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SubjectRe: [PATCH v2 2/2] x86/tsx: Disable TSX development mode at boot
On Tue, Mar 29, 2022 at 06:24:03PM +0200, Borislav Petkov wrote:
>On Thu, Mar 10, 2022 at 02:02:09PM -0800, Pawan Gupta wrote:
>> A microcode update on some Intel processors causes all TSX transactions
>> to always abort by default [*]. Microcode also added functionality to
>> re-enable TSX for development purpose. With this microcode loaded, if
>> tsx=on was passed on the cmdline, and TSX development mode was already
>> enabled before the kernel boot, it may make the system vulnerable to TSX
>> Asynchronous Abort (TAA).
>>
>> To be on safer side, unconditionally disable TSX development mode at
>> boot. If needed, a user can enable it using msr-tools.
>>
>> [*] Intel Transactional Synchronization Extension (Intel TSX) Disable Update for Selected Processors
>> https://cdrdv2.intel.com/v1/dl/getContent/643557
>>
>> Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> Suggested-by: Borislav Petkov <bp@alien8.de>
>> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
>> Cc: <stable@vger.kernel.org>
>> ---
>> arch/x86/include/asm/msr-index.h | 4 +--
>> arch/x86/kernel/cpu/cpu.h | 1 +
>> arch/x86/kernel/cpu/intel.c | 4 +++
>> arch/x86/kernel/cpu/tsx.c | 34 ++++++++++++++++++++++++++
>> tools/arch/x86/include/asm/msr-index.h | 4 +--
>> 5 files changed, 43 insertions(+), 4 deletions(-)
>
>Does this a lot more encapsulated version work too?

It look good to me.

Thanks,
Pawan

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