Re: [PATCH v2] vhost: fix add_guest_pages bug

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

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
>