linux-kernel - Re: [PATCH] vhost-vdpa: cleanup memory maps when closing vdpa fds

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <35b94992-0c6b-a190-1fce-5dda9c8dcf4b@huawei.com>
Date:   Tue, 14 Feb 2023 14:27:26 +0800
From:   "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" 
        <longpeng2@...wei.com>
To:     Jason Wang <jasowang@...hat.com>, <mst@...hat.com>
CC:     <arei.gonglei@...wei.com>, <yechuan@...wei.com>,
        <huangzhichao@...wei.com>,
        <virtualization@...ts.linux-foundation.org>,
        <linux-kernel@...r.kernel.org>, <kvm@...r.kernel.org>
Subject: Re: [PATCH] vhost-vdpa: cleanup memory maps when closing vdpa fds



在 2023/2/14 14:16, Jason Wang 写道:
> 
> 在 2023/1/31 22:53, Longpeng(Mike) 写道:
>> From: Longpeng <longpeng2@...wei.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?
> 

For example, the iommu map is setup when QEMU calls VHOST_IOTLB_UPDATE 
ioctl and it'll be freed if QEMU calls VHOST_IOTLB_INVALIDATE ioctl.

So maybe we release these resources in vdpa framework in kernel is a 
suitable choice?

By the way, Jason, can you reproduce the problem in your machine?

> Thanks
> 
> 
>>
>> Signed-off-by: Longpeng <longpeng2@...wei.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);
> 
> .