Message-ID: <db99245c-606a-2f24-52fe-836a6972437f@redhat.com>
Date:   Tue, 14 Feb 2023 14:16:02 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.6.1
Subject: Re: [PATCH] vhost-vdpa: cleanup memory maps when closing vdpa fds
To:     "Longpeng(Mike)" <longpeng2@huawei.com>, mst@redhat.com
Cc:     arei.gonglei@huawei.com, yechuan@huawei.com,
        huangzhichao@huawei.com, virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
References: <20230131145310.2069-1-longpeng2@huawei.com>
Content-Language: en-US
From:   Jason Wang <jasowang@redhat.com>
In-Reply-To: <20230131145310.2069-1-longpeng2@huawei.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


在 2023/1/31 22:53, Longpeng(Mike) 写道:
> From: Longpeng <longpeng2@huawei.com>
>
> We must cleanup all memory maps when closing the vdpa fds, otherwise
> some critical resources (e.g. memory, iommu map) will leaked if the
> userspace exits unexpectedly (e.g. kill -9).


Sounds like a bug of the kernel, should we fix there?

Thanks


>
> Signed-off-by: Longpeng <longpeng2@huawei.com>
> ---
>   drivers/vhost/vdpa.c | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index a527eeeac637..37477cffa5aa 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -823,6 +823,18 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v,
>   		vhost_vdpa_remove_as(v, asid);
>   }
>   
> +static void vhost_vdpa_clean_map(struct vhost_vdpa *v)
> +{
> +	struct vhost_vdpa_as *as;
> +	u32 asid;
> +
> +	for (asid = 0; asid < v->vdpa->nas; asid++) {
> +		as = asid_to_as(v, asid);
> +		if (as)
> +			vhost_vdpa_unmap(v, &as->iotlb, 0ULL, 0ULL - 1);
> +	}
> +}
> +
>   static int vhost_vdpa_va_map(struct vhost_vdpa *v,
>   			     struct vhost_iotlb *iotlb,
>   			     u64 iova, u64 size, u64 uaddr, u32 perm)
> @@ -1247,6 +1259,7 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
>   	vhost_vdpa_clean_irq(v);
>   	vhost_vdpa_reset(v);
>   	vhost_dev_stop(&v->vdev);
> +	vhost_vdpa_clean_map(v);
>   	vhost_vdpa_free_domain(v);
>   	vhost_vdpa_config_put(v);
>   	vhost_vdpa_cleanup(v);