Re: [PATCH xenbus 12/12] Document system start options...

[Adam Goryachev <mailinglists@xxxxxxxxxxxxxxxxxxxxxx>]

On 19/11/20 23:53, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@xxxxxxxxxx>
>
> ... and warn if bad values are specified.
>
> Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
> ---
>   README.md        | 32 ++++++++++++++++++++++++++++++++
>   src/xen/log.c    |  2 ++
>   src/xen/unplug.c |  2 ++
>   src/xenbus/fdo.c |  2 ++
>   4 files changed, 38 insertions(+)
>
> diff --git a/README.md b/README.md
> index 7bb3a8344941..547628e76c86 100644
> --- a/README.md
> +++ b/README.md
> @@ -42,3 +42,35 @@ get_xen_headers.py
>   
>   This will import any necessary headers from a given tag of that Xen
>   repository at git://xenbits.xen.org/xen.git.
> +
> +System Start Options
> +====================
> +
> +Behaviour in both the xen.sys and xenbus.sys can be configured by 'system
> +start options'. These options can be supplied on the Windows loader 'command
> +line', which can be set by hitting F10 during early boot or appended to by
> +setting the value of 'loadptions' using bcdedit.
Apologies, but just wondering if that is a type and should be loadoptions ?

I really know nothing of windows programming, but keep an eye on the 
list to see how the driver development is going. I hope this is useful 
feedback.
Regards,
Adam

> +
> +XEN:DBG_PRINT=ON|OFF (default: ON)
> +
> +This option determines with DbgPrint() output is intercepted and logged.
> +(To reduce noise, messages not prefixed with 'XEN' are ignored).
> +
> +XEN:BOOT_EMULATED=TRUE|FALSE (default: FALSE)
> +
> +This option avoids unplugging the first emulated IDE device, which is
> +useful when debugging the XENVBD driver (since the system disk remains
> +emulated).
> +
> +XEN:BALLOON=ON|OFF (default: ON)
> +
> +This option controls whether the XENBUS_BALLOON interface and thread is
> +enabled.
> +
> +XEN:WATCHDOG=<TIME-OUT> (default: 0 minimum: 10)
> +
> +This options determine whether the domain watchdog is enabled. If a non-zero
> +time-out (in seconds) is specified then the watchdog will be enabled. The
> +watchdog is patted by VIRQ_TIMER handlers and hence this is useful to
> +detect length stalls in event delivery or handling. The minimum time-out
> +value is 10s.
> diff --git a/src/xen/log.c b/src/xen/log.c
> index ed7e484cddc7..5044070392f2 100644
> --- a/src/xen/log.c
> +++ b/src/xen/log.c
> @@ -695,6 +695,8 @@ __LogDbgPrintCallbackEnable(
>   
>       if (strcmp(Value, "OFF") == 0)
>           Enable = FALSE;
> +    else if (strcmp(Value, "ON") != 0)
> +        Warning("UNRECOGNIZED VALUE OF %s: %s\n", Key, Value);
>   
>       RegistryFreeSzValue(Option);
>   
> diff --git a/src/xen/unplug.c b/src/xen/unplug.c
> index cf17b69b2442..c9a29a6a3c89 100644
> --- a/src/xen/unplug.c
> +++ b/src/xen/unplug.c
> @@ -93,6 +93,8 @@ UnplugSetBootEmulated(
>   
>       if (strcmp(Value, "TRUE") == 0)
>           Context->BootEmulated = TRUE;
> +    else if (strcmp(Value, "FALSE") != 0)
> +        Warning("UNRECOGNIZED VALUE OF %s: %s\n", Key, Value);
>   
>       RegistryFreeSzValue(Option);
>   }
> diff --git a/src/xenbus/fdo.c b/src/xenbus/fdo.c
> index d164aab8a604..5419be4911ce 100644
> --- a/src/xenbus/fdo.c
> +++ b/src/xenbus/fdo.c
> @@ -5579,6 +5579,8 @@ FdoBalloonInitialize(
>   
>       if (strcmp(Value, "OFF") == 0)
>           Enabled = FALSE;
> +    else if (strcmp(Value, "ON") != 0)
> +        Warning("UNRECOGNIZED VALUE OF %s: %s\n", Key, Value);
>   
>       RegistryFreeSzValue(Option);
>