Re: [PATCH 2/2] drm/hyperv: use VMBUS_RING_SIZE()

[Hamza Mahfooz]

On Sun, Apr 26, 2026 at 05:00:24AM +0000, Saurabh Singh Sengar wrote:
> > Subject: [PATCH 2/2] drm/hyperv: use VMBUS_RING_SIZE()
> > 
> > VMBUS ring buffers must be page aligned. So, use VMBUS_RING_SIZE() to
> > ensure they are always aligned and large enough to hold all of the relevant
> > data.
> > 
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: 76c56a5affeb ("drm/hyperv: Add DRM driver for hyperv synthetic video
> > device")
> > Signed-off-by: Hamza Mahfooz <hamzamahfooz@xxxxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/hyperv/hyperv_drm_proto.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
> > b/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
> > index 051ecc526832..753d97bff76f 100644
> > --- a/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
> > +++ b/drivers/gpu/drm/hyperv/hyperv_drm_proto.c
> > @@ -10,7 +10,7 @@
> > 
> >  #include "hyperv_drm.h"
> > 
> > -#define VMBUS_RING_BUFSIZE (256 * 1024)
> > +#define VMBUS_RING_BUFSIZE VMBUS_RING_SIZE(256 * 1024)
> >  #define VMBUS_VSP_TIMEOUT (10 * HZ)
> > 
> >  #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
> > --
> > 2.54.0
> 
> Although this lgtm, but this may change the behaviour on ARM64 systems with page size > 4K ?
> Have we tested it ?

Yup, I tested it on an ARM64 windows machine with a 64K page size guest kernel.

> 
> Reviewed-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>

Pushed to drm-misc.

>