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2024-03-11Merge tag 'x86-core-2024-03-11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core x86 updates from Ingo Molnar: - The biggest change is the rework of the percpu code, to support the 'Named Address Spaces' GCC feature, by Uros Bizjak: - This allows C code to access GS and FS segment relative memory via variables declared with such attributes, which allows the compiler to better optimize those accesses than the previous inline assembly code. - The series also includes a number of micro-optimizations for various percpu access methods, plus a number of cleanups of %gs accesses in assembly code. - These changes have been exposed to linux-next testing for the last ~5 months, with no known regressions in this area. - Fix/clean up __switch_to()'s broken but accidentally working handling of FPU switching - which also generates better code - Propagate more RIP-relative addressing in assembly code, to generate slightly better code - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to make it easier for distros to follow & maintain these options - Rework the x86 idle code to cure RCU violations and to clean up the logic - Clean up the vDSO Makefile logic - Misc cleanups and fixes * tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/idle: Select idle routine only once x86/idle: Let prefer_mwait_c1_over_halt() return bool x86/idle: Cleanup idle_setup() x86/idle: Clean up idle selection x86/idle: Sanitize X86_BUG_AMD_E400 handling sched/idle: Conditionally handle tick broadcast in default_idle_call() x86: Increase brk randomness entropy for 64-bit systems x86/vdso: Move vDSO to mmap region x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o x86/retpoline: Ensure default return thunk isn't used at runtime x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32 x86/vdso: Use $(addprefix ) instead of $(foreach ) x86/vdso: Simplify obj-y addition x86/vdso: Consolidate targets and clean-files x86/bugs: Rename CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK x86/bugs: Rename CONFIG_CPU_SRSO => CONFIG_MITIGATION_SRSO x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY => CONFIG_MITIGATION_IBRS_ENTRY x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRY x86/bugs: Rename CONFIG_SLS => CONFIG_MITIGATION_SLS ...
2024-03-11Merge tag 'x86_sev_for_v6.9_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV updates from Borislav Petkov: - Add the x86 part of the SEV-SNP host support. This will allow the kernel to be used as a KVM hypervisor capable of running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP is the ultimate goal of the AMD confidential computing side, providing the most comprehensive confidential computing environment up to date. This is the x86 part and there is a KVM part which did not get ready in time for the merge window so latter will be forthcoming in the next cycle. - Rework the early code's position-dependent SEV variable references in order to allow building the kernel with clang and -fPIE/-fPIC and -mcmodel=kernel - The usual set of fixes, cleanups and improvements all over the place * tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/sev: Disable KMSAN for memory encryption TUs x86/sev: Dump SEV_STATUS crypto: ccp - Have it depend on AMD_IOMMU iommu/amd: Fix failure return from snp_lookup_rmpentry() x86/sev: Fix position dependent variable references in startup code crypto: ccp: Make snp_range_list static x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT Documentation: virt: Fix up pre-formatted text block for SEV ioctls crypto: ccp: Add the SNP_SET_CONFIG command crypto: ccp: Add the SNP_COMMIT command crypto: ccp: Add the SNP_PLATFORM_STATUS command x86/cpufeatures: Enable/unmask SEV-SNP CPU feature KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown crypto: ccp: Handle legacy SEV commands when SNP is enabled crypto: ccp: Handle non-volatile INIT_EX data when SNP is enabled crypto: ccp: Handle the legacy TMR allocation when SNP is enabled x86/sev: Introduce an SNP leaked pages list crypto: ccp: Provide an API to issue SEV and SNP commands ...
2024-03-11Merge tag 'x86_cpu_for_v6.9_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu update from Borislav Petkov: - Have AMD Zen common init code run on all families from Zen1 onwards in order to save some future enablement effort * tag 'x86_cpu_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Do the common init on future Zens too
2024-02-16x86/CPU/AMD: Do the common init on future Zens tooBorislav Petkov (AMD)
There's no need to enable the common Zen init stuff for each new family - just do it by default on everything >= 0x17 family. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240201161024.30839-1-bp@alien8.de
2024-02-15x86/cpu: Use common topology code for AMDThomas Gleixner
Switch it over to the new topology evaluation mechanism and remove the random bits and pieces which are sprinkled all over the place. No functional change intended. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Wang Wendy <wendy.wang@intel.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20240212153625.145745053@linutronix.de
2024-02-15x86/cpu: Provide an AMD/HYGON specific topology parserThomas Gleixner
AMD/HYGON uses various methods for topology evaluation: - Leaf 0x80000008 and 0x8000001e based with an optional leaf 0xb, which is the preferred variant for modern CPUs. Leaf 0xb will be superseded by leaf 0x80000026 soon, which is just another variant of the Intel 0x1f leaf for whatever reasons. - Subleaf 0x80000008 and NODEID_MSR base - Legacy fallback That code is following the principle of random bits and pieces all over the place which results in multiple evaluations and impenetrable code flows in the same way as the Intel parsing did. Provide a sane implementation by clearly separating the three variants and bringing them in the proper preference order in one place. This provides the parsing for both AMD and HYGON because there is no point in having a separate HYGON parser which only differs by 3 lines of code. Any further divergence between AMD and HYGON can be handled in different functions, while still sharing the existing parsers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Wang Wendy <wendy.wang@intel.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/r/20240212153625.020038641@linutronix.de
2024-02-14Merge branch 'x86/bugs' into x86/core, to pick up pending changes before ↵Ingo Molnar
dependent patches Merge in pending alternatives patching infrastructure changes, before applying more patches. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-01-29x86/sev: Add SEV-SNP host initialization supportBrijesh Singh
The memory integrity guarantees of SEV-SNP are enforced through a new structure called the Reverse Map Table (RMP). The RMP is a single data structure shared across the system that contains one entry for every 4K page of DRAM that may be used by SEV-SNP VMs. The APM Volume 2 section on Secure Nested Paging (SEV-SNP) details a number of steps needed to detect/enable SEV-SNP and RMP table support on the host: - Detect SEV-SNP support based on CPUID bit - Initialize the RMP table memory reported by the RMP base/end MSR registers and configure IOMMU to be compatible with RMP access restrictions - Set the MtrrFixDramModEn bit in SYSCFG MSR - Set the SecureNestedPagingEn and VMPLEn bits in the SYSCFG MSR - Configure IOMMU RMP table entry format is non-architectural and it can vary by processor. It is defined by the PPR document for each respective CPU family. Restrict SNP support to CPU models/families which are compatible with the current RMP table entry format to guard against any undefined behavior when running on other system types. Future models/support will handle this through an architectural mechanism to allow for broader compatibility. SNP host code depends on CONFIG_KVM_AMD_SEV config flag which may be enabled even when CONFIG_AMD_MEM_ENCRYPT isn't set, so update the SNP-specific IOMMU helpers used here to rely on CONFIG_KVM_AMD_SEV instead of CONFIG_AMD_MEM_ENCRYPT. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Co-developed-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Co-developed-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Co-developed-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Co-developed-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Link: https://lore.kernel.org/r/20240126041126.1927228-5-michael.roth@amd.com
2024-01-29x86/cpufeatures: Add SEV-SNP CPU featureBrijesh Singh
Add CPU feature detection for Secure Encrypted Virtualization with Secure Nested Paging. This feature adds a strong memory integrity protection to help prevent malicious hypervisor-based attacks like data replay, memory re-mapping, and more. Since enabling the SNP CPU feature imposes a number of additional requirements on host initialization and handling legacy firmware APIs for SEV/SEV-ES guests, only introduce the CPU feature bit so that the relevant handling can be added, but leave it disabled via a disabled-features mask. Once all the necessary changes needed to maintain legacy SEV/SEV-ES support are introduced in subsequent patches, the SNP feature bit will be unmasked/enabled. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Jarkko Sakkinen <jarkko@profian.com> Signed-off-by: Ashish Kalra <Ashish.Kalra@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240126041126.1927228-2-michael.roth@amd.com
2024-01-25x86/CPU/AMD: Add more models to X86_FEATURE_ZEN5Mario Limonciello
Add model ranges starting at 0x20, 0x40 and 0x70 to the synthetic feature flag X86_FEATURE_ZEN5. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240124220749.2983-1-mario.limonciello@amd.com
2024-01-23x86/CPU/AMD: Add X86_FEATURE_ZEN5Borislav Petkov (AMD)
Add a synthetic feature flag for Zen5. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240104201138.5072-1-bp@alien8.de
2024-01-10x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRYBreno Leitao
Step 7/10 of the namespace unification of CPU mitigations related Kconfig options. Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20231121160740.1249350-8-leitao@debian.org
2024-01-08Merge tag 'x86_cpu_for_v6.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu feature updates from Borislav Petkov: - Add synthetic X86_FEATURE flags for the different AMD Zen generations and use them everywhere instead of ad-hoc family/model checks. Drop an ancient AMD errata checking facility as a result - Fix a fragile initcall ordering in intel_epb - Do not issue the MFENCE+LFENCE barrier for the TSC deadline and X2APIC MSRs on AMD as it is not needed there * tag 'x86_cpu_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Add X86_FEATURE_ZEN1 x86/CPU/AMD: Drop now unused CPU erratum checking function x86/CPU/AMD: Get rid of amd_erratum_1485[] x86/CPU/AMD: Get rid of amd_erratum_400[] x86/CPU/AMD: Get rid of amd_erratum_383[] x86/CPU/AMD: Get rid of amd_erratum_1054[] x86/CPU/AMD: Move the DIV0 bug detection to the Zen1 init function x86/CPU/AMD: Move Zenbleed check to the Zen2 init function x86/CPU/AMD: Rename init_amd_zn() to init_amd_zen_common() x86/CPU/AMD: Call the spectral chicken in the Zen2 init function x86/CPU/AMD: Move erratum 1076 fix into the Zen1 init function x86/CPU/AMD: Move the Zen3 BTC_NO detection to the Zen3 init function x86/CPU/AMD: Carve out the erratum 1386 fix x86/CPU/AMD: Add ZenX generations flags x86/cpu/intel_epb: Don't rely on link order x86/barrier: Do not serialize MSR accesses on AMD
2023-12-12x86/CPU/AMD: Add X86_FEATURE_ZEN1Borislav Petkov (AMD)
Add a synthetic feature flag specifically for first generation Zen machines. There's need to have a generic flag for all Zen generations so make X86_FEATURE_ZEN be that flag. Fixes: 30fa92832f40 ("x86/CPU/AMD: Add ZenX generations flags") Suggested-by: Brian Gerst <brgerst@gmail.com> Suggested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/dc3835e3-0731-4230-bbb9-336bbe3d042b@amd.com
2023-12-02x86/CPU/AMD: Check vendor in the AMD microcode callbackBorislav Petkov (AMD)
Commit in Fixes added an AMD-specific microcode callback. However, it didn't check the CPU vendor the kernel runs on explicitly. The only reason the Zenbleed check in it didn't run on other x86 vendors hardware was pure coincidental luck: if (!cpu_has_amd_erratum(c, amd_zenbleed)) return; gives true on other vendors because they don't have those families and models. However, with the removal of the cpu_has_amd_erratum() in 05f5f73936fa ("x86/CPU/AMD: Drop now unused CPU erratum checking function") that coincidental condition is gone, leading to the zenbleed check getting executed on other vendors too. Add the explicit vendor check for the whole callback as it should've been done in the first place. Fixes: 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix") Cc: <stable@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20231201184226.16749-1-bp@alien8.de
2023-11-29x86/CPU/AMD: Drop now unused CPU erratum checking functionBorislav Petkov (AMD)
Bye bye. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-14-bp@alien8.de
2023-11-29x86/CPU/AMD: Get rid of amd_erratum_1485[]Borislav Petkov (AMD)
No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-13-bp@alien8.de
2023-11-29x86/CPU/AMD: Get rid of amd_erratum_400[]Borislav Petkov (AMD)
Setting X86_BUG_AMD_E400 in init_amd() is early enough. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-12-bp@alien8.de
2023-11-29x86/CPU/AMD: Get rid of amd_erratum_383[]Borislav Petkov (AMD)
Set it in init_amd_gh() unconditionally as that is the F10h init function. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-11-bp@alien8.de
2023-11-29x86/CPU/AMD: Get rid of amd_erratum_1054[]Borislav Petkov (AMD)
No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-10-bp@alien8.de
2023-11-29x86/CPU/AMD: Move the DIV0 bug detection to the Zen1 init functionBorislav Petkov (AMD)
No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-9-bp@alien8.de
2023-11-29x86/CPU/AMD: Move Zenbleed check to the Zen2 init functionBorislav Petkov (AMD)
Prefix it properly so that it is clear which generation it is dealing with. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: http://lore.kernel.org/r/20231120104152.13740-8-bp@alien8.de
2023-11-29x86/CPU/AMD: Rename init_amd_zn() to init_amd_zen_common()Borislav Petkov (AMD)
Call it from all Zen init functions. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-7-bp@alien8.de
2023-11-29x86/CPU/AMD: Call the spectral chicken in the Zen2 init functionBorislav Petkov (AMD)
No functional change. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-6-bp@alien8.de
2023-11-29x86/CPU/AMD: Move erratum 1076 fix into the Zen1 init functionBorislav Petkov (AMD)
No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-5-bp@alien8.de
2023-11-29x86/CPU/AMD: Move the Zen3 BTC_NO detection to the Zen3 init functionBorislav Petkov (AMD)
No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-4-bp@alien8.de
2023-11-29x86/CPU/AMD: Carve out the erratum 1386 fixBorislav Petkov (AMD)
Call it on the affected CPU generations. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Link: http://lore.kernel.org/r/20231120104152.13740-3-bp@alien8.de
2023-11-29x86/CPU/AMD: Add ZenX generations flagsBorislav Petkov (AMD)
Add X86_FEATURE flags for each Zen generation. They should be used from now on instead of checking f/m/s. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lore.kernel.org/r/20231120104152.13740-2-bp@alien8.de
2023-11-13x86/barrier: Do not serialize MSR accesses on AMDBorislav Petkov (AMD)
AMD does not have the requirement for a synchronization barrier when acccessing a certain group of MSRs. Do not incur that unnecessary penalty there. There will be a CPUID bit which explicitly states that a MFENCE is not needed. Once that bit is added to the APM, this will be extended with it. While at it, move to processor.h to avoid include hell. Untangling that file properly is a matter for another day. Some notes on the performance aspect of why this is relevant, courtesy of Kishon VijayAbraham <Kishon.VijayAbraham@amd.com>: On a AMD Zen4 system with 96 cores, a modified ipi-bench[1] on a VM shows x2AVIC IPI rate is 3% to 4% lower than AVIC IPI rate. The ipi-bench is modified so that the IPIs are sent between two vCPUs in the same CCX. This also requires to pin the vCPU to a physical core to prevent any latencies. This simulates the use case of pinning vCPUs to the thread of a single CCX to avoid interrupt IPI latency. In order to avoid run-to-run variance (for both x2AVIC and AVIC), the below configurations are done: 1) Disable Power States in BIOS (to prevent the system from going to lower power state) 2) Run the system at fixed frequency 2500MHz (to prevent the system from increasing the frequency when the load is more) With the above configuration: *) Performance measured using ipi-bench for AVIC: Average Latency: 1124.98ns [Time to send IPI from one vCPU to another vCPU] Cumulative throughput: 42.6759M/s [Total number of IPIs sent in a second from 48 vCPUs simultaneously] *) Performance measured using ipi-bench for x2AVIC: Average Latency: 1172.42ns [Time to send IPI from one vCPU to another vCPU] Cumulative throughput: 40.9432M/s [Total number of IPIs sent in a second from 48 vCPUs simultaneously] From above, x2AVIC latency is ~4% more than AVIC. However, the expectation is x2AVIC performance to be better or equivalent to AVIC. Upon analyzing the perf captures, it is observed significant time is spent in weak_wrmsr_fence() invoked by x2apic_send_IPI(). With the fix to skip weak_wrmsr_fence() *) Performance measured using ipi-bench for x2AVIC: Average Latency: 1117.44ns [Time to send IPI from one vCPU to another vCPU] Cumulative throughput: 42.9608M/s [Total number of IPIs sent in a second from 48 vCPUs simultaneously] Comparing the performance of x2AVIC with and without the fix, it can be seen the performance improves by ~4%. Performance captured using an unmodified ipi-bench using the 'mesh-ipi' option with and without weak_wrmsr_fence() on a Zen4 system also showed significant performance improvement without weak_wrmsr_fence(). The 'mesh-ipi' option ignores CCX or CCD and just picks random vCPU. Average throughput (10 iterations) with weak_wrmsr_fence(), Cumulative throughput: 4933374 IPI/s Average throughput (10 iterations) without weak_wrmsr_fence(), Cumulative throughput: 6355156 IPI/s [1] https://github.com/bytedance/kvm-utils/tree/master/microbenchmark/ipi-bench Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230622095212.20940-1-bp@alien8.de
2023-10-30Merge tag 'x86-core-2023-10-29-v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Thomas Gleixner: - Limit the hardcoded topology quirk for Hygon CPUs to those which have a model ID less than 4. The newer models have the topology CPUID leaf 0xB correctly implemented and are not affected. - Make SMT control more robust against enumeration failures SMT control was added to allow controlling SMT at boottime or runtime. The primary purpose was to provide a simple mechanism to disable SMT in the light of speculation attack vectors. It turned out that the code is sensible to enumeration failures and worked only by chance for XEN/PV. XEN/PV has no real APIC enumeration which means the primary thread mask is not set up correctly. By chance a XEN/PV boot ends up with smp_num_siblings == 2, which makes the hotplug control stay at its default value "enabled". So the mask is never evaluated. The ongoing rework of the topology evaluation caused XEN/PV to end up with smp_num_siblings == 1, which sets the SMT control to "not supported" and the empty primary thread mask causes the hotplug core to deny the bringup of the APS. Make the decision logic more robust and take 'not supported' and 'not implemented' into account for the decision whether a CPU should be booted or not. - Fake primary thread mask for XEN/PV Pretend that all XEN/PV vCPUs are primary threads, which makes the usage of the primary thread mask valid on XEN/PV. That is consistent with because all of the topology information on XEN/PV is fake or even non-existent. - Encapsulate topology information in cpuinfo_x86 Move the randomly scattered topology data into a separate data structure for readability and as a preparatory step for the topology evaluation overhaul. - Consolidate APIC ID data type to u32 It's fixed width hardware data and not randomly u16, int, unsigned long or whatever developers decided to use. - Cure the abuse of cpuinfo for persisting logical IDs. Per CPU cpuinfo is used to persist the logical package and die IDs. That's really not the right place simply because cpuinfo is subject to be reinitialized when a CPU goes through an offline/online cycle. Use separate per CPU data for the persisting to enable the further topology management rework. It will be removed once the new topology management is in place. - Provide a debug interface for inspecting topology information Useful in general and extremly helpful for validating the topology management rework in terms of correctness or "bug" compatibility. * tag 'x86-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/apic, x86/hyperv: Use u32 in hv_snp_boot_ap() too x86/cpu: Provide debug interface x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids x86/apic: Use u32 for wakeup_secondary_cpu[_64]() x86/apic: Use u32 for [gs]et_apic_id() x86/apic: Use u32 for phys_pkg_id() x86/apic: Use u32 for cpu_present_to_apicid() x86/apic: Use u32 for check_apicid_used() x86/apic: Use u32 for APIC IDs in global data x86/apic: Use BAD_APICID consistently x86/cpu: Move cpu_l[l2]c_id into topology info x86/cpu: Move logical package and die IDs into topology info x86/cpu: Remove pointless evaluation of x86_coreid_bits x86/cpu: Move cu_id into topology info x86/cpu: Move cpu_core_id into topology info hwmon: (fam15h_power) Use topology_core_id() scsi: lpfc: Use topology_core_id() x86/cpu: Move cpu_die_id into topology info x86/cpu: Move phys_proc_id into topology info x86/cpu: Encapsulate topology information in cpuinfo_x86 ...
2023-10-30Merge tag 'x86_cpu_for_6.7_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpuid updates from Borislav Petkov: - Make sure the "svm" feature flag is cleared from /proc/cpuinfo when virtualization support is disabled in the BIOS on AMD and Hygon platforms - A minor cleanup * tag 'x86_cpu_for_6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/amd: Remove redundant 'break' statement x86/cpu: Clear SVM feature if disabled by BIOS
2023-10-11x86/cpu: Fix AMD erratum #1485 on Zen4-based CPUsBorislav Petkov (AMD)
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 <rene@exactcode.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: René Rebe <rene@exactcode.de> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/D99589F4-BC5D-430B-87B2-72C20370CF57@exactcode.com
2023-10-10x86/cpu: Move cpu_l[l2]c_id into topology infoThomas Gleixner
The topology IDs which identify the LLC and L2 domains clearly belong to the per CPU topology information. Move them into cpuinfo_x86::cpuinfo_topo and get rid of the extra per CPU data and the related exports. This also paves the way to do proper topology evaluation during early boot because it removes the only per CPU dependency for that. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230814085112.803864641@linutronix.de
2023-10-10x86/cpu: Move cu_id into topology infoThomas Gleixner
No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230814085112.628405546@linutronix.de
2023-10-10x86/cpu: Move cpu_core_id into topology infoThomas Gleixner
Rename it to core_id and stick it to the other ID fields. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230814085112.566519388@linutronix.de
2023-10-10x86/cpu: Move cpu_die_id into topology infoThomas Gleixner
Move the next member. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230814085112.388185134@linutronix.de
2023-10-10x86/cpu: Move phys_proc_id into topology infoThomas Gleixner
Rename it to pkg_id which is the terminology used in the kernel. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230814085112.329006989@linutronix.de
2023-10-10x86/cpu: Encapsulate topology information in cpuinfo_x86Thomas Gleixner
The topology related information is randomly scattered across cpuinfo_x86. Create a new structure cpuinfo_topo and move in a first step initial_apicid and apicid into it. Aside of being better readable this is in preparation for replacing the horribly fragile CPU topology evaluation code further down the road. Consolidate APIC ID fields to u32 as that represents the hardware type. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230814085112.269787744@linutronix.de
2023-09-29x86/cpu/amd: Remove redundant 'break' statementBaolin Liu
This break is after the return statement, so it is redundant & confusing, and should be deleted. Signed-off-by: Baolin Liu <liubaolin@kylinos.cn> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/396ba14d.2726.189d957b74b.Coremail.liubaolin12138@163.com
2023-09-22x86/cpu: Clear SVM feature if disabled by BIOSPaolo Bonzini
When SVM is disabled by BIOS, one cannot use KVM but the SVM feature is still shown in the output of /proc/cpuinfo. On Intel machines, VMX is cleared by init_ia32_feat_ctl(), so do the same on AMD and Hygon processors. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230921114940.957141-1-pbonzini@redhat.com
2023-09-19x86/srso: Don't probe microcode in a guestJosh Poimboeuf
To support live migration, the hypervisor sets the "lowest common denominator" of features. Probing the microcode isn't allowed because any detected features might go away after a migration. As Andy Cooper states: "Linux must not probe microcode when virtualised.  What it may see instantaneously on boot (owing to MSR_PRED_CMD being fully passed through) is not accurate for the lifetime of the VM." Rely on the hypervisor to set the needed IBPB_BRTYPE and SBPB bits. Fixes: 1b5277c0ea0b ("x86/srso: Add SRSO_NO support") Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/3938a7209606c045a3f50305d201d840e8c834c7.1693889988.git.jpoimboe@kernel.org
2023-09-19x86/srso: Set CPUID feature bits independently of bug or mitigation statusJosh Poimboeuf
Booting with mitigations=off incorrectly prevents the X86_FEATURE_{IBPB_BRTYPE,SBPB} CPUID bits from getting set. Also, future CPUs without X86_BUG_SRSO might still have IBPB with branch type prediction flushing, in which case SBPB should be used instead of IBPB. The current code doesn't allow for that. Also, cpu_has_ibpb_brtype_microcode() has some surprising side effects and the setting of these feature bits really doesn't belong in the mitigation code anyway. Move it to earlier. Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/869a1709abfe13b673bdd10c2f4332ca253a40bc.1693889988.git.jpoimboe@kernel.org
2023-08-30Merge tag 'x86_apic_for_6.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Dave Hansen: "This includes a very thorough rework of the 'struct apic' handlers. Quite a variety of them popped up over the years, especially in the 32-bit days when odd apics were much more in vogue. The end result speaks for itself, which is a removal of a ton of code and static calls to replace indirect calls. If there's any breakage here, it's likely to be around the 32-bit museum pieces that get light to no testing these days. Summary: - Rework apic callbacks, getting rid of unnecessary ones and coalescing lots of silly duplicates. - Use static_calls() instead of indirect calls for apic->foo() - Tons of cleanups an crap removal along the way" * tag 'x86_apic_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) x86/apic: Turn on static calls x86/apic: Provide static call infrastructure for APIC callbacks x86/apic: Wrap IPI calls into helper functions x86/apic: Mark all hotpath APIC callback wrappers __always_inline x86/xen/apic: Mark apic __ro_after_init x86/apic: Convert other overrides to apic_update_callback() x86/apic: Replace acpi_wake_cpu_handler_update() and apic_set_eoi_cb() x86/apic: Provide apic_update_callback() x86/xen/apic: Use standard apic driver mechanism for Xen PV x86/apic: Provide common init infrastructure x86/apic: Wrap apic->native_eoi() into a helper x86/apic: Nuke ack_APIC_irq() x86/apic: Remove pointless arguments from [native_]eoi_write() x86/apic/noop: Tidy up the code x86/apic: Remove pointless NULL initializations x86/apic: Sanitize APIC ID range validation x86/apic: Prepare x2APIC for using apic::max_apic_id x86/apic: Simplify X2APIC ID validation x86/apic: Add max_apic_id member x86/apic: Wrap APIC ID validation into an inline ...
2023-08-14x86/CPU/AMD: Fix the DIV(0) initial fix attemptBorislav Petkov (AMD)
Initially, it was thought that doing an innocuous division in the #DE handler would take care to prevent any leaking of old data from the divider but by the time the fault is raised, the speculation has already advanced too far and such data could already have been used by younger operations. Therefore, do the innocuous division on every exit to userspace so that userspace doesn't see any potentially old data from integer divisions in kernel space. Do the same before VMRUN too, to protect host data from leaking into the guest too. Fixes: 77245f1c3c64 ("x86/CPU/AMD: Do not leak quotient data after a division by 0") Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20230811213824.10025-1-bp@alien8.de
2023-08-12Merge tag 'x86_urgent_for_v6.5_rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Do not parse the confidential computing blob on non-AMD hardware as it leads to an EFI config table ending up unmapped - Use the correct segment selector in the 32-bit version of getcpu() in the vDSO - Make sure vDSO and VVAR regions are placed in the 47-bit VA range even on 5-level paging systems - Add models 0x90-0x91 to the range of AMD Zenbleed-affected CPUs * tag 'x86_urgent_for_v6.5_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/amd: Enable Zenbleed fix for AMD Custom APU 0405 x86/mm: Fix VDSO and VVAR placement on 5-level paging machines x86/linkage: Fix typo of BUILD_VDSO in asm/linkage.h x86/vdso: Choose the right GDT_ENTRY_CPUNODE for 32-bit getcpu() on 64-bit kernel x86/sev: Do not try to parse for the CC blob on non-AMD hardware
2023-08-11x86/cpu/amd: Enable Zenbleed fix for AMD Custom APU 0405Cristian Ciocaltea
Commit 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix") provided a fix for the Zen2 VZEROUPPER data corruption bug affecting a range of CPU models, but the AMD Custom APU 0405 found on SteamDeck was not listed, although it is clearly affected by the vulnerability. Add this CPU variant to the Zenbleed erratum list, in order to unconditionally enable the fallback fix until a proper microcode update is available. Fixes: 522b1d69219d ("x86/cpu/amd: Add a Zenbleed fix") Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230811203705.1699914-1-cristian.ciocaltea@collabora.com
2023-08-09x86/apic: Get rid of hard_smp_processor_id()Thomas Gleixner
No point in having a wrapper around read_apic_id(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Sohil Mehta <sohil.mehta@intel.com> Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)
2023-08-09x86/CPU/AMD: Do not leak quotient data after a division by 0Borislav Petkov (AMD)
Under certain circumstances, an integer division by 0 which faults, can leave stale quotient data from a previous division operation on Zen1 microarchitectures. Do a dummy division 0/1 before returning from the #DE exception handler in order to avoid any leaks of potentially sensitive data. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-08-07Merge tag 'x86_bugs_srso' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/srso fixes from Borislav Petkov: "Add a mitigation for the speculative RAS (Return Address Stack) overflow vulnerability on AMD processors. In short, this is yet another issue where userspace poisons a microarchitectural structure which can then be used to leak privileged information through a side channel" * tag 'x86_bugs_srso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/srso: Tie SBPB bit setting to microcode patch detection x86/srso: Add a forgotten NOENDBR annotation x86/srso: Fix return thunks in generated code x86/srso: Add IBPB on VMEXIT x86/srso: Add IBPB x86/srso: Add SRSO_NO support x86/srso: Add IBPB_BRTYPE support x86/srso: Add a Speculative RAS Overflow mitigation x86/bugs: Increase the x86 bugs vector size to two u32s
2023-08-07x86/srso: Tie SBPB bit setting to microcode patch detectionBorislav Petkov (AMD)
The SBPB bit in MSR_IA32_PRED_CMD is supported only after a microcode patch has been applied so set X86_FEATURE_SBPB only then. Otherwise, guests would attempt to set that bit and #GP on the MSR write. While at it, make SMT detection more robust as some guests - depending on how and what CPUID leafs their report - lead to cpu_smt_control getting set to CPU_SMT_NOT_SUPPORTED but SRSO_NO should be set for any guest incarnation where one simply cannot do SMT, for whatever reason. Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation") Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-by: Salvatore Bonaccorso <carnil@debian.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>