Re: [PATCH v3 05/36] Revert "drm/xe/vf: Fixup CTB send buffer messages after migration"

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 9/29/2025 4:55 AM, Matthew Brost wrote:
> This reverts commit cef88d1265cac7d415606af73ba58926fd3cd8b7.
> 
> Due to change in the VF migration recovery design this code
> is not needed any more.
> 
> v3:
>  - Add commit message (Michal / Lucas)
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_guc_ct.c   | 183 -------------------------------
>  drivers/gpu/drm/xe/xe_guc_ct.h   |   2 -
>  drivers/gpu/drm/xe/xe_map.h      |  18 ---
>  drivers/gpu/drm/xe/xe_sriov_vf.c |   2 -
>  4 files changed, 205 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> index 18f6327bf552..47079ab9922c 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> @@ -25,7 +25,6 @@
>  #include "xe_gt_printk.h"
>  #include "xe_gt_sriov_pf_control.h"
>  #include "xe_gt_sriov_pf_monitor.h"
> -#include "xe_gt_sriov_printk.h"
>  #include "xe_guc.h"
>  #include "xe_guc_log.h"
>  #include "xe_guc_relay.h"
> @@ -93,8 +92,6 @@ struct g2h_fence {
>  	bool done;
>  };
>  
> -#define make_u64(hi, lo) ((u64)((u64)(u32)(hi) << 32 | (u32)(lo)))
> -
>  static void g2h_fence_init(struct g2h_fence *g2h_fence, u32 *response_buffer)
>  {
>  	memset(g2h_fence, 0, sizeof(*g2h_fence));
> @@ -1793,186 +1790,6 @@ static void g2h_worker_func(struct work_struct *w)
>  	receive_g2h(ct);
>  }
>  
> -static void xe_fixup_u64_in_cmds(struct xe_device *xe, struct iosys_map *cmds,
> -				 u32 size, u32 idx, s64 shift)
> -{
> -	u32 hi, lo;
> -	u64 offset;
> -
> -	lo = xe_map_rd_ring_u32(xe, cmds, idx, size);
> -	hi = xe_map_rd_ring_u32(xe, cmds, idx + 1, size);
> -	offset = make_u64(hi, lo);
> -	offset += shift;
> -	lo = lower_32_bits(offset);
> -	hi = upper_32_bits(offset);
> -	xe_map_wr_ring_u32(xe, cmds, idx, size, lo);
> -	xe_map_wr_ring_u32(xe, cmds, idx + 1, size, hi);
> -}
> -
> -/*
> - * Shift any GGTT addresses within a single message left within CTB from
> - * before post-migration recovery.
> - * @ct: pointer to CT struct of the target GuC
> - * @cmds: iomap buffer containing CT messages
> - * @head: start of the target message within the buffer
> - * @len: length of the target message
> - * @size: size of the commands buffer
> - * @shift: the address shift to be added to each GGTT reference
> - * Return: true if the message was fixed or needed no fixups, false on failure
> - */
> -static bool ct_fixup_ggtt_in_message(struct xe_guc_ct *ct,
> -				     struct iosys_map *cmds, u32 head,
> -				     u32 len, u32 size, s64 shift)
> -{
> -	struct xe_gt *gt = ct_to_gt(ct);
> -	struct xe_device *xe = ct_to_xe(ct);
> -	u32 msg[GUC_HXG_MSG_MIN_LEN];
> -	u32 action, i, n;
> -
> -	xe_gt_assert(gt, len >= GUC_HXG_MSG_MIN_LEN);
> -
> -	msg[0] = xe_map_rd_ring_u32(xe, cmds, head, size);
> -	action = FIELD_GET(GUC_HXG_REQUEST_MSG_0_ACTION, msg[0]);
> -
> -	xe_gt_sriov_dbg_verbose(gt, "fixing H2G %#x\n", action);
> -
> -	switch (action) {
> -	case XE_GUC_ACTION_REGISTER_CONTEXT:
> -		if (len != XE_GUC_REGISTER_CONTEXT_MSG_LEN)
> -			goto err_len;
> -		xe_fixup_u64_in_cmds(xe, cmds, size, head +
> -				     XE_GUC_REGISTER_CONTEXT_DATA_5_WQ_DESC_ADDR_LOWER,
> -				     shift);
> -		xe_fixup_u64_in_cmds(xe, cmds, size, head +
> -				     XE_GUC_REGISTER_CONTEXT_DATA_7_WQ_BUF_BASE_LOWER,
> -				     shift);
> -		xe_fixup_u64_in_cmds(xe, cmds, size, head +
> -				     XE_GUC_REGISTER_CONTEXT_DATA_10_HW_LRC_ADDR, shift);
> -		break;
> -	case XE_GUC_ACTION_REGISTER_CONTEXT_MULTI_LRC:
> -		if (len < XE_GUC_REGISTER_CONTEXT_MULTI_LRC_MSG_MIN_LEN)
> -			goto err_len;
> -		n = xe_map_rd_ring_u32(xe, cmds, head +
> -				       XE_GUC_REGISTER_CONTEXT_MULTI_LRC_DATA_10_NUM_CTXS, size);
> -		if (len != XE_GUC_REGISTER_CONTEXT_MULTI_LRC_MSG_MIN_LEN + 2 * n)
> -			goto err_len;
> -		xe_fixup_u64_in_cmds(xe, cmds, size, head +
> -				     XE_GUC_REGISTER_CONTEXT_MULTI_LRC_DATA_5_WQ_DESC_ADDR_LOWER,
> -				     shift);
> -		xe_fixup_u64_in_cmds(xe, cmds, size, head +
> -				     XE_GUC_REGISTER_CONTEXT_MULTI_LRC_DATA_7_WQ_BUF_BASE_LOWER,
> -				     shift);
> -		for (i = 0; i < n; i++)
> -			xe_fixup_u64_in_cmds(xe, cmds, size, head +
> -					     XE_GUC_REGISTER_CONTEXT_MULTI_LRC_DATA_11_HW_LRC_ADDR
> -					     + 2 * i, shift);
> -		break;
> -	default:
> -		break;
> -	}
> -	return true;
> -
> -err_len:
> -	xe_gt_err(gt, "Skipped G2G %#x message fixups, unexpected length (%u)\n", action, len);
> -	return false;
> -}
> -
> -/*
> - * Apply fixups to the next outgoing CT message within given CTB
> - * @ct: the &xe_guc_ct struct instance representing the target GuC
> - * @h2g: the &guc_ctb struct instance of the target buffer
> - * @shift: shift to be added to all GGTT addresses within the CTB
> - * @mhead: pointer to an integer storing message start position; the
> - *   position is changed to next message before this function return
> - * @avail: size of the area available for parsing, that is length
> - *   of all remaining messages stored within the CTB
> - * Return: size of the area available for parsing after one message
> - *   has been parsed, that is length remaining from the updated mhead
> - */
> -static int ct_fixup_ggtt_in_buffer(struct xe_guc_ct *ct, struct guc_ctb *h2g,
> -				   s64 shift, u32 *mhead, s32 avail)
> -{
> -	struct xe_gt *gt = ct_to_gt(ct);
> -	struct xe_device *xe = ct_to_xe(ct);
> -	u32 msg[GUC_HXG_MSG_MIN_LEN];
> -	u32 size = h2g->info.size;
> -	u32 head = *mhead;
> -	u32 len;
> -
> -	xe_gt_assert(gt, avail >= (s32)GUC_CTB_MSG_MIN_LEN);
> -
> -	/* Read header */
> -	msg[0] = xe_map_rd_ring_u32(xe, &h2g->cmds, head, size);
> -	len = FIELD_GET(GUC_CTB_MSG_0_NUM_DWORDS, msg[0]) + GUC_CTB_MSG_MIN_LEN;
> -
> -	if (unlikely(len > (u32)avail)) {
> -		xe_gt_err(gt, "H2G channel broken on read, avail=%d, len=%d, fixups skipped\n",
> -			  avail, len);
> -		return 0;
> -	}
> -
> -	head = (head + GUC_CTB_MSG_MIN_LEN) % size;
> -	if (!ct_fixup_ggtt_in_message(ct, &h2g->cmds, head, msg_len_to_hxg_len(len), size, shift))
> -		return 0;
> -	*mhead = (head + msg_len_to_hxg_len(len)) % size;
> -
> -	return avail - len;
> -}
> -
> -/**
> - * xe_guc_ct_fixup_messages_with_ggtt - Fixup any pending H2G CTB messages
> - * @ct: pointer to CT struct of the target GuC
> - * @ggtt_shift: shift to be added to all GGTT addresses within the CTB
> - *
> - * Messages in GuC to Host CTB are owned by GuC and any fixups in them
> - * are made by GuC. But content of the Host to GuC CTB is owned by the
> - * KMD, so fixups to GGTT references in any pending messages need to be
> - * applied here.
> - * This function updates GGTT offsets in payloads of pending H2G CTB
> - * messages (messages which were not consumed by GuC before the VF got
> - * paused).
> - */
> -void xe_guc_ct_fixup_messages_with_ggtt(struct xe_guc_ct *ct, s64 ggtt_shift)
> -{
> -	struct guc_ctb *h2g = &ct->ctbs.h2g;
> -	struct xe_guc *guc = ct_to_guc(ct);
> -	struct xe_gt *gt = guc_to_gt(guc);
> -	u32 head, tail, size;
> -	s32 avail;
> -
> -	if (unlikely(h2g->info.broken))
> -		return;
> -
> -	h2g->info.head = desc_read(ct_to_xe(ct), h2g, head);
> -	head = h2g->info.head;
> -	tail = READ_ONCE(h2g->info.tail);
> -	size = h2g->info.size;
> -
> -	if (unlikely(head > size))
> -		goto corrupted;
> -
> -	if (unlikely(tail >= size))
> -		goto corrupted;
> -
> -	avail = tail - head;
> -
> -	/* beware of buffer wrap case */
> -	if (unlikely(avail < 0))
> -		avail += size;
> -	xe_gt_dbg(gt, "available %d (%u:%u:%u)\n", avail, head, tail, size);
> -	xe_gt_assert(gt, avail >= 0);
> -
> -	while (avail > 0)
> -		avail = ct_fixup_ggtt_in_buffer(ct, h2g, ggtt_shift, &head, avail);
> -
> -	return;
> -
> -corrupted:
> -	xe_gt_err(gt, "Corrupted H2G descriptor head=%u tail=%u size=%u, fixups not applied\n",
> -		  head, tail, size);
> -	h2g->info.broken = true;
> -}
> -
>  static struct xe_guc_ct_snapshot *guc_ct_snapshot_alloc(struct xe_guc_ct *ct, bool atomic,
>  							bool want_ctb)
>  {
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
> index cf41210ab30a..d6c81325a76c 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.h
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.h
> @@ -24,8 +24,6 @@ void xe_guc_ct_snapshot_print(struct xe_guc_ct_snapshot *snapshot, struct drm_pr
>  void xe_guc_ct_snapshot_free(struct xe_guc_ct_snapshot *snapshot);
>  void xe_guc_ct_print(struct xe_guc_ct *ct, struct drm_printer *p, bool want_ctb);
>  
> -void xe_guc_ct_fixup_messages_with_ggtt(struct xe_guc_ct *ct, s64 ggtt_shift);
> -
>  static inline bool xe_guc_ct_initialized(struct xe_guc_ct *ct)
>  {
>  	return ct->state != XE_GUC_CT_STATE_NOT_INITIALIZED;
> diff --git a/drivers/gpu/drm/xe/xe_map.h b/drivers/gpu/drm/xe/xe_map.h
> index 8d67f6ba2d95..f62e0c8b67ab 100644
> --- a/drivers/gpu/drm/xe/xe_map.h
> +++ b/drivers/gpu/drm/xe/xe_map.h
> @@ -78,24 +78,6 @@ static inline void xe_map_write32(struct xe_device *xe, struct iosys_map *map,
>  	iosys_map_wr(map__, offset__, type__, val__);			\
>  })
>  
> -#define xe_map_rd_array(xe__, map__, index__, type__) \
> -	xe_map_rd(xe__, map__, (index__) * sizeof(type__), type__)
> -
> -#define xe_map_wr_array(xe__, map__, index__, type__, val__) \
> -	xe_map_wr(xe__, map__, (index__) * sizeof(type__), type__, val__)
> -
> -#define xe_map_rd_array_u32(xe__, map__, index__) \
> -	xe_map_rd_array(xe__, map__, index__, u32)
> -
> -#define xe_map_wr_array_u32(xe__, map__, index__, val__) \
> -	xe_map_wr_array(xe__, map__, index__, u32, val__)
> -
> -#define xe_map_rd_ring_u32(xe__, map__, index__, size__) \
> -	xe_map_rd_array_u32(xe__, map__, (index__) % (size__))
> -
> -#define xe_map_wr_ring_u32(xe__, map__, index__, size__, val__) \
> -	xe_map_wr_array_u32(xe__, map__, (index__) % (size__), val__)
> -
>  #define xe_map_rd_field(xe__, map__, struct_offset__, struct_type__, field__) ({	\
>  	struct xe_device *__xe = xe__;					\
>  	xe_device_assert_mem_access(__xe);				\
> diff --git a/drivers/gpu/drm/xe/xe_sriov_vf.c b/drivers/gpu/drm/xe/xe_sriov_vf.c
> index 0581b881b628..da064a1e7419 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_vf.c
> +++ b/drivers/gpu/drm/xe/xe_sriov_vf.c
> @@ -12,7 +12,6 @@
>  #include "xe_gt_sriov_printk.h"
>  #include "xe_gt_sriov_vf.h"
>  #include "xe_guc.h"
> -#include "xe_guc_ct.h"
>  #include "xe_guc_submit.h"
>  #include "xe_irq.h"
>  #include "xe_lrc.h"
> @@ -340,7 +339,6 @@ static int gt_vf_post_migration_fixups(struct xe_gt *gt)
>  		err = xe_guc_contexts_hwsp_rebase(&gt->uc.guc, buf);
>  		if (err)
>  			goto out;
> -		xe_guc_ct_fixup_messages_with_ggtt(&gt->uc.guc.ct, shift);
>  	}
>  
>  out: