Re: [PATCH 7/8] drm/i915/gvt: vGPU device config data save/restore interface

From: Zhenyu Wang
Date: Wed Feb 20 2019 - 04:49:44 EST


On 2019.02.19 02:46:32 -0500, Yan Zhao wrote:
> The patch implments the gvt interface intel_gvt_save_restore to
> save/restore vGPU's device config data for live migration.
>
> vGPU device config data includes vreg, vggtt, vcfg space, workloads, ppgtt,
> execlist.
> It does not include dirty pages in system memory produced by vGPU.
>
> Signed-off-by: Yulei Zhang <yulei.zhang@xxxxxxxxx>
> Signed-off-by: Xiao Zheng <xiao.zheng@xxxxxxxxx>
> Signed-off-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
> Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>

...

> +
> +#ifndef __GVT_MIGRATE_H__
> +#define __GVT_MIGRATE_H__
> +
> +#define MIGRATION_DIRTY_BITMAP_SIZE (16*1024UL)
> +
> +/* Assume 9MB is enough to descript VM kernel state */
> +#define MIGRATION_IMG_MAX_SIZE (9*1024UL*1024UL)
> +#define GVT_MMIO_SIZE (2*1024UL*1024UL)
> +#define GVT_MIGRATION_VERSION 0
> +
> +enum gvt_migration_type_t {
> + GVT_MIGRATION_NONE,
> + GVT_MIGRATION_HEAD,
> + GVT_MIGRATION_CFG_SPACE,
> + GVT_MIGRATION_VREG,
> + GVT_MIGRATION_SREG,
> + GVT_MIGRATION_GTT,
> + GVT_MIGRATION_PPGTT,
> + GVT_MIGRATION_WORKLOAD,
> + GVT_MIGRATION_EXECLIST,
> +};
> +
> +struct gvt_ppgtt_entry_t {
> + int page_table_level;
> + u64 pdp[4];
> +};
> +
> +struct gvt_pending_workload_t {
> + int ring_id;
> + bool emulate_schedule_in;
> + struct execlist_ctx_descriptor_format ctx_desc;
> + struct intel_vgpu_elsp_dwords elsp_dwords;
> +};
> +
> +struct gvt_region_t {
> + enum gvt_migration_type_t type;
> + u32 size; /* obj size of bytes to read/write */
> +};
> +
> +struct gvt_migration_obj_t {
> + void *img;
> + void *vgpu;
> + u32 offset;
> + struct gvt_region_t region;
> + /* operation func defines how data save-restore */
> + struct gvt_migration_operation_t *ops;
> + char *name;
> +};
> +
> +struct gvt_migration_operation_t {
> + /* called during pre-copy stage, VM is still alive */
> + int (*pre_copy)(const struct gvt_migration_obj_t *obj);
> + /* called before when VM was paused,
> + * return bytes transferred
> + */
> + int (*pre_save)(const struct gvt_migration_obj_t *obj);
> + /* called before load the state of device */
> + int (*pre_load)(const struct gvt_migration_obj_t *obj, u32 size);
> + /* called after load the state of device, VM already alive */
> + int (*post_load)(const struct gvt_migration_obj_t *obj, u32 size);
> +};
> +
> +struct gvt_image_header_t {
> + int version;
> + int data_size;
> + u64 crc_check;
> + u64 global_data[64];
> +};

I think this misses device info that should ship with the image,
currently what I can think is that each platform should have seperate
type, e.g BDW, SKL, KBL, etc. We won't allow to restore onto different
platform than the source.

> +
> +#endif
> diff --git a/drivers/gpu/drm/i915/gvt/mmio.c b/drivers/gpu/drm/i915/gvt/mmio.c
> index 43f65848ecd6..6221d2f274fc 100644
> --- a/drivers/gpu/drm/i915/gvt/mmio.c
> +++ b/drivers/gpu/drm/i915/gvt/mmio.c
> @@ -50,6 +50,19 @@ int intel_vgpu_gpa_to_mmio_offset(struct intel_vgpu *vgpu, u64 gpa)
> return gpa - gttmmio_gpa;
> }
>
> +/**
> + * intel_vgpu_mmio_offset_to_GPA - translate a MMIO offset to GPA
> + * @vgpu: a vGPU
> + *
> + * Returns:
> + * Zero on success, negative error code if failed
> + */
> +int intel_vgpu_mmio_offset_to_gpa(struct intel_vgpu *vgpu, u64 offset)
> +{
> + return offset + ((*(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0)) &
> + ~GENMASK(3, 0));
> +}
> +
> #define reg_is_mmio(gvt, reg) \
> (reg >= 0 && reg < gvt->device_info.mmio_size)
>
> diff --git a/drivers/gpu/drm/i915/gvt/mmio.h b/drivers/gpu/drm/i915/gvt/mmio.h
> index 1ffc69eba30e..a2bddb0257cf 100644
> --- a/drivers/gpu/drm/i915/gvt/mmio.h
> +++ b/drivers/gpu/drm/i915/gvt/mmio.h
> @@ -82,6 +82,7 @@ void intel_vgpu_reset_mmio(struct intel_vgpu *vgpu, bool dmlr);
> void intel_vgpu_clean_mmio(struct intel_vgpu *vgpu);
>
> int intel_vgpu_gpa_to_mmio_offset(struct intel_vgpu *vgpu, u64 gpa);
> +int intel_vgpu_mmio_offset_to_gpa(struct intel_vgpu *vgpu, u64 offset);
>
> int intel_vgpu_emulate_mmio_read(struct intel_vgpu *vgpu, u64 pa,
> void *p_data, unsigned int bytes);
> diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
> index fcccda35a456..7676dcfdca09 100644
> --- a/drivers/gpu/drm/i915/gvt/vgpu.c
> +++ b/drivers/gpu/drm/i915/gvt/vgpu.c
> @@ -213,6 +213,7 @@ void intel_gvt_activate_vgpu(struct intel_vgpu *vgpu)
> {
> mutex_lock(&vgpu->gvt->lock);
> vgpu->active = true;
> + intel_vgpu_start_schedule(vgpu);
> mutex_unlock(&vgpu->gvt->lock);
> }
>
> --
> 2.17.1
>
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

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