[PATCH v6 3/6] drm/i915/gvt: Register vGPU display event irq

Tina Zhang
2019-09-24T06:43:43Z

Gvt-g emulates and injects the vGPU's display interrupts in kernel
space. However the dma-buf based framebuffer consumer in the user
land (e.g. Qemu vfio/display) may also need to be notified by this
event.

Register the display irq as VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ to
each vGPU, so that the display interrupt event can be delivered to
userspace through eventfd.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
---
drivers/gpu/drm/i915/gvt/display.c | 10 +++-
drivers/gpu/drm/i915/gvt/display.h | 3 ++
drivers/gpu/drm/i915/gvt/gvt.h | 2 +
drivers/gpu/drm/i915/gvt/hypercall.h | 1 +
drivers/gpu/drm/i915/gvt/kvmgt.c | 71 ++++++++++++++++++++++++++++
drivers/gpu/drm/i915/gvt/mpt.h | 17 +++++++
6 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/display.c b/drivers/gpu/drm/i915/gvt/display.c
index e1c313da6c00..1a0a4ae4826e 100644
--- a/drivers/gpu/drm/i915/gvt/display.c
+++ b/drivers/gpu/drm/i915/gvt/display.c
@@ -506,16 +506,22 @@ void intel_vgpu_clean_display(struct intel_vgpu *vgpu)
int intel_vgpu_init_display(struct intel_vgpu *vgpu, u64 resolution)
{
struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+ int ret;

intel_vgpu_init_i2c_edid(vgpu);

if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv) ||
IS_COFFEELAKE(dev_priv))
- return setup_virtual_dp_monitor(vgpu, PORT_D, GVT_DP_D,
+ ret = setup_virtual_dp_monitor(vgpu, PORT_D, GVT_DP_D,
resolution);
else
- return setup_virtual_dp_monitor(vgpu, PORT_B, GVT_DP_B,
+ ret = setup_virtual_dp_monitor(vgpu, PORT_B, GVT_DP_B,
resolution);
+
+ if (ret == 0)
+ intel_gvt_hypervisor_register_display_irq(vgpu);
+
+ return ret;
}

/**
diff --git a/drivers/gpu/drm/i915/gvt/display.h b/drivers/gpu/drm/i915/gvt/display.h
index a87f33e6a23c..ba07fbef9194 100644
--- a/drivers/gpu/drm/i915/gvt/display.h
+++ b/drivers/gpu/drm/i915/gvt/display.h
@@ -112,6 +112,9 @@
#define SBI_ADDR_OFFSET_SHIFT 16
#define SBI_ADDR_OFFSET_MASK (0xffff << SBI_ADDR_OFFSET_SHIFT)

+#define DISPLAY_PRI_REFRESH_EVENT_VAL (1UL << 56)
+#define DISPLAY_CUR_REFRESH_EVENT_VAL (1UL << 48)
+
struct intel_vgpu_sbi_register {
unsigned int offset;
u32 value;
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index b47c6acaf9c0..8008047d026c 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -201,6 +201,8 @@ struct intel_vgpu {
struct mdev_device *mdev;
struct vfio_region *region;
int num_regions;
+ struct vfio_irq *irq;
+ int num_irqs;
struct eventfd_ctx *intx_trigger;
struct eventfd_ctx *msi_trigger;

diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index 4862fb12778e..be33f20f3bc1 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -68,6 +68,7 @@ struct intel_gvt_mpt {
bool map);
int (*set_opregion)(void *vgpu);
int (*set_edid)(void *vgpu, int port_num);
+ int (*register_display_irq)(void *vgpu);
int (*get_vfio_device)(void *vgpu);
void (*put_vfio_device)(void *vgpu);
bool (*is_valid_gfn)(unsigned long handle, unsigned long gfn);
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 343d79c1cb7e..269506300310 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -78,6 +78,19 @@ struct vfio_region {
void *data;
};

+struct intel_vgpu_irqops {
+ int (*add_capability)(struct intel_vgpu *vgpu,
+ struct vfio_info_cap *caps);
+};
+
+struct vfio_irq {
+ u32 type;
+ u32 subtype;
+ u32 flags;
+ u32 count;
+ const struct intel_vgpu_irqops *ops;
+};
+
struct vfio_edid_region {
struct vfio_region_gfx_edid vfio_edid_regs;
void *edid_blob;
@@ -635,6 +648,59 @@ static int kvmgt_set_edid(void *p_vgpu, int port_num)
return ret;
}

+static int add_display_irq_capability(struct intel_vgpu *vgpu,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_irq_info_cap_display_plane_events cap = {
+ .header.id = VFIO_IRQ_INFO_CAP_DISPLAY,
+ .header.version = 1,
+ .cur_event_val = DISPLAY_CUR_REFRESH_EVENT_VAL,
+ .pri_event_val = DISPLAY_PRI_REFRESH_EVENT_VAL,
+ };
+
+ return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
+}
+
+
+static const struct intel_vgpu_irqops intel_vgpu_irqops_display = {
+ .add_capability = add_display_irq_capability,
+};
+
+static int intel_vgpu_register_irq(struct intel_vgpu *vgpu,
+ unsigned int type, unsigned int subtype,
+ u32 count, u32 flags,
+ const struct intel_vgpu_irqops *ops)
+{
+ struct vfio_irq *irq;
+
+ irq = krealloc(vgpu->vdev.irq,
+ (vgpu->vdev.num_irqs + 1) * sizeof(*irq),
+ GFP_KERNEL);
+ if (!irq)
+ return -ENOMEM;
+
+ vgpu->vdev.irq = irq;
+ vgpu->vdev.irq[vgpu->vdev.num_irqs].type = type;
+ vgpu->vdev.irq[vgpu->vdev.num_irqs].subtype = subtype;
+ vgpu->vdev.irq[vgpu->vdev.num_irqs].count = count;
+ vgpu->vdev.irq[vgpu->vdev.num_irqs].flags = flags;
+ vgpu->vdev.irq[vgpu->vdev.num_irqs].ops = ops;
+ vgpu->vdev.num_irqs++;
+ return 0;
+}
+
+static int kvmgt_register_display_irq(void *p_vgpu)
+{
+ struct intel_vgpu *vgpu = (struct intel_vgpu *)p_vgpu;
+
+ intel_vgpu_register_irq(vgpu, VFIO_IRQ_TYPE_GFX,
+ VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ,
+ 1,
+ VFIO_IRQ_INFO_MASKABLE | VFIO_IRQ_INFO_EVENTFD,
+ &intel_vgpu_irqops_display);
+ return 0;
+}
+
static void kvmgt_put_vfio_device(void *vgpu)
{
if (WARN_ON(!((struct intel_vgpu *)vgpu)->vdev.vfio_device))
@@ -1833,6 +1899,10 @@ static void kvmgt_detach_vgpu(void *p_vgpu)
vgpu->vdev.num_regions = 0;
kfree(vgpu->vdev.region);
vgpu->vdev.region = NULL;
+
+ vgpu->vdev.num_irqs = 0;
+ kfree(vgpu->vdev.irq);
+ vgpu->vdev.irq = NULL;
}

static int kvmgt_inject_msi(unsigned long handle, u32 addr, u16 data)
@@ -2046,6 +2116,7 @@ static struct intel_gvt_mpt kvmgt_mpt = {
.dma_unmap_guest_page = kvmgt_dma_unmap_guest_page,
.set_opregion = kvmgt_set_opregion,
.set_edid = kvmgt_set_edid,
+ .register_display_irq = kvmgt_register_display_irq,
.get_vfio_device = kvmgt_get_vfio_device,
.put_vfio_device = kvmgt_put_vfio_device,
.is_valid_gfn = kvmgt_is_valid_gfn,
diff --git a/drivers/gpu/drm/i915/gvt/mpt.h b/drivers/gpu/drm/i915/gvt/mpt.h
index 0f9440128123..abf4a69920d3 100644
--- a/drivers/gpu/drm/i915/gvt/mpt.h
+++ b/drivers/gpu/drm/i915/gvt/mpt.h
@@ -330,6 +330,23 @@ static inline int intel_gvt_hypervisor_set_edid(struct intel_vgpu *vgpu,
return intel_gvt_host.mpt->set_edid(vgpu, port_num);
}

+/**
+ * intel_gvt_hypervisor_set_irq - register vgpu specific irq
+ * @vgpu: a vGPU
+ * @port_num: display port number
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ */
+static inline int intel_gvt_hypervisor_register_display_irq(
+ struct intel_vgpu *vgpu)
+{
+ if (!intel_gvt_host.mpt->register_display_irq)
+ return 0;
+
+ return intel_gvt_host.mpt->register_display_irq(vgpu);
+}
+
/**
* intel_gvt_hypervisor_get_vfio_device - increase vfio device ref count
* @vgpu: a vGPU
--
2.17.1