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vfio/ccw: get irqs info and set the eventfd fd

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vfio-ccw resorts to the eventfd mechanism to communicate with userspace.
We fetch the irqs info via the ioctl VFIO_DEVICE_GET_IRQ_INFO,
register a event notifier to get the eventfd fd which is sent
to kernel via the ioctl VFIO_DEVICE_SET_IRQS, then we can implement
read operation once kernel sends the signal.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-10-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Dong Jia Shi 2017-05-17 02:48:09 +02:00 committed by Cornelia Huck
parent c14e706ce9
commit 4886b3e9f0
1 changed files with 101 additions and 0 deletions
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101
hw/vfio/ccw.c
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@ -22,6 +22,7 @@
#include "hw/vfio/vfio-common.h"
#include "hw/s390x/s390-ccw.h"
#include "hw/s390x/ccw-device.h"
#include "qemu/error-report.h"
#define TYPE_VFIO_CCW "vfio-ccw"
typedef struct VFIOCCWDevice {
@ -30,6 +31,7 @@ typedef struct VFIOCCWDevice {
uint64_t io_region_size;
uint64_t io_region_offset;
struct ccw_io_region *io_region;
EventNotifier io_notifier;
} VFIOCCWDevice;
static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
@ -54,6 +56,97 @@ static void vfio_ccw_reset(DeviceState *dev)
ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
}
static void vfio_ccw_io_notifier_handler(void *opaque)
{
VFIOCCWDevice *vcdev = opaque;
if (!event_notifier_test_and_clear(&vcdev->io_notifier)) {
return;
}
}
static void vfio_ccw_register_io_notifier(VFIOCCWDevice *vcdev, Error **errp)
{
VFIODevice *vdev = &vcdev->vdev;
struct vfio_irq_info *irq_info;
struct vfio_irq_set *irq_set;
size_t argsz;
int32_t *pfd;
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_set);
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;
}
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 = VFIO_CCW_IO_IRQ_INDEX;
irq_set->start = 0;
irq_set->count = 1;
pfd = (int32_t *) &irq_set->data;
*pfd = event_notifier_get_fd(&vcdev->io_notifier);
qemu_set_fd_handler(*pfd, vfio_ccw_io_notifier_handler, NULL, vcdev);
if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
error_setg(errp, "vfio: Failed to set up io notification");
qemu_set_fd_handler(*pfd, NULL, NULL, vcdev);
event_notifier_cleanup(&vcdev->io_notifier);
}
g_free(irq_set);
out_free_info:
g_free(irq_info);
}
static void vfio_ccw_unregister_io_notifier(VFIOCCWDevice *vcdev)
{
struct vfio_irq_set *irq_set;
size_t argsz;
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 = VFIO_CCW_IO_IRQ_INDEX;
irq_set->start = 0;
irq_set->count = 1;
pfd = (int32_t *) &irq_set->data;
*pfd = -1;
if (ioctl(vcdev->vdev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
error_report("vfio: Failed to de-assign device io fd: %m");
}
qemu_set_fd_handler(event_notifier_get_fd(&vcdev->io_notifier),
NULL, NULL, vcdev);
event_notifier_cleanup(&vcdev->io_notifier);
g_free(irq_set);
}
static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
{
VFIODevice *vdev = &vcdev->vdev;
@ -173,8 +266,15 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
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_put_device(vcdev);
out_device_err:
@ -195,6 +295,7 @@ static void vfio_ccw_unrealize(DeviceState *dev, Error **errp)
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_put_device(vcdev);
vfio_put_group(group);