[dpdk-dev] [PATCH] vhost: fix mmap failure as len not aligned with hugepage size

[Xie, Huawei]

On 10/30/2015 2:52 PM, Jianfeng Tan wrote:
> This patch fixes a bug under lower version linux kernel, mmap() fails when
Since which version Linux hugetlbfs changes the requirement of size
alignment?
> length is not aligned with hugepage size.
>
> Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
> ---
>  lib/librte_vhost/vhost_user/virtio-net-user.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c 
> b/lib/librte_vhost/vhost_user/virtio-net-user.c
> index a998ad8..641561c 100644
> --- a/lib/librte_vhost/vhost_user/virtio-net-user.c
> +++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
> @@ -147,6 +147,10 @@ user_set_mem_table(struct vhost_device_ctx ctx, struct 
> VhostUserMsg *pmsg)
>               /* This is ugly */
>               mapped_size = memory.regions[idx].memory_size +
>                       memory.regions[idx].mmap_offset;
> +
> +             alignment = get_blk_size(pmsg->fds[idx]);
> +             mapped_size = RTE_ALIGN_CEIL(mapped_size, alignment);
Probably we could remove the alignment of mapped size in free_mem_region
as well.
   RTE_ALIGN_CEIL(
        region[idx].mapped_size, alignment)
If we are not sure, leave it as it is.
> +
>               mapped_address = (uint64_t)(uintptr_t)mmap(NULL,
>                       mapped_size,
>                       PROT_READ | PROT_WRITE, MAP_SHARED,
> @@ -154,9 +158,11 @@ user_set_mem_table(struct vhost_device_ctx ctx, struct 
> VhostUserMsg *pmsg)
>                       0);
>  
>               RTE_LOG(INFO, VHOST_CONFIG,
> -                     "mapped region %d fd:%d to %p sz:0x%"PRIx64" 
> off:0x%"PRIx64"\n",
> +                     "mapped region %d fd:%d to:%p sz:0x%"PRIx64" "
> +                     "off:0x%"PRIx64" align:0x%"PRIx64"\n",
>                       idx, pmsg->fds[idx], (void *)(uintptr_t)mapped_address,
> -                     mapped_size, memory.regions[idx].mmap_offset);
> +                     mapped_size, memory.regions[idx].mmap_offset,
> +                     alignment);
>  
>               if (mapped_address == (uint64_t)(uintptr_t)MAP_FAILED) {
>                       RTE_LOG(ERR, VHOST_CONFIG,
> @@ -166,7 +172,7 @@ user_set_mem_table(struct vhost_device_ctx ctx, struct 
> VhostUserMsg *pmsg)
>  
>               pregion_orig[idx].mapped_address = mapped_address;
>               pregion_orig[idx].mapped_size = mapped_size;
> -             pregion_orig[idx].blksz = get_blk_size(pmsg->fds[idx]);
> +             pregion_orig[idx].blksz = alignment;
>               pregion_orig[idx].fd = pmsg->fds[idx];
>  
>               mapped_address +=  memory.regions[idx].mmap_offset;