kernel.git/arch/x86/kernel/cpu/amd.c, branch linux-4.14.y

x86/cpu: Fix AMD erratum #1485 on Zen4-based CPUs

2023-10-25T09:13:31Z

commit f454b18e07f518bcd0c05af17a2239138bff52de upstream. Fix erratum #1485 on Zen4 parts where running with STIBP disabled can cause an #UD exception. The performance impact of the fix is negligible. Reported-by: René Rebe Signed-off-by: Borislav Petkov (AMD) Tested-by: René Rebe Cc: Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@exactcode.com Signed-off-by: Greg Kroah-Hartman

x86/cpu: Fix LFENCE serialization check in init_amd()

2023-03-17T07:30:38Z

The commit: 3f235279828c ("x86/cpu: Restore AMD's DE_CFG MSR after resume") which was backported from the upstream commit: 2632daebafd0 renamed the MSR_F10H_DECFG_LFENCE_SERIALIZE macro to MSR_AMD64_DE_CFG_LFENCE_SERIALIZE. The fix for 4.14 and 4.9 changed MSR_F10H_DECFG_LFENCE_SERIALIZE to MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT in the init_amd() function, but should have used MSR_AMD64_DE_CFG_LFENCE_SERIALIZE. This causes a discrepency in the LFENCE serialization check in the init_amd() function. This causes a ~16% sysbench memory regression, when running: sysbench --test=memory run Fixes: 3f235279828c ("x86/cpu: Restore AMD's DE_CFG MSR after resume") Signed-off-by: Rhythm Mahajan Signed-off-by: Greg Kroah-Hartman

x86/CPU/AMD: Disable XSAVES on AMD family 0x17

2023-03-17T07:30:36Z

commit b0563468eeac88ebc70559d52a0b66efc37e4e9d upstream. AMD Erratum 1386 is summarised as: XSAVES Instruction May Fail to Save XMM Registers to the Provided State Save Area This piece of accidental chronomancy causes the %xmm registers to occasionally reset back to an older value. Ignore the XSAVES feature on all AMD Zen1/2 hardware. The XSAVEC instruction (which works fine) is equivalent on affected parts. [ bp: Typos, move it into the F17h-specific function. ] Reported-by: Tavis Ormandy Signed-off-by: Andrew Cooper Signed-off-by: Borislav Petkov (AMD) Cc: Link: https://lore.kernel.org/r/20230307174643.1240184-1-andrew.cooper3@citrix.com Signed-off-by: Greg Kroah-Hartman

x86/cpu: Restore AMD's DE_CFG MSR after resume

2022-11-25T16:36:48Z

commit 2632daebafd04746b4b96c2f26a6021bc38f6209 upstream. DE_CFG contains the LFENCE serializing bit, restore it on resume too. This is relevant to older families due to the way how they do S3. Unify and correct naming while at it. Fixes: e4d0e84e4907 ("x86/cpu/AMD: Make LFENCE a serializing instruction") Reported-by: Andrew Cooper Reported-by: Pawan Gupta Signed-off-by: Borislav Petkov Cc: Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86/cpu/amd: Enumerate BTC_NO

2022-11-01T18:14:46Z

commit 26aae8ccbc1972233afd08fb3f368947c0314265 upstream. BTC_NO indicates that hardware is not susceptible to Branch Type Confusion. Zen3 CPUs don't suffer BTC. Hypervisors are expected to synthesise BTC_NO when it is appropriate given the migration pool, to prevent kernels using heuristics. Signed-off-by: Andrew Cooper Signed-off-by: Borislav Petkov Signed-off-by: Thadeu Lima de Souza Cascardo [ bp: Adjust context ] Signed-off-by: Suraj Jitindar Singh Signed-off-by: Greg Kroah-Hartman

x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h

2019-08-29T06:26:43Z

commit c49a0a80137c7ca7d6ced4c812c9e07a949f6f24 upstream. There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov Cc: Andrew Cooper Cc: Andrew Morton Cc: Chen Yu Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: "linux-doc@vger.kernel.org" Cc: "linux-pm@vger.kernel.org" Cc: Nathan Chancellor Cc: Paolo Bonzini Cc: Pavel Machek Cc: "Rafael J. Wysocki" Cc: Cc: Thomas Gleixner Cc: "x86@kernel.org" Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com Signed-off-by: Greg Kroah-Hartman

x86/CPU/AMD: Don't force the CPB cap when running under a hypervisor

2019-06-22T06:16:16Z

[ Upstream commit 2ac44ab608705948564791ce1d15d43ba81a1e38 ] For F17h AMD CPUs, the CPB capability ('Core Performance Boost') is forcibly set, because some versions of that chip incorrectly report that they do not have it. However, a hypervisor may filter out the CPB capability, for good reasons. For example, KVM currently does not emulate setting the CPB bit in MSR_K7_HWCR, and unchecked MSR access errors will be thrown when trying to set it as a guest: unchecked MSR access error: WRMSR to 0xc0010015 (tried to write 0x0000000001000011) at rIP: 0xffffffff890638f4 (native_write_msr+0x4/0x20) Call Trace: boost_set_msr+0x50/0x80 [acpi_cpufreq] cpuhp_invoke_callback+0x86/0x560 sort_range+0x20/0x20 cpuhp_thread_fun+0xb0/0x110 smpboot_thread_fn+0xef/0x160 kthread+0x113/0x130 kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x35/0x40 To avoid this issue, don't forcibly set the CPB capability for a CPU when running under a hypervisor. Signed-off-by: Frank van der Linden Acked-by: Borislav Petkov Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bp@alien8.de Cc: jiaxun.yang@flygoat.com Fixes: 0237199186e7 ("x86/CPU/AMD: Set the CPB bit unconditionally on F17h") Link: http://lkml.kernel.org/r/20190522221745.GA15789@dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com [ Minor edits to the changelog. ] Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

x86/CPU/AMD: Set the CPB bit unconditionally on F17h

2019-03-13T21:03:10Z

commit 0237199186e7a4aa5310741f0a6498a20c820fd7 upstream. Some F17h models do not have CPB set in CPUID even though the CPU supports it. Set the feature bit unconditionally on all F17h. [ bp: Rewrite commit message and patch. ] Signed-off-by: Jiaxun Yang Signed-off-by: Borislav Petkov Acked-by: Tom Lendacky Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Sherry Hurwitz Cc: Suravee Suthikulpanit Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20181120030018.5185-1-jiaxun.yang@flygoat.com Signed-off-by: Greg Kroah-Hartman

x86/bugs: Update when to check for the LS_CFG SSBD mitigation

2018-12-05T18:41:18Z

commit 845d382bb15c6e7dc5026c0ff919c5b13fc7e11b upstream If either the X86_FEATURE_AMD_SSBD or X86_FEATURE_VIRT_SSBD features are present, then there is no need to perform the check for the LS_CFG SSBD mitigation support. Signed-off-by: Tom Lendacky Cc: Borislav Petkov Cc: David Woodhouse Cc: Konrad Rzeszutek Wilk Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180702213553.29202.21089.stgit@tlendack-t1.amdoffice.net Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present

2018-08-15T16:13:02Z

commit f8b64d08dde2714c62751d18ba77f4aeceb161d3 upstream. Move smp_num_siblings and cpu_llc_id to cpu/common.c so that they're always present as symbols and not only in the CONFIG_SMP case. Then, other code using them doesn't need ugly ifdeffery anymore. Get rid of some ifdeffery. Signed-off-by: Borislav Petkov Signed-off-by: Suravee Suthikulpanit Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Link: http://lkml.kernel.org/r/1524864877-111962-2-git-send-email-suravee.suthikulpanit@amd.com Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman