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2026-04-02unwind_user/x86: Fix arch=um buildPeter Zijlstra1-0/+4
commit aa7387e79a5cff0585cd1b9091944142a06872b6 upstream. Add CONFIG_HAVE_UNWIND_USER_FP guards to make sure this code doesn't break arch=um builds. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Closes: https://lore.kernel.org/oe-kbuild-all/202510291919.FFGyU7nq-lkp@intel.com/ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-19KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMMJim Mattson2-1/+3
commit e2ffe85b6d2bb7780174b87aa4468a39be17eb81 upstream. Add KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM to allow L1 to set FREEZE_IN_SMM in vmcs12's GUEST_IA32_DEBUGCTL field, as permitted prior to commit 6b1dd26544d0 ("KVM: VMX: Preserve host's DEBUGCTLMSR_FREEZE_IN_SMM while running the guest"). Enable the quirk by default for backwards compatibility (like all quirks); userspace can disable it via KVM_CAP_DISABLE_QUIRKS2 for consistency with the constraints on WRMSR(IA32_DEBUGCTL). Note that the quirk only bypasses the consistency check. The vmcs02 bit is still owned by the host, and PMCs are not frozen during virtualized SMM. In particular, if a host administrator decides that PMCs should not be frozen during physical SMM, then L1 has no say in the matter. Fixes: 095686e6fcb4 ("KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter") Cc: stable@vger.kernel.org Signed-off-by: Jim Mattson <jmattson@google.com> Link: https://patch.msgid.link/20260205231537.1278753-1-jmattson@google.com [sean: tag for stable@, clean-up and fix goofs in the comment and docs] Signed-off-by: Sean Christopherson <seanjc@google.com> [Rename quirk. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12x86/sev: Allow IBPB-on-Entry feature for SNP guestsKim Phillips1-1/+4
commit 9073428bb204d921ae15326bb7d4558d9d269aab upstream. The SEV-SNP IBPB-on-Entry feature does not require a guest-side implementation. It was added in Zen5 h/w, after the first SNP Zen implementation, and thus was not accounted for when the initial set of SNP features were added to the kernel. In its abundant precaution, commit 8c29f0165405 ("x86/sev: Add SEV-SNP guest feature negotiation support") included SEV_STATUS' IBPB-on-Entry bit as a reserved bit, thereby masking guests from using the feature. Allow guests to make use of IBPB-on-Entry when supported by the hypervisor, as the bit is now architecturally defined and safe to expose. Fixes: 8c29f0165405 ("x86/sev: Add SEV-SNP guest feature negotiation support") Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Nikunj A Dadhania <nikunj@amd.com> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: stable@kernel.org Link: https://patch.msgid.link/20260203222405.4065706-2-kim.phillips@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12x86/efi: defer freeing of boot services memoryMike Rapoport (Microsoft)1-1/+1
commit a4b0bf6a40f3c107c67a24fbc614510ef5719980 upstream. efi_free_boot_services() frees memory occupied by EFI_BOOT_SERVICES_CODE and EFI_BOOT_SERVICES_DATA using memblock_free_late(). There are two issue with that: memblock_free_late() should be used for memory allocated with memblock_alloc() while the memory reserved with memblock_reserve() should be freed with free_reserved_area(). More acutely, with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y efi_free_boot_services() is called before deferred initialization of the memory map is complete. Benjamin Herrenschmidt reports that this causes a leak of ~140MB of RAM on EC2 t3a.nano instances which only have 512MB or RAM. If the freed memory resides in the areas that memory map for them is still uninitialized, they won't be actually freed because memblock_free_late() calls memblock_free_pages() and the latter skips uninitialized pages. Using free_reserved_area() at this point is also problematic because __free_page() accesses the buddy of the freed page and that again might end up in uninitialized part of the memory map. Delaying the entire efi_free_boot_services() could be problematic because in addition to freeing boot services memory it updates efi.memmap without any synchronization and that's undesirable late in boot when there is concurrency. More robust approach is to only defer freeing of the EFI boot services memory. Split efi_free_boot_services() in two. First efi_unmap_boot_services() collects ranges that should be freed into an array then efi_free_boot_services() later frees them after deferred init is complete. Link: https://lore.kernel.org/all/ec2aaef14783869b3be6e3c253b2dcbf67dbc12a.camel@kernel.crashing.org Fixes: 916f676f8dc0 ("x86, efi: Retain boot service code until after switching to virtual mode") Cc: <stable@vger.kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-12KVM: x86: Add x2APIC "features" to control EOI broadcast suppressionKhushit Shah2-2/+11
[ Upstream commit 6517dfbcc918f970a928d9dc17586904bac06893 ] Add two flags for KVM_CAP_X2APIC_API to allow userspace to control support for Suppress EOI Broadcasts when using a split IRQCHIP (I/O APIC emulated by userspace), which KVM completely mishandles. When x2APIC support was first added, KVM incorrectly advertised and "enabled" Suppress EOI Broadcast, without fully supporting the I/O APIC side of the equation, i.e. without adding directed EOI to KVM's in-kernel I/O APIC. That flaw was carried over to split IRQCHIP support, i.e. KVM advertised support for Suppress EOI Broadcasts irrespective of whether or not the userspace I/O APIC implementation supported directed EOIs. Even worse, KVM didn't actually suppress EOI broadcasts, i.e. userspace VMMs without support for directed EOI came to rely on the "spurious" broadcasts. KVM "fixed" the in-kernel I/O APIC implementation by completely disabling support for Suppress EOI Broadcasts in commit 0bcc3fb95b97 ("KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use"), but didn't do anything to remedy userspace I/O APIC implementations. KVM's bogus handling of Suppress EOI Broadcast is problematic when the guest relies on interrupts being masked in the I/O APIC until well after the initial local APIC EOI. E.g. Windows with Credential Guard enabled handles interrupts in the following order: 1. Interrupt for L2 arrives. 2. L1 APIC EOIs the interrupt. 3. L1 resumes L2 and injects the interrupt. 4. L2 EOIs after servicing. 5. L1 performs the I/O APIC EOI. Because KVM EOIs the I/O APIC at step #2, the guest can get an interrupt storm, e.g. if the IRQ line is still asserted and userspace reacts to the EOI by re-injecting the IRQ, because the guest doesn't de-assert the line until step #4, and doesn't expect the interrupt to be re-enabled until step #5. Unfortunately, simply "fixing" the bug isn't an option, as KVM has no way of knowing if the userspace I/O APIC supports directed EOIs, i.e. suppressing EOI broadcasts would result in interrupts being stuck masked in the userspace I/O APIC due to step #5 being ignored by userspace. And fully disabling support for Suppress EOI Broadcast is also undesirable, as picking up the fix would require a guest reboot, *and* more importantly would change the virtual CPU model exposed to the guest without any buy-in from userspace. Add KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST and KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST flags to allow userspace to explicitly enable or disable support for Suppress EOI Broadcasts. This gives userspace control over the virtual CPU model exposed to the guest, as KVM should never have enabled support for Suppress EOI Broadcast without userspace opt-in. Not setting either flag will result in legacy quirky behavior for backward compatibility. Disallow fully enabling SUPPRESS_EOI_BROADCAST when using an in-kernel I/O APIC, as KVM's history/support is just as tragic. E.g. it's not clear that commit c806a6ad35bf ("KVM: x86: call irq notifiers with directed EOI") was entirely correct, i.e. it may have simply papered over the lack of Directed EOI emulation in the I/O APIC. Note, Suppress EOI Broadcasts is defined only in Intel's SDM, not in AMD's APM. But the bit is writable on some AMD CPUs, e.g. Turin, and KVM's ABI is to support Directed EOI (KVM's name) irrespective of guest CPU vendor. Fixes: 7543a635aa09 ("KVM: x86: Add KVM exit for IOAPIC EOIs") Closes: https://lore.kernel.org/kvm/7D497EF1-607D-4D37-98E7-DAF95F099342@nutanix.com Cc: stable@vger.kernel.org Suggested-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Khushit Shah <khushit.shah@nutanix.com> Link: https://patch.msgid.link/20260123125657.3384063-1-khushit.shah@nutanix.com [sean: clean up minor formatting goofs and fix a comment typo] Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-12unwind_user/x86: Teach FP unwind about start of functionPeter Zijlstra2-0/+21
[ Upstream commit ae25884ad749e7f6e0c3565513bdc8aa2554a425 ] When userspace is interrupted at the start of a function, before we get a chance to complete the frame, unwind will miss one caller. X86 has a uprobe specific fixup for this, add bits to the generic unwinder to support this. Suggested-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251024145156.GM4068168@noisy.programming.kicks-ass.net Stable-dep-of: d55c571e4333 ("x86/uprobes: Fix XOL allocation failure for 32-bit tasks") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-12unwind_user/x86: Enable frame pointer unwinding on x86Josh Poimboeuf1-0/+25
[ Upstream commit 49cf34c0815f93fb2ea3ab5cfbac1124bd9b45d0 ] Use ARCH_INIT_USER_FP_FRAME to describe how frame pointers are unwound on x86, and enable CONFIG_HAVE_UNWIND_USER_FP accordingly so the unwind_user interfaces can be used. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20250827193828.347397433@kernel.org Stable-dep-of: d55c571e4333 ("x86/uprobes: Fix XOL allocation failure for 32-bit tasks") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-12x86/cfi: Fix CFI rewrite for odd alignmentsPeter Zijlstra2-6/+10
[ Upstream commit 24c8147abb39618d74fcc36e325765e8fe7bdd7a ] Rustam reported his clang builds did not boot properly; turns out his .config has: CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y set. Fix up the FineIBT code to deal with this unusual alignment. Fixes: 931ab63664f0 ("x86/ibt: Implement FineIBT") Reported-by: Rustam Kovhaev <rkovhaev@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Rustam Kovhaev <rkovhaev@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-27x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs pathJiri Olsa1-1/+1
[ Upstream commit aea251799998aa1b78eacdfb308f18ea114ea5b3 ] Mahe reported missing function from stack trace on top of kprobe multi program. The missing function is the very first one in the stacktrace, the one that the bpf program is attached to. # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}' Attaching 1 probe... do_syscall_64+134 entry_SYSCALL_64_after_hwframe+118 ('*' is used for kprobe_multi attachment) The reason is that the previous change (the Fixes commit) fixed stack unwind for tracepoint, but removed attached function address from the stack trace on top of kprobe multi programs, which I also overlooked in the related test (check following patch). The tracepoint and kprobe_multi have different stack setup, but use same unwind path. I think it's better to keep the previous change, which fixed tracepoint unwind and instead change the kprobe multi unwind as explained below. The bpf program stack unwind calls perf_callchain_kernel for kernel portion and it follows two unwind paths based on X86_EFLAGS_FIXED bit in pt_regs.flags. When the bit set we unwind from stack represented by pt_regs argument, otherwise we unwind currently executed stack up to 'first_frame' boundary. The 'first_frame' value is taken from regs.rsp value, but ftrace_caller and ftrace_regs_caller (ftrace trampoline) functions set the regs.rsp to the previous stack frame, so we skip the attached function entry. If we switch kprobe_multi unwind to use the X86_EFLAGS_FIXED bit, we set the start of the unwind to the attached function address. As another benefit we also cut extra unwind cycles needed to reach the 'first_frame' boundary. The speedup can be measured with trigger bench for kprobe_multi program and stacktrace support. - trigger bench with stacktrace on current code: kprobe-multi : 0.810 ± 0.001M/s kretprobe-multi: 0.808 ± 0.001M/s - and with the fix: kprobe-multi : 1.264 ± 0.001M/s kretprobe-multi: 1.401 ± 0.002M/s With the fix, the entry probe stacktrace: # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}' Attaching 1 probe... __x64_sys_newuname+9 do_syscall_64+134 entry_SYSCALL_64_after_hwframe+118 The return probe skips the attached function, because it's no longer on the stack at the point of the unwind and this way is the same how standard kretprobe works. # bpftrace -e 'kretprobe:__x64_sys_newuname* { print(kstack)}' Attaching 1 probe... do_syscall_64+134 entry_SYSCALL_64_after_hwframe+118 Fixes: 6d08340d1e35 ("Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"") Reported-by: Mahe Tardy <mahe.tardy@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/bpf/20260126211837.472802-3-jolsa@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-11x86/kfence: fix booting on 32bit non-PAE systemsAndrew Cooper1-3/+4
commit 16459fe7e0ca6520a6e8f603de4ccd52b90fd765 upstream. The original patch inverted the PTE unconditionally to avoid L1TF-vulnerable PTEs, but Linux doesn't make this adjustment in 2-level paging. Adjust the logic to use the flip_protnone_guard() helper, which is a nop on 2-level paging but inverts the address bits in all other paging modes. This doesn't matter for the Xen aspect of the original change. Linux no longer supports running 32bit PV under Xen, and Xen doesn't support running any 32bit PV guests without using PAE paging. Link: https://lkml.kernel.org/r/20260126211046.2096622-1-andrew.cooper3@citrix.com Fixes: b505f1944535 ("x86/kfence: avoid writing L1TF-vulnerable PTEs") Reported-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Closes: https://lore.kernel.org/lkml/CAKFNMokwjw68ubYQM9WkzOuH51wLznHpEOMSqtMoV1Rn9JV_gw@mail.gmail.com/ Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-11x86/vmware: Fix hypercall clobbersJosh Poimboeuf1-2/+2
commit 2687c848e57820651b9f69d30c4710f4219f7dbf upstream. Fedora QA reported the following panic: BUG: unable to handle page fault for address: 0000000040003e54 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20251119-3.fc43 11/19/2025 RIP: 0010:vmware_hypercall4.constprop.0+0x52/0x90 .. Call Trace: vmmouse_report_events+0x13e/0x1b0 psmouse_handle_byte+0x15/0x60 ps2_interrupt+0x8a/0xd0 ... because the QEMU VMware mouse emulation is buggy, and clears the top 32 bits of %rdi that the kernel kept a pointer in. The QEMU vmmouse driver saves and restores the register state in a "uint32_t data[6];" and as a result restores the state with the high bits all cleared. RDI originally contained the value of a valid kernel stack address (0xff5eeb3240003e54). After the vmware hypercall it now contains 0x40003e54, and we get a page fault as a result when it is dereferenced. The proper fix would be in QEMU, but this works around the issue in the kernel to keep old setups working, when old kernels had not happened to keep any state in %rdi over the hypercall. In theory this same issue exists for all the hypercalls in the vmmouse driver; in practice it has only been seen with vmware_hypercall3() and vmware_hypercall4(). For now, just mark RDI/RSI as clobbered for those two calls. This should have a minimal effect on code generation overall as it should be rare for the compiler to want to make RDI/RSI live across hypercalls. Reported-by: Justin Forbes <jforbes@fedoraproject.org> Link: https://lore.kernel.org/all/99a9c69a-fc1a-43b7-8d1e-c42d6493b41f@broadcom.com/ Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-30x86/kfence: avoid writing L1TF-vulnerable PTEsAndrew Cooper1-5/+24
commit b505f1944535f83d369ae68813e7634d11b990d3 upstream. For native, the choice of PTE is fine. There's real memory backing the non-present PTE. However, for XenPV, Xen complains: (XEN) d1 L1TF-vulnerable L1e 8010000018200066 - Shadowing To explain, some background on XenPV pagetables: Xen PV guests are control their own pagetables; they choose the new PTE value, and use hypercalls to make changes so Xen can audit for safety. In addition to a regular reference count, Xen also maintains a type reference count. e.g. SegDesc (referenced by vGDT/vLDT), Writable (referenced with _PAGE_RW) or L{1..4} (referenced by vCR3 or a lower pagetable level). This is in order to prevent e.g. a page being inserted into the pagetables for which the guest has a writable mapping. For non-present mappings, all other bits become software accessible, and typically contain metadata rather a real frame address. There is nothing that a reference count could sensibly be tied to. As such, even if Xen could recognise the address as currently safe, nothing would prevent that frame from changing owner to another VM in the future. When Xen detects a PV guest writing a L1TF-PTE, it responds by activating shadow paging. This is normally only used for the live phase of migration, and comes with a reasonable overhead. KFENCE only cares about getting #PF to catch wild accesses; it doesn't care about the value for non-present mappings. Use a fully inverted PTE, to avoid hitting the slow path when running under Xen. While adjusting the logic, take the opportunity to skip all actions if the PTE is already in the right state, half the number PVOps callouts, and skip TLB maintenance on a !P -> P transition which benefits non-Xen cases too. Link: https://lkml.kernel.org/r/20260106180426.710013-1-andrew.cooper3@citrix.com Fixes: 1dc0da6e9ec0 ("x86, kfence: enable KFENCE for x86") Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Tested-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-02KVM: TDX: Explicitly set user-return MSRs that *may* be clobbered by the ↵Sean Christopherson1-1/+0
TDX-Module commit c0711f8c610e1634ed54fb04da1e82252730306a upstream. Set all user-return MSRs to their post-TD-exit value when preparing to run a TDX vCPU to ensure the value that KVM expects to be loaded after running the vCPU is indeed the value that's loaded in hardware. If the TDX-Module doesn't actually enter the guest, i.e. doesn't do VM-Enter, then it won't "restore" VMM state, i.e. won't clobber user-return MSRs to their expected post-run values, in which case simply updating KVM's "cached" value will effectively corrupt the cache due to hardware still holding the original value. In theory, KVM could conditionally update the current user-return value if and only if tdh_vp_enter() succeeds, but in practice "success" doesn't guarantee the TDX-Module actually entered the guest, e.g. if the TDX-Module synthesizes an EPT Violation because it suspects a zero-step attack. Force-load the expected values instead of trying to decipher whether or not the TDX-Module restored/clobbered MSRs, as the risk doesn't justify the benefits. Effectively avoiding four WRMSRs once per run loop (even if the vCPU is scheduled out, user-return MSRs only need to be reloaded if the CPU exits to userspace or runs a non-TDX vCPU) is likely in the noise when amortized over all entries, given the cost of running a TDX vCPU. E.g. the cost of the WRMSRs is somewhere between ~300 and ~500 cycles, whereas the cost of a _single_ roundtrip to/from a TDX guest is thousands of cycles. Fixes: e0b4f31a3c65 ("KVM: TDX: restore user ret MSRs") Cc: stable@vger.kernel.org Cc: Yan Zhao <yan.y.zhao@intel.com> Cc: Xiaoyao Li <xiaoyao.li@intel.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://patch.msgid.link/20251030191528.3380553-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-02x86/msi: Make irq_retrigger() functional for posted MSIThomas Gleixner1-0/+7
commit 0edc78b82bea85e1b2165d8e870a5c3535919695 upstream. Luigi reported that retriggering a posted MSI interrupt does not work correctly. The reason is that the retrigger happens at the vector domain by sending an IPI to the actual vector on the target CPU. That works correctly exactly once because the posted MSI interrupt chip does not issue an EOI as that's only required for the posted MSI notification vector itself. As a consequence the vector becomes stale in the ISR, which not only affects this vector but also any lower priority vector in the affected APIC because the ISR bit is not cleared. Luigi proposed to set the vector in the remap PIR bitmap and raise the posted MSI notification vector. That works, but that still does not cure a related problem: If there is ever a stray interrupt on such a vector, then the related APIC ISR bit becomes stale due to the lack of EOI as described above. Unlikely to happen, but if it happens it's not debuggable at all. So instead of playing games with the PIR, this can be actually solved for both cases by: 1) Keeping track of the posted interrupt vector handler state 2) Implementing a posted MSI specific irq_ack() callback which checks that state. If the posted vector handler is inactive it issues an EOI, otherwise it delegates that to the posted handler. This is correct versus affinity changes and concurrent events on the posted vector as the actual handler invocation is serialized through the interrupt descriptor lock. Fixes: ed1e48ea4370 ("iommu/vt-d: Enable posted mode for device MSIs") Reported-by: Luigi Rizzo <lrizzo@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Luigi Rizzo <lrizzo@google.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251125214631.044440658@linutronix.de Closes: https://lore.kernel.org/lkml/20251124104836.3685533-1-lrizzo@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-02x86/bug: Fix old GCC compile failsPeter Zijlstra1-1/+1
commit c56a12c71ad38f381105f6e5036dede64ad2dfee upstream. For some mysterious reasons the GCC 8 and 9 preprocessor manages to sporadically fumble _ASM_BYTES(0x0f, 0x0b): $ grep ".byte[ ]*0x0f" defconfig-build/drivers/net/wireless/realtek/rtlwifi/base.s 1: .byte0x0f,0x0b ; 1: .byte 0x0f,0x0b ; which makes the assembler upset and all that. While there are more _ASM_BYTES() users (notably the NOP instructions), those don't seem affected. Therefore replace the offending ASM_UD2 with one using the ud2 mnemonic. Reported-by: Jean Delvare <jdelvare@suse.de> Suggested-by: Uros Bizjak <ubizjak@gmail.com> Fixes: 85a2d4a890dc ("x86,ibt: Use UDB instead of 0xEA") Cc: stable@kernel.org Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251218104659.GT3911114@noisy.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-02x86/ptrace: Always inline trivial accessorsPeter Zijlstra1-10/+10
[ Upstream commit 1fe4002cf7f23d70c79bda429ca2a9423ebcfdfa ] A KASAN build bloats these single load/store helpers such that it fails to inline them: vmlinux.o: error: objtool: irqentry_exit+0x5e8: call to instruction_pointer_set() with UACCESS enabled Make sure the compiler isn't allowed to do stupid. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://patch.msgid.link/20251031105435.GU4068168@noisy.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-12KVM: SVM: Don't skip unrelated instruction if INT3/INTO is replacedOmar Sandoval1-0/+9
commit 4da3768e1820cf15cced390242d8789aed34f54d upstream. When re-injecting a soft interrupt from an INT3, INT0, or (select) INTn instruction, discard the exception and retry the instruction if the code stream is changed (e.g. by a different vCPU) between when the CPU executes the instruction and when KVM decodes the instruction to get the next RIP. As effectively predicted by commit 6ef88d6e36c2 ("KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction"), failure to verify that the correct INTn instruction was decoded can effectively clobber guest state due to decoding the wrong instruction and thus specifying the wrong next RIP. The bug most often manifests as "Oops: int3" panics on static branch checks in Linux guests. Enabling or disabling a static branch in Linux uses the kernel's "text poke" code patching mechanism. To modify code while other CPUs may be executing that code, Linux (temporarily) replaces the first byte of the original instruction with an int3 (opcode 0xcc), then patches in the new code stream except for the first byte, and finally replaces the int3 with the first byte of the new code stream. If a CPU hits the int3, i.e. executes the code while it's being modified, then the guest kernel must look up the RIP to determine how to handle the #BP, e.g. by emulating the new instruction. If the RIP is incorrect, then this lookup fails and the guest kernel panics. The bug reproduces almost instantly by hacking the guest kernel to repeatedly check a static branch[1] while running a drgn script[2] on the host to constantly swap out the memory containing the guest's TSS. [1]: https://gist.github.com/osandov/44d17c51c28c0ac998ea0334edf90b5a [2]: https://gist.github.com/osandov/10e45e45afa29b11e0c7209247afc00b Fixes: 6ef88d6e36c2 ("KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction") Cc: stable@vger.kernel.org Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Link: https://patch.msgid.link/1cc6dcdf36e3add7ee7c8d90ad58414eeb6c3d34.1762278762.git.osandov@fb.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-15Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds1-0/+5
Pull bpf fixes from Alexei Starovoitov: - Fix interaction between livepatch and BPF fexit programs (Song Liu) With Steven and Masami acks. - Fix stack ORC unwind from BPF kprobe_multi (Jiri Olsa) With Steven and Masami acks. - Fix out of bounds access in widen_imprecise_scalars() in the verifier (Eduard Zingerman) - Fix conflicts between MPTCP and BPF sockmap (Jiayuan Chen) - Fix net_sched storage collision with BPF data_meta/data_end (Eric Dumazet) - Add _impl suffix to BPF kfuncs with implicit args to avoid breaking them in bpf-next when KF_IMPLICIT_ARGS is added (Mykyta Yatsenko) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: Test widen_imprecise_scalars() with different stack depth bpf: account for current allocated stack depth in widen_imprecise_scalars() bpf: Add bpf_prog_run_data_pointers() selftests/bpf: Add mptcp test with sockmap mptcp: Fix proto fallback detection with BPF mptcp: Disallow MPTCP subflows from sockmap selftests/bpf: Add stacktrace ips test for raw_tp selftests/bpf: Add stacktrace ips test for kprobe_multi/kretprobe_multi x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()" bpf: add _impl suffix for bpf_stream_vprintk() kfunc bpf:add _impl suffix for bpf_task_work_schedule* kfuncs selftests/bpf: Add tests for livepatch + bpf trampoline ftrace: bpf: Fix IPMODIFY + DIRECT in modify_ftrace_direct() ftrace: Fix BPF fexit with livepatch
2025-11-10Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+1
Pull kvm fixes from Paolo Bonzini: "Arm: - Fix trapping regression when no in-kernel irqchip is present - Check host-provided, untrusted ranges and offsets in pKVM - Fix regression restoring the ID_PFR1_EL1 register - Fix vgic ITS locking issues when LPIs are not directly injected Arm selftests: - Correct target CPU programming in vgic_lpi_stress selftest - Fix exposure of SCTLR2_EL2 and ZCR_EL2 in get-reg-list selftest RISC-V: - Fix check for local interrupts on riscv32 - Read HGEIP CSR on the correct cpu when checking for IMSIC interrupts - Remove automatic I/O mapping from kvm_arch_prepare_memory_region() x86: - Inject #UD if the guest attempts to execute SEAMCALL or TDCALL as KVM doesn't support virtualization the instructions, but the instructions are gated only by VMXON. That is, they will VM-Exit instead of taking a #UD and until now this resulted in KVM exiting to userspace with an emulation error. - Unload the "FPU" when emulating INIT of XSTATE features if and only if the FPU is actually loaded, instead of trying to predict when KVM will emulate an INIT (CET support missed the MP_STATE path). Add sanity checks to detect and harden against similar bugs in the future. - Unregister KVM's GALog notifier (for AVIC) when kvm-amd.ko is unloaded. - Use a raw spinlock for svm->ir_list_lock as the lock is taken during schedule(), and "normal" spinlocks are sleepable locks when PREEMPT_RT=y. - Remove guest_memfd bindings on memslot deletion when a gmem file is dying to fix a use-after-free race found by syzkaller. - Fix a goof in the EPT Violation handler where KVM checks the wrong variable when determining if the reported GVA is valid. - Fix and simplify the handling of LBR virtualization on AMD, which was made buggy and unnecessarily complicated by nested VM support Misc: - Update Oliver's email address" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits) KVM: nSVM: Fix and simplify LBR virtualization handling with nested KVM: nSVM: Always recalculate LBR MSR intercepts in svm_update_lbrv() KVM: SVM: Mark VMCB_LBR dirty when MSR_IA32_DEBUGCTLMSR is updated MAINTAINERS: Switch myself to using kernel.org address KVM: arm64: vgic-v3: Release reserved slot outside of lpi_xa's lock KVM: arm64: vgic-v3: Reinstate IRQ lock ordering for LPI xarray KVM: arm64: Limit clearing of ID_{AA64PFR0,PFR1}_EL1.GIC to userspace irqchip KVM: arm64: Set ID_{AA64PFR0,PFR1}_EL1.GIC when GICv3 is configured KVM: arm64: Make all 32bit ID registers fully writable KVM: VMX: Fix check for valid GVA on an EPT violation KVM: guest_memfd: Remove bindings on memslot deletion when gmem is dying KVM: SVM: switch to raw spinlock for svm->ir_list_lock KVM: SVM: Make avic_ga_log_notifier() local to avic.c KVM: SVM: Unregister KVM's GALog notifier on kvm-amd.ko exit KVM: SVM: Initialize per-CPU svm_data at the end of hardware setup KVM: x86: Call out MSR_IA32_S_CET is not handled by XSAVES KVM: x86: Harden KVM against imbalanced load/put of guest FPU state KVM: x86: Unload "FPU" state on INIT if and only if its currently in-use KVM: arm64: Check the untrusted offset in FF-A memory share KVM: arm64: Check range args for pKVM mem transitions ...
2025-11-09Merge tag 'kvm-x86-fixes-6.18-rc5' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-0/+1
KVM x86 fixes for 6.18: - Inject #UD if the guest attempts to execute SEAMCALL or TDCALL as KVM doesn't support virtualization the instructions, but the instructions are gated only by VMXON, i.e. will VM-Exit instead of taking a #UD and thus result in KVM exiting to userspace with an emulation error. - Unload the "FPU" when emulating INIT of XSTATE features if and only if the FPU is actually loaded, instead of trying to predict when KVM will emulate an INIT (CET support missed the MP_STATE path). Add sanity checks to detect and harden against similar bugs in the future. - Unregister KVM's GALog notifier (for AVIC) when kvm-amd.ko is unloaded. - Use a raw spinlock for svm->ir_list_lock as the lock is taken during schedule(), and "normal" spinlocks are sleepable locks when PREEMPT_RT=y. - Remove guest_memfd bindings on memslot deletion when a gmem file is dying to fix a use-after-free race found by syzkaller. - Fix a goof in the EPT Violation handler where KVM checks the wrong variable when determining if the reported GVA is valid.
2025-11-08Merge tag 'x86-urgent-2025-11-08' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: - Fix AMD PCI root device caching regression that triggers on certain firmware variants - Fix the zen5_rdseed_microcode[] array to be NULL-terminated - Add more AMD models to microcode signature checking * tag 'x86-urgent-2025-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode/AMD: Add more known models to entry sign checking x86/CPU/AMD: Add missing terminator for zen5_rdseed_microcode x86/amd_node: Fix AMD root device caching
2025-11-06x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probeJiri Olsa1-0/+5
Currently we don't get stack trace via ORC unwinder on top of fgraph exit handler. We can see that when generating stacktrace from kretprobe_multi bpf program which is based on fprobe/fgraph. The reason is that the ORC unwind code won't get pass the return_to_handler callback installed by fgraph return probe machinery. Solving this by creating stack frame in return_to_handler expected by ftrace_graph_ret_addr function to recover original return address and continue with the unwind. Also updating the pt_regs data with cs/flags/rsp which are needed for successful stack retrieval from ebpf bpf_get_stackid helper. - in get_perf_callchain we check user_mode(regs) so CS has to be set - in perf_callchain_kernel we call perf_hw_regs(regs), so EFLAGS/FIXED has to be unset Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20251104215405.168643-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-11-05x86: uaccess: don't use runtime-const rewriting in modulesLinus Torvalds2-5/+9
The runtime-const infrastructure was never designed to handle the modular case, because the constant fixup is only done at boot time for core kernel code. But by the time I used it for the x86-64 user space limit handling in commit 86e6b1547b3d ("x86: fix user address masking non-canonical speculation issue"), I had completely repressed that fact. And it all happens to work because the only code that currently actually gets inlined by modules is for the access_ok() limit check, where the default constant value works even when not fixed up. Because at least I had intentionally made it be something that is in the non-canonical address space region. But it's technically very wrong, and it does mean that at least in theory, the use of 'access_ok()' + '__get_user()' can trigger the same speculation issue with non-canonical addresses that the original commit was all about. The pattern is unusual enough that this probably doesn't matter in practice, but very wrong is still very wrong. Also, let's fix it before the nice optimized scoped user accessor helpers that Thomas Gleixner is working on cause this pseudo-constant to then be more widely used. This all came up due to an unrelated discussion with Mateusz Guzik about using the runtime const infrastructure for names_cachep accesses too. There the modular case was much more obviously broken, and Mateusz noted it in his 'v2' of the patch series. That then made me notice how broken 'access_ok()' had been in modules all along. Mea culpa, mea maxima culpa. Fix it by simply not using the runtime-const code in modules, and just using the USER_PTR_MAX variable value instead. This is not performance-critical like the core user accessor functions (get_user() and friends) are. Also make sure this doesn't get forgotten the next time somebody wants to do runtime constant optimizations by having the x86 runtime-const.h header file error out if included by modules. Fixes: 86e6b1547b3d ("x86: fix user address masking non-canonical speculation issue") Acked-by: Borislav Petkov <bp@alien8.de> Acked-by: Sean Christopherson <seanjc@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Triggered-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/all/20251030105242.801528-1-mjguzik@gmail.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-11-03x86/amd_node: Fix AMD root device cachingYazen Ghannam1-1/+0
Recent AMD node rework removed the "search and count" method of caching AMD root devices. This depended on the value from a Data Fabric register that was expected to hold the PCI bus of one of the root devices attached to that fabric. However, this expectation is incorrect. The register, when read from PCI config space, returns the bitwise-OR of the buses of all attached root devices. This behavior is benign on AMD reference design boards, since the bus numbers are aligned. This results in a bitwise-OR value matching one of the buses. For example, 0x00 | 0x40 | 0xA0 | 0xE0 = 0xE0. This behavior breaks on boards where the bus numbers are not exactly aligned. For example, 0x00 | 0x07 | 0xE0 | 0x15 = 0x1F. The examples above are for AMD node 0. The first root device on other nodes will not be 0x00. The first root device for other nodes will depend on the total number of root devices, the system topology, and the specific PCI bus number assignment. For example, a system with 2 AMD nodes could have this: Node 0 : 0x00 0x07 0x0e 0x15 Node 1 : 0x1c 0x23 0x2a 0x31 The bus numbering style in the reference boards is not a requirement. The numbering found in other boards is not incorrect. Therefore, the root device caching method needs to be adjusted. Go back to the "search and count" method used before the recent rework. Search for root devices using PCI class code rather than fixed PCI IDs. This keeps the goal of the rework (remove dependency on PCI IDs) while being able to support various board designs. Merge helper functions to reduce code duplication. [ bp: Reflow comment. ] Fixes: 40a5f6ffdfc8 ("x86/amd_nb: Simplify root device search") Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/all/20251028-fix-amd-root-v2-1-843e38f8be2c@amd.com
2025-11-01x86/mm: Ensure clear_page() variants always have __kcfi_typeid_ symbolsNathan Chancellor1-0/+3
When building with CONFIG_CFI=y and CONFIG_LTO_CLANG_FULL=y, there is a series of errors from the various versions of clear_page() not having __kcfi_typeid_ symbols. $ cat kernel/configs/repro.config CONFIG_CFI=y # CONFIG_LTO_NONE is not set CONFIG_LTO_CLANG_FULL=y $ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 clean defconfig repro.config bzImage ld.lld: error: undefined symbol: __kcfi_typeid_clear_page_rep >>> referenced by ld-temp.o >>> vmlinux.o:(__cfi_clear_page_rep) ld.lld: error: undefined symbol: __kcfi_typeid_clear_page_orig >>> referenced by ld-temp.o >>> vmlinux.o:(__cfi_clear_page_orig) ld.lld: error: undefined symbol: __kcfi_typeid_clear_page_erms >>> referenced by ld-temp.o >>> vmlinux.o:(__cfi_clear_page_erms) With full LTO, it is possible for LLVM to realize that these functions never have their address taken (as they are only used within an alternative, which will make them a direct call) across the whole kernel and either drop or skip generating their kCFI type identification symbols. clear_page_{rep,orig,erms}() are defined in clear_page_64.S with SYM_TYPED_FUNC_START as a result of 2981557cb040 ("x86,kcfi: Fix EXPORT_SYMBOL vs kCFI"), as exported functions are free to be called indirectly thus need kCFI type identifiers. Use KCFI_REFERENCE with these clear_page() functions to force LLVM to see these functions as address-taken and generate then keep the kCFI type identifiers. Fixes: 2981557cb040 ("x86,kcfi: Fix EXPORT_SYMBOL vs kCFI") Closes: https://github.com/ClangBuiltLinux/linux/issues/2128 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://patch.msgid.link/20251013-x86-fix-clear_page-cfi-full-lto-errors-v1-1-d69534c0be61@kernel.org
2025-10-30x86/cpu: Add/fix core comments for {Panther,Nova} LakeTony Luck1-3/+3
The E-core in Panther Lake is Darkmont, not Crestmont. Nova Lake is built from Coyote Cove (P-core) and Arctic Wolf (E-core). Fixes: 43bb700cff6b ("x86/cpu: Update Intel Family comments") Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://patch.msgid.link/20251028172948.6721-1-tony.luck@intel.com
2025-10-20KVM: VMX: Inject #UD if guest tries to execute SEAMCALL or TDCALLSean Christopherson1-0/+1
Add VMX exit handlers for SEAMCALL and TDCALL to inject a #UD if a non-TD guest attempts to execute SEAMCALL or TDCALL. Neither SEAMCALL nor TDCALL is gated by any software enablement other than VMXON, and so will generate a VM-Exit instead of e.g. a native #UD when executed from the guest kernel. Note! No unprivileged DoS of the L1 kernel is possible as TDCALL and SEAMCALL #GP at CPL > 0, and the CPL check is performed prior to the VMX non-root (VM-Exit) check, i.e. userspace can't crash the VM. And for a nested guest, KVM forwards unknown exits to L1, i.e. an L2 kernel can crash itself, but not L1. Note #2! The Intel® Trust Domain CPU Architectural Extensions spec's pseudocode shows the CPL > 0 check for SEAMCALL coming _after_ the VM-Exit, but that appears to be a documentation bug (likely because the CPL > 0 check was incorrectly bundled with other lower-priority #GP checks). Testing on SPR and EMR shows that the CPL > 0 check is performed before the VMX non-root check, i.e. SEAMCALL #GPs when executed in usermode. Note #3! The aforementioned Trust Domain spec uses confusing pseudocode that says that SEAMCALL will #UD if executed "inSEAM", but "inSEAM" specifically means in SEAM Root Mode, i.e. in the TDX-Module. The long- form description explicitly states that SEAMCALL generates an exit when executed in "SEAM VMX non-root operation". But that's a moot point as the TDX-Module injects #UD if the guest attempts to execute SEAMCALL, as documented in the "Unconditionally Blocked Instructions" section of the TDX-Module base specification. Cc: stable@vger.kernel.org Cc: Kai Huang <kai.huang@intel.com> Cc: Xiaoyao Li <xiaoyao.li@intel.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Kai Huang <kai.huang@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20251016182148.69085-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-10-11Merge tag 'x86_core_for_v6.18_rc1' of ↵Linus Torvalds6-127/+72
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 updates from Borislav Petkov: - Remove a bunch of asm implementing condition flags testing in KVM's emulator in favor of int3_emulate_jcc() which is written in C - Replace KVM fastops with C-based stubs which avoids problems with the fastop infra related to latter not adhering to the C ABI due to their special calling convention and, more importantly, bypassing compiler control-flow integrity checking because they're written in asm - Remove wrongly used static branches and other ugliness accumulated over time in hyperv's hypercall implementation with a proper static function call to the correct hypervisor call variant - Add some fixes and modifications to allow running FRED-enabled kernels in KVM even on non-FRED hardware - Add kCFI improvements like validating indirect calls and prepare for enabling kCFI with GCC. Add cmdline params documentation and other code cleanups - Use the single-byte 0xd6 insn as the official #UD single-byte undefined opcode instruction as agreed upon by both x86 vendors - Other smaller cleanups and touchups all over the place * tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86,retpoline: Optimize patch_retpoline() x86,ibt: Use UDB instead of 0xEA x86/cfi: Remove __noinitretpoline and __noretpoline x86/cfi: Add "debug" option to "cfi=" bootparam x86/cfi: Standardize on common "CFI:" prefix for CFI reports x86/cfi: Document the "cfi=" bootparam options x86/traps: Clarify KCFI instruction layout compiler_types.h: Move __nocfi out of compiler-specific header objtool: Validate kCFI calls x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware x86/fred: Install system vector handlers even if FRED isn't fully enabled x86/hyperv: Use direct call to hypercall-page x86/hyperv: Clean up hv_do_hypercall() KVM: x86: Remove fastops KVM: x86: Convert em_salc() to C KVM: x86: Introduce EM_ASM_3WCL KVM: x86: Introduce EM_ASM_1SRC2 KVM: x86: Introduce EM_ASM_2CL KVM: x86: Introduce EM_ASM_2W ...
2025-10-11Merge tag 'x86_cleanups_for_v6.18_rc1' of ↵Linus Torvalds14-109/+32
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: - Simplify inline asm flag output operands now that the minimum compiler version supports the =@ccCOND syntax - Remove a bunch of AS_* Kconfig symbols which detect assembler support for various instruction mnemonics now that the minimum assembler version supports them all - The usual cleanups all over the place * tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__ x86/sgx: Use ENCLS mnemonic in <kernel/cpu/sgx/encls.h> x86/mtrr: Remove license boilerplate text with bad FSF address x86/asm: Use RDPKRU and WRPKRU mnemonics in <asm/special_insns.h> x86/idle: Use MONITORX and MWAITX mnemonics in <asm/mwait.h> x86/entry/fred: Push __KERNEL_CS directly x86/kconfig: Remove CONFIG_AS_AVX512 crypto: x86 - Remove CONFIG_AS_VPCLMULQDQ crypto: X86 - Remove CONFIG_AS_VAES crypto: x86 - Remove CONFIG_AS_GFNI x86/kconfig: Drop unused and needless config X86_64_SMP
2025-10-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds9-31/+118
Pull x86 kvm updates from Paolo Bonzini: "Generic: - Rework almost all of KVM's exports to expose symbols only to KVM's x86 vendor modules (kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko x86: - Rework almost all of KVM x86's exports to expose symbols only to KVM's vendor modules, i.e. to kvm-{amd,intel}.ko - Add support for virtualizing Control-flow Enforcement Technology (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD (Shadow Stacks). It is worth noting that while SHSTK and IBT can be enabled separately in CPUID, it is not really possible to virtualize them separately. Therefore, Intel processors will really allow both SHSTK and IBT under the hood if either is made visible in the guest's CPUID. The alternative would be to intercept XSAVES/XRSTORS, which is not feasible for performance reasons - Fix a variety of fuzzing WARNs all caused by checking L1 intercepts when completing userspace I/O. KVM has already committed to allowing L2 to to perform I/O at that point - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is supposed to exist for v2 PMUs - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs - Add support for the immediate forms of RDMSR and WRMSRNS, sans full emulator support (KVM should never need to emulate the MSRs outside of forced emulation and other contrived testing scenarios) - Clean up the MSR APIs in preparation for CET and FRED virtualization, as well as mediated vPMU support - Clean up a pile of PMU code in anticipation of adding support for mediated vPMUs - Reject in-kernel IOAPIC/PIT for TDX VMs, as KVM can't obtain EOI vmexits needed to faithfully emulate an I/O APIC for such guests - Many cleanups and minor fixes - Recover possible NX huge pages within the TDP MMU under read lock to reduce guest jitter when restoring NX huge pages - Return -EAGAIN during prefault if userspace concurrently deletes/moves the relevant memslot, to fix an issue where prefaulting could deadlock with the memslot update x86 (AMD): - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is supported - Require a minimum GHCB version of 2 when starting SEV-SNP guests via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate errors instead of latent guest failures - Add support for SEV-SNP's CipherText Hiding, an opt-in feature that prevents unauthorized CPU accesses from reading the ciphertext of SNP guest private memory, e.g. to attempt an offline attack. This feature splits the shared SEV-ES/SEV-SNP ASID space into separate ranges for SEV-ES and SEV-SNP guests, therefore a new module parameter is needed to control the number of ASIDs that can be used for VMs with CipherText Hiding vs. how many can be used to run SEV-ES guests - Add support for Secure TSC for SEV-SNP guests, which prevents the untrusted host from tampering with the guest's TSC frequency, while still allowing the the VMM to configure the guest's TSC frequency prior to launch - Validate the XCR0 provided by the guest (via the GHCB) to avoid bugs resulting from bogus XCR0 values - Save an SEV guest's policy if and only if LAUNCH_START fully succeeds to avoid leaving behind stale state (thankfully not consumed in KVM) - Explicitly reject non-positive effective lengths during SNP's LAUNCH_UPDATE instead of subtly relying on guest_memfd to deal with them - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the host's desired TSC_AUX, to fix a bug where KVM was keeping a different vCPU's TSC_AUX in the host MSR until return to userspace KVM (Intel): - Preparation for FRED support - Don't retry in TDX's anti-zero-step mitigation if the target memslot is invalid, i.e. is being deleted or moved, to fix a deadlock scenario similar to the aforementioned prefaulting case - Misc bugfixes and minor cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits) KVM: x86: Export KVM-internal symbols for sub-modules only KVM: x86: Drop pointless exports of kvm_arch_xxx() hooks KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.c KVM: Export KVM-internal symbols for sub-modules only KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent KVM: VMX: Make CR4.CET a guest owned bit KVM: selftests: Verify MSRs are (not) in save/restore list when (un)supported KVM: selftests: Add coverage for KVM-defined registers in MSRs test KVM: selftests: Add KVM_{G,S}ET_ONE_REG coverage to MSRs test KVM: selftests: Extend MSRs test to validate vCPUs without supported features KVM: selftests: Add support for MSR_IA32_{S,U}_CET to MSRs test KVM: selftests: Add an MSR test to exercise guest/host and read/write KVM: x86: Define AMD's #HV, #VC, and #SX exception vectors KVM: x86: Define Control Protection Exception (#CP) vector KVM: x86: Add human friendly formatting for #XM, and #VE KVM: SVM: Enable shadow stack virtualization for SVM KVM: SEV: Synchronize MSR_IA32_XSS from the GHCB when it's valid KVM: SVM: Pass through shadow stack MSRs as appropriate KVM: SVM: Update dump_vmcb with shadow stack save area additions KVM: nSVM: Save/load CET Shadow Stack state to/from vmcb12/vmcb02 ...
2025-10-04Merge tag 'x86_tdx_for_6.18-rc1' of ↵Linus Torvalds3-3/+46
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 TDX updates from Dave Hansen: "The biggest change here is making TDX and kexec play nicely together. Before this, the memory encryption hardware (which doesn't respect cache coherency) could write back old cachelines on top of data in the new kernel, so kexec and TDX were made mutually exclusive. This removes the limitation. There is also some work to tighten up a hardware bug workaround and some MAINTAINERS updates. - Make TDX and kexec work together - Skip TDX bug workaround when the bug is not present - Update maintainers entries" * tag 'x86_tdx_for_6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/virt/tdx: Use precalculated TDVPR page physical address KVM/TDX: Explicitly do WBINVD when no more TDX SEAMCALLs x86/virt/tdx: Update the kexec section in the TDX documentation x86/virt/tdx: Remove the !KEXEC_CORE dependency x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum x86/virt/tdx: Mark memory cache state incoherent when making SEAMCALL x86/sme: Use percpu boolean to control WBINVD during kexec x86/kexec: Consolidate relocate_kernel() function parameters x86/tdx: Skip clearing reclaimed pages unless X86_BUG_TDX_PW_MCE is present x86/tdx: Tidy reset_pamt functions x86/tdx: Eliminate duplicate code in tdx_clear_page() MAINTAINERS: Add KVM mail list to the TDX entry MAINTAINERS: Add Rick Edgecombe as a TDX reviewer MAINTAINERS: Update the file list in the TDX entry.
2025-10-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds3-7/+3
Pull kvm updates from Paolo Bonzini: "This excludes the bulk of the x86 changes, which I will send separately. They have two not complex but relatively unusual conflicts so I will wait for other dust to settle. guest_memfd: - Add support for host userspace mapping of guest_memfd-backed memory for VM types that do NOT use support KVM_MEMORY_ATTRIBUTE_PRIVATE (which isn't precisely the same thing as CoCo VMs, since x86's SEV-MEM and SEV-ES have no way to detect private vs. shared). This lays the groundwork for removal of guest memory from the kernel direct map, as well as for limited mmap() for guest_memfd-backed memory. For more information see: - commit a6ad54137af9 ("Merge branch 'guest-memfd-mmap' into HEAD") - guest_memfd in Firecracker: https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding - direct map removal: https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/ - mmap support: https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/ ARM: - Add support for FF-A 1.2 as the secure memory conduit for pKVM, allowing more registers to be used as part of the message payload. - Change the way pKVM allocates its VM handles, making sure that the privileged hypervisor is never tricked into using uninitialised data. - Speed up MMIO range registration by avoiding unnecessary RCU synchronisation, which results in VMs starting much quicker. - Add the dump of the instruction stream when panic-ing in the EL2 payload, just like the rest of the kernel has always done. This will hopefully help debugging non-VHE setups. - Add 52bit PA support to the stage-1 page-table walker, and make use of it to populate the fault level reported to the guest on failing to translate a stage-1 walk. - Add NV support to the GICv3-on-GICv5 emulation code, ensuring feature parity for guests, irrespective of the host platform. - Fix some really ugly architecture problems when dealing with debug in a nested VM. This has some bad performance impacts, but is at least correct. - Add enough infrastructure to be able to disable EL2 features and give effective values to the EL2 control registers. This then allows a bunch of features to be turned off, which helps cross-host migration. - Large rework of the selftest infrastructure to allow most tests to transparently run at EL2. This is the first step towards enabling NV testing. - Various fixes and improvements all over the map, including one BE fix, just in time for the removal of the feature. LoongArch: - Detect page table walk feature on new hardware - Add sign extension with kernel MMIO/IOCSR emulation - Improve in-kernel IPI emulation - Improve in-kernel PCH-PIC emulation - Move kvm_iocsr tracepoint out of generic code RISC-V: - Added SBI FWFT extension for Guest/VM with misaligned delegation and pointer masking PMLEN features - Added ONE_REG interface for SBI FWFT extension - Added Zicbop and bfloat16 extensions for Guest/VM - Enabled more common KVM selftests for RISC-V - Added SBI v3.0 PMU enhancements in KVM and perf driver s390: - Improve interrupt cpu for wakeup, in particular the heuristic to decide which vCPU to deliver a floating interrupt to. - Clear the PTE when discarding a swapped page because of CMMA; this bug was introduced in 6.16 when refactoring gmap code. x86 selftests: - Add #DE coverage in the fastops test (the only exception that's guest- triggerable in fastop-emulated instructions). - Fix PMU selftests errors encountered on Granite Rapids (GNR), Sierra Forest (SRF) and Clearwater Forest (CWF). - Minor cleanups and improvements x86 (guest side): - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping could map devices as WB and prevent the device drivers from mapping their devices with UC/UC-. - Make kvm_async_pf_task_wake() a local static helper and remove its export. - Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU bindings even when PV_UNHALT is unsupported. Generic: - Remove a redundant __GFP_NOWARN from kvm_setup_async_pf() as __GFP_NOWARN is now included in GFP_NOWAIT. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (178 commits) KVM: s390: Fix to clear PTE when discarding a swapped page KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs KVM: arm64: selftests: Cope with arch silliness in EL2 selftest KVM: arm64: selftests: Add basic test for running in VHE EL2 KVM: arm64: selftests: Enable EL2 by default KVM: arm64: selftests: Initialize HCR_EL2 KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2 KVM: arm64: selftests: Select SMCCC conduit based on current EL KVM: arm64: selftests: Provide helper for getting default vCPU target KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts KVM: arm64: selftests: Create a VGICv3 for 'default' VMs KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation KVM: arm64: selftests: Add helper to check for VGICv3 support KVM: arm64: selftests: Initialize VGICv3 only once KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code KVM: selftests: Add ex_str() to print human friendly name of exception vectors selftests/kvm: remove stale TODO in xapic_state_test KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount ...
2025-10-02Merge tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-0/+2
Pull drm updates from Dave Airlie: "cross-subsystem: - i2c-hid: Make elan touch controllers power on after panel is enabled - dt bindings for STM32MP25 SoC - pci vgaarb: use screen_info helpers - rust pin-init updates - add MEI driver for late binding firmware update/load uapi: - add ioctl for reassigning GEM handles - provide boot_display attribute on boot-up devices core: - document DRM_MODE_PAGE_FLIP_EVENT - add vendor specific recovery method to drm device wedged uevent gem: - Simplify gpuvm locking ttm: - add interface to populate buffers sched: - Fix race condition in trace code atomic: - Reallow no-op async page flips display: - dp: Fix command length video: - Improve pixel-format handling for struct screen_info rust: - drop Opaque<> from ioctl args - Alloc: - BorrowedPage type and AsPageIter traits - Implement Vmalloc::to_page() and VmallocPageIter - DMA/Scatterlist: - Add dma::DataDirection and type alias for dma_addr_t - Abstraction for struct scatterlist and sg_table - DRM: - simplify use of generics - add DriverFile type alias - drop Object::SIZE - Rust: - pin-init tree merge - Various methods for AsBytes and FromBytes traits gpuvm: - Support madvice in Xe driver gpusvm: - fix hmm_pfn_to_map_order usage in gpusvm bridge: - Improve and fix ref counting on bridge management - cdns-dsi: Various improvements to mode setting - Support Solomon SSD2825 plus DT bindings - Support Waveshare DSI2DPI plus DT bindings - Support Content Protection property - display-connector: Improve DP display detection - Add support for Radxa Ra620 plus DT bindings - adv7511: Provide SPD and HDMI infoframes - it6505: Replace crypto_shash with sha() - synopsys: Add support for DW DPTX Controller plus DT bindings - adv7511: Write full Audio infoframe - ite6263: Support vendor-specific infoframes - simple: Add support for Realtek RTD2171 DP-to-HDMI plus DT bindings panel: - panel-edp: Support mt8189 Chromebooks; Support BOE NV140WUM-N64; Support SHP LQ134Z1; Fixes - panel-simple: Support Olimex LCD-OLinuXino-5CTS plus DT bindings - Support Samsung AMS561RA01 - Support Hydis HV101HD1 plus DT bindings - ilitek-ili9881c: Refactor mode setting; Add support for Bestar BSD1218-A101KL68 LCD plus DT bindings - lvds: Add support for Ampire AMP19201200B5TZQW-T03 to DT bindings - edp: Add support for additonal mt8189 Chromebook panels - lvds: Add DT bindings for EDT ETML0700Z8DHA amdgpu: - add CRIU support for gem objects - RAS updates - VCN SRAM load fixes - EDID read fixes - eDP ALPM support - Documentation updates - Rework PTE flag generation - DCE6 fixes - VCN devcoredump cleanup - MMHUB client id fixes - VCN 5.0.1 RAS support - SMU 13.0.x updates - Expanded PCIe DPC support - Expanded VCN reset support - VPE per queue reset support - give kernel jobs unique id for tracing - pre-populate exported buffers - cyan skillfish updates - make vbios build number available in sysfs - userq updates - HDCP updates - support MMIO remap page as ttm pool - JPEG parser updates - DCE6 DC updates - use devm for i2c buses - GPUVM locking updates - Drop non-DC DCE11 code - improve fallback handling for pixel encoding amdkfd: - SVM/page migration fixes - debugfs fixes - add CRIO support for gem objects - SVM updates radeon: - use dev_warn_once in CS parsers xe: - add madvise interface - add DRM_IOCTL_XE_VM_QUERY_MEMORY_RANGE_ATTRS to query VMA count and memory attributes - drop L# bank mask reporting from media GT3 on Xe3+. - add SLPC power_profile sysfs interface - add configs attribs to add post/mid context-switch commands - handle firmware reported hardware errors notifying userspace with device wedged uevent - use same dir structure across sysfs/debugfs - cleanup and future proof vram region init - add G-states and PCI link states to debugfs - Add SRIOV support for CCS surfaces on Xe2+ - Enable SRIOV PF mode by default on supported platforms - move flush to common code - extended core workarounds for Xe2/3 - use DRM scheduler for delayed GT TLB invalidations - configs improvements and allow VF device enablement - prep work to expose mmio regions to userspace - VF migration support added - prepare GPU SVM for THP migration - start fixing XE_PAGE_SIZE vs PAGE_SIZE - add PSMI support for hw validation - resize VF bars to max possible size according to number of VFs - Ensure GT is in C0 during resume - pre-populate exported buffers - replace xe_hmm with gpusvm - add more SVM GT stats to debugfs - improve fake pci and WA kunnit handle for new platform testing - Test GuC to GuC comms to add debugging - use attribute groups to simplify sysfs registration - add Late Binding firmware code to interact with MEI i915: - apply multiple JSL/EHL/Gen7/Gen6 workarounds properly - protect against overflow in active_engine() - Use try_cmpxchg64() in __active_lookup() - include GuC registers in error state - get rid of dev->struct_mutex - iopoll: generalize read_poll_timout - lots more display refactoring - Reject HBR3 in any eDP Panel - Prune modes for YUV420 - Display Wa fix, additions, and updates - DP: Fix 2.7 Gbps link training on g4x - DP: Adjust the idle pattern handling - DP: Shuffle the link training code a bit - Don't set/read the DSI C clock divider on GLK - Enable_psr kernel parameter changes - Type-C enabled/disconnected dp-alt sink - Wildcat Lake enabling - DP HDR updates - DRAM detection - wait PSR idle on dsb commit - Remove FBC modulo 4 restriction for ADL-P+ - panic: refactor framebuffer allocation habanalabs: - debug/visibility improvements - vmalloc-backed coherent mmap support - HLDIO infrastructure nova-core: - various register!() macro improvements - minor vbios/firmware fixes/refactoring - advance firmware boot stages; process Booter and patch signatures - process GSP and GSP bootloader - Add r570.144 firmware bindings and update to it - Move GSP boot code to own module - Use new pin-init features to store driver's private data in a single allocation - Update ARef import from sync::aref nova-drm: - Update ARef import from sync::aref tyr: - initial driver skeleton for a rust driver for ARM Mali GPUs - capable of powering up, query metadata and provide it to userspace. msm: - GPU and Core: - in DT bindings describe clocks per GPU type - GMU bandwidth voting for x1-85 - a623/a663 speedbins - cleanup some remaining no-iommu leftovers after VM_BIND conversion - fix GEM obj 32b size truncation - add missing VM_BIND param validation - IFPC for x1-85 and a750 - register xml and gen_header.py sync from mesa - Display: - add missing bindings for display on SC8180X - added DisplayPort MST bindings - conversion from round_rate() to determine_rate() amdxdna: - add IOCTL_AMDXDNA_GET_ARRAY - support user space allocated buffers - streamline PM interfaces - Refactoring wrt. hardware contexts - improve error reporting nouveau: - use GSP firmware by default - improve error reporting - Pre-populate exported buffers ast: - Clean up detection of DRAM config exynos: - add DSIM bridge driver support for Exynos7870 - Document Exynos7870 DSIM compatible in dt-binding panthor: - Print task/pid on errors - Add support for Mali G710, G510, G310, Gx15, Gx20, Gx25 - Improve cache flushing - Fail VM bind if BO has offset renesas: - convert to RUNTIME_PM_OPS rcar-du: - Make number of lanes configurable - Use RUNTIME_PM_OPS - Add support for DSI commands rocket: - Add driver for Rockchip NPU plus DT bindings - Use kfree() and sizeof() correctly - Test DMA status rockchip: - dsi2: Add support for RK3576 plus DT bindings - Add support for RK3588 DPTX output tidss: - Use crtc_ fields for programming display mode - Remove other drivers from aperture pixpaper: - Add support for Mayqueen Pixpaper plus DT bindings v3d: - Support querying nubmer of GPU resets for KHR_robustness stm: - Clean up logging - ltdc: Add support support for STM32MP257F-EV1 plus DT bindings sitronix: - st7571-i2c: Add support for inverted displays and 2-bit grayscale tidss: - Convert to kernel's FIELD_ macros vesadrm: - Support 8-bit palette mode imagination: - Improve power management - Add support for TH1520 GPU - Support Risc-V architectures v3d: - Improve job management and locking vkms: - Support variants of ARGB8888, ARGB16161616, RGB565, RGB888 and P01x - Spport YUV with 16-bit components" * tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel: (1455 commits) drm/amd: Add name to modes from amdgpu_connector_add_common_modes() drm/amd: Drop some common modes from amdgpu_connector_add_common_modes() drm/amdgpu: update MODULE_PARM_DESC for freesync_video drm/amd: Use dynamic array size declaration for amdgpu_connector_add_common_modes() drm/amd/display: Share dce100_validate_global with DCE6-8 drm/amd/display: Share dce100_validate_bandwidth with DCE6-8 drm/amdgpu: Fix fence signaling race condition in userqueue amd/amdkfd: enhance kfd process check in switch partition amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw drm/amd/display: Reject modes with too high pixel clock on DCE6-10 drm/amd: Drop unnecessary check in amdgpu_connector_add_common_modes() drm/amd/display: Only enable common modes for eDP and LVDS drm/amdgpu: remove the redeclaration of variable i drm/amdgpu/userq: assign an error code for invalid userq va drm/amdgpu: revert "rework reserved VMID handling" v2 drm/amdgpu: remove leftover from enforcing isolation by VMID drm/amdgpu: Add fallback to pipe reset if KCQ ring reset fails accel/habanalabs: add Infineon version check accel/habanalabs/gaudi2: read preboot status after recovering from dirty state accel/habanalabs: add HL_GET_P_STATE passthrough type ...
2025-10-02Merge tag 'for-6.18/block-20250929' of ↵Linus Torvalds1-5/+3
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull block updates from Jens Axboe: - NVMe pull request via Keith: - FC target fixes (Daniel) - Authentication fixes and updates (Martin, Chris) - Admin controller handling (Kamaljit) - Target lockdep assertions (Max) - Keep-alive updates for discovery (Alastair) - Suspend quirk (Georg) - MD pull request via Yu: - Add support for a lockless bitmap. A key feature for the new bitmap are that the IO fastpath is lockless. If a user issues lots of write IO to the same bitmap bit in a short time, only the first write has additional overhead to update bitmap bit, no additional overhead for the following writes. By supporting only resync or recover written data, means in the case creating new array or replacing with a new disk, there is no need to do a full disk resync/recovery. - Switch ->getgeo() and ->bios_param() to using struct gendisk rather than struct block_device. - Rust block changes via Andreas. This series adds configuration via configfs and remote completion to the rnull driver. The series also includes a set of changes to the rust block device driver API: a few cleanup patches, and a few features supporting the rnull changes. The series removes the raw buffer formatting logic from `kernel::block` and improves the logic available in `kernel::string` to support the same use as the removed logic. - floppy arch cleanups - Reduce the number of dereferencing needed for ublk commands - Restrict supported sockets for nbd. Mostly done to eliminate a class of issues perpetually reported by syzbot, by using nonsensical socket setups. - A few s390 dasd block fixes - Fix a few issues around atomic writes - Improve DMA interation for integrity requests - Improve how iovecs are treated with regards to O_DIRECT aligment constraints. We used to require each segment to adhere to the constraints, now only the request as a whole needs to. - Clean up and improve p2p support, enabling use of p2p for metadata payloads - Improve locking of request lookup, using SRCU where appropriate - Use page references properly for brd, avoiding very long RCU sections - Fix ordering of recursively submitted IOs - Clean up and improve updating nr_requests for a live device - Various fixes and cleanups * tag 'for-6.18/block-20250929' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (164 commits) s390/dasd: enforce dma_alignment to ensure proper buffer validation s390/dasd: Return BLK_STS_INVAL for EINVAL from do_dasd_request ublk: remove redundant zone op check in ublk_setup_iod() nvme: Use non zero KATO for persistent discovery connections nvmet: add safety check for subsys lock nvme-core: use nvme_is_io_ctrl() for I/O controller check nvme-core: do ioccsz/iorcsz validation only for I/O controllers nvme-core: add method to check for an I/O controller blk-cgroup: fix possible deadlock while configuring policy blk-mq: fix null-ptr-deref in blk_mq_free_tags() from error path blk-mq: Fix more tag iteration function documentation selftests: ublk: fix behavior when fio is not installed ublk: don't access ublk_queue in ublk_unmap_io() ublk: pass ublk_io to __ublk_complete_rq() ublk: don't access ublk_queue in ublk_need_complete_req() ublk: don't access ublk_queue in ublk_check_commit_and_fetch() ublk: don't pass ublk_queue to ublk_fetch() ublk: don't access ublk_queue in ublk_config_io_buf() ublk: don't access ublk_queue in ublk_check_fetch_buf() ublk: pass q_id and tag to __ublk_check_and_get_req() ...
2025-10-01Merge tag 'core-core-2025-09-29' of ↵Linus Torvalds1-45/+31
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull TIF bit unification updates from Thomas Gleixner: "A set of changes to consolidate the generic TIF (thread info flag) bits accross architectures. All architectures define the same set of generic TIF bits. This makes it pointlessly hard to add a new generic TIF bit or to change an existing one. Provide a generic variant and convert the architectures which utilize the generic entry code over to use it. The TIF space is divided into 16 generic bits and 16 architecture specific bits, which turned out to provide enough space on both sides" * tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: LoongArch: Fix bitflag conflict for TIF_FIXADE riscv: Use generic TIF bits loongarch: Use generic TIF bits s390/entry: Remove unused TIF flags s390: Use generic TIF bits x86: Use generic TIF bits asm-generic: Provide generic TIF infrastructure
2025-09-30Merge tag 'x86_apic_for_v6.18_rc1' of ↵Linus Torvalds10-38/+67
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV and apic updates from Borislav Petkov: - Add functionality to provide runtime firmware updates for the non-x86 parts of an AMD platform like the security processor (ASP) firmware, modules etc, for example. The intent being that these updates are interim, live fixups before a proper BIOS update can be attempted - Add guest support for AMD's Secure AVIC feature which gives encrypted guests the needed protection against a malicious hypervisor generating unexpected interrupts and injecting them into such guest, thus interfering with its operation in an unexpected and negative manner. The advantage of this scheme is that the guest determines which interrupts and when to accept them vs leaving that to the benevolence (or not) of the hypervisor - Strictly separate the startup code from the rest of the kernel where former is executed from the initial 1:1 mapping of memory. The problem was that the toolchain-generated version of the code was being executed from a different mapping of memory than what was "assumed" during code generation, needing an ever-growing pile of fixups for absolute memory references which are invalid in the early, 1:1 memory mapping during boot. The major advantage of this is that there's no need to check the 1:1 mapping portion of the code for absolute relocations anymore and get rid of the RIP_REL_REF() macro sprinkling all over the place. For more info, see Ard's very detailed writeup on this [1] - The usual cleanups and fixes Link: https://lore.kernel.org/r/CAMj1kXEzKEuePEiHB%2BHxvfQbFz0sTiHdn4B%2B%2BzVBJ2mhkPkQ4Q@mail.gmail.com [1] * tag 'x86_apic_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits) x86/boot: Drop erroneous __init annotation from early_set_pages_state() crypto: ccp - Add AMD Seamless Firmware Servicing (SFS) driver crypto: ccp - Add new HV-Fixed page allocation/free API x86/sev: Add new dump_rmp parameter to snp_leak_pages() API x86/startup/sev: Document the CPUID flow in the boot #VC handler objtool: Ignore __pi___cfi_ prefixed symbols x86/sev: Zap snp_abort() x86/apic/savic: Do not use snp_abort() x86/boot: Get rid of the .head.text section x86/boot: Move startup code out of __head section efistub/x86: Remap inittext read-execute when needed x86/boot: Create a confined code area for startup code x86/kbuild: Incorporate boot/startup/ via Kbuild makefile x86/boot: Revert "Reject absolute references in .head.text" x86/boot: Check startup code for absence of absolute relocations objtool: Add action to check for absence of absolute relocations x86/sev: Export startup routines for later use x86/sev: Move __sev_[get|put]_ghcb() into separate noinstr object x86/sev: Provide PIC aliases for SEV related data objects x86/boot: Provide PIC aliases for 5-level paging related constants ...
2025-09-30Merge tag 'x86_cache_for_v6.18_rc1' of ↵Linus Torvalds3-16/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 resource control updates from Borislav Petkov: "Add support on AMD for assigning QoS bandwidth counters to resources (RMIDs) with the ability for those resources to be tracked by the counters as long as they're assigned to them. Previously, due to hw limitations, bandwidth counts from untracked resources would get lost when those resources are not tracked. Refactor the code and user interfaces to be able to also support other, similar features on ARM, for example" * tag 'x86_cache_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) fs/resctrl: Fix counter auto-assignment on mkdir with mbm_event enabled MAINTAINERS: resctrl: Add myself as reviewer x86/resctrl: Configure mbm_event mode if supported fs/resctrl: Introduce the interface to switch between monitor modes fs/resctrl: Disable BMEC event configuration when mbm_event mode is enabled fs/resctrl: Introduce the interface to modify assignments in a group fs/resctrl: Introduce mbm_L3_assignments to list assignments in a group fs/resctrl: Auto assign counters on mkdir and clean up on group removal fs/resctrl: Introduce mbm_assign_on_mkdir to enable assignments on mkdir fs/resctrl: Provide interface to update the event configurations fs/resctrl: Add event configuration directory under info/L3_MON/ fs/resctrl: Support counter read/reset with mbm_event assignment mode x86/resctrl: Implement resctrl_arch_reset_cntr() and resctrl_arch_cntr_read() x86/resctrl: Refactor resctrl_arch_rmid_read() fs/resctrl: Introduce counter ID read, reset calls in mbm_event mode fs/resctrl: Pass struct rdtgroup instead of individual members fs/resctrl: Add the functionality to unassign MBM events fs/resctrl: Add the functionality to assign MBM events x86,fs/resctrl: Implement resctrl_arch_config_cntr() to assign a counter with ABMC fs/resctrl: Introduce event configuration field in struct mon_evt ...
2025-09-30Merge tag 'x86_cpu_for_v6.18_rc1' of ↵Linus Torvalds3-4/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpuid updates from Borislav Petkov: - Make UMIP instruction detection more robust - Correct and cleanup AMD CPU topology detection; document the relevant CPUID leaves topology parsing precedence on AMD - Add support for running the kernel as guest on FreeBSD's Bhyve hypervisor - Cleanups and improvements * tag 'x86_cpu_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/umip: Fix decoding of register forms of 0F 01 (SGDT and SIDT aliases) x86/umip: Check that the instruction opcode is at least two bytes Documentation/x86/topology: Detail CPUID leaves used for topology enumeration x86/cpu/topology: Define AMD64_CPUID_EXT_FEAT MSR x86/cpu/topology: Check for X86_FEATURE_XTOPOLOGY instead of passing has_xtopology x86/cpu/cacheinfo: Simplify cacheinfo_amd_init_llc_id() using _cpuid4_info x86/cpu: Rename and move CPU model entry for Diamond Rapids x86/cpu: Detect FreeBSD Bhyve hypervisor
2025-09-30Merge tag 'x86_bugs_for_v6.18_rc1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mitigation updates from Borislav Petkov: - Add VMSCAPE to the attack vector controls infrastructure - A bunch of the usual cleanups and fixlets, some of them resulting from fuzzing the different mitigation options * tag 'x86_bugs_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/bugs: Report correct retbleed mitigation status x86/bugs: Fix reporting of LFENCE retpoline x86/bugs: Fix spectre_v2 forcing x86/bugs: Remove uses of cpu_mitigations_off() x86/bugs: Simplify SSB cmdline parsing x86/bugs: Use early_param() for spectre_v2 x86/bugs: Use early_param() for spectre_v2_user x86/bugs: Add attack vector controls for VMSCAPE x86/its: Move ITS indirect branch thunks to .text..__x86.indirect_thunk
2025-09-30Merge tag 'ras_core_for_v6.18_rc1' of ↵Linus Torvalds1-8/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 RAS updates from Borislav Petkov: - Unify and refactor the MCA arch side and better separate code - Cleanup and simplify the AMD RAS side, unify code, drop unused stuff * tag 'ras_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Add a clear_bank() helper x86/mce: Move machine_check_poll() status checks to helper functions x86/mce: Separate global and per-CPU quirks x86/mce: Do 'UNKNOWN' vendor check early x86/mce: Define BSP-only SMCA init x86/mce: Define BSP-only init x86/mce: Set CR4.MCE last during init x86/mce: Remove __mcheck_cpu_init_early() x86/mce: Cleanup bank processing on init x86/mce/amd: Put list_head in threshold_bank x86/mce/amd: Remove smca_banks_map x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device() x86/mce/amd: Rename threshold restart function
2025-09-30Merge tag 'x86_asm_for_v6.18_rc1' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm update from Borislav Petkov: - Fix RDPID's output operand size in inline asm and use the insn mnemonic because the minimum binutils version supports it * tag 'x86_asm_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Fix output operand size of RDPID
2025-09-30Merge tag 'x86_misc_for_v6.18_rc1' of ↵Linus Torvalds2-3/+63
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 instruction decoder update from Borislav Petkov: - Add instruction decoding support for the XOP-prefixed instruction set present on the AMD Bulldozer uarch [ These instructions don't normally happen, but a X86_NATIVE_CPU build on a bulldozer host can make the compiler then use these unusual instruction encodings ] * tag 'x86_misc_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/insn: Add XOP prefix instructions decoder support
2025-09-30Merge tag 'perf-core-2025-09-26' of ↵Linus Torvalds4-8/+25
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance events updates from Ingo Molnar: "Core perf code updates: - Convert mmap() related reference counts to refcount_t. This is in reaction to the recently fixed refcount bugs, which could have been detected earlier and could have mitigated the bug somewhat (Thomas Gleixner, Peter Zijlstra) - Clean up and simplify the callchain code, in preparation for sframes (Steven Rostedt, Josh Poimboeuf) Uprobes updates: - Add support to optimize usdt probes on x86-64, which gives a substantial speedup (Jiri Olsa) - Cleanups and fixes on x86 (Peter Zijlstra) PMU driver updates: - Various optimizations and fixes to the Intel PMU driver (Dapeng Mi) Misc cleanups and fixes: - Remove redundant __GFP_NOWARN (Qianfeng Rong)" * tag 'perf-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value uprobes/x86: Return error from uprobe syscall when not called from trampoline perf: Skip user unwind if the task is a kernel thread perf: Simplify get_perf_callchain() user logic perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL perf: Have get_perf_callchain() return NULL if crosstask and user are set perf: Remove get_perf_callchain() init_nr argument perf/x86: Print PMU counters bitmap in x86_pmu_show_pmu_cap() perf/x86/intel: Add ICL_FIXED_0_ADAPTIVE bit into INTEL_FIXED_BITS_MASK perf/x86/intel: Change macro GLOBAL_CTRL_EN_PERF_METRICS to BIT_ULL(48) perf/x86: Add PERF_CAP_PEBS_TIMING_INFO flag perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error perf/x86/intel: Use early_initcall() to hook bts_init() uprobes: Remove redundant __GFP_NOWARN selftests/seccomp: validate uprobe syscall passes through seccomp seccomp: passthrough uprobe systemcall without filtering selftests/bpf: Fix uprobe syscall shadow stack test selftests/bpf: Change test_uretprobe_regs_change for uprobe and uretprobe selftests/bpf: Add uprobe_regs_equal test selftests/bpf: Add optimized usdt variant for basic usdt test ...
2025-09-30KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.cSean Christopherson1-3/+0
Move kvm_intr_is_single_vcpu() to lapic.c, drop its export, and make its "fast" helper local to lapic.c. kvm_intr_is_single_vcpu() is only usable if the local APIC is in-kernel, i.e. it most definitely belongs in the local APIC code. No functional change intended. Fixes: cf04ec393ed0 ("KVM: x86: Dedup AVIC vs. PI code for identifying target vCPU") Link: https://lore.kernel.org/r/20250919003303.1355064-4-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30KVM: Export KVM-internal symbols for sub-modules onlySean Christopherson1-0/+10
Rework the vast majority of KVM's exports to expose symbols only to KVM submodules, i.e. to x86's kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko. With few exceptions, KVM's exported APIs are intended (and safe) for KVM- internal usage only. Keep kvm_get_kvm(), kvm_get_kvm_safe(), and kvm_put_kvm() as normal exports, as they are needed by VFIO, and are generally safe for external usage (though ideally even the get/put APIs would be KVM-internal, and VFIO would pin a VM by grabbing a reference to its associated file). Implement a framework in kvm_types.h in anticipation of providing a macro to restrict KVM-specific kernel exports, i.e. to provide symbol exports for KVM if and only if KVM is built as one or more modules. Link: https://lore.kernel.org/r/20250919003303.1355064-3-seanjc@google.com Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30Merge tag 'kvm-x86-cet-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini3-2/+47
KVM x86 CET virtualization support for 6.18 Add support for virtualizing Control-flow Enforcement Technology (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD (Shadow Stacks). CET is comprised of two distinct features, Shadow Stacks (SHSTK) and Indirect Branch Tracking (IBT), that can be utilized by software to help provide Control-flow integrity (CFI). SHSTK defends against backward-edge attacks (a.k.a. Return-oriented programming (ROP)), while IBT defends against forward-edge attacks (a.k.a. similarly CALL/JMP-oriented programming (COP/JOP)). Attackers commonly use ROP and COP/JOP methodologies to redirect the control- flow to unauthorized targets in order to execute small snippets of code, a.k.a. gadgets, of the attackers choice. By chaining together several gadgets, an attacker can perform arbitrary operations and circumvent the system's defenses. SHSTK defends against backward-edge attacks, which execute gadgets by modifying the stack to branch to the attacker's target via RET, by providing a second stack that is used exclusively to track control transfer operations. The shadow stack is separate from the data/normal stack, and can be enabled independently in user and kernel mode. When SHSTK is is enabled, CALL instructions push the return address on both the data and shadow stack. RET then pops the return address from both stacks and compares the addresses. If the return addresses from the two stacks do not match, the CPU generates a Control Protection (#CP) exception. IBT defends against backward-edge attacks, which branch to gadgets by executing indirect CALL and JMP instructions with attacker controlled register or memory state, by requiring the target of indirect branches to start with a special marker instruction, ENDBRANCH. If an indirect branch is executed and the next instruction is not an ENDBRANCH, the CPU generates a #CP. Note, ENDBRANCH behaves as a NOP if IBT is disabled or unsupported. From a virtualization perspective, CET presents several problems. While SHSTK and IBT have two layers of enabling, a global control in the form of a CR4 bit, and a per-feature control in user and kernel (supervisor) MSRs (U_CET and S_CET respectively), the {S,U}_CET MSRs can be context switched via XSAVES/XRSTORS. Practically speaking, intercepting and emulating XSAVES/XRSTORS is not a viable option due to complexity, and outright disallowing use of XSTATE to context switch SHSTK/IBT state would render the features unusable to most guests. To limit the overall complexity without sacrificing performance or usability, simply ignore the potential virtualization hole, but ensure that all paths in KVM treat SHSTK/IBT as usable by the guest if the feature is supported in hardware, and the guest has access to at least one of SHSTK or IBT. I.e. allow userspace to advertise one of SHSTK or IBT if both are supported in hardware, even though doing so would allow a misbehaving guest to use the unadvertised feature. Fully emulating SHSTK and IBT would also require significant complexity, e.g. to track and update branch state for IBT, and shadow stack state for SHSTK. Given that emulating large swaths of the guest code stream isn't necessary on modern CPUs, punt on emulating instructions that meaningful impact or consume SHSTK or IBT. However, instead of doing nothing, explicitly reject emulation of such instructions so that KVM's emulator can't be abused to circumvent CET. Disable support for SHSTK and IBT if KVM is configured such that emulation of arbitrary guest instructions may be required, specifically if Unrestricted Guest (Intel only) is disabled, or if KVM will emulate a guest.MAXPHYADDR that is smaller than host.MAXPHYADDR. Lastly disable SHSTK support if shadow paging is enabled, as the protections for the shadow stack are novel (shadow stacks require Writable=0,Dirty=1, so that they can't be directly modified by software), i.e. would require non-trivial support in the Shadow MMU. Note, AMD CPUs currently only support SHSTK. Explicitly disable IBT support so that KVM doesn't over-advertise if AMD CPUs add IBT, and virtualizing IBT in SVM requires KVM modifications.
2025-09-30Merge tag 'kvm-x86-misc-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini5-19/+37
KVM x86 changes for 6.18 - Don't (re)check L1 intercepts when completing userspace I/O to fix a flaw where a misbehaving usersepace (a.k.a. syzkaller) could swizzle L1's intercepts and trigger a variety of WARNs in KVM. - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is supposed to exist for v2 PMUs. - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs. - Clean up KVM's vector hashing code for delivering lowest priority IRQs. - Clean up the fastpath handler code to only handle IPIs and WRMSRs that are actually "fast", as opposed to handling those that KVM _hopes_ are fast, and in the process of doing so add fastpath support for TSC_DEADLINE writes on AMD CPUs. - Clean up a pile of PMU code in anticipation of adding support for mediated vPMUs. - Add support for the immediate forms of RDMSR and WRMSRNS, sans full emulator support (KVM should never need to emulate the MSRs outside of forced emulation and other contrived testing scenarios). - Clean up the MSR APIs in preparation for CET and FRED virtualization, as well as mediated vPMU support. - Rejecting a fully in-kernel IRQCHIP if EOIs are protected, i.e. for TDX VMs, as KVM can't faithfully emulate an I/O APIC for such guests. - KVM_REQ_MSR_FILTER_CHANGED into a generic RECALC_INTERCEPTS in preparation for mediated vPMU support, as KVM will need to recalculate MSR intercepts in response to PMU refreshes for guests with mediated vPMUs. - Misc cleanups and minor fixes.
2025-09-30Merge tag 'kvm-x86-svm-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini3-0/+4
KVM SVM changes for 6.18 - Require a minimum GHCB version of 2 when starting SEV-SNP guests via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate errors instead of latent guest failures. - Add support for Secure TSC for SEV-SNP guests, which prevents the untrusted host from tampering with the guest's TSC frequency, while still allowing the the VMM to configure the guest's TSC frequency prior to launch. - Mitigate the potential for TOCTOU bugs when accessing GHCB fields by wrapping all accesses via READ_ONCE(). - Validate the XCR0 provided by the guest (via the GHCB) to avoid tracking a bogous XCR0 value in KVM's software model. - Save an SEV guest's policy if and only if LAUNCH_START fully succeeds to avoid leaving behind stale state (thankfully not consumed in KVM). - Explicitly reject non-positive effective lengths during SNP's LAUNCH_UPDATE instead of subtly relying on guest_memfd to do the "heavy" lifting. - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the host's desired TSC_AUX, to fix a bug where KVM could clobber a different vCPU's TSC_AUX due to hardware not matching the value cached in the user-return MSR infrastructure. - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is supported, and clean up the AVIC initialization code along the way.
2025-09-30Merge tag 'kvm-x86-mmu-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-13/+26
KVM x86 MMU changes for 6.18 - Recover possible NX huge pages within the TDP MMU under read lock to reduce guest jitter when restoring NX huge pages. - Return -EAGAIN during prefault if userspace concurrently deletes/moves the relevant memslot to fix an issue where prefaulting could deadlock with the memslot update. - Don't retry in TDX's anti-zero-step mitigation if the target memslot is invalid, i.e. is being deleted or moved, to fix a deadlock scenario similar to the aforementioned prefaulting case.
2025-09-30Merge tag 'kvm-x86-guest-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-2/+0
x86/kvm guest side changes for 6.18 - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping could map devices as WB and prevent the device drivers from mapping their devices with UC/UC-. - Make kvm_async_pf_task_wake() a local static helper and remove its export. - Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU bindings even when PV_UNHALT is unsupported.