drm/xe/pf: Fix potential GGTT allocation leak

In unlikely event that we fail during sending the new VF GGTT
configuration to the GuC, we will free only the GGTT node data
struct but will miss to release the actual GGTT allocation.

This will later lead to list corruption, GGTT space leak and
finally risking crash when unloading the driver:

 [ ] ... [drm] GT0: PF: Failed to provision VF1 with 1073741824 (1.00 GiB) GGTT (-EIO)
 [ ] ... [drm] GT0: PF: VF1 provisioning remains at 0 (0 B) GGTT

 [ ] list_add corruption. next->prev should be prev (ffff88813cfcd628), but was 0000000000000000. (next=ffff88813cfe2028).
 [ ] RIP: 0010:__list_add_valid_or_report+0x6b/0xb0
 [ ] Call Trace:
 [ ]  drm_mm_insert_node_in_range+0x2c0/0x4e0
 [ ]  xe_ggtt_node_insert+0x46/0x70 [xe]
 [ ]  pf_provision_vf_ggtt+0x7f5/0xa70 [xe]
 [ ]  xe_gt_sriov_pf_config_set_ggtt+0x5e/0x770 [xe]
 [ ]  ggtt_set+0x4b/0x70 [xe]
 [ ]  simple_attr_write_xsigned.constprop.0.isra.0+0xb0/0x110

 [ ] ... [drm] GT0: PF: Failed to provision VF1 with 1073741824 (1.00 GiB) GGTT (-ENOSPC)
 [ ] ... [drm] GT0: PF: VF1 provisioning remains at 0 (0 B) GGTT

 [ ] Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b7b: 0000 [#1] PREEMPT SMP NOPTI
 [ ] RIP: 0010:drm_mm_remove_node+0x1b7/0x390
 [ ] Call Trace:
 [ ]  <TASK>
 [ ]  ? die_addr+0x2e/0x80
 [ ]  ? exc_general_protection+0x1a1/0x3e0
 [ ]  ? asm_exc_general_protection+0x22/0x30
 [ ]  ? drm_mm_remove_node+0x1b7/0x390
 [ ]  ggtt_node_remove+0xa5/0xf0 [xe]
 [ ]  xe_ggtt_node_remove+0x35/0x70 [xe]
 [ ]  xe_ttm_bo_destroy+0x123/0x220 [xe]
 [ ]  intel_user_framebuffer_destroy+0x44/0x70 [xe]
 [ ]  intel_plane_destroy_state+0x3b/0xc0 [xe]
 [ ]  drm_atomic_state_default_clear+0x1cd/0x2f0
 [ ]  intel_atomic_state_clear+0x9/0x20 [xe]
 [ ]  __drm_atomic_state_free+0x1d/0xb0

Fix that by using pf_release_ggtt() on the error path, which now
works regardless if the node has GGTT allocation or not.

Fixes: 34e804220f69 ("drm/xe: Make xe_ggtt_node struct independent")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104144901.1903-1-michal.wajdeczko@intel.com

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
index 062a0c2..192643d 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -395,6 +395,8 @@ static void pf_release_ggtt(struct xe_tile *tile, struct xe_ggtt_node *node)
                 * the xe_ggtt_clear() called by below xe_ggtt_remove_node().
                 */
                xe_ggtt_node_remove(node, false);
+       } else {
+               xe_ggtt_node_fini(node);
        }
 }
 
@@ -450,7 +452,7 @@ static int pf_provision_vf_ggtt(struct xe_gt *gt, unsigned int vfid, u64 size)
        config->ggtt_region = node;
        return 0;
 err:
-       xe_ggtt_node_fini(node);
+       pf_release_ggtt(tile, node);
        return err;
 }