linux-dev/tools/arch/x86/include/asm, branch master

tools headers cpufeatures: Sync with the kernel sources

2022-10-25T20:40:48Z

To pick the changes from: 257449c6a50298bd ("x86/cpufeatures: Add LbrExtV2 feature bit") This only causes these perf files to be rebuilt: CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o And addresses this perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h' diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Link: https://lore.kernel.org/lkml/Y1g6vGPqPhOrXoaN@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools arch x86: Sync the msr-index.h copy with the kernel sources

2022-10-15T13:13:16Z

To pick up the changes in: b8d1d163604bd1e6 ("x86/apic: Don't disable x2APIC if locked") ca5b7c0d9621702e ("perf/x86/amd/lbr: Add LbrExtV2 branch record support") Addressing these tools/perf build warnings: diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h' That makes the beautification scripts to pick some new entries: $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after $ diff -u before after --- before 2022-10-14 18:06:34.294561729 -0300 +++ after 2022-10-14 18:06:41.285744044 -0300 @@ -264,6 +264,7 @@ [0xc0000102 - x86_64_specific_MSRs_offset] = "KERNEL_GS_BASE", [0xc0000103 - x86_64_specific_MSRs_offset] = "TSC_AUX", [0xc0000104 - x86_64_specific_MSRs_offset] = "AMD64_TSC_RATIO", + [0xc000010e - x86_64_specific_MSRs_offset] = "AMD64_LBR_SELECT", [0xc000010f - x86_64_specific_MSRs_offset] = "AMD_DBG_EXTN_CFG", [0xc0000300 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS", [0xc0000301 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_CTL", $ Now one can trace systemwide asking to see backtraces to where that MSR is being read/written, see this example with a previous update: # perf trace -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" ^C# If we use -v (verbose mode) we can see what it does behind the scenes: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" Using CPUID AuthenticAMD-25-21-0 0x6a0 0x6a8 New filter for msr:read_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) 0x6a0 0x6a8 New filter for msr:write_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) mmap size 528384B ^C# Example with a frequent msr: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2 Using CPUID AuthenticAMD-25-21-0 0x48 New filter for msr:read_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) 0x48 New filter for msr:write_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) mmap size 528384B Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols 0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) futex_wait_queue_me ([kernel.kallsyms]) futex_wait ([kernel.kallsyms]) do_futex ([kernel.kallsyms]) __x64_sys_futex ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so) 0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule_idle ([kernel.kallsyms]) do_idle ([kernel.kallsyms]) cpu_startup_entry ([kernel.kallsyms]) secondary_startup_64_no_verify ([kernel.kallsyms]) # Cc: Adrian Hunter Cc: Daniel Sneddon Cc: Dave Hansen Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Link: https://lore.kernel.org/lkml/Y0nQkz2TUJxwfXJd@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf amd ibs: Sync arch/x86/include/asm/amd-ibs.h header with the kernel

2022-10-06T19:27:38Z

Although new details added into this header is currently used by kernel only, tools copy needs to be in sync with kernel file to avoid tools/perf/check-headers.sh warnings. Signed-off-by: Ravi Bangoria Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ali Saidi Cc: Ananth Narayan Cc: Andi Kleen Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Ian Rogers Cc: Ingo Molnar Cc: Joe Mario Cc: Kan Liang Cc: Kim Phillips Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Cc: Santosh Shukla Cc: Stephane Eranian Cc: Thomas Gleixner Cc: x86@kernel.org Link: https://lore.kernel.org/r/20221006153946.7816-3-ravi.bangoria@amd.com Signed-off-by: Arnaldo Carvalho de Melo

tools headers cpufeatures: Sync with the kernel sources

2022-09-21T19:08:00Z

To pick the changes from: 7df548840c496b01 ("x86/bugs: Add "unknown" reporting for MMIO Stale Data") This only causes these perf files to be rebuilt: CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o And addresses this perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h' diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h Cc: Adrian Hunter Cc: Borislav Petkov Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Pawan Gupta Link: https://lore.kernel.org/lkml/YysTRji90sNn2p5f@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

asm goto: eradicate CC_HAS_ASM_GOTO

2022-08-21T17:06:28Z

GCC has supported asm goto since 4.5, and Clang has since version 9.0.0. The minimum supported versions of these tools for the build according to Documentation/process/changes.rst are 5.1 and 11.0.0 respectively. Remove the feature detection script, Kconfig option, and clean up some fallback code that is no longer supported. The removed script was also testing for a GCC specific bug that was fixed in the 4.7 release. Also remove workarounds for bpftrace using clang older than 9.0.0, since other BPF backend fixes are required at this point. Link: https://lore.kernel.org/lkml/CAK7LNATSr=BXKfkdW8f-H5VT_w=xBpT2ZQcZ7rm6JfkdE+QnmA@mail.gmail.com/ Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 Acked-by: Borislav Petkov Suggested-by: Masahiro Yamada Suggested-by: Alexei Starovoitov Signed-off-by: Nick Desaulniers Reviewed-by: Ingo Molnar Reviewed-by: Nathan Chancellor Reviewed-by: Alexandre Belloni Signed-off-by: Linus Torvalds

tools headers cpufeatures: Sync with the kernel sources

2022-08-19T18:30:33Z

To pick the changes from: 2b1299322016731d ("x86/speculation: Add RSB VM Exit protections") 28a99e95f55c6185 ("x86/amd: Use IBPB for firmware calls") 4ad3278df6fe2b08 ("x86/speculation: Disable RRSBA behavior") 26aae8ccbc197223 ("x86/cpu/amd: Enumerate BTC_NO") 9756bba28470722d ("x86/speculation: Fill RSB on vmexit for IBRS") 3ebc170068885b6f ("x86/bugs: Add retbleed=ibpb") 2dbb887e875b1de3 ("x86/entry: Add kernel IBRS implementation") 6b80b59b35557065 ("x86/bugs: Report AMD retbleed vulnerability") a149180fbcf336e9 ("x86: Add magic AMD return-thunk") 15e67227c49a5783 ("x86: Undo return-thunk damage") a883d624aed463c8 ("x86/cpufeatures: Move RETPOLINE flags to word 11") aae99a7c9ab371b2 ("x86/cpufeatures: Introduce x2AVIC CPUID bit") 6f33a9daff9f0790 ("x86: Fix comment for X86_FEATURE_ZEN") 51802186158c74a0 ("x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug") This only causes these perf files to be rebuilt: CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o And addresses this perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h' diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h Cc: Adrian Hunter Cc: Alexandre Chartre Cc: Andrew Cooper Cc: Borislav Petkov Cc: Daniel Sneddon Cc: Dave Hansen Cc: Ian Rogers Cc: Jiri Olsa Cc: Josh Poimboeuf Cc: Namhyung Kim Cc: Paolo Bonzini Cc: Pawan Gupta Cc: Peter Zijlstra Cc: Suravee Suthikulpanit Cc: Wyes Karny Link: https://lore.kernel.org/lkml/Yvznmu5oHv0ZDN2w@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools arch x86: Sync the msr-index.h copy with the kernel sources

2022-08-19T18:30:33Z

To pick up the changes in: 2b1299322016731d ("x86/speculation: Add RSB VM Exit protections") 4af184ee8b2c0a69 ("tools/power turbostat: dump secondary Turbo-Ratio-Limit") 4ad3278df6fe2b08 ("x86/speculation: Disable RRSBA behavior") d7caac991feeef1b ("x86/cpu/amd: Add Spectral Chicken") 6ad0ad2bf8a67e27 ("x86/bugs: Report Intel retbleed vulnerability") c59a1f106f5cd484 ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS") 465932db25f36648 ("x86/cpu: Add new VMX feature, Tertiary VM-Execution control") 027bbb884be006b0 ("KVM: x86/speculation: Disable Fill buffer clear within guests") 51802186158c74a0 ("x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug") Addressing these tools/perf build warnings: diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h' That makes the beautification scripts to pick some new entries: $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after $ diff -u before after --- before 2022-08-17 09:05:13.938246475 -0300 +++ after 2022-08-17 09:05:22.221455851 -0300 @@ -161,6 +161,7 @@ [0x0000048f] = "IA32_VMX_TRUE_EXIT_CTLS", [0x00000490] = "IA32_VMX_TRUE_ENTRY_CTLS", [0x00000491] = "IA32_VMX_VMFUNC", + [0x00000492] = "IA32_VMX_PROCBASED_CTLS3", [0x000004c1] = "IA32_PMC0", [0x000004d0] = "IA32_MCG_EXT_CTL", [0x00000560] = "IA32_RTIT_OUTPUT_BASE", @@ -212,6 +213,7 @@ [0x0000064D] = "PLATFORM_ENERGY_STATUS", [0x0000064e] = "PPERF", [0x0000064f] = "PERF_LIMIT_REASONS", + [0x00000650] = "SECONDARY_TURBO_RATIO_LIMIT", [0x00000658] = "PKG_WEIGHTED_CORE_C0_RES", [0x00000659] = "PKG_ANY_CORE_C0_RES", [0x0000065A] = "PKG_ANY_GFXE_C0_RES", $ Now one can trace systemwide asking to see backtraces to where those MSRs are being read/written, see this example with a previous update: # perf trace -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" ^C# If we use -v (verbose mode) we can see what it does behind the scenes: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" Using CPUID AuthenticAMD-25-21-0 0x6a0 0x6a8 New filter for msr:read_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) 0x6a0 0x6a8 New filter for msr:write_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) mmap size 528384B ^C# Example with a frequent msr: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2 Using CPUID AuthenticAMD-25-21-0 0x48 New filter for msr:read_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) 0x48 New filter for msr:write_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) mmap size 528384B Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols 0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) futex_wait_queue_me ([kernel.kallsyms]) futex_wait ([kernel.kallsyms]) do_futex ([kernel.kallsyms]) __x64_sys_futex ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so) 0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule_idle ([kernel.kallsyms]) do_idle ([kernel.kallsyms]) cpu_startup_entry ([kernel.kallsyms]) secondary_startup_64_no_verify ([kernel.kallsyms]) # Cc: Adrian Hunter Cc: Daniel Sneddon Cc: Ian Rogers Cc: Jiri Olsa Cc: Len Brown Cc: Like Xu Cc: Namhyung Kim Cc: Paolo Bonzini Cc: Pawan Gupta Cc: Peter Zijlstra Cc: Robert Hoo Signed-off-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/lkml/YvzbT24m2o5U%2F7+q@kernel.org/ Signed-off-by: Arnaldo Carvalho de Melo

Merge tag 'x86_bugs_pbrsb' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-08-09T16:29:07Z

Pull x86 eIBRS fixes from Borislav Petkov: "More from the CPU vulnerability nightmares front: Intel eIBRS machines do not sufficiently mitigate against RET mispredictions when doing a VM Exit therefore an additional RSB, one-entry stuffing is needed" * tag 'x86_bugs_pbrsb' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation: Add LFENCE to RSB fill sequence x86/speculation: Add RSB VM Exit protections

x86/speculation: Add RSB VM Exit protections

2022-08-03T09:23:52Z

tl;dr: The Enhanced IBRS mitigation for Spectre v2 does not work as documented for RET instructions after VM exits. Mitigate it with a new one-entry RSB stuffing mechanism and a new LFENCE. == Background == Indirect Branch Restricted Speculation (IBRS) was designed to help mitigate Branch Target Injection and Speculative Store Bypass, i.e. Spectre, attacks. IBRS prevents software run in less privileged modes from affecting branch prediction in more privileged modes. IBRS requires the MSR to be written on every privilege level change. To overcome some of the performance issues of IBRS, Enhanced IBRS was introduced. eIBRS is an "always on" IBRS, in other words, just turn it on once instead of writing the MSR on every privilege level change. When eIBRS is enabled, more privileged modes should be protected from less privileged modes, including protecting VMMs from guests. == Problem == Here's a simplification of how guests are run on Linux' KVM: void run_kvm_guest(void) { // Prepare to run guest VMRESUME(); // Clean up after guest runs } The execution flow for that would look something like this to the processor: 1. Host-side: call run_kvm_guest() 2. Host-side: VMRESUME 3. Guest runs, does "CALL guest_function" 4. VM exit, host runs again 5. Host might make some "cleanup" function calls 6. Host-side: RET from run_kvm_guest() Now, when back on the host, there are a couple of possible scenarios of post-guest activity the host needs to do before executing host code: * on pre-eIBRS hardware (legacy IBRS, or nothing at all), the RSB is not touched and Linux has to do a 32-entry stuffing. * on eIBRS hardware, VM exit with IBRS enabled, or restoring the host IBRS=1 shortly after VM exit, has a documented side effect of flushing the RSB except in this PBRSB situation where the software needs to stuff the last RSB entry "by hand". IOW, with eIBRS supported, host RET instructions should no longer be influenced by guest behavior after the host retires a single CALL instruction. However, if the RET instructions are "unbalanced" with CALLs after a VM exit as is the RET in #6, it might speculatively use the address for the instruction after the CALL in #3 as an RSB prediction. This is a problem since the (untrusted) guest controls this address. Balanced CALL/RET instruction pairs such as in step #5 are not affected. == Solution == The PBRSB issue affects a wide variety of Intel processors which support eIBRS. But not all of them need mitigation. Today, X86_FEATURE_RSB_VMEXIT triggers an RSB filling sequence that mitigates PBRSB. Systems setting RSB_VMEXIT need no further mitigation - i.e., eIBRS systems which enable legacy IBRS explicitly. However, such systems (X86_FEATURE_IBRS_ENHANCED) do not set RSB_VMEXIT and most of them need a new mitigation. Therefore, introduce a new feature flag X86_FEATURE_RSB_VMEXIT_LITE which triggers a lighter-weight PBRSB mitigation versus RSB_VMEXIT. The lighter-weight mitigation performs a CALL instruction which is immediately followed by a speculative execution barrier (INT3). This steers speculative execution to the barrier -- just like a retpoline -- which ensures that speculation can never reach an unbalanced RET. Then, ensure this CALL is retired before continuing execution with an LFENCE. In other words, the window of exposure is opened at VM exit where RET behavior is troublesome. While the window is open, force RSB predictions sampling for RET targets to a dead end at the INT3. Close the window with the LFENCE. There is a subset of eIBRS systems which are not vulnerable to PBRSB. Add these systems to the cpu_vuln_whitelist[] as NO_EIBRS_PBRSB. Future systems that aren't vulnerable will set ARCH_CAP_PBRSB_NO. [ bp: Massage, incorporate review comments from Andy Cooper. ] Signed-off-by: Daniel Sneddon Co-developed-by: Pawan Gupta Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov

Merge remote-tracking branch 'torvalds/master' into perf/core

2022-08-01T11:59:31Z

To pick up the fixes that went upstream via acme/perf/urgent and to get to v5.19. Signed-off-by: Arnaldo Carvalho de Melo