From: Boqun Feng <boqun.feng@xxxxxxxxx> commit 8a7eb2d476c6823cd44d8c25a6230a52417d7ef8 upstream. Baihua reported an error when boot an ARM64 guest with PAGE_SIZE=64k and BALLOON is enabled: hv_vmbus: registering driver hv_balloon hv_vmbus: probe failed for device 1eccfd72-4b41-45ef-b73a-4a6e44c12924 (-22) The cause of this is that the ringbuffer size for hv_balloon is not adjusted with VMBUS_RING_SIZE(), which makes the size not large enough for ringbuffers on guest with PAGE_SIZE=64k. Therefore use VMBUS_RING_SIZE() to calculate the ringbuffer size. Note that the old size (20 * 1024) counts a 4k header in the total size, while VMBUS_RING_SIZE() expects the parameter as the payload size, so use 16 * 1024. Cc: <stable@xxxxxxxxxxxxxxx> # 5.15.x Reported-by: Baihua Lu <baihua.lu@xxxxxxxxxxxxx> Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx> Tested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211101150026.736124-1-boqun.feng@xxxxxxxxx Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hv/hv_balloon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -480,7 +480,7 @@ module_param(pressure_report_delay, uint MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure"); static atomic_t trans_id = ATOMIC_INIT(0); -static int dm_ring_size = 20 * 1024; +static int dm_ring_size = VMBUS_RING_SIZE(16 * 1024); /* * Driver specific state.
