[v1] hv_sock: fix ARM64 support

[PATCH] hv_sock: fix ARM64 support

Posted by Hamza Mahfooz 1 month, 2 weeks ago

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@vger.kernel.org
Fixes: 77ffe33363c0 ("hv_sock: use HV_HYP_PAGE_SIZE for Hyper-V communication")
Tested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
---
 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

Re: [PATCH] hv_sock: fix ARM64 support

Posted by Stefano Garzarella 1 month, 2 weeks ago

No version number in the subject?

Please next time follow 
https://docs.kernel.org/process/submitting-patches.html#subject-line

   Common tags might include a version descriptor if the multiple 
   versions of the patch have been sent out in response to comments 
   (i.e., “v1, v2, v3”), or “RFC” to indicate a request for comments.

On Tue, Apr 28, 2026 at 08:53:39AM -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@vger.kernel.org
>Fixes: 77ffe33363c0 ("hv_sock: use HV_HYP_PAGE_SIZE for Hyper-V communication")
>Tested-by: Dexuan Cui <decui@microsoft.com>
>Reviewed-by: Dexuan Cui <decui@microsoft.com>
>Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
>---
> net/vmw_vsock/hyperv_transport.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)

Acked-by: Stefano Garzarella <sgarzare@redhat.com>

>
>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
>

Re: [PATCH] hv_sock: fix ARM64 support

Posted by Hamza Mahfooz 1 month, 2 weeks ago

On Tue, Apr 28, 2026 at 03:12:40PM +0200, Stefano Garzarella wrote:
> No version number in the subject?

I generally on increment the version number if I make changes to the code
itself I did try to change the subject prefix to "PATCH RESEND" but it
appears something is off about my config that prevented from going
through.

> 
> Please next time follow
> https://docs.kernel.org/process/submitting-patches.html#subject-line
> 
>   Common tags might include a version descriptor if the multiple   versions
> of the patch have been sent out in response to comments   (i.e., “v1, v2,
> v3”), or “RFC” to indicate a request for comments.
> 
> On Tue, Apr 28, 2026 at 08:53:39AM -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@vger.kernel.org
> > Fixes: 77ffe33363c0 ("hv_sock: use HV_HYP_PAGE_SIZE for Hyper-V communication")
> > Tested-by: Dexuan Cui <decui@microsoft.com>
> > Reviewed-by: Dexuan Cui <decui@microsoft.com>
> > Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
> > ---
> > net/vmw_vsock/hyperv_transport.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> Acked-by: Stefano Garzarella <sgarzare@redhat.com>
> 
> > 
> > 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
> > 
>