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2017-01-23x86/MSR: Carve out bare minimum accessorsBorislav Petkov1-20/+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>
2016-11-16x86/msr: Cleanup/streamline MSR helpersBorislav Petkov1-19/+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>
2016-11-10x86/msr: Add wrmsr_notrace()Wanpeng Li1-1/+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>
2016-06-06x86/msr: Use the proper trace point conditional for writesDr. David Alan Gilbert1-2/+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>
2016-04-13x86/msr: Set the return value to zero when native_rdmsr_safe() failsAndy Lutomirski1-1/+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>
2016-04-13x86/paravirt: Add paravirt_{read,write}_msr()Andy Lutomirski1-2/+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>
2016-04-13x86/msr: Carry on after a non-"safe" MSR access failsAndy Lutomirski1-2/+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>
2016-03-23x86/msr: Remove unused native_read_tscp()Prarit Bhargava1-8/+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>
2016-01-12Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds1-0/+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
2016-01-12Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds1-1/+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
2015-12-06x86, tracing, perf: Add trace point for MSR accessesAndi Kleen1-0/+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>
2015-11-26x86/pm: Introduce quirk framework to save/restore extra MSR registers around ↵Chen Yu1-0/+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>
2015-11-24x86/MSR: Chop off lower 32-bit valueBorislav Petkov1-1/+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>
2015-08-23x86/asm/msr: Make wrmsrl() a functionAndy Lutomirski1-2/+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>
2015-08-21x86/asm/tsc: Add rdtscll() merge helperIngo Molnar1-0/+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>
2015-07-06x86/asm/tsc: Save an instruction in DECLARE_ARGS usersGeorge Spelvin1-4/+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>
2015-07-06x86/asm/tsc: Add rdtsc_ordered() and use it in trivial call sitesAndy Lutomirski1-0/+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>
2015-07-06x86/asm/tsc: Rename native_read_tsc() to rdtsc()Andy Lutomirski1-1/+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>
2015-07-06x86/asm/tsc: Remove rdtscl()Andy Lutomirski1-3/+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>
2015-07-06x86/asm/tsc: Remove the rdtscp() and rdtscpll() macrosAndy Lutomirski1-9/+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>
2015-07-06x86/asm/tsc: Replace rdtscll() with native_read_tsc()Andy Lutomirski1-3/+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>
2015-07-06x86/asm/tsc, x86/paravirt: Remove read_tsc() and read_tscp() paravirt hooksAndy Lutomirski1-8/+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>
2015-07-06x86/asm/tsc: Inline native_read_tsc() and remove __native_read_tsc()Andy Lutomirski1-5/+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>
2015-06-08Merge branch 'x86/asm' into x86/core, to prepare for new patchIngo Molnar1-2/+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>
2015-06-07x86/uapi: Do not export <asm/msr-index.h> as part of the user API headersBorislav Petkov1-1/+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>
2015-06-05x86/asm/msr: Make wrmsrl_safe() a functionAndy Lutomirski1-2/+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>
2014-03-14x86: Add another set of MSR accessor functionsBorislav Petkov1-0/+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>
2013-10-17x86 / msr: add 64bit _on_cpu access functionsJacob Pan1-0/+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>
2013-04-03x86, msr: Unify variable namesBorislav Petkov1-7/+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>
2012-12-15UAPI: (Scripted) Disintegrate arch/x86/include/asmDavid Howells1-10/+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>
2012-07-05Merge branch 'x86/cpu' into perf/coreIngo Molnar1-41/+3
Merge this branch because we changed the wrmsr*_safe() API and there's a conflict. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-08x86, cpu: Rename checking_wrmsrl() to wrmsrl_safe()H. Peter Anvin1-1/+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>
2012-06-07x86, cpu, amd: Deprecate AMD-specific MSR variantsBorislav Petkov1-27/+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>
2012-06-07x86, pvops: Remove hooks for {rd,wr}msr_safe_regsAndre Przywara1-39/+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>
2012-06-06x86: Add rdpmcl()Andi Kleen1-0/+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>
2012-04-20x86, doc: Revert "x86: Document rdmsr_safe restrictions"H. Peter Anvin1-8/+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>
2011-12-05x86: Document rdmsr_safe restrictionsBorislav Petkov1-1/+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>
2010-07-21x86, gcc-4.6: Avoid unused by set variables in rdmsrAndi Kleen1-2/+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>
2009-12-17x86, msr: msrs_alloc/free for CONFIG_SMP=nBorislav Petkov1-0/+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>
2009-12-16x86: Add IA32_TSC_AUX MSR and use itSheng Yang1-2/+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>
2009-12-11x86, msr: Add support for non-contiguous cpumasksBorislav Petkov1-0/+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>
2009-11-08x86, msr, cpumask: Use struct cpumask rather than the deprecated cpumask_tRusty Russell1-2/+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>
2009-09-15x86, msr: Unify rdmsr_on_cpus/wrmsr_on_cpusBorislav Petkov1-2/+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>
2009-09-01x86, msr: Export the register-setting MSR functions via /dev/*/msrH. Peter Anvin1-2/+8
Make it possible to access the all-register-setting/getting MSR functions via the MSR driver. This is implemented as an ioctl() on the standard MSR device node. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <petkovbb@gmail.com>
2009-09-01x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs()H. Peter Anvin1-4/+14
Create _on_cpu helpers for {rw,wr}msr_safe_regs() analogously with the other MSR functions. This will be necessary to add support for these to the MSR driver. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <petkovbb@gmail.com>
2009-09-01x86, msr: Have the _safe MSR functions return -EIO, not -EFAULTH. Peter Anvin1-2/+2
For some reason, the _safe MSR functions returned -EFAULT, not -EIO. However, the only user which cares about the return code as anything other than a boolean is the MSR driver, which wants -EIO. Change it to -EIO across the board. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Alok Kataria <akataria@vmware.com> Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-09-01x86, msr: Rewrite AMD rd/wrmsr variantsBorislav Petkov1-17/+21
Switch them to native_{rd,wr}msr_safe_regs and remove pv_cpu_ops.read_msr_amd. Signed-off-by: Borislav Petkov <petkovbb@gmail.com> LKML-Reference: <1251705011-18636-2-git-send-email-petkovbb@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-09-01x86, msr: Add rd/wrmsr interfaces with preset registersBorislav Petkov1-0/+13
native_{rdmsr,wrmsr}_safe_regs are two new interfaces which allow presetting of a subset of eight x86 GPRs before executing the rd/wrmsr instructions. This is needed at least on AMD K8 for accessing an erratum workaround MSR. Originally based on an idea by H. Peter Anvin. Signed-off-by: Borislav Petkov <petkovbb@gmail.com> LKML-Reference: <1251705011-18636-1-git-send-email-petkovbb@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-17x86: msr.h linux/types.h is only required for __KERNEL__Jaswinder Singh Rajput1-6/+1
<linux/types.h> is only required for __KERNEL__ as whole file is covered with it Also fixed some spacing issues for usr/include/asm-x86/msr.h Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: "H. Peter Anvin" <hpa@kernel.org> LKML-Reference: <1245228070.2662.1.camel@ht.satnam> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-10x86: MSR: add methods for writing of an MSR on several CPUsBorislav Petkov1-0/+12
Provide for concurrent MSR writes on all the CPUs in the cpumask. Also, add a temporary workaround for smp_call_function_many which skips the CPU we're executing on. Bart: zero out rv struct which is allocated on stack. CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-27 01:34:46 +0300