diff mbox

[dpdk-dev,v2] vhost: fix add_guest_pages bug

Message ID 1480592522-26096-1-git-send-email-haifeng.lin@huawei.com (mailing list archive)
State Accepted, archived
Delegated to: Yuanhan Liu
Headers

Checks

Context Check Description
checkpatch/checkpatch success coding style OK

Commit Message

Linhaifeng Dec. 1, 2016, 11:42 a.m. UTC 
  When reg_size < page_size the function read in
rte_mem_virt2phy would not return, becausue
host_user_addr is invalid.

Signed-off-by: Haifeng Lin <haifeng.lin@huawei.com>
---
v2:
fix TYPO_SPELLING warning
---
 lib/librte_vhost/vhost_user.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Yuanhan Liu Dec. 6, 2016, 2:28 a.m. UTC | #1 
On Thu, Dec 01, 2016 at 07:42:02PM +0800, Haifeng Lin wrote:
> When reg_size < page_size the function read in
> rte_mem_virt2phy would not return, becausue
> host_user_addr is invalid.
> 
> Signed-off-by: Haifeng Lin <haifeng.lin@huawei.com>
> ---
> v2:
> fix TYPO_SPELLING warning
> ---
>  lib/librte_vhost/vhost_user.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 6b83c15..ce55e85 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -447,14 +447,14 @@ add_guest_pages(struct virtio_net *dev, struct virtio_memory_region *reg,
>  	reg_size -= size;
>  
>  	while (reg_size > 0) {
> +		size = reg_size >= page_size ? page_size : reg_size;

I'd use RTE_MIN(reg_size, page_size) here. Also, this patch miss a
fixline (http://dpdk.org/dev):

    Fixes: e246896178e6 ("vhost: get guest/host physical address mappings")

Applied to dpdk-next-virtio, with above fixed.

Thanks for the fix!

	--yliu

>  		host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)
>  						  host_user_addr);
> -		add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
> -				   page_size);
> +		add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size);
>  
> -		host_user_addr  += page_size;
> -		guest_phys_addr += page_size;
> -		reg_size -= page_size;
> +		host_user_addr  += size;
> +		guest_phys_addr += size;
> +		reg_size -= size;
>  	}
>  }
>  
> -- 
> 1.8.3.1
>
Linhaifeng Dec. 6, 2016, 5:40 a.m. UTC | #2 
在 2016/12/6 10:28, Yuanhan Liu 写道:
> On Thu, Dec 01, 2016 at 07:42:02PM +0800, Haifeng Lin wrote:
>> When reg_size < page_size the function read in
>> rte_mem_virt2phy would not return, becausue
>> host_user_addr is invalid.
>>
>> Signed-off-by: Haifeng Lin <haifeng.lin@huawei.com>
>> ---
>> v2:
>> fix TYPO_SPELLING warning
>> ---
>>  lib/librte_vhost/vhost_user.c | 10 +++++-----
>>  1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>> index 6b83c15..ce55e85 100644
>> --- a/lib/librte_vhost/vhost_user.c
>> +++ b/lib/librte_vhost/vhost_user.c
>> @@ -447,14 +447,14 @@ add_guest_pages(struct virtio_net *dev, struct virtio_memory_region *reg,
>>  	reg_size -= size;
>>  
>>  	while (reg_size > 0) {
>> +		size = reg_size >= page_size ? page_size : reg_size;
> 
> I'd use RTE_MIN(reg_size, page_size) here. Also, this patch miss a
> fixline (http://dpdk.org/dev):
> 
>     Fixes: e246896178e6 ("vhost: get guest/host physical address mappings")
> 
> Applied to dpdk-next-virtio, with above fixed.
> 
> Thanks for the fix!
> 
> 	--yliu
> 
>>  		host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)
>>  						  host_user_addr);
>> -		add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
>> -				   page_size);
>> +		add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size);
>>  
>> -		host_user_addr  += page_size;
>> -		guest_phys_addr += page_size;
>> -		reg_size -= page_size;
>> +		host_user_addr  += size;
>> +		guest_phys_addr += size;
>> +		reg_size -= size;
>>  	}
>>  }
>>  
>> -- 
>> 1.8.3.1
>>
> 
> .
> 

Hi，yliu
The bug would happen like this：

        -----------------------------
        |     region                |
        -----------------------------
        :                  : remain :
 --------------            ---------------
 |  hugepage  |   ...      |   hugepage   |
 --------------            ---------------
so the remain reg_size maybe smaller than a hugepage size, and "reg_size -= page_size" is not correct.

apply all the patch?
Yuanhan Liu Dec. 6, 2016, 5:44 a.m. UTC | #3 
On Tue, Dec 06, 2016 at 01:40:52PM +0800, linhaifeng wrote:
> 在 2016/12/6 10:28, Yuanhan Liu 写道:
> > On Thu, Dec 01, 2016 at 07:42:02PM +0800, Haifeng Lin wrote:
> >> When reg_size < page_size the function read in
> >> rte_mem_virt2phy would not return, becausue
> >> host_user_addr is invalid.
> >>
> >> Signed-off-by: Haifeng Lin <haifeng.lin@huawei.com>
> >> ---
> >> v2:
> >> fix TYPO_SPELLING warning
> >> ---
> >>  lib/librte_vhost/vhost_user.c | 10 +++++-----
> >>  1 file changed, 5 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> >> index 6b83c15..ce55e85 100644
> >> --- a/lib/librte_vhost/vhost_user.c
> >> +++ b/lib/librte_vhost/vhost_user.c
> >> @@ -447,14 +447,14 @@ add_guest_pages(struct virtio_net *dev, struct virtio_memory_region *reg,
> >>  	reg_size -= size;
> >>  
> >>  	while (reg_size > 0) {
> >> +		size = reg_size >= page_size ? page_size : reg_size;
> > 
> > I'd use RTE_MIN(reg_size, page_size) here. Also, this patch miss a
> > fixline (http://dpdk.org/dev):
> > 
> >     Fixes: e246896178e6 ("vhost: get guest/host physical address mappings")
> > 
> > Applied to dpdk-next-virtio, with above fixed.
> > 
> > Thanks for the fix!
> > 
> > 	--yliu
> > 
> >>  		host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)
> >>  						  host_user_addr);
> >> -		add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
> >> -				   page_size);
> >> +		add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size);
> >>  
> >> -		host_user_addr  += page_size;
> >> -		guest_phys_addr += page_size;
> >> -		reg_size -= page_size;
> >> +		host_user_addr  += size;
> >> +		guest_phys_addr += size;
> >> +		reg_size -= size;
> >>  	}
> >>  }
> >>  
> >> -- 
> >> 1.8.3.1
> >>
> > 
> > .
> > 
> 
> Hi，yliu
> The bug would happen like this：
> 
>         -----------------------------
>         |     region                |
>         -----------------------------
>         :                  : remain :
>  --------------            ---------------
>  |  hugepage  |   ...      |   hugepage   |
>  --------------            ---------------
> so the remain reg_size maybe smaller than a hugepage size, and "reg_size -= page_size" is not correct.
> 
> apply all the patch?

Yes, I actually have applied the whole patch, with some minor fixes
stated above. It makes no senes to apply partial of one patch after
all.

	--yliu
diff mbox

Patch

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 6b83c15..ce55e85 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -447,14 +447,14 @@  add_guest_pages(struct virtio_net *dev, struct virtio_memory_region *reg,
 	reg_size -= size;
 
 	while (reg_size > 0) {
+		size = reg_size >= page_size ? page_size : reg_size;
 		host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)
 						  host_user_addr);
-		add_one_guest_page(dev, guest_phys_addr, host_phys_addr,
-				   page_size);
+		add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size);
 
-		host_user_addr  += page_size;
-		guest_phys_addr += page_size;
-		reg_size -= page_size;
+		host_user_addr  += size;
+		guest_phys_addr += size;
+		reg_size -= size;
 	}
 }