Re: [PATCH v6 12/14] platform/x86: dell-smbios-smm: test for WSMT

From: Pali RohÃr
Date: Tue Oct 10 2017 - 15:11:19 EST


On Monday 09 October 2017 17:51:50 Mario Limonciello wrote:
> WSMT is as an attestation to the OS that the platform won't
> modify memory outside of pre-defined areas.
>
> If a platform has WSMT enabled in BIOS setup, SMM calls through
> dcdbas will fail. The only way to access platform data in these
> instances is through the WMI SMBIOS calling interface.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
> ---
> drivers/platform/x86/dell-smbios-smm.c | 34 ++++++++++++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/drivers/platform/x86/dell-smbios-smm.c b/drivers/platform/x86/dell-smbios-smm.c
> index 223531e43fea..ba315753e847 100644
> --- a/drivers/platform/x86/dell-smbios-smm.c
> +++ b/drivers/platform/x86/dell-smbios-smm.c
> @@ -25,6 +25,8 @@ static struct calling_interface_buffer *buffer;
> struct platform_device *platform_device;
> static DEFINE_MUTEX(smm_mutex);
>
> +#define WSMT_EN_TOKEN 0x04EC

Maybe there should be some comment in code what does this WSMT
abbreviation mean...

> static const struct dmi_system_id dell_device_table[] __initconst = {
> {
> .ident = "Dell laptop",

--
Pali RohÃr
pali.rohar@xxxxxxxxx