasedev.name, nr);
/* A "slow" read/write mapping underlies all regions */
memory_region_init_io(&region->mem, OBJECT(vdev), &vfio_region_ops,
region, name, size);
g_strlcat(name, " mmap", sizeof(name));
if (vfio_mmap_region(OBJECT(vdev), region, &region->mem,
&region->mmap_mem, &region->mmap, size, 0, name)) {
error_report("%s unsupported. Performance may be slow", name);
}
}
/**
* 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;
VFIOINTp *intp;
int i, ret;
vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
vbasedev->ops = &vfio_platform_ops;
trace_vfio_platform_realize(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++) {
vfio_map_region(vdev, i);
sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
}
QLIST_FOREACH(intp, &vdev->intp_list, next) {
vfio_start_eventfd_injection(intp);
}
}
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_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)