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2016-03-10x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixupAndy Lutomirski
Right after SYSENTER, we can get a #DB or NMI. On x86_32, there's no IST, so the exception handler is invoked on the temporary SYSENTER stack. Because the SYSENTER stack is very small, we have a fixup to switch off the stack quickly when this happens. The old fixup had several issues: 1. It checked the interrupt frame's CS and EIP. This wasn't obviously correct on Xen or if vm86 mode was in use [1]. 2. In the NMI handler, it did some frightening digging into the stack frame. I'm not convinced this digging was correct. 3. The fixup didn't switch stacks and then switch back. Instead, it synthesized a brand new stack frame that would redirect the IRET back to the SYSENTER code. That frame was highly questionable. For one thing, if NMI nested inside #DB, we would effectively abort the #DB prologue, which was probably safe but was frightening. For another, the code used PUSHFL to write the FLAGS portion of the frame, which was simply bogus -- by the time PUSHFL was called, at least TF, NT, VM, and all of the arithmetic flags were clobbered. Simplify this considerably. Instead of looking at the saved frame to see where we came from, check the hardware ESP register against the SYSENTER stack directly. Malicious user code cannot spoof the kernel ESP register, and by moving the check after SAVE_ALL, we can use normal PER_CPU accesses to find all the relevant addresses. With this patch applied, the improved syscall_nt_32 test finally passes on 32-bit kernels. [1] It isn't obviously correct, but it is nonetheless safe from vm86 shenanigans as far as I can tell. A user can't point EIP at entry_SYSENTER_32 while in vm86 mode because entry_SYSENTER_32, like all kernel addresses, is greater than 0xffff and would thus violate the CS segment limit. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/b2cdbc037031c07ecf2c40a96069318aec0e7971.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry: Only allocate space for tss_struct::SYSENTER_stack if neededAndy Lutomirski
The SYSENTER stack is only used on 32-bit kernels. Remove it on 64-bit kernels. ( We may end up using it down the road on 64-bit kernels. If so, we'll re-enable it for CONFIG_IA32_EMULATION. ) Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/9dbd18429f9ff61a76b6eda97a9ea20510b9f6ba.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry: Vastly simplify SYSENTER TF (single-step) handlingAndy Lutomirski
Due to a blatant design error, SYSENTER doesn't clear TF (single-step). As a result, if a user does SYSENTER with TF set, we will single-step through the kernel until something clears TF. There is absolutely nothing we can do to prevent this short of turning off SYSENTER [1]. Simplify the handling considerably with two changes: 1. We already sanitize EFLAGS in SYSENTER to clear NT and AC. We can add TF to that list of flags to sanitize with no overhead whatsoever. 2. Teach do_debug() to ignore single-step traps in the SYSENTER prologue. That's all we need to do. Don't get too excited -- our handling is still buggy on 32-bit kernels. There's nothing wrong with the SYSENTER code itself, but the #DB prologue has a clever fixup for traps on the very first instruction of entry_SYSENTER_32, and the fixup doesn't work quite correctly. The next two patches will fix that. [1] We could probably prevent it by forcing BTF on at all times and making sure we clear TF before any branches in the SYSENTER code. Needless to say, this is a bad idea. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a30d2ea06fe4b621fe6a9ef911b02c0f38feb6f2.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry/traps: Clear DR6 early in do_debug() and improve the commentAndy Lutomirski
Leaving any bits set in DR6 on return from a debug exception is asking for trouble. Prevent it by writing zero right away and clarify the comment. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3857676e1be8fb27db4b89bbb1e2052b7f435ff4.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptionsAndy Lutomirski
The SDM says that debug exceptions clear BTF, and we need to keep TIF_BLOCKSTEP in sync with BTF. Clear it unconditionally and improve the comment. I suspect that the fact that kmemcheck could cause TIF_BLOCKSTEP not to be cleared was just an oversight. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/fa86e55d196e6dde5b38839595bde2a292c52fdc.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry/32: Restore FLAGS on SYSEXITAndy Lutomirski
We weren't restoring FLAGS at all on SYSEXIT. Apparently no one cared. With this patch applied, native kernels should always honor task_pt_regs()->flags, which opens the door for some sys_iopl() cleanups. I'll do those as a separate series, though, since getting it right will involve tweaking some paravirt ops. ( The short version is that, before this patch, sys_iopl(), invoked via SYSENTER, wasn't guaranteed to ever transfer the updated regs->flags, so sys_iopl() had to change the hardware flags register as well. ) Reported-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3f98b207472dc9784838eb5ca2b89dcc845ce269.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry/32: Filter NT and speed up AC filtering in SYSENTERAndy Lutomirski
This makes the 32-bit code work just like the 64-bit code. It should speed up syscalls on 32-bit kernels on Skylake by something like 20 cycles (by analogy to the 64-bit compat case). It also cleans up NT just like we do for the 64-bit case. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/07daef3d44bd1ed62a2c866e143e8df64edb40ee.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS testAndy Lutomirski
CLAC is slow, and the SYSENTER code already has an unlikely path that runs if unusual flags are set. Drop the CLAC and instead rely on the unlikely path to clear AC. This seems to save ~24 cycles on my Skylake laptop. (Hey, Intel, make this faster please!) Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/90d6db2189f9add83bc7bddd75a0c19ebbd676b2.1457578375.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-09Merge branch 'for-4.6/pfn' into libnvdimm-for-nextDan Williams
2016-03-09libnvdimm, pmem: clear poison on writeDan Williams
If a write is directed at a known bad block perform the following: 1/ write the data 2/ send a clear poison command 3/ invalidate the poison out of the cache hierarchy Cc: <x86@kernel.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-03-09x86/defconfigs/32: Set CONFIG_FRAME_WARN to the Kconfig defaultBorislav Petkov
Sync it to the Kconfig default for 32-bit. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: tim.gardner@canonical.com Link: http://lkml.kernel.org/r/20160309134821.GD6564@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-09KVM: x86: remove eager_fpu field of struct kvm_vcpu_archPaolo Bonzini
It is now equal to use_eager_fpu(), which simply tests a cpufeature bit. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-09KVM: x86: disable MPX if host did not enable MPX XSAVE featuresPaolo Bonzini
When eager FPU is disabled, KVM will still see the MPX bit in CPUID and presumably the MPX vmentry and vmexit controls. However, it will not be able to expose the MPX XSAVE features to the guest, because the guest's accessible XSAVE features are always a subset of host_xcr0. In this case, we should disable the MPX CPUID bit, the BNDCFGS MSR, and the MPX vmentry and vmexit controls for nested virtualization. It is then unnecessary to enable guest eager FPU if the guest has the MPX CPUID bit set. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-09x86/fpu: Fix 'no387' regressionAndy Lutomirski
After fixing FPU option parsing, we now parse the 'no387' boot option too early: no387 clears X86_FEATURE_FPU before it's even probed, so the boot CPU promptly re-enables it. I suspect it gets even more confused on SMP. Fix the probing code to leave X86_FEATURE_FPU off if it's been disabled by setup_clear_cpu_cap(). 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: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Fixes: 4f81cbafcce2 ("x86/fpu: Fix early FPU command-line parsing") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-09Merge tag 'kvm-arm-for-4.6' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM updates for 4.6 - VHE support so that we can run the kernel at EL2 on ARMv8.1 systems - PMU support for guests - 32bit world switch rewritten in C - Various optimizations to the vgic save/restore code Conflicts: include/uapi/linux/kvm.h
2016-03-09Merge branch 'ib-mfd-regulator-gpio-4.6' of ↵Linus Walleij
git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd into devel
2016-03-08PCI: Include pci/hotplug Kconfig directly from pci/KconfigBjorn Helgaas
Include pci/hotplug/Kconfig directly from pci/Kconfig, so arches don't have to source both pci/Kconfig and pci/hotplug/Kconfig. Note that this effectively adds pci/hotplug/Kconfig to the following arches, because they already sourced drivers/pci/Kconfig but they previously did not source drivers/pci/hotplug/Kconfig: alpha arm avr32 frv m68k microblaze mn10300 sparc unicore32 Inspired-by-patch-from: Bogicevic Sasa <brutallesale@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-03-08PCI: Include pci/pcie/Kconfig directly from pci/KconfigBogicevic Sasa
Include pci/pcie/Kconfig directly from pci/Kconfig, so arches don't have to source both pci/Kconfig and pci/pcie/Kconfig. Note that this effectively adds pci/pcie/Kconfig to the following arches, because they already sourced drivers/pci/Kconfig but they previously did not source drivers/pci/pcie/Kconfig: alpha avr32 blackfin frv m32r m68k microblaze mn10300 parisc sparc unicore32 xtensa [bhelgaas: changelog, source pci/pcie/Kconfig at top of pci/Kconfig, whitespace] Signed-off-by: Sasa Bogicevic <brutallesale@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-03-08PCI: Set ROM shadow location in arch code, not in PCI coreBjorn Helgaas
IORESOURCE_ROM_SHADOW means there is a copy of a device's option ROM in RAM. The existence of such a copy and its location are arch-specific. Previously the IORESOURCE_ROM_SHADOW flag was set in arch code, but the 0xC0000-0xDFFFF location was hard-coded into the PCI core. If we're using a shadow copy in RAM, disable the ROM BAR and release the address space it was consuming. Move the location information from the PCI core to the arch code that sets IORESOURCE_ROM_SHADOW. Save the location of the RAM copy in the struct resource for PCI_ROM_RESOURCE. After this change, pci_map_rom() will call pci_assign_resource() and pci_enable_rom() for these IORESOURCE_ROM_SHADOW resources, which we did not do before. This is safe because: - pci_assign_resource() will do nothing because the resource is marked IORESOURCE_PCI_FIXED, which means we can't move it, and - pci_enable_rom() will not turn on the ROM BAR's enable bit because the resource is marked IORESOURCE_ROM_SHADOW, which means it is in RAM rather than in PCI memory space. Storing the location in the struct resource means "lspci" will show the shadow location, not the value from the ROM BAR. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-03-08PCI: Mark shadow copy of VGA ROM as IORESOURCE_PCI_FIXEDBjorn Helgaas
A shadow copy of an option ROM is placed by the BIOS as a fixed address. Set IORESOURCE_PCI_FIXED to indicate that we can't move the shadow copy. This prevents warnings like the following when we assign resources: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment This warning is emitted by pdev_sort_resources(), which already ignores IORESOURCE_PCI_FIXED resources. Link: http://lkml.kernel.org/r/CA+55aFyVMfTBB0oz_yx8+eQOEJnzGtCsYSj9QuhEpdZ9BHdq5A@mail.gmail.com Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-03-08x86/PCI: Mark Broadwell-EP Home Agent & PCU as having non-compliant BARsBjorn Helgaas
The Home Agent and PCU PCI devices in Broadwell-EP have a non-BAR register where a BAR should be. We don't know what the side effects of sizing the "BAR" would be, and we don't know what address space the "BAR" might appear to describe. Mark these devices as having non-compliant BARs so the PCI core doesn't touch them. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Andi Kleen <ak@linux.intel.com> CC: stable@vger.kernel.org
2016-03-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Several cases of overlapping changes, as well as one instance (vxlan) of a bug fix in 'net' overlapping with code movement in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08x86/mm, x86/mce: Add memcpy_mcsafe()Tony Luck
Make use of the EXTABLE_FAULT exception table entries to write a kernel copy routine that doesn't crash the system if it encounters a machine check. Prime use case for this is to copy from large arrays of non-volatile memory used as storage. We have to use an unrolled copy loop for now because current hardware implementations treat a machine check in "rep mov" as fatal. When that is fixed we can simplify. Return type is a "bool". True means that we copied OK, false means that it didn't. Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@gmail.com> Link: http://lkml.kernel.org/r/a44e1055efc2d2a9473307b22c91caa437aa3f8b.1456439214.git.tony.luck@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/intel/rapl: Simplify quirk handling even moreBorislav Petkov
Drop the quirk() function pointer in favor of a simple boolean which says whether the quirk should be applied or not. Update comment while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Harish Chegondi <harish.chegondi@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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> Cc: linux-tip-commits@vger.kernel.org Link: http://lkml.kernel.org/r/20160308164041.GF16568@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08Merge branch 'linus' into x86/fpu, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/asm-offsets: Remove PARAVIRT_enabledAndy Lutomirski
It no longer has any users. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: konrad.wilk@oracle.com Cc: lguest@lists.ozlabs.org Cc: xen-devel@lists.xensource.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabledAndy Lutomirski
x86_64 has very clean espfix handling on paravirt: espfix64 is set up in native_iret, so paravirt systems that override iret bypass espfix64 automatically. This is robust and straightforward. x86_32 is messier. espfix is set up before the IRET paravirt patch point, so it can't be directly conditionalized on whether we use native_iret. We also can't easily move it into native_iret without regressing performance due to a bizarre consideration. Specifically, on 64-bit kernels, the logic is: if (regs->ss & 0x4) setup_espfix; On 32-bit kernels, the logic is: if ((regs->ss & 0x4) && (regs->cs & 0x3) == 3 && (regs->flags & X86_EFLAGS_VM) == 0) setup_espfix; The performance of setup_espfix itself is essentially irrelevant, but the comparison happens on every IRET so its performance matters. On x86_64, there's no need for any registers except flags to implement the comparison, so we fold the whole thing into native_iret. On x86_32, we don't do that because we need a free register to implement the comparison efficiently. We therefore do espfix setup before restoring registers on x86_32. This patch gets rid of the explicit paravirt_enabled check by introducing X86_BUG_ESPFIX on 32-bit systems and using an ALTERNATIVE to skip espfix on paravirt systems where iret != native_iret. This is also messy, but it's at least in line with other things we do. This improves espfix performance by removing a branch, but no one cares. More importantly, it removes a paravirt_enabled user, which is good because paravirt_enabled is ill-defined and is going away. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> 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: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: konrad.wilk@oracle.com Cc: lguest@lists.ozlabs.org Cc: xen-devel@lists.xensource.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/nmi: Mark 'ignore_nmis' as __read_mostlyKostenzer Felix
ignore_nmis is used in two distinct places: 1. modified through {stop,restart}_nmi by alternative_instructions 2. read by do_nmi to determine if default_do_nmi should be called or not thus the access pattern conforms to __read_mostly and do_nmi() is a fastpath. Signed-off-by: Kostenzer Felix <fkostenzer@live.at> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08KVM: VMX: disable PEBS before a guest entryRadim Krčmář
Linux guests on Haswell (and also SandyBridge and Broadwell, at least) would crash if you decided to run a host command that uses PEBS, like perf record -e 'cpu/mem-stores/pp' -a This happens because KVM is using VMX MSR switching to disable PEBS, but SDM [2015-12] 18.4.4.4 Re-configuring PEBS Facilities explains why it isn't safe: When software needs to reconfigure PEBS facilities, it should allow a quiescent period between stopping the prior event counting and setting up a new PEBS event. The quiescent period is to allow any latent residual PEBS records to complete its capture at their previously specified buffer address (provided by IA32_DS_AREA). There might not be a quiescent period after the MSR switch, so a CPU ends up using host's MSR_IA32_DS_AREA to access an area in guest's memory. (Or MSR switching is just buggy on some models.) The guest can learn something about the host this way: If the guest doesn't map address pointed by MSR_IA32_DS_AREA, it results in #PF where we leak host's MSR_IA32_DS_AREA through CR2. After that, a malicious guest can map and configure memory where MSR_IA32_DS_AREA is pointing and can therefore get an output from host's tracing. This is not a critical leak as the host must initiate with PEBS tracing and I have not been able to get a record from more than one instruction before vmentry in vmx_vcpu_run() (that place has most registers already overwritten with guest's). We could disable PEBS just few instructions before vmentry, but disabling it earlier shouldn't affect host tracing too much. We also don't need to switch MSR_IA32_PEBS_ENABLE on VMENTRY, but that optimization isn't worth its code, IMO. (If you are implementing PEBS for guests, be sure to handle the case where both host and guest enable PEBS, because this patch doesn't.) Fixes: 26a4f3c08de4 ("perf/x86: disable PEBS on a guest entry.") Cc: <stable@vger.kernel.org> Reported-by: Jiří Olša <jolsa@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: micro-optimize gpte_accessPaolo Bonzini
Avoid AND-NOT, most x86 processor lack an instruction for it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: simplify last_pte_bitmapPaolo Bonzini
Branch-free code is fun and everybody knows how much Avi loves it, but last_pte_bitmap takes it a bit to the extreme. Since the code is simply doing a range check, like (level == 1 || ((gpte & PT_PAGE_SIZE_MASK) && level < N) we can make it branch-free without storing the entire truth table; it is enough to cache N. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: coalesce more page zapping in mmu_sync_childrenPaolo Bonzini
mmu_sync_children can only process up to 16 pages at a time. Check if we need to reschedule, and do not bother zapping the pages until that happens. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: move zap/flush to kvm_mmu_get_pagePaolo Bonzini
kvm_mmu_get_page is the only caller of kvm_sync_page_transient and kvm_sync_pages. Moving the handling of the invalid_list there removes the need for the underdocumented kvm_sync_page_transient function. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: invert return value of mmu.sync_page and *kvm_sync_page*Paolo Bonzini
Return true if the page was synced (and the TLB must be flushed) and false if the page was zapped. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: cleanup __kvm_sync_page and its callersPaolo Bonzini
Calling kvm_unlink_unsync_page in the middle of __kvm_sync_page makes things unnecessarily tricky. If kvm_mmu_prepare_zap_page is called, it will call kvm_unlink_unsync_page too. So kvm_unlink_unsync_page can be called just as well at the beginning or the end of __kvm_sync_page... which means that we might do it in kvm_sync_page too and remove the parameter. kvm_sync_page ends up being the same code that kvm_sync_pages used to have before the previous patch. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: use kvm_sync_page in kvm_sync_pagesPaolo Bonzini
If the last argument is true, kvm_unlink_unsync_page is called anyway in __kvm_sync_page (either by kvm_mmu_prepare_zap_page or by __kvm_sync_page itself). Therefore, kvm_sync_pages can just call kvm_sync_page, instead of going through kvm_unlink_unsync_page+__kvm_sync_page. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: move TLB flush out of __kvm_sync_pagePaolo Bonzini
By doing this, kvm_sync_pages can use __kvm_sync_page instead of reinventing it. Because of kvm_mmu_flush_or_zap, the code does not end up being more complex than before, and more cleanups to kvm_sync_pages will come in the next patches. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08KVM: MMU: introduce kvm_mmu_flush_or_zapPaolo Bonzini
This is a generalization of mmu_pte_write_flush_tlb, that also takes care of calling kvm_mmu_commit_zap_page. The next patches will introduce more uses. Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-08x86/apic: Deinline _flat_send_IPI_mask, save ~150 bytesDenys Vlasenko
_flat_send_IPI_mask: 157 bytes, 3 callsites text data bss dec hex filename 96183823 20860520 36122624 153166967 9212477 vmlinux1_before 96183699 20860520 36122624 153166843 92123fb vmlinux Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Borislav Petkov <bp@alien.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Travis <travis@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1457287876-6001-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/apic: Deinline __default_send_IPI_*, save ~200 bytesDenys Vlasenko
__default_send_IPI_shortcut: 49 bytes, 2 callsites __default_send_IPI_dest_field: 108 bytes, 7 callsites text data bss dec hex filename 96184086 20860488 36122624 153167198 921255e vmlinux_before 96183823 20860520 36122624 153166967 9212477 vmlinux Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Borislav Petkov <bp@alien.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Travis <travis@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1457287876-6001-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/intel: Fix PEBS data source interpretation on Nehalem/WestmereAndi Kleen
Jiri reported some time ago that some entries in the PEBS data source table in perf do not agree with the SDM. We investigated and the bits changed for Sandy Bridge, but the SDM was not updated. perf already implements the bits correctly for Sandy Bridge and later. This patch patches it up for Nehalem and Westmere. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1456871124-15985-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/pebs: Add proper PEBS constraints for BroadwellStephane Eranian
This patch adds a Broadwell specific PEBS event constraint table. Broadwell has a fix for the HT corruption bug erratum HSD29 on Haswell. Therefore, there is no need to mark events 0xd0, 0xd1, 0xd2, 0xd3 has requiring the exclusive mode across both sibling HT threads. This holds true for regular counting and sampling (see core.c) and PEBS (ds.c) which we fix in this patch. In doing so, we relax evnt scheduling for these events, they can now be programmed on any 4 counters without impacting what is measured on the sibling thread. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@redhat.com Cc: adrian.hunter@intel.com Cc: jolsa@redhat.com Cc: kan.liang@intel.com Cc: namhyung@kernel.org Link: http://lkml.kernel.org/r/1457034642-21837-4-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/pebs: Add workaround for broken OVFL status on HSW+Stephane Eranian
This patch fixes an issue with the GLOBAL_OVERFLOW_STATUS bits on Haswell, Broadwell and Skylake processors when using PEBS. The SDM stipulates that when the PEBS iterrupt threshold is crossed, an interrupt is posted and the kernel is interrupted. The kernel will find GLOBAL_OVF_SATUS bit 62 set indicating there are PEBS records to drain. But the bits corresponding to the actual counters should NOT be set. The kernel follows the SDM and assumes that all PEBS events are processed in the drain_pebs() callback. The kernel then checks for remaining overflows on any other (non-PEBS) events and processes these in the for_each_bit_set(&status) loop. As it turns out, under certain conditions on HSW and later processors, on PEBS buffer interrupt, bit 62 is set but the counter bits may be set as well. In that case, the kernel drains PEBS and generates SAMPLES with the EXACT tag, then it processes the counter bits, and generates normal (non-EXACT) SAMPLES. I ran into this problem by trying to understand why on HSW sampling on a PEBS event was sometimes returning SAMPLES without the EXACT tag. This should not happen on user level code because HSW has the eventing_ip which always point to the instruction that caused the event. The workaround in this patch simply ensures that the bits for the counters used for PEBS events are cleared after the PEBS buffer has been drained. With this fix 100% of the PEBS samples on my user code report the EXACT tag. Before: $ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase $ perf report -D | fgrep SAMPLES PERF_RECORD_SAMPLE(IP, 0x2): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y \--- EXACT tag is missing After: $ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase $ perf report -D | fgrep SAMPLES PERF_RECORD_SAMPLE(IP, 0x4002): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y \--- EXACT tag is set The problem tends to appear more often when multiple PEBS events are used. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: namhyung@kernel.org Link: http://lkml.kernel.org/r/1457034642-21837-3-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/intel: Add definition for PT PMI bitStephane Eranian
This patch adds a definition for GLOBAL_OVFL_STATUS bit 55 which is used with the Processor Trace (PT) feature. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: namhyung@kernel.org Link: http://lkml.kernel.org/r/1457034642-21837-2-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/intel: Fix PEBS warning by only restoring active PMU in pmiKan Liang
This patch tries to fix a PEBS warning found in my stress test. The following perf command can easily trigger the pebs warning or spurious NMI error on Skylake/Broadwell/Haswell platforms: sudo perf record -e 'cpu/umask=0x04,event=0xc4/pp,cycles,branches,ref-cycles,cache-misses,cache-references' --call-graph fp -b -c1000 -a Also the NMI watchdog must be enabled. For this case, the events number is larger than counter number. So perf has to do multiplexing. In perf_mux_hrtimer_handler, it does perf_pmu_disable(), schedule out old events, rotate_ctx, schedule in new events and finally perf_pmu_enable(). If the old events include precise event, the MSR_IA32_PEBS_ENABLE should be cleared when perf_pmu_disable(). The MSR_IA32_PEBS_ENABLE should keep 0 until the perf_pmu_enable() is called and the new event is precise event. However, there is a corner case which could restore PEBS_ENABLE to stale value during the above period. In perf_pmu_disable(), GLOBAL_CTRL will be set to 0 to stop overflow and followed PMI. But there may be pending PMI from an earlier overflow, which cannot be stopped. So even GLOBAL_CTRL is cleared, the kernel still be possible to get PMI. At the end of the PMI handler, __intel_pmu_enable_all() will be called, which will restore the stale values if old events haven't scheduled out. Once the stale pebs value is set, it's impossible to be corrected if the new events are non-precise. Because the pebs_enabled will be set to 0. x86_pmu.enable_all() will ignore the MSR_IA32_PEBS_ENABLE setting. As a result, the following NMI with stale PEBS_ENABLE trigger pebs warning. The pending PMI after enabled=0 will become harmless if the NMI handler does not change the state. This patch checks cpuc->enabled in pmi and only restore the state when PMU is active. Here is the dump: Call Trace: <NMI> [<ffffffff813c3a2e>] dump_stack+0x63/0x85 [<ffffffff810a46f2>] warn_slowpath_common+0x82/0xc0 [<ffffffff810a483a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8100fe2e>] intel_pmu_drain_pebs_nhm+0x2be/0x320 [<ffffffff8100caa9>] intel_pmu_handle_irq+0x279/0x460 [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 [<ffffffff811f290d>] ? vunmap_page_range+0x20d/0x330 [<ffffffff811f2f11>] ? unmap_kernel_range_noflush+0x11/0x20 [<ffffffff8148379f>] ? ghes_copy_tofrom_phys+0x10f/0x2a0 [<ffffffff814839c8>] ? ghes_read_estatus+0x98/0x170 [<ffffffff81005a7d>] perf_event_nmi_handler+0x2d/0x50 [<ffffffff810310b9>] nmi_handle+0x69/0x120 [<ffffffff810316f6>] default_do_nmi+0xe6/0x100 [<ffffffff810317f2>] do_nmi+0xe2/0x130 [<ffffffff817aea71>] end_repeat_nmi+0x1a/0x1e [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 <<EOE>> <IRQ> [<ffffffff81006df8>] ? x86_perf_event_set_period+0xd8/0x180 [<ffffffff81006eec>] x86_pmu_start+0x4c/0x100 [<ffffffff8100722d>] x86_pmu_enable+0x28d/0x300 [<ffffffff811994d7>] perf_pmu_enable.part.81+0x7/0x10 [<ffffffff8119cb70>] perf_mux_hrtimer_handler+0x200/0x280 [<ffffffff8119c970>] ? __perf_install_in_context+0xc0/0xc0 [<ffffffff8110f92d>] __hrtimer_run_queues+0xfd/0x280 [<ffffffff811100d8>] hrtimer_interrupt+0xa8/0x190 [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0 [<ffffffff81051bd8>] local_apic_timer_interrupt+0x38/0x60 [<ffffffff817af01d>] smp_apic_timer_interrupt+0x3d/0x50 [<ffffffff817ad15c>] apic_timer_interrupt+0x8c/0xa0 <EOI> [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0 [<ffffffff81123de5>] ? smp_call_function_single+0xd5/0x130 [<ffffffff81123ddb>] ? smp_call_function_single+0xcb/0x130 [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0 [<ffffffff8119765a>] event_function_call+0x10a/0x120 [<ffffffff8119c660>] ? ctx_resched+0x90/0x90 [<ffffffff811971e0>] ? cpu_clock_event_read+0x30/0x30 [<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60 [<ffffffff8119772b>] _perf_event_enable+0x5b/0x70 [<ffffffff81197388>] perf_event_for_each_child+0x38/0xa0 [<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60 [<ffffffff811a0ffd>] perf_ioctl+0x12d/0x3c0 [<ffffffff8134d855>] ? selinux_file_ioctl+0x95/0x1e0 [<ffffffff8124a3a1>] do_vfs_ioctl+0xa1/0x5a0 [<ffffffff81036d29>] ? sched_clock+0x9/0x10 [<ffffffff8124a919>] SyS_ioctl+0x79/0x90 [<ffffffff817ac4b2>] entry_SYSCALL_64_fastpath+0x1a/0xa4 ---[ end trace aef202839fe9a71d ]--- Uhhuh. NMI received for unknown reason 2d on CPU 2. Do you have a strange power saving mode enabled? Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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/1457046448-6184-1-git-send-email-kan.liang@intel.com [ Fixed various typos and other small details. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08perf/x86/intel: Use PAGE_SIZE for PEBS buffer size on Core2Jiri Olsa
Using PAGE_SIZE buffers makes the WRMSR to PERF_GLOBAL_CTRL in intel_pmu_enable_all() mysteriously hang on Core2. As a workaround, we don't do this. The hard lockup is easily triggered by running 'perf test attr' repeatedly. Most of the time it gets stuck on sample session with small periods. # perf test attr -vv 14: struct perf_event_attr setup : --- start --- ... 'PERF_TEST_ATTR=/tmp/tmpuEKz3B /usr/bin/perf record -o /tmp/tmpuEKz3B/perf.data -c 123 kill >/dev/null 2>&1' ret 1 Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20160301190352.GA8355@krava.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/mce/AMD: Document some functionalityAravind Gopalakrishnan
In an attempt to aid in understanding of what the threshold_block structure holds, provide comments to describe the members here. Also, trim comments around threshold_restart_bank() and update copyright info. No functional change is introduced. Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> [ Shorten comments. ] Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1457021458-2522-6-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/mce: Clarify comments regarding deferred errorAravind Gopalakrishnan
Deferred errors indicate errors that hardware could not fix. But it still does not cause any interruption to program flow. So it does not generate any #MC and UC bit in MCx_STATUS is not set. Correct comment. Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1457021458-2522-5-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/mce/AMD: Fix logic to obtain block addressAravind Gopalakrishnan
In upcoming processors, the BLKPTR field is no longer used to indicate the MSR number of the additional register. Insted, it simply indicates the prescence of additional MSRs. Fix the logic here to gather MSR address from MSR_AMD64_SMCA_MCx_MISC() for newer processors and fall back to existing logic for older processors. [ Drop nextaddr_out label; style cleanups. ] Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1457021458-2522-4-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08x86/mce/AMD, EDAC: Enable error decoding of Scalable MCA errorsAravind Gopalakrishnan
For Scalable MCA enabled processors, errors are listed per IP block. And since it is not required for an IP to map to a particular bank, we need to use HWID and McaType values from the MCx_IPID register to figure out which IP a given bank represents. We also have a new bit (TCC) in the MCx_STATUS register to indicate Task context is corrupt. Add logic here to decode errors from all known IP blocks for Fam17h Model 00-0fh and to print TCC errors. [ Minor fixups. ] Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1457021458-2522-3-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>