wireguard-linux/arch/x86/kernel/cpu/tsx.c, branch jd/unified-crypt-queue

Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-01-28T20:46:42Z

Pull x86 cpu-features updates from Ingo Molnar: "The biggest change in this cycle was a large series from Sean Christopherson to clean up the handling of VMX features. This both fixes bugs/inconsistencies and makes the code more coherent and future-proof. There are also two cleanups and a minor TSX syslog messages enhancement" * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/cpu: Remove redundant cpu_detect_cache_sizes() call x86/cpu: Print "VMX disabled" error message iff KVM is enabled KVM: VMX: Allow KVM_INTEL when building for Centaur and/or Zhaoxin CPUs perf/x86: Provide stubs of KVM helpers for non-Intel CPUs KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bits KVM: VMX: Check for full VMX support when verifying CPU compatibility KVM: VMX: Use VMX feature flag to query BIOS enabling KVM: VMX: Drop initialization of IA32_FEAT_CTL MSR x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured x86/cpu: Set synthetic VMX cpufeatures during init_ia32_feat_ctl() x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_* x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs x86/vmx: Introduce VMX_FEATURES_* x86/cpu: Clear VMX feature flag if VMX is not fully enabled x86/zhaoxin: Use common IA32_FEAT_CTL MSR initialization x86/centaur: Use common IA32_FEAT_CTL MSR initialization x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked x86/intel: Initialize IA32_FEAT_CTL MSR at boot tools/x86: Sync msr-index.h from kernel sources selftests, kvm: Replace manual MSR defs with common msr-index.h ...

x86/cpu: Update cached HLE state on write to TSX_CTRL_CPUID_CLEAR

2020-01-17T18:13:46Z

/proc/cpuinfo currently reports Hardware Lock Elision (HLE) feature to be present on boot cpu even if it was disabled during the bootup. This is because cpuinfo_x86->x86_capability HLE bit is not updated after TSX state is changed via the new MSR IA32_TSX_CTRL. Update the cached HLE bit also since it is expected to change after an update to CPUID_CLEAR bit in MSR IA32_TSX_CTRL. Fixes: 95c5824f75f3 ("x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default") Signed-off-by: Pawan Gupta Signed-off-by: Thomas Gleixner Tested-by: Neelima Krishnan Reviewed-by: Dave Hansen Reviewed-by: Josh Poimboeuf Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/2529b99546294c893dfa1c89e2b3e46da3369a59.1578685425.git.pawan.kumar.gupta@linux.intel.com

x86/cpu/tsx: Define pr_fmt()

2019-12-15T09:58:54Z

... so that all current and future pr_* statements in this file have the proper prefix. No functional changes. Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20191112221823.19677-2-bp@alien8.de

x86/tsx: Add config options to set tsx=on|off|auto

2019-10-28T08:12:18Z

There is a general consensus that TSX usage is not largely spread while the history shows there is a non trivial space for side channel attacks possible. Therefore the tsx is disabled by default even on platforms that might have a safe implementation of TSX according to the current knowledge. This is a fair trade off to make. There are, however, workloads that really do benefit from using TSX and updating to a newer kernel with TSX disabled might introduce a noticeable regressions. This would be especially a problem for Linux distributions which will provide TAA mitigations. Introduce config options X86_INTEL_TSX_MODE_OFF, X86_INTEL_TSX_MODE_ON and X86_INTEL_TSX_MODE_AUTO to control the TSX feature. The config setting can be overridden by the tsx cmdline options. [ bp: Text cleanups from Josh. ] Suggested-by: Borislav Petkov Signed-off-by: Michal Hocko Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf

x86/tsx: Add "auto" option to the tsx= cmdline parameter

2019-10-28T07:37:00Z

Platforms which are not affected by X86_BUG_TAA may want the TSX feature enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto disable TSX when X86_BUG_TAA is present, otherwise enable TSX. More details on X86_BUG_TAA can be found here: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html [ bp: Extend the arg buffer to accommodate "auto\0". ] Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Reviewed-by: Tony Luck Reviewed-by: Josh Poimboeuf

x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default

2019-10-28T07:36:58Z

Add a kernel cmdline parameter "tsx" to control the Transactional Synchronization Extensions (TSX) feature. On CPUs that support TSX control, use "tsx=on|off" to enable or disable TSX. Not specifying this option is equivalent to "tsx=off". This is because on certain processors TSX may be used as a part of a speculative side channel attack. Carve out the TSX controlling functionality into a separate compilation unit because TSX is a CPU feature while the TSX async abort control machinery will go to cpu/bugs.c. [ bp: - Massage, shorten and clear the arg buffer. - Clarifications of the tsx= possible options - Josh. - Expand on TSX_CTRL availability - Pawan. ] Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Reviewed-by: Josh Poimboeuf