Thomas Gleixner e261f209c3 x86/speculation/mds: Add BUG_MSBDS_ONLY ... This bug bit is set on CPUs which are only affected by Microarchitectural Store Buffer Data Sampling (MSBDS) and not by any other MDS variant. This is important because the Store Buffers are partitioned between Hyper-Threads so cross thread forwarding is not possible. But if a thread enters or exits a sleep state the store buffer is repartitioned which can expose data from one thread to the other. This transition can be mitigated. That means that for CPUs which are only affected by MSBDS SMT can be enabled, if the CPU is not affected by other SMT sensitive vulnerabilities, e.g. L1TF. The XEON PHI variants fall into that category. Also the Silvermont/Airmont ATOMs, but for them it's not really relevant as they do not support SMT, but mark them for completeness sake. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>		2019-03-06 21:52:11 +01:00
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asm	x86/speculation/mds: Add BUG_MSBDS_ONLY	2019-03-06 21:52:11 +01:00
uapi/asm	arch: remove redundant UAPI generic-y defines	2019-01-06 10:22:15 +09:00