This is a note to let you know that I've just added the patch titled
vhost: Allow null msg.size on VHOST_IOTLB_INVALIDATE
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vhost-allow-null-msg.size-on-vhost_iotlb_invalidate.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ca50ec377c2e94b0a9f8735de2856cd0f13beab4 Mon Sep 17 00:00:00 2001
From: Eric Auger <eric.auger@xxxxxxxxxx>
Date: Wed, 27 Sep 2023 16:05:44 +0200
Subject: vhost: Allow null msg.size on VHOST_IOTLB_INVALIDATE
From: Eric Auger <eric.auger@xxxxxxxxxx>
commit ca50ec377c2e94b0a9f8735de2856cd0f13beab4 upstream.
Commit e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb
entries") Forbade vhost iotlb msg with null size to prevent entries
with size = start = 0 and last = ULONG_MAX to end up in the iotlb.
Then commit 95932ab2ea07 ("vhost: allow batching hint without size")
only applied the check for VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE
message types to fix a regression observed with batching hit.
Still, the introduction of that check introduced a regression for
some users attempting to invalidate the whole ULONG_MAX range by
setting the size to 0. This is the case with qemu/smmuv3/vhost
integration which does not work anymore. It Looks safe to partially
revert the original commit and allow VHOST_IOTLB_INVALIDATE messages
with null size. vhost_iotlb_del_range() will compute a correct end
iova. Same for vhost_vdpa_iotlb_unmap().
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Fixes: e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries")
Cc: stable@xxxxxxxxxxxxxxx # v5.17+
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Message-Id: <20230927140544.205088-1-eric.auger@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vhost/vhost.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1458,9 +1458,7 @@ ssize_t vhost_chr_write_iter(struct vhos
goto done;
}
- if ((msg.type == VHOST_IOTLB_UPDATE ||
- msg.type == VHOST_IOTLB_INVALIDATE) &&
- msg.size == 0) {
+ if (msg.type == VHOST_IOTLB_UPDATE && msg.size == 0) {
ret = -EINVAL;
goto done;
}
Patches currently in stable-queue which might be from eric.auger@xxxxxxxxxx are
queue-6.5/vhost-allow-null-msg.size-on-vhost_iotlb_invalidate.patch
