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hw/vfio/platform: add irq assignment

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This patch adds the code requested to assign interrupts to
a guest. The interrupts are mediated through user handled
eventfds only.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Vikram Sethi <vikrams@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Eric Auger 2015-06-08 09:25:26 -06:00 committed by Alex Williamson
parent 0ea2730bef
commit 38559979bf
3 changed files with 368 additions and 1 deletions
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331
hw/vfio/platform.c
View File

@ -22,10 +22,299 @@
#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"
/*
* 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;
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;
}
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)\n",
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;
}
/* VFIO skeleton */
static void vfio_platform_compute_needs_reset(VFIODevice *vbasedev)
@ -41,12 +330,13 @@ static int vfio_platform_hot_reset_multi(VFIODevice *vbasedev)
/**
* vfio_populate_device - Allocate and populate MMIO region
* structs according to driver returned information
* 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);
@ -84,7 +374,38 @@ static int vfio_populate_device(VFIODevice *vbasedev)
(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]);
@ -97,6 +418,7 @@ reg_error:
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,
};
/**
@ -228,6 +550,7 @@ 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;
@ -246,6 +569,10 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
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 = {
@ -256,6 +583,8 @@ static const VMStateDescription vfio_platform_vmstate = {
static Property vfio_platform_dev_properties[] = {
DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
DEFINE_PROP_BOOL("x-mmap", VFIOPlatformDevice, vbasedev.allow_mmap, true),
DEFINE_PROP_UINT32("mmap-timeout-ms", VFIOPlatformDevice,
mmap_timeout, 1100),
DEFINE_PROP_END_OF_LIST(),
};

31
include/hw/vfio/vfio-platform.h
View File

@ -18,14 +18,45 @@
#include "hw/sysbus.h"
#include "hw/vfio/vfio-common.h"
#include "qemu/event_notifier.h"
#include "qemu/queue.h"
#include "hw/irq.h"
#define TYPE_VFIO_PLATFORM "vfio-platform"
enum {
VFIO_IRQ_INACTIVE = 0,
VFIO_IRQ_PENDING = 1,
VFIO_IRQ_ACTIVE = 2,
/* VFIO_IRQ_ACTIVE_AND_PENDING cannot happen with VFIO */
};
typedef struct VFIOINTp {
QLIST_ENTRY(VFIOINTp) next; /* entry for IRQ list */
QSIMPLEQ_ENTRY(VFIOINTp) pqnext; /* entry for pending IRQ queue */
EventNotifier interrupt; /* eventfd triggered on interrupt */
EventNotifier unmask; /* eventfd for unmask on QEMU bypass */
qemu_irq qemuirq;
struct VFIOPlatformDevice *vdev; /* back pointer to device */
int state; /* inactive, pending, active */
uint8_t pin; /* index */
uint32_t flags; /* IRQ info flags */
} VFIOINTp;
/* function type for user side eventfd handler */
typedef void (*eventfd_user_side_handler_t)(VFIOINTp *intp);
typedef struct VFIOPlatformDevice {
SysBusDevice sbdev;
VFIODevice vbasedev; /* not a QOM object */
VFIORegion **regions;
QLIST_HEAD(, VFIOINTp) intp_list; /* list of IRQs */
/* queue of pending IRQs */
QSIMPLEQ_HEAD(pending_intp_queue, VFIOINTp) pending_intp_queue;
char *compat; /* compatibility string */
uint32_t mmap_timeout; /* delay to re-enable mmaps after interrupt */
QEMUTimer *mmap_timer; /* allows fast-path resume after IRQ hit */
QemuMutex intp_mutex; /* protect the intp_list IRQ state */
} VFIOPlatformDevice;
typedef struct VFIOPlatformDeviceClass {

7
trace-events
View File

@ -1568,6 +1568,13 @@ vfio_put_base_device(int fd) "close vdev->fd=%d"
vfio_platform_populate_regions(int region_index, unsigned long flag, unsigned long size, int fd, unsigned long offset) "- region %d flags = 0x%lx, size = 0x%lx, fd= %d, offset = 0x%lx"
vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"
vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
vfio_platform_eoi(int pin, int fd) "EOI IRQ pin %d (fd=%d)"
vfio_platform_mmap_set_enabled(bool enabled) "fast path = %d"
vfio_platform_intp_mmap_enable(int pin) "IRQ #%d still active, stay in slow path"
vfio_platform_intp_interrupt(int pin, int fd) "Inject IRQ #%d (fd = %d)"
vfio_platform_intp_inject_pending_lockheld(int pin, int fd) "Inject pending IRQ #%d (fd = %d)"
vfio_platform_populate_interrupts(int pin, int count, int flags) "- IRQ index %d: count %d, flags=0x%x"
vfio_intp_interrupt_set_pending(int index) "irq %d is set PENDING"
#hw/acpi/memory_hotplug.c
mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32