From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Jianfeng Tan <jianfeng.tan@intel.com>, dev@dpdk.org
Cc: stable@dpdk.org, Yuanhan Liu <yliu@fridaylinux.org>,
Yi Yang <yi.y.yang@intel.com>
Subject: Re: [dpdk-stable] [PATCH] vhost: fix segfault as handle set_mem_table message
Date: Tue, 28 Nov 2017 13:09:29 +0100 [thread overview]
Message-ID: <caffd24f-f229-4484-3d25-b7d615b88566@redhat.com> (raw)
In-Reply-To: <1510746068-143223-1-git-send-email-jianfeng.tan@intel.com>
On 11/15/2017 12:41 PM, Jianfeng Tan wrote:
> In a running VM, operations (like device attach/detach) will
> trigger the QEMU to resend set_mem_table to vhost-user backend.
>
> DPDK vhost-user handles this message rudely by unmap all existing
> regions and map new ones. This might lead to segfault if there
> is pmd thread just trying to touch those unmapped memory regions.
>
> But for most cases, except VM memory hotplug, QEMU still sends the
> set_mem_table message even the memory regions are not changed as
> QEMU vhost-user filters out those not backed by file (fd > 0).
>
> To fix this case, we add a check in the handler to see if the
> memory regions are really changed; if not, we just keep old memory
> regions.
>
> Fixes: 8f972312b8f4 ("vhost: support vhost-user")
>
> CC: stable@dpdk.org
>
> CC: Yuanhan Liu <yliu@fridaylinux.org>
> CC: Maxime Coquelin <maxime.coquelin@redhat.com>
>
> Reported-by: Yang Zhang <zy107165@alibaba-inc.com>
> Reported-by: Xin Long <longxin.xl@alibaba-inc.com>
> Signed-off-by: Yi Yang <yi.y.yang@intel.com>
> Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
> ---
> lib/librte_vhost/vhost_user.c | 33 +++++++++++++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
next prev parent reply other threads:[~2017-11-28 12:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-15 11:41 Jianfeng Tan
2017-11-28 12:09 ` Maxime Coquelin [this message]
2017-12-05 14:19 ` Yuanhan Liu
2017-12-05 14:28 ` Maxime Coquelin
2018-03-29 7:01 ` Tan, Jianfeng
2018-03-29 7:35 ` Maxime Coquelin
2018-03-29 12:57 ` Wodkowski, PawelX
2018-03-29 13:20 ` Tan, Jianfeng
2018-03-29 16:37 ` Maxime Coquelin
2018-03-29 18:09 ` Wodkowski, PawelX
2018-03-29 12:59 ` Tan, Jianfeng
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