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* x86/TSC: Use RDTSCPBorislav Petkov2019-01-161-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the kernel uses [LM]FENCE; RDTSC in the timekeeping code, to guarantee monotonicity of time where the *FENCE is selected based on vendor. Replace that sequence with RDTSCP which is faster or on-par and gives the same guarantees. A microbenchmark on Intel shows that the change is on-par. On AMD, the change is either on-par with the current LFENCE-prefixed RDTSC or slightly better with RDTSCP. The comparison is done with the LFENCE-prefixed RDTSC (and not with the MFENCE-prefixed one, as one would normally expect) because all modern AMD families make LFENCE serializing and thus avoid the heavy MFENCE by effectively enabling X86_FEATURE_LFENCE_RDTSC. Co-developed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: John Stultz <john.stultz@linaro.org> Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181119184556.11479-1-bp@alien8.de
* x86/paravirt: Move the Xen-only pv_cpu_ops under the PARAVIRT_XXL umbrellaJuergen Gross2018-09-031-2/+2
| | | | | | | | | | | | | | | | Most of the paravirt ops defined in pv_cpu_ops are for Xen PV guests only. Define them only if CONFIG_PARAVIRT_XXL is set. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel@lists.xenproject.org Cc: virtualization@lists.linux-foundation.org Cc: akataria@vmware.com Cc: rusty@rustcorp.com.au Cc: boris.ostrovsky@oracle.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20180828074026.820-13-jgross@suse.com
* Merge branch 'x86-timers-for-linus' of ↵Linus Torvalds2018-04-021-3/+0
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 timer updates from Ingo Molnar: "Two changes: add the new convert_art_ns_to_tsc() API for upcoming Intel Goldmont+ drivers, and remove the obsolete rdtscll() API" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tsc: Get rid of rdtscll() x86/tsc: Convert ART in nanoseconds to TSC
| * x86/tsc: Get rid of rdtscll()Thomas Gleixner2018-03-231-3/+0
| | | | | | | | | | | | | | | | | | | | | | Commit 99770737ca7e ("x86/asm/tsc: Add rdtscll() merge helper") added rdtscll() in August 2015 along with the comment: /* Deprecated, keep it for a cycle for easier merging: */ 12 cycles later it's really overdue for removal. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | x86/MSR: Move native_* variants to msr.hBorislav Petkov2018-03-081-0/+14
|/ | | | | | | | | | | | | ... where they belong. No functional change. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Cc: kvm@vger.kernel.org Link: https://lkml.kernel.org/r/20180301151336.12948-1-bp@alien8.de
* x86: Introduce barrier_nospecDan Williams2018-01-301-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename the open coded form of this instruction sequence from rdtsc_ordered() into a generic barrier primitive, barrier_nospec(). One of the mitigations for Spectre variant1 vulnerabilities is to fence speculative execution after successfully validating a bounds check. I.e. force the result of a bounds check to resolve in the instruction pipeline to ensure speculative execution honors that result before potentially operating on out-of-bounds data. No functional changes. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Andi Kleen <ak@linux.intel.com> Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727415361.33451.9049453007262764675.stgit@dwillia2-desk3.amr.corp.intel.com
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/MSR: Carve out bare minimum accessorsBorislav Petkov2017-01-231-20/+31
| | | | | | | | | | | | | | | Add __rdmsr() and __wrmsr() which *only* read and write an MSR with exception handling. Those are going to be used in early code, like the microcode loader, which cannot stomach tracing code piggybacking on the MSR operation. While at it, get rid of __native_write_msr_notrace(). Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170120202955.4091-3-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86/msr: Cleanup/streamline MSR helpersBorislav Petkov2016-11-161-19/+21
| | | | | | | | | Make the MSR argument an unsigned int, both low and high u32, put "notrace" last in the function signature. Reflow function signatures for better readability and cleanup white space. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86/msr: Add wrmsr_notrace()Wanpeng Li2016-11-091-1/+13
| | | | | | | | | | | | | | | | Required to remove the extra irq_enter()/irq_exit() in smp_reschedule_interrupt(). Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: kvm@vger.kernel.org Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/1478488420-5982-2-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86/msr: Use the proper trace point conditional for writesDr. David Alan Gilbert2016-06-061-2/+2
| | | | | | | | | | | | The msr tracing for writes is incorrectly conditional on the read trace. Fixes: 7f47d8cc039f "x86, tracing, perf: Add trace point for MSR accesses" Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: stable@vger.kernel.org Cc: ak@linux.intel.com Link: http://lkml.kernel.org/r/1464976859-21850-1-git-send-email-dgilbert@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86/msr: Set the return value to zero when native_rdmsr_safe() failsAndy Lutomirski2016-04-131-1/+4
| | | | | | | | | | | | | | | | | | | This will cause unchecked native_rdmsr_safe() failures to return deterministic results. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/515fb611449a755312a476cfe11675906e7ddf6c.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/paravirt: Add paravirt_{read,write}_msr()Andy Lutomirski2016-04-131-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | This adds paravirt callbacks for unsafe MSR access. On native, they call native_{read,write}_msr(). On Xen, they use xen_{read,write}_msr_safe(). Nothing uses them yet for ease of bisection. The next patch will use them in rdmsrl(), wrmsrl(), etc. I intentionally didn't make them warn on #GP on Xen. I think that should be done separately by the Xen maintainers. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/880eebc5dcd2ad9f310d41345f82061ea500e9fa.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/msr: Carry on after a non-"safe" MSR access failsAndy Lutomirski2016-04-131-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | This demotes an OOPS and likely panic due to a failed non-"safe" MSR access to a WARN_ONCE() and, for RDMSR, a return value of zero. To be clear, this type of failure should *not* happen. This patch exists to minimize the chance of nasty undebuggable failures happening when a CONFIG_PARAVIRT=y bug in the non-"safe" MSR helpers gets fixed. Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: KVM list <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel <Xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/26567b216aae70e795938f4b567eace5a0eb90ba.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/msr: Remove unused native_read_tscp()Prarit Bhargava2016-03-231-8/+0
| | | | | | | | | | | | | After e76b027 ("x86,vdso: Use LSL unconditionally for vgetcpu") native_read_tscp() is unused in the kernel. The function can be removed like native_read_tsc() was. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1458687968-9106-1-git-send-email-prarit@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds2016-01-111-0/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Ingo Molnar: "Two changes: - one to quirk-save/restore certain system MSRs across suspend/resume, to make certain Intel systems work better (Chen Yu) - and also to constify a read only structure (Julia Lawall)" * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/calgary: Constify cal_chipset_ops structures x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume
| * x86/pm: Introduce quirk framework to save/restore extra MSR registers around ↵Chen Yu2015-11-261-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | suspend/resume A bug was reported that on certain Broadwell platforms, after resuming from S3, the CPU is running at an anomalously low speed. It turns out that the BIOS has modified the value of the THERM_CONTROL register during S3, and changed it from 0 to 0x10, thus enabled clock modulation(bit4), but with undefined CPU Duty Cycle(bit1:3) - which causes the problem. Here is a simple scenario to reproduce the issue: 1. Boot up the system 2. Get MSR 0x19a, it should be 0 3. Put the system into sleep, then wake it up 4. Get MSR 0x19a, it shows 0x10, while it should be 0 Although some BIOSen want to change the CPU Duty Cycle during S3, in our case we don't want the BIOS to do any modification. Fix this issue by introducing a more generic x86 framework to save/restore specified MSR registers(THERM_CONTROL in this case) for suspend/resume. This allows us to fix similar bugs in a much simpler way in the future. When the kernel wants to protect certain MSRs during suspending, we simply add a quirk entry in msr_save_dmi_table, and customize the MSR registers inside the quirk callback, for example: u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; and the quirk mechanism ensures that, once resumed from suspend, the MSRs indicated by these IDs will be restored to their original, pre-suspend values. Since both 64-bit and 32-bit kernels are affected, this patch covers the common 64/32-bit suspend/resume code path. And because the MSRs specified by the user might not be available or readable in any situation, we use rdmsrl_safe() to safely save these MSRs. Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: len.brown@intel.com Cc: linux@horizon.com Cc: luto@kernel.org Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com [ More edits to the naming of data structures. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds2016-01-111-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu updates from Ingo Molnar: "The main changes in this cycle were: - Improved CPU ID handling code and related enhancements (Borislav Petkov) - RDRAND fix (Len Brown)" * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Replace RDRAND forced-reseed with simple sanity check x86/MSR: Chop off lower 32-bit value x86/cpu: Fix MSR value truncation issue x86/cpu/amd, kvm: Satisfy guest kernel reads of IC_CFG MSR kvm: Add accessors for guest CPU's family, model, stepping x86/cpu: Unify CPU family, model, stepping calculation
| * | x86/MSR: Chop off lower 32-bit valueBorislav Petkov2015-11-241-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sparse complains that the cast truncates the high bits. But here we really do know what we're doing and we need the lower 32 bits only as the @low argument. So make that explicit. Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1448273546-2567-7-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* / x86, tracing, perf: Add trace point for MSR accessesAndi Kleen2015-12-061-0/+31
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For debugging low level code interacting with the CPU it is often useful to trace the MSR read/writes. This gives a concise summary of PMU and other operations. perf has an ad-hoc way to do this using trace_printk, but it's somewhat limited (and also now spews ugly boot messages when enabled) Instead define real trace points for all MSR accesses. This adds three new trace points: read_msr and write_msr and rdpmc. They also report if the access faulted (if *_safe is used) This allows filtering and triggering on specific MSR values, which allows various more advanced debugging techniques. All the values are well defined in the CPU documentation. The trace can be post processed with Documentation/trace/postprocess/decode_msr.py to add symbolic MSR names to the trace. I only added it to native MSR accesses in C, not paravirtualized or in entry*.S (which is not too interesting) Originally the patch kit moved the MSRs out of line. This uses an alternative approach recommended by Steven Rostedt of only moving the trace calls out of line, but open coding the access to the jump label. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1449018060-1742-3-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/msr: Make wrmsrl() a functionAndy Lutomirski2015-08-231-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | As of cf991de2f614 ("x86/asm/msr: Make wrmsrl_safe() a function"), wrmsrl_safe is a function, but wrmsrl is still a macro. The wrmsrl macro performs invalid shifts if the value argument is 32 bits. This makes it unnecessarily awkward to write code that puts an unsigned long into an MSR. To make this work, syscall_init needs tweaking to stop passing a function pointer to wrmsrl. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Willy Tarreau <w@1wt.eu> Link: http://lkml.kernel.org/r/690f0c629a1085d054e2d1ef3da073cfb3f7db92.1437678821.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Add rdtscll() merge helperIngo Molnar2015-08-211-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Some in-flight code makes use of the old rdtscll() (now removed), provide a wrapper for a kernel cycle to smooth the transition to rdtsc(). ( We use the safest variant, rdtsc_ordered(), which has barriers - this adds another incentive to remove the wrapper in the future. ) Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/dddbf98a2af53312e9aa73a5a2b1622fe5d6f52b.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Save an instruction in DECLARE_ARGS usersGeorge Spelvin2015-07-061-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before, the code to do RDTSC looked like: rdtsc shl $0x20, %rdx mov %eax, %eax or %rdx, %rax The "mov %eax, %eax" is required to clear the high 32 bits of RAX. By declaring low and high as 64-bit variables, the code is simplified to: rdtsc shl $0x20,%rdx or %rdx,%rax Yes, it's a 2-byte instruction that's not on a critical path, but there are principles to be upheld. Every user of EAX_EDX_RET has been checked. I tried to check users of EAX_EDX_ARGS, but there weren't any, so I deleted it to be safe. ( There's no benefit to making "high" 64 bits, but it was the simplest way to proceed. ) Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jacob.jun.pan@linux.intel.com Link: http://lkml.kernel.org/r/20150618075906.4615.qmail@ns.horizon.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Add rdtsc_ordered() and use it in trivial call sitesAndy Lutomirski2015-07-061-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | rdtsc_barrier(); rdtsc() is an unnecessary mouthful and requires more thought than should be necessary. Add an rdtsc_ordered() helper and replace the trivial call sites with it. This should not change generated code. The duplication of the fence asm is temporary. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/dddbf98a2af53312e9aa73a5a2b1622fe5d6f52b.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Rename native_read_tsc() to rdtsc()Andy Lutomirski2015-07-061-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that there is no paravirt TSC, the "native" is inappropriate. The function does RDTSC, so give it the obvious name: rdtsc(). Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org [ Ported it to v4.2-rc1. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Remove rdtscl()Andy Lutomirski2015-07-061-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | It has no more callers, and it was never a very sensible interface to begin with. Users of the TSC should either read all 64 bits or explicitly throw out the high bits. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/250105f7cee519be9d7fc4464b5784caafc8f4fe.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Remove the rdtscp() and rdtscpll() macrosAndy Lutomirski2015-07-061-9/+0
| | | | | | | | | | | | | | | | | | | | | | | They have no users. Leave native_read_tscp() which seems potentially useful despite also having no callers. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/6abfa3ef80534b5d73898a48c4d25e069303cbe5.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Replace rdtscll() with native_read_tsc()Andy Lutomirski2015-07-061-3/+0
| | | | | | | | | | | | | | | | | | | | | | | Now that the ->read_tsc() paravirt hook is gone, rdtscll() is just a wrapper around native_read_tsc(). Unwrap it. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/d2449ae62c1b1fb90195bcfb19ef4a35883a04dc.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc, x86/paravirt: Remove read_tsc() and read_tscp() paravirt hooksAndy Lutomirski2015-07-061-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've had ->read_tsc() and ->read_tscp() paravirt hooks since the very beginning of paravirt, i.e., d3561b7fa0fb ("[PATCH] paravirt: header and stubs for paravirtualisation"). AFAICT, the only paravirt guest implementation that ever replaced these calls was vmware, and it's gone. Arguably even vmware shouldn't have hooked RDTSC -- we fully support systems that don't have a TSC at all, so there's no point for a paravirt implementation to pretend that we have a TSC but to replace it. I also doubt that these hooks actually worked. Calls to rdtscl() and rdtscll(), which respected the hooks, were used seemingly interchangeably with native_read_tsc(), which did not. Just remove them. If anyone ever needs them again, they can try to make a case for why they need them. Before, on a paravirt config: text data bss dec hex filename 12618257 1816384 1093632 15528273 ecf151 vmlinux After: text data bss dec hex filename 12617207 1816384 1093632 15527223 eced37 vmlinux Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Cc: virtualization@lists.linux-foundation.org Link: http://lkml.kernel.org/r/d08a2600fb298af163681e5efd8e599d889a5b97.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm/tsc: Inline native_read_tsc() and remove __native_read_tsc()Andy Lutomirski2015-07-061-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the following commit: cdc7957d1954 ("x86: move native_read_tsc() offline") ... native_read_tsc() was moved out of line, presumably for some now-obsolete vDSO-related reason. Undo it. The entire rdtsc, shl, or sequence is only 11 bytes, and calls via rdtscl() and similar helpers were already inlined. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/d05ffe2aaf8468ca475ebc00efad7b2fa174af19.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86/asm' into x86/core, to prepare for new patchIngo Molnar2015-06-081-2/+7
|\ | | | | | | | | | | | | Collect all changes to arch/x86/entry/entry_64.S, before applying patch that changes most of the file. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/asm/msr: Make wrmsrl_safe() a functionAndy Lutomirski2015-06-051-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The wrmsrl_safe macro performs invalid shifts if the value argument is 32 bits. This makes it unnecessarily awkward to write code that puts an unsigned long into an MSR. Convert it to a real inline function. For inspiration, see: 7c74d5b7b7b6 ("x86/asm/entry/64: Fix MSR_IA32_SYSENTER_CS MSR value"). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: <linux-kernel@vger.kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> [ Applied small improvements. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/uapi: Do not export <asm/msr-index.h> as part of the user API headersBorislav Petkov2015-06-071-1/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | This header containing all MSRs and respective bit definitions got exported to userspace in conjunction with the big UAPI shuffle. But, it doesn't belong in the UAPI headers because userspace can do its own MSR defines and exporting them from the kernel blocks us from doing cleanups/renames in that header. Which is ridiculous - it is not kernel's job to export such a header and keep MSRs list and their names stable. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433436928-31903-19-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86: Add another set of MSR accessor functionsBorislav Petkov2014-03-131-0/+2
| | | | | | | | | | | We very often need to set or clear a bit in an MSR as a result of doing some sort of a hardware configuration. Add generic versions of that repeated functionality in order to save us a bunch of duplicated code in the early CPU vendor detection/config code. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1394384725-10796-2-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86 / msr: add 64bit _on_cpu access functionsJacob Pan2013-10-171-0/+22
| | | | | | | | | | | Having 64-bit MSR access methods on given CPU can avoid shifting and simplify MSR content manipulation. We already have other combinations of rdmsrl_xxx and wrmsrl_xxx but missing the _on_cpu version. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* x86, msr: Unify variable namesBorislav Petkov2013-04-021-7/+7
| | | | | | | | | | Make sure all MSR-accessing primitives which split MSR values in two 32-bit parts have their variables called 'low' and 'high' for consistence with the rest of the code and for ease of staring. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1362428180-8865-5-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* UAPI: (Scripted) Disintegrate arch/x86/include/asmDavid Howells2012-12-141-10/+1
| | | | | | | | | Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
* Merge branch 'x86/cpu' into perf/coreIngo Molnar2012-07-051-41/+3
|\ | | | | | | | | | | | | Merge this branch because we changed the wrmsr*_safe() API and there's a conflict. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86, cpu: Rename checking_wrmsrl() to wrmsrl_safe()H. Peter Anvin2012-06-071-1/+1
| | | | | | | | | | | | | | Rename checking_wrmsrl() to wrmsrl_safe(), to match the naming convention used by all the other MSR access functions/macros. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * x86, cpu, amd: Deprecate AMD-specific MSR variantsBorislav Petkov2012-06-071-27/+0
| | | | | | | | | | | | | | | | | | | | | | Now that all users of {rd,wr}msr_amd_safe have been fixed, deprecate its use by making them private to amd.c and adding warnings when used on anything else beside K8. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1338562358-28182-5-git-send-email-bp@amd64.org Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * x86, pvops: Remove hooks for {rd,wr}msr_safe_regsAndre Przywara2012-06-071-39/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | There were paravirt_ops hooks for the full register set variant of {rd,wr}msr_safe which are actually not used by anyone anymore. Remove them to make the code cleaner and avoid silent breakages when the pvops members were uninitialized. This has been boot-tested natively and under Xen with PVOPS enabled and disabled on one machine. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Link: http://lkml.kernel.org/r/1338562358-28182-2-git-send-email-bp@amd64.org Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86: Add rdpmcl()Andi Kleen2012-06-061-0/+2
|/ | | | | | | | | Add a version of rdpmc() that directly reads into a u64 Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1338944211-28275-4-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86, doc: Revert "x86: Document rdmsr_safe restrictions"H. Peter Anvin2012-04-191-8/+1
| | | | | | | | | This reverts commit ce37defc0f6673f5ca2c92ed5cfcaf290ae7dd16 "x86: Document rdmsr_safe restrictions", as these restrictions no longer apply. Reported-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/20120419171609.GH3221@aftab.osrc.amd.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: Document rdmsr_safe restrictionsBorislav Petkov2011-12-051-1/+8
| | | | | | | | Recently, I got bitten by using rdmsr_safe too early in the boot process. Document its shortcomings for future reference. Link: http://lkml.kernel.org/r/4ED5B70F.606@lwfinger.net Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
* x86, gcc-4.6: Avoid unused by set variables in rdmsrAndi Kleen2010-07-201-2/+2
| | | | | | | | | | Avoids quite a lot of warnings with a gcc 4.6 -Wall build because this happens in a commonly used header file (apic.h) Signed-off-by: Andi Kleen <ak@linux.intel.com> LKML-Reference: <201007202219.o6KMJme6021066@imap1.linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86, msr: msrs_alloc/free for CONFIG_SMP=nBorislav Petkov2009-12-161-0/+12
| | | | | | | | | | | | | | | | | | | | Randy Dunlap reported the following build error: "When CONFIG_SMP=n, CONFIG_X86_MSR=m: ERROR: "msrs_free" [drivers/edac/amd64_edac_mod.ko] undefined! ERROR: "msrs_alloc" [drivers/edac/amd64_edac_mod.ko] undefined!" This is due to the fact that <arch/x86/lib/msr.c> is conditioned on CONFIG_SMP and in the UP case we have only the stubs in the header. Fork off SMP functionality into a new file (msr-smp.c) and build msrs_{alloc,free} unconditionally. Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <petkovbb@gmail.com> LKML-Reference: <20091216231625.GD27228@liondog.tnic> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86: Add IA32_TSC_AUX MSR and use itSheng Yang2009-12-161-2/+2
| | | | | | | | | | | | | Clean up write_tsc() and write_tscp_aux() by replacing hardcoded values. No change in functionality. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> LKML-Reference: <1260942485-19156-4-git-send-email-sheng@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, msr: Add support for non-contiguous cpumasksBorislav Petkov2009-12-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | The current rd/wrmsr_on_cpus helpers assume that the supplied cpumasks are contiguous. However, there are machines out there like some K8 multinode Opterons which have a non-contiguous core enumeration on each node (e.g. cores 0,2 on node 0 instead of 0,1), see http://www.gossamer-threads.com/lists/linux/kernel/1160268. This patch fixes out-of-bounds writes (see URL above) by adding per-CPU msr structs which are used on the respective cores. Additionally, two helpers, msrs_{alloc,free}, are provided for use by the callers of the MSR accessors. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Aristeu Rozanski <aris@redhat.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> LKML-Reference: <20091211171440.GD31998@aftab> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86, msr, cpumask: Use struct cpumask rather than the deprecated cpumask_tRusty Russell2009-11-081-2/+2
| | | | | | | | | | This makes the declarations match the definitions, which already use 'struct cpumask'. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Borislav Petkov <borislav.petkov@amd.com> LKML-Reference: <200911052245.41803.rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86, msr: Unify rdmsr_on_cpus/wrmsr_on_cpusBorislav Petkov2009-09-151-2/+2
| | | | | | | | | | | Since rdmsr_on_cpus and wrmsr_on_cpus are almost identical, unify them into a common __rwmsr_on_cpus helper thus avoiding code duplication. While at it, convert cpumask_t's to const struct cpumask *. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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