Testing on a Kaby Lake box with 8 CPUs leads to the serial buffer being filled halfway during dom0 boot, and thus a non-trivial chunk of Linux boot messages are dropped.
Increasing the buffer to 32K does fix the issue and Linux boot messages are no longer dropped. There's no justification either on why 16K was chosen, and hence bumping to 32K in order to cope with current systems generating output faster does seem appropriate to have a better user experience with the provided defaults. Signed-off-by: Roger Pau Monné <roger....@citrix.com> --- xen/drivers/char/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index dec58bc993..294b3509c7 100644 --- a/xen/drivers/char/Kconfig +++ b/xen/drivers/char/Kconfig @@ -77,10 +77,10 @@ config HAS_EHCI config SERIAL_TX_BUFSIZE int "Size of the transmit serial buffer" - default 16384 + default 32768 help Controls the default size of the transmit buffer (in bytes) used by the serial driver. Note the value provided will be rounded down to the nearest power of 2. - Default value is 16384 (16kiB). + Default value is 32768 (32kiB). -- 2.36.1