Re: [Intel-gfx] [PATCH v1 03/12] drm/i915: vgpu pv command buffer transport protocol
On Thu, 2020-09-10 at 16:20 +0300, Jani Nikula wrote:
> On Sat, 05 Sep 2020, Xiaolin Zhang wrote:
> > based on the common shared memory, vgpu pv command transport buffer
> > (CTB)
> > protocol is implemented which is a simple pv command buffer ring
> > with pv
> > command descriptor used to perform guest-2-gvt single direction
> > commucation
> > between guest and host GVTg.
> >
> > with this CTB, guest can send PV command with PV data to host to
> > perform PV
> > commands in host side.
> >
> > Signed-off-by: Xiaolin Zhang
> > ---
> > drivers/gpu/drm/i915/i915_pvinfo.h | 1 +
> > drivers/gpu/drm/i915/i915_vgpu.c | 195
> > -
> > drivers/gpu/drm/i915/i915_vgpu.h | 53 ++
> > 3 files changed, 247 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h
> > b/drivers/gpu/drm/i915/i915_pvinfo.h
> > index 1d44876..ded93c5 100644
> > --- a/drivers/gpu/drm/i915/i915_pvinfo.h
> > +++ b/drivers/gpu/drm/i915/i915_pvinfo.h
> > @@ -49,6 +49,7 @@ enum vgt_g2v_type {
> > VGT_G2V_EXECLIST_CONTEXT_CREATE,
> > VGT_G2V_EXECLIST_CONTEXT_DESTROY,
> > VGT_G2V_SHARED_PAGE_REGISTER,
> > + VGT_G2V_PV_SEND_TRIGGER,
> > VGT_G2V_MAX,
> > };
> >
> > diff --git a/drivers/gpu/drm/i915/i915_vgpu.c
> > b/drivers/gpu/drm/i915/i915_vgpu.c
> > index 8b2b451..e856eff 100644
> > --- a/drivers/gpu/drm/i915/i915_vgpu.c
> > +++ b/drivers/gpu/drm/i915/i915_vgpu.c
> > @@ -370,6 +370,183 @@ int intel_vgt_balloon(struct i915_ggtt *ggtt)
> > * i915 vgpu PV support for Linux
> > */
> >
> > +/**
> > + * wait_for_desc_update - Wait for the command buffer descriptor
> > update.
> > + * @desc: buffer descriptor
> > + * @fence: response fence
> > + * @status:placeholder for status
> > + *
> > + * GVTg will update command buffer descriptor with new fence and
> > status
> > + * after processing the command identified by the fence. Wait for
> > + * specified fence and then read from the descriptor status of the
> > + * command.
> > + *
> > + * Return:
> > + * * 0 response received (status is valid)
> > + * * -ETIMEDOUT no response within hardcoded timeout
> > + */
> > +static int wait_for_desc_update(struct vgpu_pv_ct_buffer_desc
> > *desc,
> > + u32 fence, u32 *status)
> > +{
> > + int err;
> > +
> > +#define done (READ_ONCE(desc->fence) == fence)
> > + err = wait_for_us(done, 5);
> > + if (err)
> > + err = wait_for(done, 10);
> > +#undef done
> > +
> > + if (unlikely(err)) {
> > + DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
> > + fence, desc->fence);
>
> drm_err() please.
Sure. will change all the similar code. thanks.
>
> > + }
> > +
> > + *status = desc->status;
>
> Please have a blank line before the return. Recommended throughout
> the
> series.
Sure, will do it in whole series. thanks.
>
> > + return err;
> > +}
> > +
> > +/**
> > + * CTB Guest to GVT request
> > + *
> > + * Format of the CTB Guest to GVT request message is as follows::
> > + *
> > + * ++-+-+-+-+
> > + * | msg[0] | [1] | [2] | ... | [n-1] |
> > + * ++-+-+-+-+
> > + * | MESSAGE | MESSAGE PAYLOAD |
> > + * + HEADER +-+-+-+-+
> > + * ||0|1| ... |n|
> > + * ++=+=+=+=+
> > + * | len >= 1 | FENCE | request specific data |
> > + * +--+-+-+-+-+-+
> > + *
> > + * ^-len---^
> > + */
> > +static int pv_command_buffer_write(struct i915_virtual_gpu_pv *pv,
> > + const u32 *action, u32 len /* in dwords */, u32 fence)
> > +{
> > + struct vgpu_pv_ct_buffer_desc *desc = pv->ctb.desc;
> > + u32 head = desc->head / 4; /* in dwords */
> > + u32 tail = desc->tail / 4; /* in dwords */
> > + u32 size = desc->size / 4; /* in dwords */
> > + u32 used; /* in dwords */
> > + u32 header;
> > + u32 *cmds = pv->ctb.cmds;
> > + unsigned int i;
> > +
> > + GEM_BUG_ON(desc->size % 4);
> > + GEM_BUG_ON(desc->head % 4);
> > + GEM_BUG_ON(desc->tail % 4);
> > + GEM_BUG_ON(tail >= size);
> > +
> > +/* tail == head condition indicates empty */
> > + if (tail < head)
> > + used = (size - head) + tail;
> > + else
> > + used = tail - head;
> > +
> > + /* make sure there is a space including extra dw for the fence
> > */
> > + if (unlikely(used + len + 1 >= size))
> > + return -ENOSPC;
> > +
> > + /*
> > +* Write the message. The format is the following:
> > +* DW0: header (including action code)
> > +* DW1: fence
> > +* DW2+: action data
> > +*/
> > + header = (len <<
Re: [Intel-gfx] [PATCH v1 03/12] drm/i915: vgpu pv command buffer transport protocol
On Sat, 05 Sep 2020, Xiaolin Zhang wrote:
> based on the common shared memory, vgpu pv command transport buffer (CTB)
> protocol is implemented which is a simple pv command buffer ring with pv
> command descriptor used to perform guest-2-gvt single direction commucation
> between guest and host GVTg.
>
> with this CTB, guest can send PV command with PV data to host to perform PV
> commands in host side.
>
> Signed-off-by: Xiaolin Zhang
> ---
> drivers/gpu/drm/i915/i915_pvinfo.h | 1 +
> drivers/gpu/drm/i915/i915_vgpu.c | 195
> -
> drivers/gpu/drm/i915/i915_vgpu.h | 53 ++
> 3 files changed, 247 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h
> b/drivers/gpu/drm/i915/i915_pvinfo.h
> index 1d44876..ded93c5 100644
> --- a/drivers/gpu/drm/i915/i915_pvinfo.h
> +++ b/drivers/gpu/drm/i915/i915_pvinfo.h
> @@ -49,6 +49,7 @@ enum vgt_g2v_type {
> VGT_G2V_EXECLIST_CONTEXT_CREATE,
> VGT_G2V_EXECLIST_CONTEXT_DESTROY,
> VGT_G2V_SHARED_PAGE_REGISTER,
> + VGT_G2V_PV_SEND_TRIGGER,
> VGT_G2V_MAX,
> };
>
> diff --git a/drivers/gpu/drm/i915/i915_vgpu.c
> b/drivers/gpu/drm/i915/i915_vgpu.c
> index 8b2b451..e856eff 100644
> --- a/drivers/gpu/drm/i915/i915_vgpu.c
> +++ b/drivers/gpu/drm/i915/i915_vgpu.c
> @@ -370,6 +370,183 @@ int intel_vgt_balloon(struct i915_ggtt *ggtt)
> * i915 vgpu PV support for Linux
> */
>
> +/**
> + * wait_for_desc_update - Wait for the command buffer descriptor update.
> + * @desc:buffer descriptor
> + * @fence: response fence
> + * @status: placeholder for status
> + *
> + * GVTg will update command buffer descriptor with new fence and status
> + * after processing the command identified by the fence. Wait for
> + * specified fence and then read from the descriptor status of the
> + * command.
> + *
> + * Return:
> + * * 0 response received (status is valid)
> + * * -ETIMEDOUT no response within hardcoded timeout
> + */
> +static int wait_for_desc_update(struct vgpu_pv_ct_buffer_desc *desc,
> + u32 fence, u32 *status)
> +{
> + int err;
> +
> +#define done (READ_ONCE(desc->fence) == fence)
> + err = wait_for_us(done, 5);
> + if (err)
> + err = wait_for(done, 10);
> +#undef done
> +
> + if (unlikely(err)) {
> + DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
> + fence, desc->fence);
drm_err() please.
> + }
> +
> + *status = desc->status;
Please have a blank line before the return. Recommended throughout the
series.
> + return err;
> +}
> +
> +/**
> + * CTB Guest to GVT request
> + *
> + * Format of the CTB Guest to GVT request message is as follows::
> + *
> + * ++-+-+-+-+
> + * | msg[0] | [1] | [2] | ... | [n-1] |
> + * ++-+-+-+-+
> + * | MESSAGE | MESSAGE PAYLOAD |
> + * + HEADER +-+-+-+-+
> + * ||0|1| ... |n|
> + * ++=+=+=+=+
> + * | len >= 1 | FENCE | request specific data |
> + * +--+-+-+-+-+-+
> + *
> + * ^-len---^
> + */
> +static int pv_command_buffer_write(struct i915_virtual_gpu_pv *pv,
> + const u32 *action, u32 len /* in dwords */, u32 fence)
> +{
> + struct vgpu_pv_ct_buffer_desc *desc = pv->ctb.desc;
> + u32 head = desc->head / 4; /* in dwords */
> + u32 tail = desc->tail / 4; /* in dwords */
> + u32 size = desc->size / 4; /* in dwords */
> + u32 used; /* in dwords */
> + u32 header;
> + u32 *cmds = pv->ctb.cmds;
> + unsigned int i;
> +
> + GEM_BUG_ON(desc->size % 4);
> + GEM_BUG_ON(desc->head % 4);
> + GEM_BUG_ON(desc->tail % 4);
> + GEM_BUG_ON(tail >= size);
> +
> + /* tail == head condition indicates empty */
> + if (tail < head)
> + used = (size - head) + tail;
> + else
> + used = tail - head;
> +
> + /* make sure there is a space including extra dw for the fence */
> + if (unlikely(used + len + 1 >= size))
> + return -ENOSPC;
> +
> + /*
> + * Write the message. The format is the following:
> + * DW0: header (including action code)
> + * DW1: fence
> + * DW2+: action data
> + */
> + header = (len << PV_CT_MSG_LEN_SHIFT) |
> + (PV_CT_MSG_WRITE_FENCE_TO_DESC) |
> + (action[0] << PV_CT_MSG_ACTION_SHIFT);
> +
> + cmds[tail] = header;
> + tail = (tail + 1) % size;
> +
> + cmds[tail] = fence;
> + tail = (tail + 1) % size;
> +
> + for (i = 1; i < len; i++) {
> + cmds[tail] = action[i];
> + tail = (tail + 1) % size;
> +
[Intel-gfx] [PATCH v1 03/12] drm/i915: vgpu pv command buffer transport protocol
based on the common shared memory, vgpu pv command transport buffer (CTB)
protocol is implemented which is a simple pv command buffer ring with pv
command descriptor used to perform guest-2-gvt single direction commucation
between guest and host GVTg.
with this CTB, guest can send PV command with PV data to host to perform PV
commands in host side.
Signed-off-by: Xiaolin Zhang
---
drivers/gpu/drm/i915/i915_pvinfo.h | 1 +
drivers/gpu/drm/i915/i915_vgpu.c | 195 -
drivers/gpu/drm/i915/i915_vgpu.h | 53 ++
3 files changed, 247 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_pvinfo.h
b/drivers/gpu/drm/i915/i915_pvinfo.h
index 1d44876..ded93c5 100644
--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -49,6 +49,7 @@ enum vgt_g2v_type {
VGT_G2V_EXECLIST_CONTEXT_CREATE,
VGT_G2V_EXECLIST_CONTEXT_DESTROY,
VGT_G2V_SHARED_PAGE_REGISTER,
+ VGT_G2V_PV_SEND_TRIGGER,
VGT_G2V_MAX,
};
diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index 8b2b451..e856eff 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -370,6 +370,183 @@ int intel_vgt_balloon(struct i915_ggtt *ggtt)
* i915 vgpu PV support for Linux
*/
+/**
+ * wait_for_desc_update - Wait for the command buffer descriptor update.
+ * @desc: buffer descriptor
+ * @fence: response fence
+ * @status:placeholder for status
+ *
+ * GVTg will update command buffer descriptor with new fence and status
+ * after processing the command identified by the fence. Wait for
+ * specified fence and then read from the descriptor status of the
+ * command.
+ *
+ * Return:
+ * * 0 response received (status is valid)
+ * * -ETIMEDOUT no response within hardcoded timeout
+ */
+static int wait_for_desc_update(struct vgpu_pv_ct_buffer_desc *desc,
+ u32 fence, u32 *status)
+{
+ int err;
+
+#define done (READ_ONCE(desc->fence) == fence)
+ err = wait_for_us(done, 5);
+ if (err)
+ err = wait_for(done, 10);
+#undef done
+
+ if (unlikely(err)) {
+ DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
+ fence, desc->fence);
+ }
+
+ *status = desc->status;
+ return err;
+}
+
+/**
+ * CTB Guest to GVT request
+ *
+ * Format of the CTB Guest to GVT request message is as follows::
+ *
+ * ++-+-+-+-+
+ * | msg[0] | [1] | [2] | ... | [n-1] |
+ * ++-+-+-+-+
+ * | MESSAGE | MESSAGE PAYLOAD |
+ * + HEADER +-+-+-+-+
+ * ||0|1| ... |n|
+ * ++=+=+=+=+
+ * | len >= 1 | FENCE | request specific data |
+ * +--+-+-+-+-+-+
+ *
+ * ^-len---^
+ */
+static int pv_command_buffer_write(struct i915_virtual_gpu_pv *pv,
+ const u32 *action, u32 len /* in dwords */, u32 fence)
+{
+ struct vgpu_pv_ct_buffer_desc *desc = pv->ctb.desc;
+ u32 head = desc->head / 4; /* in dwords */
+ u32 tail = desc->tail / 4; /* in dwords */
+ u32 size = desc->size / 4; /* in dwords */
+ u32 used; /* in dwords */
+ u32 header;
+ u32 *cmds = pv->ctb.cmds;
+ unsigned int i;
+
+ GEM_BUG_ON(desc->size % 4);
+ GEM_BUG_ON(desc->head % 4);
+ GEM_BUG_ON(desc->tail % 4);
+ GEM_BUG_ON(tail >= size);
+
+/* tail == head condition indicates empty */
+ if (tail < head)
+ used = (size - head) + tail;
+ else
+ used = tail - head;
+
+ /* make sure there is a space including extra dw for the fence */
+ if (unlikely(used + len + 1 >= size))
+ return -ENOSPC;
+
+ /*
+* Write the message. The format is the following:
+* DW0: header (including action code)
+* DW1: fence
+* DW2+: action data
+*/
+ header = (len << PV_CT_MSG_LEN_SHIFT) |
+(PV_CT_MSG_WRITE_FENCE_TO_DESC) |
+(action[0] << PV_CT_MSG_ACTION_SHIFT);
+
+ cmds[tail] = header;
+ tail = (tail + 1) % size;
+
+ cmds[tail] = fence;
+ tail = (tail + 1) % size;
+
+ for (i = 1; i < len; i++) {
+ cmds[tail] = action[i];
+ tail = (tail + 1) % size;
+ }
+
+ /* now update desc tail (back in bytes) */
+ desc->tail = tail * 4;
+ GEM_BUG_ON(desc->tail > desc->size);
+
+ return 0;
+}
+
+static u32 pv_get_next_fence(struct i915_virtual_gpu_pv *pv)
+{
+ /* For now it's trivial */
+ return ++pv->next_fence;
+}
+
