[lkml]   [2022]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRE: [PATCH 1/1] scsi: storvsc: Fix swiotlb bounce buffer leak in confidential VM
> From: Michael Kelley (LINUX) <>
> Sent: Sunday, December 4, 2022 11:53 AM
> storvsc_queuecommand() maps the scatter/gather list using scsi_dma_map(),
> which in a confidential VM allocates swiotlb bounce buffers. If the
> I/O submission fails in storvsc_do_io(), the I/O is typically retried
> by higher level code, but the bounce buffer memory is never freed.
> The mostly like cause of I/O submission failure is a full VMBus
> channel ring buffer, which is not uncommon under high I/O loads.
> Eventually enough bounce buffer memory leaks that the confidential
> VM can't do any I/O. The same problem can arise in a non-confidential
> VM with kernel boot parameter swiotlb=force.
> Fix this by doing scsi_dma_unmap() in the case of an I/O submission
> error, which frees the bounce buffer memory.
> Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for storvsc
> driver")
> Signed-off-by: Michael Kelley <>
> ---

Reviewed-by: Dexuan Cui <>
Tested-by: Dexuan Cui <>

I hope this fix can be included in v6.1.

 \ /
  Last update: 2022-12-04 22:17    [W:0.058 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site