2021-11-01 15:03:41

by Boqun Feng

[permalink] [raw]
Subject: [PATCH] Drivers: hv: balloon: Use VMBUS_RING_SIZE() wrapper for dm_ring_size

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: <[email protected]> # 5.15.x
Reported-by: Baihua Lu <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
---
drivers/hv/hv_balloon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 7f11ea07d698..ca873a3b98db 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -480,7 +480,7 @@ module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
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.
--
2.33.0


2021-11-02 13:06:00

by Vitaly Kuznetsov

[permalink] [raw]
Subject: Re: [PATCH] Drivers: hv: balloon: Use VMBUS_RING_SIZE() wrapper for dm_ring_size

Boqun Feng <[email protected]> writes:

> 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: <[email protected]> # 5.15.x
> Reported-by: Baihua Lu <[email protected]>
> Signed-off-by: Boqun Feng <[email protected]>
> ---
> drivers/hv/hv_balloon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index 7f11ea07d698..ca873a3b98db 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -480,7 +480,7 @@ module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
> 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.

Tested-by: Vitaly Kuznetsov <[email protected]>

Thanks!

--
Vitaly

2021-11-04 12:24:25

by Wei Liu

[permalink] [raw]
Subject: Re: [PATCH] Drivers: hv: balloon: Use VMBUS_RING_SIZE() wrapper for dm_ring_size

On Tue, Nov 02, 2021 at 02:03:57PM +0100, Vitaly Kuznetsov wrote:
> Boqun Feng <[email protected]> writes:
[...]
>
> Tested-by: Vitaly Kuznetsov <[email protected]>
>

Applied to hyperv-fixes. Thanks.


> Thanks!
>
> --
> Vitaly
>