* [PATCH] hv_sock: fix ARM64 support
@ 2026-04-28 11:05 Hamza Mahfooz
2026-04-28 12:15 ` Stefano Garzarella
0 siblings, 1 reply; 6+ messages in thread
From: Hamza Mahfooz @ 2026-04-28 11:05 UTC (permalink / raw)
To: netdev
Cc: K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li,
Stefano Garzarella, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Michael Kelley, Himadri Pandya,
linux-hyperv, virtualization, linux-kernel, Hamza Mahfooz, stable
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@kernel.vger.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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] hv_sock: fix ARM64 support
2026-04-28 11:05 Hamza Mahfooz
@ 2026-04-28 12:15 ` Stefano Garzarella
2026-04-28 12:35 ` Hamza Mahfooz
0 siblings, 1 reply; 6+ messages in thread
From: Stefano Garzarella @ 2026-04-28 12:15 UTC (permalink / raw)
To: Hamza Mahfooz
Cc: netdev, K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui,
Long Li, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Michael Kelley, Himadri Pandya,
linux-hyperv, virtualization, linux-kernel, stable
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@kernel.vger.org
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@vger.kernel.org
The patch LGTM.
Thanks,
Stefano
>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
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] hv_sock: fix ARM64 support
2026-04-28 12:15 ` Stefano Garzarella
@ 2026-04-28 12:35 ` Hamza Mahfooz
0 siblings, 0 replies; 6+ messages in thread
From: Hamza Mahfooz @ 2026-04-28 12:35 UTC (permalink / raw)
To: Stefano Garzarella
Cc: netdev, K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui,
Long Li, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Michael Kelley, Himadri Pandya,
linux-hyperv, virtualization, linux-kernel, stable
On Tue, Apr 28, 2026 at 02:15:26PM +0200, Stefano Garzarella wrote:
> 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@kernel.vger.org
>
> 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@vger.kernel.org
Ya, that is the address I intended to Cc, not sure how I ended up
mangling it though.
>
>
> The patch LGTM.
>
> Thanks,
> Stefano
>
> > 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
> >
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] hv_sock: fix ARM64 support
@ 2026-04-28 12:53 Hamza Mahfooz
2026-04-28 13:12 ` Stefano Garzarella
0 siblings, 1 reply; 6+ messages in thread
From: Hamza Mahfooz @ 2026-04-28 12:53 UTC (permalink / raw)
To: netdev
Cc: K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li,
Stefano Garzarella, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Michael Kelley, Himadri Pandya,
linux-hyperv, virtualization, linux-kernel
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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] hv_sock: fix ARM64 support
2026-04-28 12:53 [PATCH] hv_sock: fix ARM64 support Hamza Mahfooz
@ 2026-04-28 13:12 ` Stefano Garzarella
2026-04-28 17:15 ` Hamza Mahfooz
0 siblings, 1 reply; 6+ messages in thread
From: Stefano Garzarella @ 2026-04-28 13:12 UTC (permalink / raw)
To: Hamza Mahfooz
Cc: netdev, K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui,
Long Li, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Michael Kelley, Himadri Pandya,
linux-hyperv, virtualization, linux-kernel
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
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] hv_sock: fix ARM64 support
2026-04-28 13:12 ` Stefano Garzarella
@ 2026-04-28 17:15 ` Hamza Mahfooz
0 siblings, 0 replies; 6+ messages in thread
From: Hamza Mahfooz @ 2026-04-28 17:15 UTC (permalink / raw)
To: Stefano Garzarella
Cc: netdev, K. Y. Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui,
Long Li, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Simon Horman, Michael Kelley, Himadri Pandya,
linux-hyperv, virtualization, linux-kernel
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
> >
>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2026-04-28 12:53 [PATCH] hv_sock: fix ARM64 support Hamza Mahfooz
2026-04-28 13:12 ` Stefano Garzarella
2026-04-28 17:15 ` Hamza Mahfooz
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2026-04-28 11:05 Hamza Mahfooz
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