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drm/i915/gvt: add VFIO EDID region
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Implement VFIO EDID region for vgpu. Support EDID blob update and notify
guest on link state change via hotplug event.

v3: move struct edid_region to kvmgt.c <zhenyu>
v2: add EDID sanity check and size update <zhenyu>

Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
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Hang Yuan authored and Zhenyu Wang committed Jan 31, 2019
1 parent 1ca20f3 commit 39c68e8
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Showing 4 changed files with 167 additions and 0 deletions.
1 change: 1 addition & 0 deletions drivers/gpu/drm/i915/gvt/hypercall.h
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Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,7 @@ struct intel_gvt_mpt {
int (*set_trap_area)(unsigned long handle, u64 start, u64 end,
bool map);
int (*set_opregion)(void *vgpu);
int (*set_edid)(void *vgpu, int port_num);
int (*get_vfio_device)(void *vgpu);
void (*put_vfio_device)(void *vgpu);
bool (*is_valid_gfn)(unsigned long handle, unsigned long gfn);
Expand Down
143 changes: 143 additions & 0 deletions drivers/gpu/drm/i915/gvt/kvmgt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,8 @@ static const struct intel_gvt_ops *intel_gvt_ops;
#define VFIO_PCI_INDEX_TO_OFFSET(index) ((u64)(index) << VFIO_PCI_OFFSET_SHIFT)
#define VFIO_PCI_OFFSET_MASK (((u64)(1) << VFIO_PCI_OFFSET_SHIFT) - 1)

#define EDID_BLOB_OFFSET (PAGE_SIZE/2)

#define OPREGION_SIGNATURE "IntelGraphicsMem"

struct vfio_region;
Expand All @@ -76,6 +78,11 @@ struct vfio_region {
void *data;
};

struct vfio_edid_region {
struct vfio_region_gfx_edid vfio_edid_regs;
void *edid_blob;
};

struct kvmgt_pgfn {
gfn_t gfn;
struct hlist_node hnode;
Expand Down Expand Up @@ -427,6 +434,111 @@ static const struct intel_vgpu_regops intel_vgpu_regops_opregion = {
.release = intel_vgpu_reg_release_opregion,
};

static int handle_edid_regs(struct intel_vgpu *vgpu,
struct vfio_edid_region *region, char *buf,
size_t count, u16 offset, bool is_write)
{
struct vfio_region_gfx_edid *regs = &region->vfio_edid_regs;
unsigned int data;

if (offset + count > sizeof(*regs))
return -EINVAL;

if (count != 4)
return -EINVAL;

if (is_write) {
data = *((unsigned int *)buf);
switch (offset) {
case offsetof(struct vfio_region_gfx_edid, link_state):
if (data == VFIO_DEVICE_GFX_LINK_STATE_UP) {
if (!drm_edid_block_valid(
(u8 *)region->edid_blob,
0,
true,
NULL)) {
gvt_vgpu_err("invalid EDID blob\n");
return -EINVAL;
}
intel_gvt_ops->emulate_hotplug(vgpu, true);
} else if (data == VFIO_DEVICE_GFX_LINK_STATE_DOWN)
intel_gvt_ops->emulate_hotplug(vgpu, false);
else {
gvt_vgpu_err("invalid EDID link state %d\n",
regs->link_state);
return -EINVAL;
}
regs->link_state = data;
break;
case offsetof(struct vfio_region_gfx_edid, edid_size):
if (data > regs->edid_max_size) {
gvt_vgpu_err("EDID size is bigger than %d!\n",
regs->edid_max_size);
return -EINVAL;
}
regs->edid_size = data;
break;
default:
/* read-only regs */
gvt_vgpu_err("write read-only EDID region at offset %d\n",
offset);
return -EPERM;
}
} else {
memcpy(buf, (char *)regs + offset, count);
}

return count;
}

static int handle_edid_blob(struct vfio_edid_region *region, char *buf,
size_t count, u16 offset, bool is_write)
{
if (offset + count > region->vfio_edid_regs.edid_size)
return -EINVAL;

if (is_write)
memcpy(region->edid_blob + offset, buf, count);
else
memcpy(buf, region->edid_blob + offset, count);

return count;
}

static size_t intel_vgpu_reg_rw_edid(struct intel_vgpu *vgpu, char *buf,
size_t count, loff_t *ppos, bool iswrite)
{
int ret;
unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) -
VFIO_PCI_NUM_REGIONS;
struct vfio_edid_region *region =
(struct vfio_edid_region *)vgpu->vdev.region[i].data;
loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;

if (pos < region->vfio_edid_regs.edid_offset) {
ret = handle_edid_regs(vgpu, region, buf, count, pos, iswrite);
} else {
pos -= EDID_BLOB_OFFSET;
ret = handle_edid_blob(region, buf, count, pos, iswrite);
}

if (ret < 0)
gvt_vgpu_err("failed to access EDID region\n");

return ret;
}

static void intel_vgpu_reg_release_edid(struct intel_vgpu *vgpu,
struct vfio_region *region)
{
kfree(region->data);
}

static const struct intel_vgpu_regops intel_vgpu_regops_edid = {
.rw = intel_vgpu_reg_rw_edid,
.release = intel_vgpu_reg_release_edid,
};

static int intel_vgpu_register_reg(struct intel_vgpu *vgpu,
unsigned int type, unsigned int subtype,
const struct intel_vgpu_regops *ops,
Expand Down Expand Up @@ -493,6 +605,36 @@ static int kvmgt_set_opregion(void *p_vgpu)
return ret;
}

static int kvmgt_set_edid(void *p_vgpu, int port_num)
{
struct intel_vgpu *vgpu = (struct intel_vgpu *)p_vgpu;
struct intel_vgpu_port *port = intel_vgpu_port(vgpu, port_num);
struct vfio_edid_region *base;
int ret;

base = kzalloc(sizeof(*base), GFP_KERNEL);
if (!base)
return -ENOMEM;

/* TODO: Add multi-port and EDID extension block support */
base->vfio_edid_regs.edid_offset = EDID_BLOB_OFFSET;
base->vfio_edid_regs.edid_max_size = EDID_SIZE;
base->vfio_edid_regs.edid_size = EDID_SIZE;
base->vfio_edid_regs.max_xres = vgpu_edid_xres(port->id);
base->vfio_edid_regs.max_yres = vgpu_edid_yres(port->id);
base->edid_blob = port->edid->edid_block;

ret = intel_vgpu_register_reg(vgpu,
VFIO_REGION_TYPE_GFX,
VFIO_REGION_SUBTYPE_GFX_EDID,
&intel_vgpu_regops_edid, EDID_SIZE,
VFIO_REGION_INFO_FLAG_READ |
VFIO_REGION_INFO_FLAG_WRITE |
VFIO_REGION_INFO_FLAG_CAPS, base);

return ret;
}

static void kvmgt_put_vfio_device(void *vgpu)
{
if (WARN_ON(!((struct intel_vgpu *)vgpu)->vdev.vfio_device))
Expand Down Expand Up @@ -1874,6 +2016,7 @@ static struct intel_gvt_mpt kvmgt_mpt = {
.dma_map_guest_page = kvmgt_dma_map_guest_page,
.dma_unmap_guest_page = kvmgt_dma_unmap_guest_page,
.set_opregion = kvmgt_set_opregion,
.set_edid = kvmgt_set_edid,
.get_vfio_device = kvmgt_get_vfio_device,
.put_vfio_device = kvmgt_put_vfio_device,
.is_valid_gfn = kvmgt_is_valid_gfn,
Expand Down
17 changes: 17 additions & 0 deletions drivers/gpu/drm/i915/gvt/mpt.h
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Original file line number Diff line number Diff line change
Expand Up @@ -313,6 +313,23 @@ static inline int intel_gvt_hypervisor_set_opregion(struct intel_vgpu *vgpu)
return intel_gvt_host.mpt->set_opregion(vgpu);
}

/**
* intel_gvt_hypervisor_set_edid - Set EDID region for guest
* @vgpu: a vGPU
* @port_num: display port number
*
* Returns:
* Zero on success, negative error code if failed.
*/
static inline int intel_gvt_hypervisor_set_edid(struct intel_vgpu *vgpu,
int port_num)
{
if (!intel_gvt_host.mpt->set_edid)
return 0;

return intel_gvt_host.mpt->set_edid(vgpu, port_num);
}

/**
* intel_gvt_hypervisor_get_vfio_device - increase vfio device ref count
* @vgpu: a vGPU
Expand Down
6 changes: 6 additions & 0 deletions drivers/gpu/drm/i915/gvt/vgpu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -428,6 +428,12 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
if (ret)
goto out_clean_sched_policy;

/*TODO: add more platforms support */
if (IS_SKYLAKE(gvt->dev_priv) || IS_KABYLAKE(gvt->dev_priv))
ret = intel_gvt_hypervisor_set_edid(vgpu, PORT_D);
if (ret)
goto out_clean_sched_policy;

return vgpu;

out_clean_sched_policy:
Expand Down

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