Re: [PATCH] hv_sock: fix ARM64 support

[Stefano Garzarella]

On Tue, Apr 28, 2026 at 07:05:30AM -0400, Hamza Mahfooz wrote:
> VMBUS ring buffers must be page aligned. Therefore, the current value of
> 24K presents a challenge on ARM64 kernels (with 64K pages). So, use
> VMBUS_RING_SIZE() to ensure they are always aligned and large enough to
> hold all of the relevant data.
>
> Cc: stable@xxxxxxxxxxxxxxx

mmm, this is the first time I've seen this address used for stable. Even 
after searching in the log, I don't see anyone else who's used it.
Where did you get it from?

From Documentation/process/stable-kernel-rules.rst :

  To have a patch you submit for mainline inclusion later automatically 
  picked up for stable trees, add this tag in the sign-off area::

    Cc: stable@xxxxxxxxxxxxxxx


The patch LGTM.

Thanks,
Stefano

> Fixes: 77ffe33363c0 ("hv_sock: use HV_HYP_PAGE_SIZE for Hyper-V communication")
> Tested-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Reviewed-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Signed-off-by: Hamza Mahfooz <hamzamahfooz@xxxxxxxxxxxxxxxxxxx>
> ---
> net/vmw_vsock/hyperv_transport.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index 069386a74557..40f09b23efa3 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -375,10 +375,10 @@ static void hvs_open_connection(struct vmbus_channel *chan)
> 	} else {
> 		sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE);
> 		sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE);
> -		sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE);
> +		sndbuf = VMBUS_RING_SIZE(sndbuf);
> 		rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE);
> 		rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE);
> -		rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE);
> +		rcvbuf = VMBUS_RING_SIZE(rcvbuf);
> 	}
>
> 	chan->max_pkt_size = HVS_MAX_PKT_SIZE;
> --
> 2.54.0