Re: [tboot-devel] [PATCH v2] Xen/ACPI: support sleep state entering on hardware reduced systems

[Jan B. <JBe...@su...>]

>>> On 12.03.13 at 07:39, "Wei, Gang" <gan...@in...> wrote:
> Jan Beulich wrote on 2013-03-11:
>> In version 3.4 acpi_os_prepare_sleep() got introduced in parallel with
>> reduced hardware sleep support, and the two changes didn't get
>> synchronized: The new code doesn't call the hook function (if so
>> requested). Fix this, requiring a boolean parameter to be added to the
>> hook function to distinguish "extended" from "legacy" sleep.
>> 
>> This requires adjusting TXT, but the adjustments only go as far as
>> failing the extended mode call (since, looking at the TXT interface,
>> there doesn't even appear to be precautions to deal with that
>> alternative interface).
>> 
>> The hypervisor change underlying this is commit 62d1a69 ("ACPI: support
>> v5 (reduced HW) sleep interface") on the master branch of
>> git://xenbits.xen.org/xen.git.
>> 
>> Signed-off-by: Jan Beulich <jbe...@su...>
>> Cc: Richard L Maliszewski <ric...@in...>
>> Cc: Gang Wei <gan...@in...>
>> Cc: Shane Wang <sha...@in...>
>> ---
>> v2: Extend description to include reference to hypervisor side change.
>> 
>> ---
>>  arch/x86/kernel/tboot.c          |    6 +++++-
>>  drivers/acpi/acpica/hwesleep.c   |    8 ++++++++
>>  drivers/acpi/acpica/hwsleep.c    |    2 +-
>>  drivers/acpi/osl.c               |   16 ++++++++--------
>>  drivers/xen/acpi.c               |   26 +++++++++++++-------------
>>  include/linux/acpi.h             |   10 +++++-----
>>  include/xen/acpi.h               |    4 ++--
>>  include/xen/interface/platform.h |    7 ++++---
>>  8 files changed, 46 insertions(+), 33 deletions(-)
>> --- 3.9-rc2/arch/x86/kernel/tboot.c
>> +++ 3.9-rc2-xen-ACPI-v5-sleep/arch/x86/kernel/tboot.c
>> @@ -273,7 +273,8 @@ static void tboot_copy_fadt(const struct
>>  		offsetof(struct acpi_table_facs, firmware_waking_vector);
>>  }
>> -static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32
> pm1b_control)
>> +static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32
> pm1b_control,
>> +		       bool extended)
>>  { 	static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 		/*
> S0,1,2: */
>>  -1, -1, -1, @@ -284,6 +285,9 @@ static int tboot_sleep(u8 sleep_state,
>>  u 	if (!tboot_enabled()) 		return 0;
>> +	if (extended)
>> +		return -1;
>> +
>>  	tboot_copy_fadt(&acpi_gbl_FADT);
>>  	tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
>>  	tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
> 
> So looks like to make the extended way go further with TXT case other than
> failing, tboot & its' interface have to be modified to support Reduced
> Hardware sleeping first, is that true?

Yes, afaict.

Jan