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Message-ID: <20250708120424.2363354-2-dtatulea@nvidia.com>
Date: Tue, 8 Jul 2025 12:04:24 +0000
From: Dragos Tatulea <dtatulea@...dia.com>
To: Dragos Tatulea <dtatulea@...dia.com>, "Michael S. Tsirkin"
<mst@...hat.com>, Jason Wang <jasowang@...hat.com>, Xuan Zhuo
<xuanzhuo@...ux.alibaba.com>, Eugenio Pérez
<eperezma@...hat.com>
CC: Wenli Quan <wquan@...hat.com>, Tariq Toukan <tariqt@...dia.com>, "Cosmin
Ratiu" <cratiu@...dia.com>, <virtualization@...ts.linux.dev>,
<linux-kernel@...r.kernel.org>
Subject: [PATCH vhost] vdpa/mlx5: Fix release of uninitialized resources on error path
The commit in the fixes tag made sure that mlx5_vdpa_free()
is the single entrypoint for removing the vdpa device resources
added in mlx5_vdpa_dev_add(), even in the cleanup path of
mlx5_vdpa_dev_add().
This means that all functions from mlx5_vdpa_free() should be able to
handle uninitialized resources. This was not the case though:
mlx5_vdpa_destroy_mr_resources() and mlx5_cmd_cleanup_async_ctx()
were not able to do so. This caused the splat below when adding
a vdpa device without a MAC address.
This patch fixes these remaining issues:
- Makes mlx5_vdpa_destroy_mr_resources() return early if called on
uninitialized resources.
- Moves mlx5_cmd_init_async_ctx() early on during device addition
because it can't fail. This means that mlx5_cmd_cleanup_async_ctx()
also can't fail. To mirror this, move the call site of
mlx5_cmd_cleanup_async_ctx() in mlx5_vdpa_free().
An additional comment was added in mlx5_vdpa_free() to document
the expectations of functions called from this context.
Splat:
mlx5_core 0000:b5:03.2: mlx5_vdpa_dev_add:3950:(pid 2306) warning: No mac address provisioned?
------------[ cut here ]------------
WARNING: CPU: 13 PID: 2306 at kernel/workqueue.c:4207 __flush_work+0x9a/0xb0
[...]
Call Trace:
<TASK>
? __try_to_del_timer_sync+0x61/0x90
? __timer_delete_sync+0x2b/0x40
mlx5_vdpa_destroy_mr_resources+0x1c/0x40 [mlx5_vdpa]
mlx5_vdpa_free+0x45/0x160 [mlx5_vdpa]
vdpa_release_dev+0x1e/0x50 [vdpa]
device_release+0x31/0x90
kobject_cleanup+0x37/0x130
mlx5_vdpa_dev_add+0x327/0x890 [mlx5_vdpa]
vdpa_nl_cmd_dev_add_set_doit+0x2c1/0x4d0 [vdpa]
genl_family_rcv_msg_doit+0xd8/0x130
genl_family_rcv_msg+0x14b/0x220
? __pfx_vdpa_nl_cmd_dev_add_set_doit+0x10/0x10 [vdpa]
genl_rcv_msg+0x47/0xa0
? __pfx_genl_rcv_msg+0x10/0x10
netlink_rcv_skb+0x53/0x100
genl_rcv+0x24/0x40
netlink_unicast+0x27b/0x3b0
netlink_sendmsg+0x1f7/0x430
__sys_sendto+0x1fa/0x210
? ___pte_offset_map+0x17/0x160
? next_uptodate_folio+0x85/0x2b0
? percpu_counter_add_batch+0x51/0x90
? filemap_map_pages+0x515/0x660
__x64_sys_sendto+0x20/0x30
do_syscall_64+0x7b/0x2c0
? do_read_fault+0x108/0x220
? do_pte_missing+0x14a/0x3e0
? __handle_mm_fault+0x321/0x730
? count_memcg_events+0x13f/0x180
? handle_mm_fault+0x1fb/0x2d0
? do_user_addr_fault+0x20c/0x700
? syscall_exit_work+0x104/0x140
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f0c25b0feca
[...]
---[ end trace 0000000000000000 ]---
Signed-off-by: Dragos Tatulea <dtatulea@...dia.com>
Fixes: 83e445e64f48 ("vdpa/mlx5: Fix error path during device add")
Reported-by: Wenli Quan <wquan@...hat.com>
Closes: https://lore.kernel.org/virtualization/CADZSLS0r78HhZAStBaN1evCSoPqRJU95Lt8AqZNJ6+wwYQ6vPQ@mail.gmail.com/
Reviewed-by: Tariq Toukan <tariqt@...dia.com>
Reviewed-by: Cosmin Ratiu <cratiu@...dia.com>
---
drivers/vdpa/mlx5/core/mr.c | 3 +++
drivers/vdpa/mlx5/net/mlx5_vnet.c | 10 ++++++----
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index 61424342c096..c7a20278bc3c 100644
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -908,6 +908,9 @@ void mlx5_vdpa_destroy_mr_resources(struct mlx5_vdpa_dev *mvdev)
{
struct mlx5_vdpa_mr_resources *mres = &mvdev->mres;
+ if (!mres->wq_gc)
+ return;
+
atomic_set(&mres->shutdown, 1);
flush_delayed_work(&mres->gc_dwork_ent);
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index cccc49a08a1a..571d6502be59 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3432,15 +3432,17 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev)
ndev = to_mlx5_vdpa_ndev(mvdev);
+ /* Functions called here should be able to work with
+ * uninitialized resources.
+ */
free_fixed_resources(ndev);
mlx5_vdpa_clean_mrs(mvdev);
mlx5_vdpa_destroy_mr_resources(&ndev->mvdev);
- mlx5_cmd_cleanup_async_ctx(&mvdev->async_ctx);
-
if (!is_zero_ether_addr(ndev->config.mac)) {
pfmdev = pci_get_drvdata(pci_physfn(mvdev->mdev->pdev));
mlx5_mpfs_del_mac(pfmdev, ndev->config.mac);
}
+ mlx5_cmd_cleanup_async_ctx(&mvdev->async_ctx);
mlx5_vdpa_free_resources(&ndev->mvdev);
free_irqs(ndev);
kfree(ndev->event_cbs);
@@ -3888,6 +3890,8 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
mvdev->actual_features =
(device_features & BIT_ULL(VIRTIO_F_VERSION_1));
+ mlx5_cmd_init_async_ctx(mdev, &mvdev->async_ctx);
+
ndev->vqs = kcalloc(max_vqs, sizeof(*ndev->vqs), GFP_KERNEL);
ndev->event_cbs = kcalloc(max_vqs + 1, sizeof(*ndev->event_cbs), GFP_KERNEL);
if (!ndev->vqs || !ndev->event_cbs) {
@@ -3960,8 +3964,6 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
ndev->rqt_size = 1;
}
- mlx5_cmd_init_async_ctx(mdev, &mvdev->async_ctx);
-
ndev->mvdev.mlx_features = device_features;
mvdev->vdev.dma_dev = &mdev->pdev->dev;
err = mlx5_vdpa_alloc_resources(&ndev->mvdev);
--
2.43.0
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