Re: [PATCH v3 08/11] Input: hyperv-keyboard: Make ringbuffer at least take two pages
flat view
From: Boqun Feng <hidden>
Date: 2020-09-14 08:46:19
Also in:
linux-arm-kernel, linux-hyperv, linux-scsi, lkml, netdev
On Thu, Sep 10, 2020 at 10:34:52PM +0800, Boqun Feng wrote:
quoted hunk ↗ jump to hunk
When PAGE_SIZE > HV_HYP_PAGE_SIZE, we need the ringbuffer size to be at least 2 * PAGE_SIZE: one page for the header and at least one page of the data part (because of the alignment requirement for double mapping). So make sure the ringbuffer sizes to be at least 2 * PAGE_SIZE when using vmbus_open() to establish the vmbus connection. Signed-off-by: Boqun Feng <redacted> --- drivers/input/serio/hyperv-keyboard.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c index df4e9f6f4529..6ebc61e2db3f 100644 --- a/drivers/input/serio/hyperv-keyboard.c +++ b/drivers/input/serio/hyperv-keyboard.c@@ -75,8 +75,8 @@ struct synth_kbd_keystroke { #define HK_MAXIMUM_MESSAGE_SIZE 256 -#define KBD_VSC_SEND_RING_BUFFER_SIZE (40 * 1024) -#define KBD_VSC_RECV_RING_BUFFER_SIZE (40 * 1024) +#define KBD_VSC_SEND_RING_BUFFER_SIZE max(40 * 1024, (int)(2 * PAGE_SIZE)) +#define KBD_VSC_RECV_RING_BUFFER_SIZE max(40 * 1024, (int)(2 * PAGE_SIZE))
Hmm.. just realized there is a problem here, if PAGE_SIZE = 16k, then 40 * 1024 > 2 * PAGE_SIZE, however in the ring buffer size should also be page aligned, otherwise vmbus_open() will fail. I plan to modify this as in linux/hyperv.h: #define VMBUS_RING_SIZE(payload_sz) PAGE_ALIGN(sizeof(struct hv_ring_buffer) + (playload_sz)) and here: #define KBD_VSC_SEND_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024) #define KBD_VSC_RECV_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024) and the similar change for patch #9. Thoughts? Regards, Boqun
#define XTKBD_EMUL0 0xe0 #define XTKBD_EMUL1 0xe1 -- 2.28.0