[RFC PATCH v3 4/4] drm/i915/gvt: Deliver vGPU vblank event to userspace

From: Tina Zhang
Date: Wed Jun 26 2019 - 23:44:18 EST


Deliver the display vblank event to the user land. Userspace can use
the irq mask/unmask mechanism to disable or enable the event delivery.

Signed-off-by: Tina Zhang <tina.zhang@xxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/display.c | 4 +
drivers/gpu/drm/i915/gvt/gvt.h | 4 +
drivers/gpu/drm/i915/gvt/kvmgt.c | 150 +++++++++++++++++++++++++++--
3 files changed, 149 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/display.c b/drivers/gpu/drm/i915/gvt/display.c
index 1a0a4ae4826e..e62313b5f8a6 100644
--- a/drivers/gpu/drm/i915/gvt/display.c
+++ b/drivers/gpu/drm/i915/gvt/display.c
@@ -412,6 +412,10 @@ static void emulate_vblank_on_pipe(struct intel_vgpu *vgpu, int pipe)

if (pipe_is_enabled(vgpu, pipe)) {
vgpu_vreg_t(vgpu, PIPE_FRMCOUNT_G4X(pipe))++;
+ if (vgpu->vdev.vblank_trigger &&
+ !(vgpu->vdev.display_event_mask & DISPLAY_VBLANK_EVENT))
+ eventfd_signal(vgpu->vdev.vblank_trigger, 1);
+
intel_vgpu_trigger_virtual_event(vgpu, vblank_event[pipe]);
}
}
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index cd29ea28d7ed..b3b476ee5acf 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -165,6 +165,8 @@ struct intel_vgpu_submission {
bool active;
};

+#define DISPLAY_VBLANK_EVENT (1 << 0)
+
struct intel_vgpu {
struct intel_gvt *gvt;
struct mutex vgpu_lock;
@@ -205,6 +207,8 @@ struct intel_vgpu {
int num_irqs;
struct eventfd_ctx *intx_trigger;
struct eventfd_ctx *msi_trigger;
+ struct eventfd_ctx *vblank_trigger;
+ u32 display_event_mask;

/*
* Two caches are used to avoid mapping duplicated pages (eg.
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index f222c9cd7a56..7a84222d7d2d 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1222,6 +1222,8 @@ static int intel_vgpu_get_irq_count(struct intel_vgpu *vgpu, int type)
{
if (type == VFIO_PCI_INTX_IRQ_INDEX || type == VFIO_PCI_MSI_IRQ_INDEX)
return 1;
+ else if (type < VFIO_PCI_NUM_IRQS + vgpu->vdev.num_irqs)
+ return vgpu->vdev.irq[type - VFIO_PCI_NUM_IRQS].count;

return 0;
}
@@ -1269,7 +1271,60 @@ static int intel_vgpu_set_msi_trigger(struct intel_vgpu *vgpu,
return 0;
}

-static int intel_vgpu_set_irqs(struct intel_vgpu *vgpu, u32 flags,
+static int intel_vgu_set_display_irq_mask(struct intel_vgpu *vgpu,
+ unsigned int index, unsigned int start, unsigned int count,
+ u32 flags, void *data)
+{
+ if (start != 0 || count != 1)
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE)
+ vgpu->vdev.display_event_mask |= DISPLAY_VBLANK_EVENT;
+
+ return 0;
+}
+
+static int intel_vgu_set_display_irq_unmask(struct intel_vgpu *vgpu,
+ unsigned int index, unsigned int start, unsigned int count,
+ u32 flags, void *data)
+{
+ if (start != 0 || count != 1)
+ return -EINVAL;
+
+ if (flags & VFIO_IRQ_SET_DATA_NONE)
+ vgpu->vdev.display_event_mask &= ~DISPLAY_VBLANK_EVENT;
+
+ return 0;
+}
+
+static int intel_vgpu_set_display_event_trigger(struct intel_vgpu *vgpu,
+ unsigned int index, unsigned int start, unsigned int count,
+ u32 flags, void *data)
+{
+ struct eventfd_ctx *trigger;
+
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ int fd = *(int *)data;
+
+ trigger = eventfd_ctx_fdget(fd);
+ if (IS_ERR(trigger)) {
+ gvt_vgpu_err("eventfd_ctx_fdget failed\n");
+ return PTR_ERR(trigger);
+ }
+ vgpu->vdev.vblank_trigger = trigger;
+ vgpu->vdev.display_event_mask = 0;
+ } else if ((flags & VFIO_IRQ_SET_DATA_NONE) && !count) {
+ trigger = vgpu->vdev.vblank_trigger;
+ if (trigger) {
+ eventfd_ctx_put(trigger);
+ vgpu->vdev.vblank_trigger = NULL;
+ }
+ }
+
+ return 0;
+}
+
+int intel_vgpu_set_irqs(struct intel_vgpu *vgpu, u32 flags,
unsigned int index, unsigned int start, unsigned int count,
void *data)
{
@@ -1302,6 +1357,35 @@ static int intel_vgpu_set_irqs(struct intel_vgpu *vgpu, u32 flags,
break;
}
break;
+ default:
+ {
+ int i;
+
+ if (index >= VFIO_PCI_NUM_IRQS +
+ vgpu->vdev.num_irqs)
+ return -EINVAL;
+ index =
+ array_index_nospec(index,
+ VFIO_PCI_NUM_IRQS +
+ vgpu->vdev.num_irqs);
+
+ i = index - VFIO_PCI_NUM_IRQS;
+ if (vgpu->vdev.irq[i].type == VFIO_IRQ_TYPE_GFX &&
+ vgpu->vdev.irq[i].subtype ==
+ VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ) {
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_MASK:
+ func = intel_vgu_set_display_irq_mask;
+ break;
+ case VFIO_IRQ_SET_ACTION_UNMASK:
+ func = intel_vgu_set_display_irq_unmask;
+ break;
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ func = intel_vgpu_set_display_event_trigger;
+ break;
+ }
+ }
+ }
}

if (!func)
@@ -1333,7 +1417,7 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
info.flags |= VFIO_DEVICE_FLAGS_RESET;
info.num_regions = VFIO_PCI_NUM_REGIONS +
vgpu->vdev.num_regions;
- info.num_irqs = VFIO_PCI_NUM_IRQS;
+ info.num_irqs = VFIO_PCI_NUM_IRQS + vgpu->vdev.num_irqs;

return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
@@ -1493,32 +1577,79 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
+ struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
+ unsigned int i;
+ int ret;

minsz = offsetofend(struct vfio_irq_info, count);

if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;

- if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
+ if (info.argsz < minsz)
return -EINVAL;

switch (info.index) {
case VFIO_PCI_INTX_IRQ_INDEX:
case VFIO_PCI_MSI_IRQ_INDEX:
+ info.flags = VFIO_IRQ_INFO_EVENTFD;
break;
- default:
+ case VFIO_PCI_MSIX_IRQ_INDEX:
+ case VFIO_PCI_ERR_IRQ_INDEX:
+ case VFIO_PCI_REQ_IRQ_INDEX:
return -EINVAL;
- }
+ default:
+ {
+ struct vfio_irq_info_cap_type cap_type = {
+ .header.id = VFIO_IRQ_INFO_CAP_TYPE,
+ .header.version = 1 };

- info.flags = VFIO_IRQ_INFO_EVENTFD;
+ if (info.index >= VFIO_PCI_NUM_IRQS +
+ vgpu->vdev.num_irqs)
+ return -EINVAL;
+ info.index =
+ array_index_nospec(info.index,
+ VFIO_PCI_NUM_IRQS +
+ vgpu->vdev.num_irqs);
+
+ i = info.index - VFIO_PCI_NUM_IRQS;
+
+ info.flags = vgpu->vdev.irq[i].flags;
+ cap_type.type = vgpu->vdev.irq[i].type;
+ cap_type.subtype = vgpu->vdev.irq[i].subtype;
+
+ ret = vfio_info_add_capability(&caps,
+ &cap_type.header,
+ sizeof(cap_type));
+ if (ret)
+ return ret;
+ }
+ }

info.count = intel_vgpu_get_irq_count(vgpu, info.index);

if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
info.flags |= (VFIO_IRQ_INFO_MASKABLE |
VFIO_IRQ_INFO_AUTOMASKED);
- else
- info.flags |= VFIO_IRQ_INFO_NORESIZE;
+
+ if (caps.size) {
+ info.flags |= VFIO_IRQ_INFO_FLAG_CAPS;
+ if (info.argsz < sizeof(info) + caps.size) {
+ info.argsz = sizeof(info) + caps.size;
+ info.cap_offset = 0;
+ } else {
+ vfio_info_cap_shift(&caps, sizeof(info));
+ if (copy_to_user((void __user *)arg +
+ sizeof(info), caps.buf,
+ caps.size)) {
+ kfree(caps.buf);
+ return -EFAULT;
+ }
+ info.cap_offset = sizeof(info);
+ }
+
+ kfree(caps.buf);
+ }

return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
@@ -1537,7 +1668,8 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
int max = intel_vgpu_get_irq_count(vgpu, hdr.index);

ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
- VFIO_PCI_NUM_IRQS, &data_size);
+ VFIO_PCI_NUM_IRQS + vgpu->vdev.num_irqs,
+ &data_size);
if (ret) {
gvt_vgpu_err("intel:vfio_set_irqs_validate_and_prepare failed\n");
return -EINVAL;
--
2.17.1