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2025-05-02x86/msr: Rename rdpmcl() to rdpmc()Xin Li (Intel)
Now that rdpmc() is gone, rdpmcl() is the sole PMC read helper, simply rename rdpmcl() to rdpmc(). Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250427092027.1598740-5-xin@zytor.com
2025-05-02x86/msr: Remove the unused rdpmc() methodXin Li (Intel)
rdpmc() is not used anywhere anymore, remove it. Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250427092027.1598740-4-xin@zytor.com
2025-05-02x86/msr: Move rdtsc{,_ordered}() to <asm/tsc.h>Xin Li (Intel)
Relocate rdtsc{,_ordered}() from <asm/msr.h> to <asm/tsc.h>. [ mingo: Do not remove the <asm/tsc.h> inclusion from <asm/msr.h> just yet, to reduce -next breakages. We can do this later on, separately, shortly before the next -rc1. ] Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250427092027.1598740-3-xin@zytor.com
2025-05-02x86/msr: Add explicit includes of <asm/msr.h>Xin Li (Intel)
For historic reasons there are some TSC-related functions in the <asm/msr.h> header, even though there's an <asm/tsc.h> header. To facilitate the relocation of rdtsc{,_ordered}() from <asm/msr.h> to <asm/tsc.h> and to eventually eliminate the inclusion of <asm/msr.h> in <asm/tsc.h>, add an explicit <asm/msr.h> dependency to the source files that reference definitions from <asm/msr.h>. [ mingo: Clarified the changelog. ] Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250501054241.1245648-1-xin@zytor.com
2025-05-02x86/msr: Move the EAX_EDX_*() methods from <asm/msr.h> to <asm/asm.h>Ingo Molnar
We are going to use them from multiple headers, and in any case, such register access wrapper macros are better in <asm/asm.h> anyway. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: linux-kernel@vger.kernel.org
2025-05-02x86/msr: Rename DECLARE_ARGS() to EAX_EDX_DECLARE_ARGSIngo Molnar
DECLARE_ARGS() is way too generic of a name that says very little about why these args are declared in that fashion - use the EAX_EDX_ prefix to create a common prefix between the three helper methods: EAX_EDX_DECLARE_ARGS() EAX_EDX_VAL() EAX_EDX_RET() Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: linux-kernel@vger.kernel.org
2025-05-02x86/msr: Improve the comments of the ↵Ingo Molnar
DECLARE_ARGS()/EAX_EDX_VAL()/EAX_EDX_RET() facility Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: linux-kernel@vger.kernel.org
2025-05-02Merge tag 'v6.15-rc4' into x86/msr, to pick up fixes and resolve conflictsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-29x86/bugs: Restructure L1TF mitigationDavid Kaplan
Restructure L1TF to use select/apply functions to create consistent vulnerability handling. Define new AUTO mitigation for L1TF. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/20250418161721.1855190-16-david.kaplan@amd.com
2025-04-26Merge tag 'x86-urgent-2025-04-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 fixes from Ingo Molnar: - Fix 32-bit kernel boot crash if passed physical memory with more than 32 address bits - Fix Xen PV crash - Work around build bug in certain limited build environments - Fix CTEST instruction decoding in insn_decoder_test * tag 'x86-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/insn: Fix CTEST instruction decoding x86/boot: Work around broken busybox 'truncate' tool x86/mm: Fix _pgd_alloc() for Xen PV mode x86/e820: Discard high memory that can't be addressed by 32-bit systems
2025-04-26platform/x86/amd/pmc: Use FCH_PM_BASE definitionMario Limonciello
The s2idle MMIO quirk uses a scratch register in the FCH. Adjust the code to clarify that. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Cc: Yazen Ghannam <yazen.ghannam@amd.com> Cc: platform-driver-x86@vger.kernel.org Link: https://lore.kernel.org/r/20250422234830.2840784-5-superm1@kernel.org
2025-04-26i2c: piix4, x86/platform: Move the SB800 PIIX4 FCH definitions to ↵Mario Limonciello
<asm/amd/fch.h> SB800_PIIX4_FCH_PM_ADDR is used to indicate the base address for the FCH PM registers. Multiple drivers may need this base address, so move related defines to a common header location and rename them accordingly. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andi Shyti <andi.shyti@kernel.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Cc: Jean Delvare <jdelvare@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sanket Goswami <Sanket.Goswami@amd.com> Cc: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Cc: Yazen Ghannam <yazen.ghannam@amd.com> Cc: linux-i2c@vger.kernel.org Link: https://lore.kernel.org/r/20250422234830.2840784-4-superm1@kernel.org
2025-04-25KVM: SEV: Configure "ALLOWED_SEV_FEATURES" VMCB FieldKim Phillips
AMD EPYC 5th generation processors have introduced a feature that allows the hypervisor to control the SEV_FEATURES that are set for, or by, a guest [1]. ALLOWED_SEV_FEATURES can be used by the hypervisor to enforce that SEV-ES and SEV-SNP guests cannot enable features that the hypervisor does not want to be enabled. Always enable ALLOWED_SEV_FEATURES. A VMRUN will fail if any non-reserved bits are 1 in SEV_FEATURES but are 0 in ALLOWED_SEV_FEATURES. Some SEV_FEATURES - currently PmcVirtualization and SecureAvic (see Appendix B, Table B-4) - require an opt-in via ALLOWED_SEV_FEATURES, i.e. are off-by-default, whereas all other features are effectively on-by-default, but still honor ALLOWED_SEV_FEATURES. [1] Section 15.36.20 "Allowed SEV Features", AMD64 Architecture Programmer's Manual, Pub. 24593 Rev. 3.42 - March 2024: https://bugzilla.kernel.org/attachment.cgi?id=306250 Co-developed-by: Kishon Vijay Abraham I <kvijayab@amd.com> Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Signed-off-by: Kim Phillips <kim.phillips@amd.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20250310201603.1217954-3-kim.phillips@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-25x86/cpufeatures: Add "Allowed SEV Features" FeatureKishon Vijay Abraham I
Add CPU feature detection for "Allowed SEV Features" to allow the Hypervisor to enforce that SEV-ES and SEV-SNP guest VMs cannot enable features (via SEV_FEATURES) that the Hypervisor does not support or wish to be enabled. Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Kim Phillips <kim.phillips@amd.com> Link: https://lore.kernel.org/r/20250310201603.1217954-2-kim.phillips@amd.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-25Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "ARM: - Single fix for broken usage of 'multi-MIDR' infrastructure in PI code, adding an open-coded erratum check for everyone's favorite pile of sand: Cavium ThunderX x86: - Bugfixes from a planned posted interrupt rework - Do not use kvm_rip_read() unconditionally to cater for guests with inaccessible register state" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Do not use kvm_rip_read() unconditionally for KVM_PROFILING KVM: x86: Do not use kvm_rip_read() unconditionally in KVM tracepoints KVM: SVM: WARN if an invalid posted interrupt IRTE entry is added iommu/amd: WARN if KVM attempts to set vCPU affinity without posted intrrupts iommu/amd: Return an error if vCPU affinity is set for non-vCPU IRTE KVM: x86: Take irqfds.lock when adding/deleting IRQ bypass producer KVM: x86: Explicitly treat routing entry type changes as changes KVM: x86: Reset IRTE to host control if *new* route isn't postable KVM: SVM: Allocate IR data using atomic allocation KVM: SVM: Don't update IRTEs if APICv/AVIC is disabled KVM: arm64, x86: make kvm_arch_has_irq_bypass() inline arm64: Rework checks for broken Cavium HW in the PI code
2025-04-25Merge branch 'perf/urgent'Peter Zijlstra
Merge urgent fixes for dependencies. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-04-24KVM: SVM: Fix SNP AP destroy race with VMRUNTom Lendacky
An AP destroy request for a target vCPU is typically followed by an RMPADJUST to remove the VMSA attribute from the page currently being used as the VMSA for the target vCPU. This can result in a vCPU that is about to VMRUN to exit with #VMEXIT_INVALID. This usually does not happen as APs are typically sitting in HLT when being destroyed and therefore the vCPU thread is not running at the time. However, if HLT is allowed inside the VM, then the vCPU could be about to VMRUN when the VMSA attribute is removed from the VMSA page, resulting in a #VMEXIT_INVALID when the vCPU actually issues the VMRUN and causing the guest to crash. An RMPADJUST against an in-use (already running) VMSA results in a #NPF for the vCPU issuing the RMPADJUST, so the VMSA attribute cannot be changed until the VMRUN for target vCPU exits. The Qemu command line option '-overcommit cpu-pm=on' is an example of allowing HLT inside the guest. Update the KVM_REQ_UPDATE_PROTECTED_GUEST_STATE event to include the KVM_REQUEST_WAIT flag. The kvm_vcpu_kick() function will not wait for requests to be honored, so create kvm_make_request_and_kick() that will add a new event request and honor the KVM_REQUEST_WAIT flag. This will ensure that the target vCPU sees the AP destroy request before returning to the initiating vCPU should the target vCPU be in guest mode. Fixes: e366f92ea99e ("KVM: SEV: Support SEV-SNP AP Creation NAE event") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/fe2c885bf35643dd224e91294edb6777d5df23a4.1743097196.git.thomas.lendacky@amd.com [sean: add a comment explaining the use of smp_send_reschedule()] Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24x86/irq: KVM: Add helper for harvesting PIR to deduplicate KVM and posted MSIsSean Christopherson
Now that posted MSI and KVM harvesting of PIR is identical, extract the code (and posted MSI's wonderful comment) to a common helper. No functional change intended. Link: https://lore.kernel.org/r/20250401163447.846608-9-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24x86/irq: KVM: Track PIR bitmap as an "unsigned long" arraySean Christopherson
Track the PIR bitmap in posted interrupt descriptor structures as an array of unsigned longs instead of using unionized arrays for KVM (u32s) versus IRQ management (u64s). In practice, because the non-KVM usage is (sanely) restricted to 64-bit kernels, all existing usage of the u64 variant is already working with unsigned longs. Using "unsigned long" for the array will allow reworking KVM's processing of the bitmap to read/write in 64-bit chunks on 64-bit kernels, i.e. will allow optimizing KVM by reducing the number of atomic accesses to PIR. Opportunstically replace the open coded literals in the posted MSIs code with the appropriate macro. Deliberately don't use ARRAY_SIZE() in the for-loops, even though it would be cleaner from a certain perspective, in anticipation of decoupling the processing from the array declaration. No functional change intended. Link: https://lore.kernel.org/r/20250401163447.846608-5-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24KVM: x86: Add module param to control and enumerate device posted IRQsSean Christopherson
Add a module param to each KVM vendor module to allow disabling device posted interrupts without having to sacrifice all of APICv/AVIC, and to also effectively enumerate to userspace whether or not KVM may be utilizing device posted IRQs. Disabling device posted interrupts is very desirable for testing, and can even be desirable for production environments, e.g. if the host kernel wants to interpose on device interrupts. Put the module param in kvm-{amd,intel}.ko instead of kvm.ko to match the overall APICv/AVIC controls, and to avoid complications with said controls. E.g. if the param is in kvm.ko, KVM needs to be snapshot the original user-defined value to play nice with a vendor module being reloaded with different enable_apicv settings. Link: https://lore.kernel.org/r/20250401161804.842968-4-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24KVM: x86: Rescan I/O APIC routes after EOI interception for old routingweizijie
Rescan I/O APIC routes for a vCPU after handling an intercepted I/O APIC EOI for an IRQ that is not targeting said vCPU, i.e. after handling what's effectively a stale EOI VM-Exit. If a level-triggered IRQ is in-flight when IRQ routing changes, e.g. because the guest changes routing from its IRQ handler, then KVM intercepts EOIs on both the new and old target vCPUs, so that the in-flight IRQ can be de-asserted when it's EOI'd. However, only the EOI for the in-flight IRQ needs to be intercepted, as IRQs on the same vector with the new routing are coincidental, i.e. occur only if the guest is reusing the vector for multiple interrupt sources. If the I/O APIC routes aren't rescanned, KVM will unnecessarily intercept EOIs for the vector and negative impact the vCPU's interrupt performance. Note, both commit db2bdcbbbd32 ("KVM: x86: fix edge EOI and IOAPIC reconfig race") and commit 0fc5a36dd6b3 ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race") mentioned this issue, but it was considered a "rare" occurrence thus was not addressed. However in real environments, this issue can happen even in a well-behaved guest. Cc: Kai Huang <kai.huang@intel.com> Co-developed-by: xuyun <xuyun_xy.xy@linux.alibaba.com> Signed-off-by: xuyun <xuyun_xy.xy@linux.alibaba.com> Signed-off-by: weizijie <zijie.wei@linux.alibaba.com> [sean: massage changelog and comments, use int/-1, reset at scan] Reviewed-by: Kai Huang <kai.huang@intel.com> Link: https://lore.kernel.org/r/20250304013335.4155703-4-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24KVM: x86: Advertise support for AMD's PREFETCHIBabu Moger
The latest AMD platform has introduced a new instruction called PREFETCHI. This instruction loads a cache line from a specified memory address into the indicated data or instruction cache level, based on locality reference hints. Feature bit definition: CPUID_Fn80000021_EAX [bit 20] - Indicates support for IC prefetch. This feature is analogous to Intel's PREFETCHITI (CPUID.(EAX=7,ECX=1):EDX), though the CPUID bit definitions differ between AMD and Intel. Advertise support to userspace, as no additional enabling is necessary (PREFETCHI can't be intercepted as there's no instruction specific behavior that needs to be virtualize). The feature is documented in Processor Programming Reference (PPR) for AMD Family 1Ah Model 02h, Revision C1 (Link below). Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Signed-off-by: Babu Moger <babu.moger@amd.com> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/ee1c08fc400bb574a2b8f2c6a0bd9def10a29d35.1744130533.git.babu.moger@amd.com [sean: rewrite shortlog to highlight the KVM functionality] Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24x86/msr: Rename the WRMSRNS opcode macro to ASM_WRMSRNS (for KVM)Sean Christopherson
Rename the WRMSRNS instruction opcode macro so that it doesn't collide with X86_FEATURE_WRMSRNS when using token pasting to generate references to X86_FEATURE_WRMSRNS. KVM heavily uses token pasting to generate KVM's set of support feature bits, and adding WRMSRNS support in KVM will run will run afoul of the opcode macro. arch/x86/kvm/cpuid.c:719:37: error: pasting "X86_FEATURE_" and "" "" does not give a valid preprocessing token 719 | u32 __leaf = __feature_leaf(X86_FEATURE_##name); \ | ^~~~~~~~~~~~ KVM has worked around one such collision in the past by #undef'ing the problematic macro in order to avoid blocking a KVM rework, but such games are generally undesirable, e.g. requires bleeding macro details into KVM, risks weird behavior if what KVM is #undef'ing changes, etc. Reviewed-by: Xin Li (Intel) <xin@zytor.com> Link: https://lore.kernel.org/r/20250227010111.3222742-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24x86/cpufeatures: Define X86_FEATURE_AMD_IBRS_SAME_MODEYosry Ahmed
Per the APM [1]: Some processors, identified by CPUID Fn8000_0008_EBX[IbrsSameMode] (bit 19) = 1, provide additional speculation limits. For these processors, when IBRS is set, indirect branch predictions are not influenced by any prior indirect branches, regardless of mode (CPL and guest/host) and regardless of whether the prior indirect branches occurred before or after the setting of IBRS. This is referred to as Same Mode IBRS. Define this feature bit, which will be used by KVM to determine if an IBPB is required on nested VM-exits in SVM. [1] AMD64 Architecture Programmer's Manual Pub. 40332, Rev 4.08 - April 2024, Volume 2, 3.2.9 Speculation Control MSRs Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev> Reviewed-by: Jim Mattson <jmattson@google.com> Link: https://lore.kernel.org/r/20250221163352.3818347-2-yosry.ahmed@linux.dev Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24Merge branch 'kvm-fixes-6.15-rc4' into HEADPaolo Bonzini
* Single fix for broken usage of 'multi-MIDR' infrastructure in PI code, adding an open-coded erratum check for Cavium ThunderX * Bugfixes from a planned posted interrupt rework * Do not use kvm_rip_read() unconditionally to cater for guests with inaccessible register state.
2025-04-24x86/sev: Share the sev_secrets_pa value againTom Lendacky
This commits breaks SNP guests: 234cf67fc3bd ("x86/sev: Split off startup code from core code") The SNP guest boots, but no longer has access to the VMPCK keys needed to communicate with the ASP, which is used, for example, to obtain an attestation report. The secrets_pa value is defined as static in both startup.c and core.c. It is set by a function in startup.c and so when used in core.c its value will be 0. Share it again and add the sev_ prefix to put it into the global SEV symbols namespace. [ mingo: Renamed to sev_secrets_pa ] Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Cc: Dionna Amalie Glaze <dionnaglaze@google.com> Cc: Kevin Loughlin <kevinloughlin@google.com> Link: https://lore.kernel.org/r/cf878810-81ed-3017-52c6-ce6aa41b5f01@amd.com
2025-04-24KVM: arm64, x86: make kvm_arch_has_irq_bypass() inlinePaolo Bonzini
kvm_arch_has_irq_bypass() is a small function and even though it does not appear in any *really* hot paths, it's also not entirely rare. Make it inline---it also works out nicely in preparation for using it in kvm-intel.ko and kvm-amd.ko, since the function is not currently exported. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-04-23x86/mm: Fix _pgd_alloc() for Xen PV modeJuergen Gross
Recently _pgd_alloc() was switched from using __get_free_pages() to pagetable_alloc_noprof(), which might return a compound page in case the allocation order is larger than 0. On x86 this will be the case if CONFIG_MITIGATION_PAGE_TABLE_ISOLATION is set, even if PTI has been disabled at runtime. When running as a Xen PV guest (this will always disable PTI), using a compound page for a PGD will result in VM_BUG_ON_PGFLAGS being triggered when the Xen code tries to pin the PGD. Fix the Xen issue together with the not needed 8k allocation for a PGD with PTI disabled by replacing PGD_ALLOCATION_ORDER with an inline helper returning the needed order for PGD allocations. Fixes: a9b3c355c2e6 ("asm-generic: pgalloc: provide generic __pgd_{alloc,free}") Reported-by: Petr Vaněk <arkamar@atlas.cz> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Petr Vaněk <arkamar@atlas.cz> Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250422131717.25724-1-jgross%40suse.com
2025-04-22x86/vdso: Remove #ifdeffery around page setup variantsThomas Weißschuh
Replace the open-coded ifdefs in C sources files with IS_ENABLED(). This makes the code easier to read and enables the compiler to typecheck also the disabled parts, before optimizing them away. To make this work, also remove the ifdefs from declarations of used variables. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <kees@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lore.kernel.org/r/20240910-x86-vdso-ifdef-v1-1-877c9df9b081@linutronix.de
2025-04-22x86/asm: Retire RIP_REL_REF()Ard Biesheuvel
Now that all users have been moved into startup/ where PIC codegen is used, RIP_REL_REF() is no longer needed. Remove it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Dionna Amalie Glaze <dionnaglaze@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Loughlin <kevinloughlin@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20250418141253.2601348-14-ardb+git@google.com
2025-04-22x86/boot: Drop RIP_REL_REF() uses from early SEV codeArd Biesheuvel
Now that the early SEV code is built with -fPIC, RIP_REL_REF() has no effect and can be dropped. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Dionna Amalie Glaze <dionnaglaze@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Loughlin <kevinloughlin@google.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20250418141253.2601348-13-ardb+git@google.com
2025-04-22Merge branch 'x86/urgent' into x86/boot, to merge dependent commit and ↵Ingo Molnar
upstream fixes In particular we need this fix before applying subsequent changes: d54d610243a4 ("x86/boot/sev: Avoid shared GHCB page for early memory acceptance") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-22x86/cpu: Help users notice when running old Intel microcodeDave Hansen
Old microcode is bad for users and for kernel developers. For users, it exposes them to known fixed security and/or functional issues. These obviously rarely result in instant dumpster fires in every environment. But it is as important to keep your microcode up to date as it is to keep your kernel up to date. Old microcode also makes kernels harder to debug. A developer looking at an oops need to consider kernel bugs, known CPU issues and unknown CPU issues as possible causes. If they know the microcode is up to date, they can mostly eliminate known CPU issues as the cause. Make it easier to tell if CPU microcode is out of date. Add a list of released microcode. If the loaded microcode is older than the release, tell users in a place that folks can find it: /sys/devices/system/cpu/vulnerabilities/old_microcode Tell kernel kernel developers about it with the existing taint flag: TAINT_CPU_OUT_OF_SPEC == Discussion == When a user reports a potential kernel issue, it is very common to ask them to reproduce the issue on mainline. Running mainline, they will (independently from the distro) acquire a more up-to-date microcode version list. If their microcode is old, they will get a warning about the taint and kernel developers can take that into consideration when debugging. Just like any other entry in "vulnerabilities/", users are free to make their own assessment of their exposure. == Microcode Revision Discussion == The microcode versions in the table were generated from the Intel microcode git repo: 8ac9378a8487 ("microcode-20241112 Release") which as of this writing lags behind the latest microcode-20250211. It can be argued that the versions that the kernel picks to call "old" should be a revision or two old. Which specific version is picked is less important to me than picking *a* version and enforcing it. This repository contains only microcode versions that Intel has deemed to be OS-loadable. It is quite possible that the BIOS has loaded a newer microcode than the latest in this repo. If this happens, the system is considered to have new microcode, not old. Specifically, the sysfs file and taint flag answer the question: Is the CPU running on the latest OS-loadable microcode, or something even later that the BIOS loaded? In other words, Intel never publishes an authoritative list of CPUs and latest microcode revisions. Until it does, this is the best that Linux can do. Also note that the "intel-ucode-defs.h" file is simple, ugly and has lots of magic numbers. That's on purpose and should allow a single file to be shared across lots of stable kernel regardless of if they have the new "VFM" infrastructure or not. It was generated with a dumb script. == FAQ == Q: Does this tell me if my system is secure or insecure? A: No. It only tells you if your microcode was old when the system booted. Q: Should the kernel warn if the microcode list itself is too old? A: No. New kernels will get new microcode lists, both mainline and stable. The only way to have an old list is to be running an old kernel in which case you have bigger problems. Q: Is this for security or functional issues? A: Both. Q: If a given microcode update only has functional problems but no security issues, will it be considered old? A: Yes. All microcode image versions within a microcode release are treated identically. Intel appears to make security updates without disclosing them in the release notes. Thus, all updates are considered to be security-relevant. Q: Who runs old microcode? A: Anybody with an old distro. This happens all the time inside of Intel where there are lots of weird systems in labs that might not be getting regular distro updates and might also be running rather exotic microcode images. Q: If I update my microcode after booting will it stop saying "Vulnerable"? A: No. Just like all the other vulnerabilies, you need to reboot before the kernel will reassess your vulnerability. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: "Ahmed S. Darwish" <darwi@linutronix.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/all/20250421195659.CF426C07%40davehans-spike.ostc.intel.com (cherry picked from commit 9127865b15eb0a1bd05ad7efe29489c44394bdc1)
2025-04-18x86/asm: Rename rep_nop() to native_pause()Uros Bizjak
Rename rep_nop() function to what it really does. No functional change intended. Suggested-by: David Laight <david.laight.linux@gmail.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Link: https://lore.kernel.org/r/20250418080805.83679-1-ubizjak@gmail.com
2025-04-18x86/asm: Replace "REP; NOP" with PAUSE mnemonicUros Bizjak
Current minimum required version of binutils is 2.25, which supports PAUSE instruction mnemonic. Replace "REP; NOP" with this proper mnemonic. No functional change intended. Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Link: https://lore.kernel.org/r/20250418080805.83679-2-ubizjak@gmail.com
2025-04-18x86/asm: Remove semicolon from "rep" prefixesUros Bizjak
Minimum version of binutils required to compile the kernel is 2.25. This version correctly handles the "rep" prefixes, so it is possible to remove the semicolon, which was used to support ancient versions of GNU as. Due to the semicolon, the compiler considers "rep; insn" (or its alternate "rep\n\tinsn" form) as two separate instructions. Removing the semicolon makes asm length calculations more accurate, consequently making scheduling and inlining decisions of the compiler more accurate. Removing the semicolon also enables assembler checks involving "rep" prefixes. Trying to assemble e.g. "rep addl %eax, %ebx" results in: Error: invalid instruction `add' after `rep' Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20250418071437.4144391-2-ubizjak@gmail.com
2025-04-17x86/mm: Remove now unused SHARED_KERNEL_PMDDave Hansen
All the users of SHARED_KERNEL_PMD are gone. Zap it. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/20250414173244.1125BEC3%40davehans-spike.ostc.intel.com
2025-04-17x86/mm: Always tell core mm to sync kernel mappingsDave Hansen
Each mm_struct has its own copy of the page tables. When core mm code makes changes to a copy of the page tables those changes sometimes need to be synchronized with other mms' copies of the page tables. But when this synchronization actually needs to happen is highly architecture and configuration specific. In cases where kernel PMDs are shared across processes (SHARED_KERNEL_PMD) the core mm does not itself need to do that synchronization for kernel PMD changes. The x86 code communicates this by clearing the PGTBL_PMD_MODIFIED bit cleared in those configs to avoid expensive synchronization. The kernel is moving toward never sharing kernel PMDs on 32-bit. Prepare for that and make 32-bit PAE always set PGTBL_PMD_MODIFIED, even if there is no modification to synchronize. This obviously adds some synchronization overhead in cases where the kernel page tables are being changed. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/20250414173237.EC790E95%40davehans-spike.ostc.intel.com
2025-04-17Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-16x86/bugs: Rename mmio_stale_data_clear to cpu_buf_vm_clearPawan Gupta
The static key mmio_stale_data_clear controls the KVM-only mitigation for MMIO Stale Data vulnerability. Rename it to reflect its purpose. No functional change. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250416-mmio-rename-v2-1-ad1f5488767c@linux.intel.com
2025-04-16x86/fpu/apx: Enable APX state supportChang S. Bae
With securing APX against conflicting MPX, it is now ready to be enabled. Include APX in the enabled xfeature set. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250416021720.12305-5-chang.seok.bae@intel.com
2025-04-16x86/fpu/apx: Define APX state componentChang S. Bae
Advanced Performance Extensions (APX) is associated with a new state component number 19. To support saving and restoring of the corresponding registers via the XSAVE mechanism, introduce the component definition along with the necessary sanity checks. Define the new component number, state name, and those register data type. Then, extend the size checker to validate the register data type and explicitly list the APX feature flag as a dependency for the new component in xsave_cpuid_features[]. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250416021720.12305-3-chang.seok.bae@intel.com
2025-04-16x86/cpufeatures: Add X86_FEATURE_APXChang S. Bae
Intel Advanced Performance Extensions (APX) introduce a new set of general-purpose registers, managed as an extended state component via the xstate management facility. Before enabling this new xstate, define a feature flag to clarify the dependency in xsave_cpuid_features[]. APX is enumerated under CPUID level 7 with EDX=1. Since this CPUID leaf is not yet allocated, place the flag in a scattered feature word. While this feature is intended only for userspace, exposing it via /proc/cpuinfo is unnecessary. Instead, the existing arch_prctl(2) mechanism with the ARCH_GET_XCOMP_SUPP option can be used to query the feature availability. Finally, clarify that APX depends on XSAVE. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250416021720.12305-2-chang.seok.bae@intel.com
2025-04-16x86: Make simd.h more resilientHerbert Xu
Add missing header inclusions and protect against double inclusion. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-04-16Merge branch 'x86/cpu' into x86/fpu, to pick up dependent commitsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-16x86/cpu: Add CPU model number for Bartlett Lake CPUs with Raptor Cove coresPi Xiange
Bartlett Lake has a P-core only product with Raptor Cove. [ mingo: Switch around the define as pointed out by Christian Ludloff: Ratpr Cove is the core, Bartlett Lake is the product. Signed-off-by: Pi Xiange <xiange.pi@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Christian Ludloff <ludloff@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: "Ahmed S. Darwish" <darwi@linutronix.de> Cc: x86-cpuid@lists.linux.dev Link: https://lore.kernel.org/r/20250414032839.5368-1-xiange.pi@intel.com
2025-04-16Merge branch 'linus' into x86/cpu, to resolve conflictsIngo Molnar
Conflicts: tools/arch/x86/include/asm/cpufeatures.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-15x86/cpufeatures: Shorten X86_FEATURE_AMD_HETEROGENEOUS_CORESXin Li (Intel)
Shorten X86_FEATURE_AMD_HETEROGENEOUS_CORES to X86_FEATURE_AMD_HTR_CORES to make the last column aligned consistently in the whole file. No functional changes. Suggested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250415175410.2944032-4-xin@zytor.com
2025-04-15x86/cpufeatures: Shorten X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXITXin Li (Intel)
Shorten X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT to X86_FEATURE_CLEAR_BHB_VMEXIT to make the last column aligned consistently in the whole file. There's no need to explain in the name what the mitigation does. No functional changes. Suggested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250415175410.2944032-3-xin@zytor.com
2025-04-15x86/cpufeatures: Clean up formattingBorislav Petkov (AMD)
It is a special file with special formatting so remove one whitespace damage and format newer defines like the rest. No functional changes. [ Xin: Do the same to tools/arch/x86/include/asm/cpufeatures.h. ] Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250415175410.2944032-2-xin@zytor.com