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vhost-scsi: use kvzalloc for vq array allocation

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vhost_scsi_open() allocates one "struct vhost_scsi_virtqueue" for each
virtqueue. With large max_io_vqs values, this array can require a
high-order contiguous allocation and trigger a page allocator warning.

hv# cat /sys/module/vhost_scsi/parameters/max_io_vqs
256

[  766.075787] ------------[ cut here ]------------
[  766.077030] WARNING: mm/page_alloc.c:5280 at __alloc_frozen_pages_noprof+0x32c/0x15c0, CPU#23: qemu-system-x86/5964
... ...
[  766.080351] RIP: 0010:__alloc_frozen_pages_noprof+0x32c/0x15c0
... ...
[  766.085813] Call Trace:
[  766.085969]  <TASK>
[  766.086098]  ? srso_alias_return_thunk+0x5/0xfbef5
[  766.086365]  ? context_struct_compute_av+0x38a/0x4b0
[  766.086652]  alloc_pages_mpol+0x9f/0x170
[  766.086883]  ___kmalloc_large_node+0xb6/0xd0
[  766.087124]  ? srso_alias_return_thunk+0x5/0xfbef5
[  766.087389]  __kmalloc_large_node_noprof+0x18/0xa0
[  766.087655]  __kmalloc_noprof+0x3a0/0x440
[  766.087877]  ? vhost_scsi_open+0xcb/0x2d0 [vhost_scsi]
[  766.088162]  vhost_scsi_open+0xcb/0x2d0 [vhost_scsi]
[  766.088449]  misc_open+0x123/0x160
[  766.088679]  chrdev_open+0xb1/0x230
[  766.088885]  ? __pfx_chrdev_open+0x10/0x10
[  766.089157]  do_dentry_open+0x11a/0x470
[  766.089389]  vfs_open+0x29/0xf0
[  766.089596]  path_openat+0x7c0/0x1100
[  766.089821]  do_file_open+0xdd/0x190
[  766.090032]  ? srso_alias_return_thunk+0x5/0xfbef5
[  766.090332]  do_sys_openat2+0x7e/0x100
[  766.090601]  __x64_sys_openat+0x51/0xa0
[  766.090857]  do_syscall_64+0xfe/0x590
[  766.091087]  entry_SYSCALL_64_after_hwframe+0x77/0x7f
[  766.091411] RIP: 0033:0x7f9525a11fa6

The array does not require physical contiguity, so allocate it with
kvzalloc_objs() and free it with kvfree().

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260802172534.260047-2-dongli.zhang@oracle.com>
This commit is contained in:
Dongli Zhang 2026-08-02 10:24:55 -07:00 committed by Michael S. Tsirkin
parent 93fa09455f
commit c952e607cb
1 changed files with 3 additions and 3 deletions
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6
drivers/vhost/scsi.c
View File

@ -2312,7 +2312,7 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
if (!vs->old_inflight)
goto err_inflight;
vs->vqs = kmalloc_objs(*vs->vqs, nvqs, GFP_KERNEL | __GFP_ZERO);
vs->vqs = kvzalloc_objs(*vs->vqs, nvqs);
if (!vs->vqs)
goto err_vqs;
@ -2348,7 +2348,7 @@ static int vhost_scsi_open(struct inode *inode, struct file *f)
return 0;
err_local_vqs:
kfree(vs->vqs);
kvfree(vs->vqs);
err_vqs:
kfree(vs->old_inflight);
err_inflight:
@ -2369,7 +2369,7 @@ static int vhost_scsi_release(struct inode *inode, struct file *f)
vhost_dev_stop(&vs->dev);
vhost_dev_cleanup(&vs->dev);
kfree(vs->dev.vqs);
kfree(vs->vqs);
kvfree(vs->vqs);
kfree(vs->old_inflight);
kvfree(vs);
return 0;