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2025-10-28x86/split_lock: turn off by defaultJason A. Donenfeld1-1/+1
I don't want the log spam. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2025-10-23x86/resctrl: Fix miscount of bandwidth event when reactivating previously unavailable RMIDBabu Moger1-4/+10
[ Upstream commit 15292f1b4c55a3a7c940dbcb6cb8793871ed3d92 ] Users can create as many monitoring groups as the number of RMIDs supported by the hardware. However, on AMD systems, only a limited number of RMIDs are guaranteed to be actively tracked by the hardware. RMIDs that exceed this limit are placed in an "Unavailable" state. When a bandwidth counter is read for such an RMID, the hardware sets MSR_IA32_QM_CTR.Unavailable (bit 62). When such an RMID starts being tracked again the hardware counter is reset to zero. MSR_IA32_QM_CTR.Unavailable remains set on first read after tracking re-starts and is clear on all subsequent reads as long as the RMID is tracked. resctrl miscounts the bandwidth events after an RMID transitions from the "Unavailable" state back to being tracked. This happens because when the hardware starts counting again after resetting the counter to zero, resctrl in turn compares the new count against the counter value stored from the previous time the RMID was tracked. This results in resctrl computing an event value that is either undercounting (when new counter is more than stored counter) or a mistaken overflow (when new counter is less than stored counter). Reset the stored value (arch_mbm_state::prev_msr) of MSR_IA32_QM_CTR to zero whenever the RMID is in the "Unavailable" state to ensure accurate counting after the RMID resets to zero when it starts to be tracked again. Example scenario that results in mistaken overflow ================================================== 1. The resctrl filesystem is mounted, and a task is assigned to a monitoring group. $mount -t resctrl resctrl /sys/fs/resctrl $mkdir /sys/fs/resctrl/mon_groups/test1/ $echo 1234 > /sys/fs/resctrl/mon_groups/test1/tasks $cat /sys/fs/resctrl/mon_groups/test1/mon_data/mon_L3_*/mbm_total_bytes 21323 <- Total bytes on domain 0 "Unavailable" <- Total bytes on domain 1 Task is running on domain 0. Counter on domain 1 is "Unavailable". 2. The task runs on domain 0 for a while and then moves to domain 1. The counter starts incrementing on domain 1. $cat /sys/fs/resctrl/mon_groups/test1/mon_data/mon_L3_*/mbm_total_bytes 7345357 <- Total bytes on domain 0 4545 <- Total bytes on domain 1 3. At some point, the RMID in domain 0 transitions to the "Unavailable" state because the task is no longer executing in that domain. $cat /sys/fs/resctrl/mon_groups/test1/mon_data/mon_L3_*/mbm_total_bytes "Unavailable" <- Total bytes on domain 0 434341 <- Total bytes on domain 1 4. Since the task continues to migrate between domains, it may eventually return to domain 0. $cat /sys/fs/resctrl/mon_groups/test1/mon_data/mon_L3_*/mbm_total_bytes 17592178699059 <- Overflow on domain 0 3232332 <- Total bytes on domain 1 In this case, the RMID on domain 0 transitions from "Unavailable" state to active state. The hardware sets MSR_IA32_QM_CTR.Unavailable (bit 62) when the counter is read and begins tracking the RMID counting from 0. Subsequent reads succeed but return a value smaller than the previously saved MSR value (7345357). Consequently, the resctrl's overflow logic is triggered, it compares the previous value (7345357) with the new, smaller value and incorrectly interprets this as a counter overflow, adding a large delta. In reality, this is a false positive: the counter did not overflow but was simply reset when the RMID transitioned from "Unavailable" back to active state. Here is the text from APM [1] available from [2]. "In PQOS Version 2.0 or higher, the MBM hardware will set the U bit on the first QM_CTR read when it begins tracking an RMID that it was not previously tracking. The U bit will be zero for all subsequent reads from that RMID while it is still tracked by the hardware. Therefore, a QM_CTR read with the U bit set when that RMID is in use by a processor can be considered 0 when calculating the difference with a subsequent read." [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming Publication # 24593 Revision 3.41 section 19.3.3 Monitoring L3 Memory Bandwidth (MBM). [ bp: Split commit message into smaller paragraph chunks for better consumption. ] Fixes: 4d05bf71f157d ("x86/resctrl: Introduce AMD QOS feature") Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Cc: stable@vger.kernel.org # needs adjustments for <= v6.17 Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 # [2] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23x86/resctrl: Refactor resctrl_arch_rmid_read()Babu Moger1-15/+23
[ Upstream commit 7c9ac605e202c4668e441fc8146a993577131ca1 ] resctrl_arch_rmid_read() adjusts the value obtained from MSR_IA32_QM_CTR to account for the overflow for MBM events and apply counter scaling for all the events. This logic is common to both reading an RMID and reading a hardware counter directly. Refactor the hardware value adjustment logic into get_corrected_val() to prepare for support of reading a hardware counter. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com Stable-dep-of: 15292f1b4c55 ("x86/resctrl: Fix miscount of bandwidth event when reactivating previously unavailable RMID") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23x86/CPU/AMD: Prevent reset reasons from being retained across rebootRong Zhang1-2/+14
commit e6416c2dfe23c9a6fec881fda22ebb9ae486cfc5 upstream. The S5_RESET_STATUS register is parsed on boot and printed to kmsg. However, this could sometimes be misleading and lead to users wasting a lot of time on meaningless debugging for two reasons: * Some bits are never cleared by hardware. It's the software's responsibility to clear them as per the Processor Programming Reference (see [1]). * Some rare hardware-initiated platform resets do not update the register at all. In both cases, a previous reboot could leave its trace in the register, resulting in users seeing unrelated reboot reasons while debugging random reboots afterward. Write the read value back to the register in order to clear all reason bits since they are write-1-to-clear while the others must be preserved. [1]: https://bugzilla.kernel.org/show_bug.cgi?id=206537#attach_303991 [ bp: Massage commit message. ] Fixes: ab8131028710 ("x86/CPU/AMD: Print the reason for the last reset") Signed-off-by: Rong Zhang <i@rong.moe> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org> Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/all/20250913144245.23237-1-i@rong.moe/ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-22x86/topology: Implement topology_is_core_online() to address SMT regressionThomas Gleixner1-0/+13
Christian reported that commit a430c11f4015 ("intel_idle: Rescan "dead" SMT siblings during initialization") broke the use case in which both 'nosmt' and 'maxcpus' are on the kernel command line because it onlines primary threads, which were offline due to the maxcpus limit. The initially proposed fix to skip primary threads in the loop is inconsistent. While it prevents the primary thread to be onlined, it then onlines the corresponding hyperthread(s), which does not really make sense. The CPU iterator in cpuhp_smt_enable() contains a check which excludes all threads of a core, when the primary thread is offline. The default implementation is a NOOP and therefore not effective on x86. Implement topology_is_core_online() on x86 to address this issue. This makes the behaviour consistent between x86 and PowerPC. Fixes: a430c11f4015 ("intel_idle: Rescan "dead" SMT siblings during initialization") Fixes: f694481b1d31 ("ACPI: processor: Rescan "dead" SMT siblings during initialization") Closes: https://lore.kernel.org/linux-pm/724616a2-6374-4ba3-8ce3-ea9c45e2ae3b@arm.com/ Reported-by: Christian Loehle <christian.loehle@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Tested-by: Christian Loehle <christian.loehle@arm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/12740505.O9o76ZdvQC@rafael.j.wysocki
2025-09-14Merge tag 'x86-urgent-2025-09-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-11/+14
Pull x86 fixes from Ingo Molnar: "Fix a CPU topology parsing bug on AMD guests, and address a lockdep warning in the resctrl filesystem" * tag 'x86-urgent-2025-09-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fs/resctrl: Eliminate false positive lockdep warning when reading SNC counters x86/cpu/topology: Always try cpu_parse_topology_ext() on AMD/Hygon
2025-09-10Merge tag 'vmscape-for-linus-20250904' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-113/+258
Pull vmescape mitigation fixes from Dave Hansen: "Mitigate vmscape issue with indirect branch predictor flushes. vmscape is a vulnerability that essentially takes Spectre-v2 and attacks host userspace from a guest. It particularly affects hypervisors like QEMU. Even if a hypervisor may not have any sensitive data like disk encryption keys, guest-userspace may be able to attack the guest-kernel using the hypervisor as a confused deputy. There are many ways to mitigate vmscape using the existing Spectre-v2 defenses like IBRS variants or the IBPB flushes. This series focuses solely on IBPB because it works universally across vendors and all vulnerable processors. Further work doing vendor and model-specific optimizations can build on top of this if needed / wanted. Do the normal issue mitigation dance: - Add the CPU bug boilerplate - Add a list of vulnerable CPUs - Use IBPB to flush the branch predictors after running guests" * tag 'vmscape-for-linus-20250904' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vmscape: Add old Intel CPUs to affected list x86/vmscape: Warn when STIBP is disabled with SMT x86/bugs: Move cpu_bugs_smt_update() down x86/vmscape: Enable the mitigation x86/vmscape: Add conditional IBPB mitigation x86/vmscape: Enumerate VMSCAPE bug Documentation/hw-vuln: Add VMSCAPE documentation
2025-09-08x86/cpu/topology: Always try cpu_parse_topology_ext() on AMD/HygonK Prateek Nayak1-11/+14
Support for parsing the topology on AMD/Hygon processors using CPUID leaf 0xb was added in 3986a0a805e6 ("x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available"). In an effort to keep all the topology parsing bits in one place, this commit also introduced a pseudo dependency on the TOPOEXT feature to parse the CPUID leaf 0xb. The TOPOEXT feature (CPUID 0x80000001 ECX[22]) advertises the support for Cache Properties leaf 0x8000001d and the CPUID leaf 0x8000001e EAX for "Extended APIC ID" however support for 0xb was introduced alongside the x2APIC support not only on AMD [1], but also historically on x86 [2]. Similar to 0xb, the support for extended CPU topology leaf 0x80000026 too does not depend on the TOPOEXT feature. The support for these leaves is expected to be confirmed by ensuring leaf <= {extended_}cpuid_level and then parsing the level 0 of the respective leaf to confirm EBX[15:0] (LogProcAtThisLevel) is non-zero as stated in the definition of "CPUID_Fn0000000B_EAX_x00 [Extended Topology Enumeration] (Core::X86::Cpuid::ExtTopEnumEax0)" in Processor Programming Reference (PPR) for AMD Family 19h Model 01h Rev B1 Vol1 [3] Sec. 2.1.15.1 "CPUID Instruction Functions". This has not been a problem on baremetal platforms since support for TOPOEXT (Fam 0x15 and later) predates the support for CPUID leaf 0xb (Fam 0x17[Zen2] and later), however, for AMD guests on QEMU, the "x2apic" feature can be enabled independent of the "topoext" feature where QEMU expects topology and the initial APICID to be parsed using the CPUID leaf 0xb (especially when number of cores > 255) which is populated independent of the "topoext" feature flag. Unconditionally call cpu_parse_topology_ext() on AMD and Hygon processors to first parse the topology using the XTOPOLOGY leaves (0x80000026 / 0xb) before using the TOPOEXT leaf (0x8000001e). While at it, break down the single large comment in parse_topology_amd() to better highlight the purpose of each CPUID leaf. Fixes: 3986a0a805e6 ("x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available") Suggested-by: Naveen N Rao (AMD) <naveen@kernel.org> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org # Only v6.9 and above; depends on x86 topology rewrite Link: https://lore.kernel.org/lkml/1529686927-7665-1-git-send-email-suravee.suthikulpanit@amd.com/ [1] Link: https://lore.kernel.org/lkml/20080818181435.523309000@linux-os.sc.intel.com/ [2] Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 [3]
2025-08-29x86/vmscape: Add old Intel CPUs to affected listPawan Gupta1-9/+12
These old CPUs are not tested against VMSCAPE, but are likely vulnerable. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
2025-08-27x86/bugs: Add attack vector controls for SSBDavid Kaplan1-0/+9
Attack vector controls for SSB were missed in the initial attack vector series. The default mitigation for SSB requires user-space opt-in so it is only relevant for user->user attacks. Check with attack vector controls when the command is auto - i.e., no explicit user selection has been done. Fixes: 2d31d2874663 ("x86/bugs: Define attack vectors relevant for each bug") Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250819192200.2003074-5-david.kaplan@amd.com
2025-08-27x86/cpu/topology: Use initial APIC ID from XTOPOLOGY leaf on AMD/HYGONK Prateek Nayak1-9/+14
Prior to the topology parsing rewrite and the switchover to the new parsing logic for AMD processors in c749ce393b8f ("x86/cpu: Use common topology code for AMD"), the initial_apicid on these platforms was: - First initialized to the LocalApicId from CPUID leaf 0x1 EBX[31:24]. - Then overwritten by the ExtendedLocalApicId in CPUID leaf 0xb EDX[31:0] on processors that supported topoext. With the new parsing flow introduced in f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser"), parse_8000_001e() now unconditionally overwrites the initial_apicid already parsed during cpu_parse_topology_ext(). Although this has not been a problem on baremetal platforms, on virtualized AMD guests that feature more than 255 cores, QEMU zeros out the CPUID leaf 0x8000001e on CPUs with CoreID > 255 to prevent collision of these IDs in EBX[7:0] which can only represent a maximum of 255 cores [1]. This results in the following FW_BUG being logged when booting a guest with more than 255 cores: [Firmware Bug]: CPU 512: APIC ID mismatch. CPUID: 0x0000 APIC: 0x0200 AMD64 Architecture Programmer's Manual Volume 2: System Programming Pub. 24593 Rev. 3.42 [2] Section 16.12 "x2APIC_ID" mentions the Extended Enumeration leaf 0xb (Fn0000_000B_EDX[31:0])(which was later superseded by the extended leaf 0x80000026) provides the full x2APIC ID under all circumstances unlike the one reported by CPUID leaf 0x8000001e EAX which depends on the mode in which APIC is configured. Rely on the APIC ID parsed during cpu_parse_topology_ext() from CPUID leaf 0x80000026 or 0xb and only use the APIC ID from leaf 0x8000001e if cpu_parse_topology_ext() failed (has_topoext is false). On platforms that support the 0xb leaf (Zen2 or later, AMD guests on QEMU) or the extended leaf 0x80000026 (Zen4 or later), the initial_apicid is now set to the value parsed from EDX[31:0]. On older AMD/Hygon platforms that do not support the 0xb leaf but support the TOPOEXT extension (families 0x15, 0x16, 0x17[Zen1], and Hygon), retain current behavior where the initial_apicid is set using the 0x8000001e leaf. Issue debugged by Naveen N Rao (AMD) <naveen@kernel.org> and Sairaj Kodilkar <sarunkod@amd.com>. [ bp: Massage commit message. ] Fixes: c749ce393b8f ("x86/cpu: Use common topology code for AMD") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Naveen N Rao (AMD) <naveen@kernel.org> Cc: stable@vger.kernel.org Link: https://github.com/qemu/qemu/commit/35ac5dfbcaa4b [1] Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 [2] Link: https://lore.kernel.org/20250825075732.10694-2-kprateek.nayak@amd.com
2025-08-27x86/microcode/AMD: Handle the case of no BIOS microcodeBorislav Petkov (AMD)1-2/+20
Machines can be shipped without any microcode in the BIOS. Which means, the microcode patch revision is 0. Handle that gracefully. Fixes: 94838d230a6c ("x86/microcode/AMD: Use the family,model,stepping encoded in the patch ID") Reported-by: Vítek Vávra <vit.vavra.kh@gmail.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org>
2025-08-25x86/cpu/intel: Fix the constant_tsc model check for Pentium 4Suchit Karunakaran1-1/+1
Pentium 4's which are INTEL_P4_PRESCOTT (model 0x03) and later have a constant TSC. This was correctly captured until commit fadb6f569b10 ("x86/cpu/intel: Limit the non-architectural constant_tsc model checks"). In that commit, an error was introduced while selecting the last P4 model (0x06) as the upper bound. Model 0x06 was transposed to INTEL_P4_WILLAMETTE, which is just plain wrong. That was presumably a simple typo, probably just copying and pasting the wrong P4 model. Fix the constant TSC logic to cover all later P4 models. End at INTEL_P4_CEDARMILL which accurately corresponds to the last P4 model. Fixes: fadb6f569b10 ("x86/cpu/intel: Limit the non-architectural constant_tsc model checks") Signed-off-by: Suchit Karunakaran <suchitkarunakaran@gmail.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250816065126.5000-1-suchitkarunakaran%40gmail.com
2025-08-19x86/bugs: Fix GDS mitigation selecting when mitigation is offLi RongQing1-3/+1
The current GDS mitigation logic incorrectly returns early when the attack vector mitigation is turned off, which leads to two problems: 1. CPUs without ARCH_CAP_GDS_CTRL support are incorrectly marked with GDS_MITIGATION_OFF when they should be marked as GDS_MITIGATION_UCODE_NEEDED. 2. The mitigation state checks and locking verification that follow are skipped, which means: - fail to detect if the mitigation was locked - miss the warning when trying to disable a locked mitigation Remove the early return to ensure proper mitigation state handling. This allows: - Proper mitigation classification for non-ARCH_CAP_GDS_CTRL CPUs - Complete mitigation state verification This also addresses the failed MSR 0x123 write attempt at boot on non-ARCH_CAP_GDS_CTRL CPUs: unchecked MSR access error: WRMSR to 0x123 (tried to write 0x0000000000000010) at rIP: ... (update_gds_msr) Call Trace: identify_secondary_cpu start_secondary common_startup_64 WARNING: CPU: 1 PID: 0 at arch/x86/kernel/cpu/bugs.c:1053 update_gds_msr [ bp: Massage, zap superfluous braces. ] Fixes: 8c7261abcb7ad ("x86/bugs: Add attack vector controls for GDS") Suggested-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Link: https://lore.kernel.org/20250819023356.2012-1-lirongqing@baidu.com
2025-08-18x86/CPU/AMD: Ignore invalid reset reason valueYazen Ghannam1-2/+6
The reset reason value may be "all bits set", e.g. 0xFFFFFFFF. This is a commonly used error response from hardware. This may occur due to a real hardware issue or when running in a VM. The user will see all reset reasons reported in this case. Check for an error response value and return early to avoid decoding invalid data. Also, adjust the data variable type to match the hardware register size. Fixes: ab8131028710 ("x86/CPU/AMD: Print the reason for the last reset") Reported-by: Libing He <libhe@redhat.com> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250721181155.3536023-1-yazen.ghannam@amd.com
2025-08-18x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helperTianxiang Peng1-0/+3
Since 923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot") resctrl_cpu_detect() has been moved from common CPU initialization code to the vendor-specific BSP init helper, while Hygon didn't put that call in their code. This triggers a division by zero fault during early booting stage on our machines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries to calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale. Add the missing resctrl_cpu_detect() in the Hygon BSP init helper. [ bp: Massage commit message. ] Fixes: 923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot") Signed-off-by: Tianxiang Peng <txpeng@tencent.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Hui Li <caelli@tencent.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/20250623093153.3016937-1-txpeng@tencent.com
2025-08-17Merge tag 'x86_urgent_for_v6.17_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+11
Pull x86 fixes from Borislav Petkov: - Remove a transitional asm/cpuid.h header which was added only as a fallback during cpuid helpers reorg - Initialize reserved fields in the SVSM page validation calls structure to zero in order to allow for future structure extensions - Have the sev-guest driver's buffers used in encryption operations be in linear mapping space as the encryption operation can be offloaded to an accelerator - Have a read-only MSR write when in an AMD SNP guest trap to the hypervisor as it is usually done. This makes the guest user experience better by simply raising a #GP instead of terminating said guest - Do not output AVX512 elapsed time for kernel threads because the data is wrong and fix a NULL pointer dereferencing in the process - Adjust the SRSO mitigation selection to the new attack vectors * tag 'x86_urgent_for_v6.17_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpuid: Remove transitional <asm/cpuid.h> header x86/sev: Ensure SVSM reserved fields in a page validation entry are initialized to zero virt: sev-guest: Satisfy linear mapping requirement in get_derived_key() x86/sev: Improve handling of writes to intercepted TSC MSRs x86/fpu: Fix NULL dereference in avx512_status() x86/bugs: Select best SRSO mitigation
2025-08-14x86/vmscape: Warn when STIBP is disabled with SMTPawan Gupta1-0/+22
Cross-thread attacks are generally harder as they require the victim to be co-located on a core. However, with VMSCAPE the adversary targets belong to the same guest execution, that are more likely to get co-located. In particular, a thread that is currently executing userspace hypervisor (after the IBPB) may still be targeted by a guest execution from a sibling thread. Issue a warning about the potential risk, except when: - SMT is disabled - STIBP is enabled system-wide - Intel eIBRS is enabled (which implies STIBP protection) Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
2025-08-14x86/bugs: Move cpu_bugs_smt_update() downPawan Gupta1-82/+83
cpu_bugs_smt_update() uses global variables from different mitigations. For SMT updates it can't currently use vmscape_mitigation that is defined after it. Since cpu_bugs_smt_update() depends on many other mitigations, move it after all mitigations are defined. With that, it can use vmscape_mitigation in a moment. No functional change. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
2025-08-14x86/vmscape: Enable the mitigationPawan Gupta1-0/+90
Enable the previously added mitigation for VMscape. Add the cmdline vmscape={off|ibpb|force} and sysfs reporting. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
2025-08-14x86/vmscape: Add conditional IBPB mitigationPawan Gupta1-0/+8
VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit. Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB. This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace. The intent is to integrate and optimize these cases post-embargo. [ dhansen: elaborate on suboptimal IBPB solution ] Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Sean Christopherson <seanjc@google.com>
2025-08-14x86/vmscape: Enumerate VMSCAPE bugPawan Gupta1-22/+43
The VMSCAPE vulnerability may allow a guest to cause Branch Target Injection (BTI) in userspace hypervisors. Kernels (both host and guest) have existing defenses against direct BTI attacks from guests. There are also inter-process BTI mitigations which prevent processes from attacking each other. However, the threat in this case is to a userspace hypervisor within the same process as the attacker. Userspace hypervisors have access to their own sensitive data like disk encryption keys and also typically have access to all guest data. This means guest userspace may use the hypervisor as a confused deputy to attack sensitive guest kernel data. There are no existing mitigations for these attacks. Introduce X86_BUG_VMSCAPE for this vulnerability and set it on affected Intel and AMD CPUs. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
2025-08-12Merge tag 'snp_cache_coherency' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
- Add a mitigation for a cache coherency vulnerability when running an SNP guest which makes sure all cache lines belonging to a 4K page are evicted after latter has been converted to a guest-private page [ SNP: Secure Nested Paging - not to be confused with Single Nucleotide Polymorphism, which is the more common use of that TLA. I am on a mission to write out the more obscure TLAs in order to keep track of them. Because while math tells us that there are only about 17k different combinations of three-letter acronyms using English letters (26^3), I am convinced that somehow Intel, AMD and ARM have together figured out new mathematics, and have at least a million different TLAs that they use. - Linus ] * tag 'snp_cache_coherency' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev: Evict cache lines during SNP memory validation
2025-08-11x86/bugs: Select best SRSO mitigationDavid Kaplan1-2/+11
The SRSO bug can theoretically be used to conduct user->user or guest->guest attacks and requires a mitigation (namely IBPB instead of SBPB on context switch) for these. So mark SRSO as being applicable to the user->user and guest->guest attack vectors. Additionally, SRSO supports multiple mitigations which mitigate different potential attack vectors. Some CPUs are also immune to SRSO from certain attack vectors (like user->kernel). Use the specific attack vectors requiring mitigation to select the best SRSO mitigation to avoid unnecessary performance hits. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250721160310.1804203-1-david.kaplan@amd.com
2025-08-06x86/sev: Evict cache lines during SNP memory validationTom Lendacky1-0/+1
An SNP cache coherency vulnerability requires a cache line eviction mitigation when validating memory after a page state change to private. The specific mitigation is to touch the first and last byte of each 4K page that is being validated. There is no need to perform the mitigation when performing a page state change to shared and rescinding validation. CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit that, when set, indicates that the software mitigation for this vulnerability is not needed. Implement the mitigation and invoke it when validating memory (making it private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP guest is vulnerable. Co-developed-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2025-07-31Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds2-5/+5
Pull MM updates from Andrew Morton: "As usual, many cleanups. The below blurbiage describes 42 patchsets. 21 of those are partially or fully cleanup work. "cleans up", "cleanup", "maintainability", "rationalizes", etc. I never knew the MM code was so dirty. "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes) addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for merging with existing adjacent VMAs. "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park) adds a new kernel module which simplifies the setup and usage of DAMON in production environments. "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig) is a cleanup to the writeback code which removes a couple of pointers from struct writeback_control. "drivers/base/node.c: optimization and cleanups" (Donet Tom) contains largely uncorrelated cleanups to the NUMA node setup and management code. "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman) does some maintenance work on the userfaultfd code. "Readahead tweaks for larger folios" (Ryan Roberts) implements some tuneups for pagecache readahead when it is reading into order>0 folios. "selftests/mm: Tweaks to the cow test" (Mark Brown) provides some cleanups and consistency improvements to the selftests code. "Optimize mremap() for large folios" (Dev Jain) does that. A 37% reduction in execution time was measured in a memset+mremap+munmap microbenchmark. "Remove zero_user()" (Matthew Wilcox) expunges zero_user() in favor of the more modern memzero_page(). "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand) addresses some warts which David noticed in the huge page code. These were not known to be causing any issues at this time. "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park) provides some cleanup and consolidation work in DAMON. "use vm_flags_t consistently" (Lorenzo Stoakes) uses vm_flags_t in places where we were inappropriately using other types. "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy) increases the reliability of large page allocation in the memfd code. "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple) removes several now-unneeded PFN_* flags. "mm/damon: decouple sysfs from core" (SeongJae Park) implememnts some cleanup and maintainability work in the DAMON sysfs layer. "madvise cleanup" (Lorenzo Stoakes) does quite a lot of cleanup/maintenance work in the madvise() code. "madvise anon_name cleanups" (Vlastimil Babka) provides additional cleanups on top or Lorenzo's effort. "Implement numa node notifier" (Oscar Salvador) creates a standalone notifier for NUMA node memory state changes. Previously these were lumped under the more general memory on/offline notifier. "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan) cleans up the pageblock isolation code and fixes a potential issue which doesn't seem to cause any problems in practice. "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park) adds additional drgn- and python-based DAMON selftests which are more comprehensive than the existing selftest suite. "Misc rework on hugetlb faulting path" (Oscar Salvador) fixes a rather obscure deadlock in the hugetlb fault code and follows that fix with a series of cleanups. "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport) rationalizes and cleans up the highmem-specific code in the CMA allocator. "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand) provides cleanups and future-preparedness to the migration code. "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park) adds some tracepoints to some DAMON auto-tuning code. "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park) does that. "mm/damon: misc cleanups" (SeongJae Park) also does what it claims. "mm: folio_pte_batch() improvements" (David Hildenbrand) cleans up the large folio PTE batching code. "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park) facilitates dynamic alteration of DAMON's inter-node allocation policy. "Remove unmap_and_put_page()" (Vishal Moola) provides a couple of page->folio conversions. "mm: per-node proactive reclaim" (Davidlohr Bueso) implements a per-node control of proactive reclaim - beyond the current memcg-based implementation. "mm/damon: remove damon_callback" (SeongJae Park) replaces the damon_callback interface with a more general and powerful damon_call()+damos_walk() interface. "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes) implements a number of mremap cleanups (of course) in preparation for adding new mremap() functionality: newly permit the remapping of multiple VMAs when the user is specifying MREMAP_FIXED. It still excludes some specialized situations where this cannot be performed reliably. "drop hugetlb_free_pgd_range()" (Anthony Yznaga) switches some sparc hugetlb code over to the generic version and removes the thus-unneeded hugetlb_free_pgd_range(). "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park) augments the present userspace-requested update of DAMON sysfs monitoring files. Automatic update is now provided, along with a tunable to control the update interval. "Some randome fixes and cleanups to swapfile" (Kemeng Shi) does what is claims. "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand) provides (and uses) a means by which debug-style functions can grab a copy of a pageframe and inspect it locklessly without tripping over the races inherent in operating on the live pageframe directly. "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan) addresses the large contention issues which can be triggered by reads from that procfs file. Latencies are reduced by more than half in some situations. The series also introduces several new selftests for the /proc/pid/maps interface. "__folio_split() clean up" (Zi Yan) cleans up __folio_split()! "Optimize mprotect() for large folios" (Dev Jain) provides some quite large (>3x) speedups to mprotect() when dealing with large folios. "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian) does some cleanup work in the selftests code. "tools/testing: expand mremap testing" (Lorenzo Stoakes) extends the mremap() selftest in several ways, including adding more checking of Lorenzo's recently added "permit mremap() move of multiple VMAs" feature. "selftests/damon/sysfs.py: test all parameters" (SeongJae Park) extends the DAMON sysfs interface selftest so that it tests all possible user-requested parameters. Rather than the present minimal subset" * tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits) MAINTAINERS: add missing headers to mempory policy & migration section MAINTAINERS: add missing file to cgroup section MAINTAINERS: add MM MISC section, add missing files to MISC and CORE MAINTAINERS: add missing zsmalloc file MAINTAINERS: add missing files to page alloc section MAINTAINERS: add missing shrinker files MAINTAINERS: move memremap.[ch] to hotplug section MAINTAINERS: add missing mm_slot.h file THP section MAINTAINERS: add missing interval_tree.c to memory mapping section MAINTAINERS: add missing percpu-internal.h file to per-cpu section mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info() selftests/damon: introduce _common.sh to host shared function selftests/damon/sysfs.py: test runtime reduction of DAMON parameters selftests/damon/sysfs.py: test non-default parameters runtime commit selftests/damon/sysfs.py: generalize DAMON context commit assertion selftests/damon/sysfs.py: generalize monitoring attributes commit assertion selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion selftests/damon/sysfs.py: test DAMOS filters commitment selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion selftests/damon/sysfs.py: test DAMOS destinations commitment ...
2025-07-29Merge tag 'x86-cpu-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+3
Pull x86 cpu update from Ingo Molnar: "Add user-space CPUID faulting support for AMD CPUs" * tag 'x86-cpu-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Add CPUID faulting support
2025-07-29Merge tag 'x86-boot-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+7
Pull x86 boot updates from Ingo Molnar: - Implement support for embedding EFI SBAT data (Secure Boot Advanced Targeting: a secure boot image revocation facility) on x86 (Vitaly Kuznetsov) - Move the efi_enter_virtual_mode() initialization call from the generic init code to x86 init code (Alexander Shishkin) * tag 'x86-boot-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/efi: Implement support for embedding SBAT data for x86 x86/efi: Move runtime service initialization to arch/x86
2025-07-29Merge tag 'x86_microcode_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-7/+7
Pull x86 microcode loader update from Borislav Petkov: - Switch the microcode loader from using the fake platform device to the new simple faux bus * tag 'x86_microcode_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Move away from using a fake platform device
2025-07-29Merge tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-142/+323
Pull x86 CPU mitigation updates from Borislav Petkov: - Untangle the Retbleed from the ITS mitigation on Intel. Allow for ITS to enable stuffing independently from Retbleed, do some cleanups to simplify and streamline the code - Simplify SRSO and make mitigation types selection more versatile depending on the Retbleed mitigation selection. Simplify code some - Add the second part of the attack vector controls which provide a lot friendlier user interface to the speculation mitigations than selecting each one by one as it is now. Instead, the selection of whole attack vectors which are relevant to the system in use can be done and protection against only those vectors is enabled, thus giving back some performance to the users * tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86/bugs: Print enabled attack vectors x86/bugs: Add attack vector controls for TSA x86/pti: Add attack vector controls for PTI x86/bugs: Add attack vector controls for ITS x86/bugs: Add attack vector controls for SRSO x86/bugs: Add attack vector controls for L1TF x86/bugs: Add attack vector controls for spectre_v2 x86/bugs: Add attack vector controls for BHI x86/bugs: Add attack vector controls for spectre_v2_user x86/bugs: Add attack vector controls for retbleed x86/bugs: Add attack vector controls for spectre_v1 x86/bugs: Add attack vector controls for GDS x86/bugs: Add attack vector controls for SRBDS x86/bugs: Add attack vector controls for RFDS x86/bugs: Add attack vector controls for MMIO x86/bugs: Add attack vector controls for TAA x86/bugs: Add attack vector controls for MDS x86/bugs: Define attack vectors relevant for each bug x86/Kconfig: Add arch attack vector support cpu: Define attack vectors ...
2025-07-28Merge tag 'v6.16' into x86/cpu, to resolve conflictIngo Molnar9-49/+354
Resolve overlapping context conflict between this upstream fix: d8010d4ba43e ("x86/bugs: Add a Transient Scheduler Attacks mitigation") And this pending commit in tip:x86/cpu: 65f55a301766 ("x86/CPU/AMD: Add CPUID faulting support") Conflicts: arch/x86/kernel/cpu/amd.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-07-13Merge tag 'x86_urgent_for_v6.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+10
Pull x86 fixes from Borislav Petkov: - Update Kirill's email address - Allow hugetlb PMD sharing only on 64-bit as it doesn't make a whole lotta sense on 32-bit - Add fixes for a misconfigured AMD Zen2 client which wasn't even supposed to run Linux * tag 'x86_urgent_for_v6.16_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Update Kirill Shutemov's email address for TDX x86/mm: Disable hugetlb page table sharing on 32-bit x86/CPU/AMD: Disable INVLPGB on Zen2 x86/rdrand: Disable RDSEED on AMD Cyan Skillfish
2025-07-11x86/bugs: Print enabled attack vectorsDavid Kaplan1-0/+35
Print the status of enabled attack vectors and SMT mitigation status in the boot log for easier reporting and debugging. This information will also be available through sysfs. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-21-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for TSADavid Kaplan1-8/+23
Use attack vector controls to determine which TSA mitigation to use. [ bp: Simplify the condition in the select function for better readability. ] Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250709155844.3279471-1-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for ITSDavid Kaplan1-5/+10
Use attack vector controls to determine if ITS mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-19-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for SRSODavid Kaplan1-5/+10
Use attack vector controls to determine if SRSO mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-18-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for L1TFDavid Kaplan1-6/+12
Use attack vector controls to determine if L1TF mitigation is required. Disable SMT if cross-thread protection is desired. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-17-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for spectre_v2David Kaplan1-4/+6
Use attack vector controls to determine if spectre_v2 mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-16-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for BHIDavid Kaplan1-3/+12
Use attack vector controls to determine if BHI mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-15-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for spectre_v2_userDavid Kaplan1-1/+8
Use attack vector controls to determine if spectre_v2_user mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-14-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for retbleedDavid Kaplan1-3/+8
Use attack vector controls to determine if retbleed mitigation is required. Disable SMT if cross-thread protection is desired and STIBP is not available. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-13-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for spectre_v1David Kaplan1-2/+5
Use attack vector controls to determine if spectre_v1 mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-12-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for GDSDavid Kaplan1-5/+8
Use attack vector controls to determine if GDS mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-11-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for SRBDSDavid Kaplan1-3/+9
Use attack vector controls to determine if SRBDS mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-10-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for RFDSDavid Kaplan1-4/+8
Use attack vector controls to determine if RFDS mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-9-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for MMIODavid Kaplan1-4/+8
Use attack vectors controls to determine if MMIO mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-8-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for TAADavid Kaplan1-7/+8
Use attack vector controls to determine if TAA mitigation is required. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-7-david.kaplan@amd.com
2025-07-11x86/bugs: Add attack vector controls for MDSDavid Kaplan1-5/+9
Use attack vector controls to determine if MDS mitigation is required. The global mitigations=off command now simply disables all attack vectors so explicit checking of mitigations=off is no longer needed. If cross-thread attack mitigations are required, disable SMT. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-6-david.kaplan@amd.com
2025-07-11x86/bugs: Define attack vectors relevant for each bugDavid Kaplan1-0/+56
Add a function which defines which vulnerabilities should be mitigated based on the selected attack vector controls. The selections here are based on the individual characteristics of each vulnerability. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-5-david.kaplan@amd.com
2025-07-09mm: update architecture and driver code to use vm_flags_tLorenzo Stoakes2-5/+5
In future we intend to change the vm_flags_t type, so it isn't correct for architecture and driver code to assume it is unsigned long. Correct this assumption across the board. Overall, this patch does not introduce any functional change. Link: https://lkml.kernel.org/r/b6eb1894abc5555ece80bb08af5c022ef780c8bc.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Kees Cook <kees@kernel.org> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>