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Date:   Fri, 18 Mar 2022 10:54:22 +0100
From:   Stefano Garzarella <sgarzare@redhat.com>
To:     Anirudh Rayabharam <mail@anirudhrb.com>
Cc:     "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>, kvm@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] vhost: handle error while adding split ranges to iotlb
Message-ID: <20220318095422.a37g7vxaiwqo5wxx@sgarzare-redhat>
References: <20220312141121.4981-1-mail@anirudhrb.com>
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On Sat, Mar 12, 2022 at 07:41:21PM +0530, Anirudh Rayabharam wrote:
>vhost_iotlb_add_range_ctx() handles the range [0, ULONG_MAX] by
>splitting it into two ranges and adding them separately. The return
>value of adding the first range to the iotlb is currently ignored.
>Check the return value and bail out in case of an error.
>

We could add:

Fixes: e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries")

>Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
>---
> drivers/vhost/iotlb.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
>index 40b098320b2a..5829cf2d0552 100644
>--- a/drivers/vhost/iotlb.c
>+++ b/drivers/vhost/iotlb.c
>@@ -62,8 +62,12 @@ int vhost_iotlb_add_range_ctx(struct vhost_iotlb *iotlb,
> 	 */
> 	if (start == 0 && last == ULONG_MAX) {
> 		u64 mid = last / 2;
>+		int err = vhost_iotlb_add_range_ctx(iotlb, start, mid, addr,
>+				perm, opaque);
>+
>+		if (err)
>+			return err;
>
>-		vhost_iotlb_add_range_ctx(iotlb, start, mid, addr, perm, opaque);
> 		addr += mid + 1;
> 		start = mid + 1;
> 	}
>-- 
>2.35.1
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>