| Message ID | 20190924064143.9282-3-tina.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Deliver vGPU display refresh event to userspace | expand |
On Tue, 24 Sep 2019 14:41:39 +0800 Tina Zhang <tina.zhang@intel.com> wrote: > Introduce vGPU specific irq type VFIO_IRQ_TYPE_GFX, and > VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ as the subtype for vGPU display. > > Introduce vfio_irq_info_cap_display_plane_events capability to notify > user space with the vGPU's plane update events > > v3: > - Add more description to VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ and > VFIO_IRQ_INFO_CAP_DISPLAY. (Alex & Gerd) > > v2: > - Add VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ description. (Alex & Kechen) > - Introduce vfio_irq_info_cap_display_plane_events. (Gerd & Alex) > > Signed-off-by: Tina Zhang <tina.zhang@intel.com> > --- > include/uapi/linux/vfio.h | 38 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index aa6850f1daef..2946a028b0c3 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -476,6 +476,44 @@ struct vfio_irq_info_cap_type { > __u32 subtype; /* type specific */ > }; > > +/* vGPU IRQ TYPE */ > +#define VFIO_IRQ_TYPE_GFX (1) > + > +/* sub-types for VFIO_IRQ_TYPE_GFX */ > +/* > + * vGPU device display refresh interrupt request. This irq asking for > + * a user space display refresh, covers all display updates events, > + * i.e. user space can stop the display update timer and fully depend > + * on getting the notification if an update is needed. > + */ > +#define VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ (1) > + > +/* > + * Display capability of reporting display refresh interrupt events. Perhaps, "Capability for interpreting GFX_DISPLAY_IRQ eventfd value" > + * This gives user space the capability to identify different display > + * updates events of the display refresh interrupt request. > + * > + * When notified by VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ, user space can > + * use the eventfd counter value to identify which plane has been > + * updated. > + * > + * Note that there might be some cases like counter_value > > + * (cur_event_val + pri_event_val), if notifications haven't been > + * handled on time in user mode. These cases can be handled as all > + * plane updated case or signle plane updated case depending on the > + * value. Seems like in the GVT-g implementation such a value is not possible. In fact, when this capability is provided, doesn't userspace interpret the eventfd value more as a bitmask of events rather than a counter? If so, (cur_event_val + pri_event_val) may be mathematically accurate, but maybe obfuscates the logical interpretation... or maybe that's just me. > + * > + * cur_event_val: eventfd counter value for cursor plane change event. > + * pri_event_val: eventfd counter value for primary plane change event. I think there should be a note that this capability is optional and lacking this feature, userspace should refresh all display events on notification. > + */ > +#define VFIO_IRQ_INFO_CAP_DISPLAY 2 > + > +struct vfio_irq_info_cap_display_plane_events { > + struct vfio_info_cap_header header; > + __u64 cur_event_val; > + __u64 pri_event_val; AIUI, the GVT-g implementation sets a single bit and userspace expects one or both of those bits to be set on notification. Should we simplify this a bit and just define these as cur_event_bit, pri_event_bit and use a __u8 for each to define the bit position? Thanks, Alex
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index aa6850f1daef..2946a028b0c3 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -476,6 +476,44 @@ struct vfio_irq_info_cap_type { __u32 subtype; /* type specific */ }; +/* vGPU IRQ TYPE */ +#define VFIO_IRQ_TYPE_GFX (1) + +/* sub-types for VFIO_IRQ_TYPE_GFX */ +/* + * vGPU device display refresh interrupt request. This irq asking for + * a user space display refresh, covers all display updates events, + * i.e. user space can stop the display update timer and fully depend + * on getting the notification if an update is needed. + */ +#define VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ (1) + +/* + * Display capability of reporting display refresh interrupt events. + * This gives user space the capability to identify different display + * updates events of the display refresh interrupt request. + * + * When notified by VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ, user space can + * use the eventfd counter value to identify which plane has been + * updated. + * + * Note that there might be some cases like counter_value > + * (cur_event_val + pri_event_val), if notifications haven't been + * handled on time in user mode. These cases can be handled as all + * plane updated case or signle plane updated case depending on the + * value. + * + * cur_event_val: eventfd counter value for cursor plane change event. + * pri_event_val: eventfd counter value for primary plane change event. + */ +#define VFIO_IRQ_INFO_CAP_DISPLAY 2 + +struct vfio_irq_info_cap_display_plane_events { + struct vfio_info_cap_header header; + __u64 cur_event_val; + __u64 pri_event_val; +}; + /** * VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set) *
Introduce vGPU specific irq type VFIO_IRQ_TYPE_GFX, and VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ as the subtype for vGPU display. Introduce vfio_irq_info_cap_display_plane_events capability to notify user space with the vGPU's plane update events v3: - Add more description to VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ and VFIO_IRQ_INFO_CAP_DISPLAY. (Alex & Gerd) v2: - Add VFIO_IRQ_SUBTYPE_GFX_DISPLAY_IRQ description. (Alex & Kechen) - Introduce vfio_irq_info_cap_display_plane_events. (Gerd & Alex) Signed-off-by: Tina Zhang <tina.zhang@intel.com> --- include/uapi/linux/vfio.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)