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[PATCH v4 net-next 00/13] AccECN protocol case handling series

by chia-yu.chang＠nokia-bell-labs.com

From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com> Hello, Plesae find the v4 AccECN case handling patch series, which covers several excpetional case handling of Accurate ECN spec (RFC9768), adds new identifiers to be used by CC modules, adds ecn_delta into rate_sample, and keeps the ACE counter for computation, etc. This patch series is part of the full AccECN patch series, which is available at https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/ Best regards, Chia-Yu --- v4: - Add previous #13 in v2 back after dicussion with the RFC author. - Add TCP_ACCECN_OPTION_PERSIST to tcp_ecn_option sysctl to ignore AccECN fallback policy on sending AccECN option. v3: - Add additional min() check if pkts_acked_ewma is not initialized in #1. - Change TCP_CONG_WANTS_ECT_1 into individual flag add helper function INET_ECN_xmit_wants_ect_1() in #3. - Add empty line between variable declarations and code in #4. - Update commit message to fix old AccECN commits in #5. - Remove unnecessary brackets in #10. - Move patch #3 in v2 to a later Prague patch serise and remove patch #13 in v2. --- Chia-Yu Chang (11): tcp: L4S ECT(1) identifier and NEEDS_ACCECN for CC modules tcp: disable RFC3168 fallback identifier for CC modules tcp: accecn: handle unexpected AccECN negotiation feedback tcp: accecn: retransmit downgraded SYN in AccECN negotiation tcp: move increment of num_retrans tcp: accecn: retransmit SYN/ACK without AccECN option or non-AccECN SYN/ACK tcp: accecn: unset ECT if receive or send ACE=0 in AccECN negotiaion tcp: accecn: fallback outgoing half link to non-AccECN tcp: accecn: verify ACE counter in 1st ACK after AccECN negotiation tcp: accecn: detect loss ACK w/ AccECN option and add TCP_ACCECN_OPTION_PERSIST tcp: accecn: enable AccECN Ilpo Järvinen (2): tcp: try to avoid safer when ACKs are thinned gro: flushing when CWR is set negatively affects AccECN Documentation/networking/ip-sysctl.rst | 4 +- .../networking/net_cachelines/tcp_sock.rst | 1 + include/linux/tcp.h | 4 +- include/net/inet_ecn.h | 20 +++- include/net/tcp.h | 32 ++++++- include/net/tcp_ecn.h | 92 ++++++++++++++----- net/ipv4/sysctl_net_ipv4.c | 4 +- net/ipv4/tcp.c | 2 + net/ipv4/tcp_cong.c | 10 +- net/ipv4/tcp_input.c | 58 ++++++++++-- net/ipv4/tcp_minisocks.c | 40 +++++--- net/ipv4/tcp_offload.c | 3 +- net/ipv4/tcp_output.c | 42 ++++++--- 13 files changed, 241 insertions(+), 71 deletions(-) -- 2.34.1

1 week, 1 day

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[PATCH] KVM: selftests: Don't fall over when only one CPU

by Brendan Jackman

Running this test on a system with only one CPU is not a recipe for success. However, there's no clear-cut reason why it absolutely shouldn't work, so the test shouldn't completely reject such a platform. At present, the *3/4 calculation will return zero on these platforms and the test fails. So, instead just skip that calculation. Suggested-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Brendan Jackman <jackmanb(a)google.com> --- tools/testing/selftests/kvm/mmu_stress_test.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/mmu_stress_test.c b/tools/testing/selftests/kvm/mmu_stress_test.c index 6a437d2be9fa444b34c2a73308a9d1c7ff3cc4f5..b5bd6fbad32a9ad5247a52ecf811b29293763e2e 100644 --- a/tools/testing/selftests/kvm/mmu_stress_test.c +++ b/tools/testing/selftests/kvm/mmu_stress_test.c @@ -263,8 +263,10 @@ static void calc_default_nr_vcpus(void) TEST_ASSERT(!r, "sched_getaffinity failed, errno = %d (%s)", errno, strerror(errno)); - nr_vcpus = CPU_COUNT(&possible_mask) * 3/4; + nr_vcpus = CPU_COUNT(&possible_mask); TEST_ASSERT(nr_vcpus > 0, "Uh, no CPUs?"); + if (nr_vcpus >= 2) + nr_vcpus = nr_vcpus * 3/4; } int main(int argc, char *argv[]) --- base-commit: 6b36119b94d0b2bb8cea9d512017efafd461d6ac change-id: 20251007-b4-kvm-mmu-stresstest-1proc-e6157c13787a Best regards, -- Brendan Jackman <jackmanb(a)google.com>

1 week, 1 day

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[PATCH kvm-next V11 0/7] Add NUMA mempolicy support for KVM guest-memfd

by Shivank Garg

This series introduces NUMA-aware memory placement support for KVM guests with guest_memfd memory backends. It builds upon Fuad Tabba's work (V17) that enabled host-mapping for guest_memfd memory [1] and can be applied directly applied on KVM tree [2] (branch kvm-next, base commit: a6ad5413, Merge branch 'guest-memfd-mmap' into HEAD) == Background == KVM's guest-memfd memory backend currently lacks support for NUMA policy enforcement, causing guest memory allocations to be distributed across host nodes according to kernel's default behavior, irrespective of any policy specified by the VMM. This limitation arises because conventional userspace NUMA control mechanisms like mbind(2) don't work since the memory isn't directly mapped to userspace when allocations occur. Fuad's work [1] provides the necessary mmap capability, and this series leverages it to enable mbind(2). == Implementation == This series implements proper NUMA policy support for guest-memfd by: 1. Adding mempolicy-aware allocation APIs to the filemap layer. 2. Introducing custom inodes (via a dedicated slab-allocated inode cache, kvm_gmem_inode_info) to store NUMA policy and metadata for guest memory. 3. Implementing get/set_policy vm_ops in guest_memfd to support NUMA policy. With these changes, VMMs can now control guest memory placement by mapping guest_memfd file descriptor and using mbind(2) to specify: - Policy modes: default, bind, interleave, or preferred - Host NUMA nodes: List of target nodes for memory allocation These Policies affect only future allocations and do not migrate existing memory. This matches mbind(2)'s default behavior which affects only new allocations unless overridden with MPOL_MF_MOVE/MPOL_MF_MOVE_ALL flags (Not supported for guest_memfd as it is unmovable by design). == Upstream Plan == Phased approach as per David's guest_memfd extension overview [3] and community calls [4]: Phase 1 (this series): 1. Focuses on shared guest_memfd support (non-CoCo VMs). 2. Builds on Fuad's host-mapping work [1]. Phase2 (future work): 1. NUMA support for private guest_memfd (CoCo VMs). 2. Depends on SNP in-place conversion support [5]. This series provides a clean integration path for NUMA-aware memory management for guest_memfd and lays the groundwork for future confidential computing NUMA capabilities. Thanks, Shivank == Changelog == - v1,v2: Extended the KVM_CREATE_GUEST_MEMFD IOCTL to pass mempolicy. - v3: Introduced fbind() syscall for VMM memory-placement configuration. - v4-v6: Current approach using shared_policy support and vm_ops (based on suggestions from David [6] and guest_memfd bi-weekly upstream call discussion [7]). - v7: Use inodes to store NUMA policy instead of file [8]. - v8: Rebase on top of Fuad's V12: Host mmaping for guest_memfd memory. - v9: Rebase on top of Fuad's V13 and incorporate review comments - V10: Rebase on top of Fuad's V17. Use latest guest_memfd inode patch from Ackerley (with David's review comments). Use newer kmem_cache_create() API variant with arg parameter (Vlastimil) - V11: Rebase on kvm-next, remove RFC tag, use Ackerley's latest patch and fix a rcu race bug during kvm module unload. [1] https://lore.kernel.org/all/20250729225455.670324-1-seanjc@google.com [2] https://git.kernel.org/pub/scm/virt/kvm/kvm.git/log/?h=next [3] https://lore.kernel.org/all/c1c9591d-218a-495c-957b-ba356c8f8e09@redhat.com [4] https://docs.google.com/document/d/1M6766BzdY1Lhk7LiR5IqVR8B8mG3cr-cxTxOrAo… [5] https://lore.kernel.org/all/20250613005400.3694904-1-michael.roth@amd.com [6] https://lore.kernel.org/all/6fbef654-36e2-4be5-906e-2a648a845278@redhat.com [7] https://lore.kernel.org/all/2b77e055-98ac-43a1-a7ad-9f9065d7f38f@amd.com [8] https://lore.kernel.org/all/diqzbjumm167.fsf@ackerleytng-ctop.c.googlers.com Ackerley Tng (1): KVM: guest_memfd: Use guest mem inodes instead of anonymous inodes Matthew Wilcox (Oracle) (2): mm/filemap: Add NUMA mempolicy support to filemap_alloc_folio() mm/filemap: Extend __filemap_get_folio() to support NUMA memory policies Shivank Garg (4): mm/mempolicy: Export memory policy symbols KVM: guest_memfd: Add slab-allocated inode cache KVM: guest_memfd: Enforce NUMA mempolicy using shared policy KVM: guest_memfd: selftests: Add tests for mmap and NUMA policy support fs/bcachefs/fs-io-buffered.c | 2 +- fs/btrfs/compression.c | 4 +- fs/btrfs/verity.c | 2 +- fs/erofs/zdata.c | 2 +- fs/f2fs/compress.c | 2 +- include/linux/pagemap.h | 18 +- include/uapi/linux/magic.h | 1 + mm/filemap.c | 23 +- mm/mempolicy.c | 6 + mm/readahead.c | 2 +- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../testing/selftests/kvm/guest_memfd_test.c | 121 ++++++++ virt/kvm/guest_memfd.c | 262 ++++++++++++++++-- virt/kvm/kvm_main.c | 7 +- virt/kvm/kvm_mm.h | 9 +- 15 files changed, 412 insertions(+), 50 deletions(-) -- 2.43.0 --- == Earlier Postings == v10: https://lore.kernel.org/all/20250811090605.16057-2-shivankg@amd.com v9: https://lore.kernel.org/all/20250713174339.13981-2-shivankg@amd.com v8: https://lore.kernel.org/all/20250618112935.7629-1-shivankg@amd.com v7: https://lore.kernel.org/all/20250408112402.181574-1-shivankg@amd.com v6: https://lore.kernel.org/all/20250226082549.6034-1-shivankg@amd.com v5: https://lore.kernel.org/all/20250219101559.414878-1-shivankg@amd.com v4: https://lore.kernel.org/all/20250210063227.41125-1-shivankg@amd.com v3: https://lore.kernel.org/all/20241105164549.154700-1-shivankg@amd.com v2: https://lore.kernel.org/all/20240919094438.10987-1-shivankg@amd.com v1: https://lore.kernel.org/all/20240916165743.201087-1-shivankg@amd.com

1 week, 1 day

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[PATCH] KVM: selftests: fix ITS collection target addresses in vgic_lpi_stress

by Maximilian Dittgen

When mapping guest ITS collections, vgic_lpi_stress iterates over integers in the range [0, nr_cpus), passing them as the target_addr parameter to its_send_mapc_cmd(). These integers correspond to the selftest userspace vCPU IDs that we intend to map each ITS collection to. However, its_encode_target() within its_send_mapc_cmd() expects a vCPU's redistributor address--not the vCPU ID--as the target_addr parameter. This is evident from how its_encode_target() encodes the target_addr parameter as: its_mask_encode(&cmd->raw_cmd[2], target_addr >> 16, 51, 16) This shows that we right-shift the input target_addr parameter by 16 bits before encoding it. This makes sense when the parameter refers to redistributor addresses (e.g., 0x20000, 0x30000) but not vCPU IDs (e.g., 0x2, 0x3). The current impact of passing vCPU IDs to its_send_mapc_cmd() is that all vCPU IDs become 0x0 after the bit shift. Thus, when vgic_its_cmd_handle_mapc() receives the ITS command in vgic-its.c, it always interprets the collection's target_vcpu as 0. All interrupts sent to collections will be processed by vCPU 0, which defeats the purpose of this multi-vCPU test. Fix by left-shifting the vCPU parameter received by its_send_mapc_cmd 16 bits before passing it into its_encode_target for encoding. Signed-off-by: Maximilian Dittgen <mdittgen(a)amazon.com> --- To validate the patch, I added the following debug code at the top of vgic_its_cmd_handle_mapc: u64 raw_cmd2 = le64_to_cpu(its_cmd[2]); u32 target_addr = its_cmd_get_target_addr(its_cmd); kvm_info("MAPC: coll_id=%d, raw_cmd[2]=0x%llx, parsed_target=%u\n", coll_id, raw_cmd2, target_addr); vcpu = kvm_get_vcpu_by_id(kvm, its_cmd_get_target_addr(its_cmd)); kvm_info("MAPC: coll_id=%d, vcpu_id=%d\n", coll_id, vcpu ? vcpu->vcpu_id : -1); I then ran `./vgic_lpi_stress -v 3` to trigger the stress selftest with 3 vCPUs. Before the patch, the debug logs read: kvm [20832]: MAPC: coll_id=0, raw_cmd[2]=0x8000000000000000, parsed_target=0 kvm [20832]: MAPC: coll_id=0, vcpu_id=0 kvm [20832]: MAPC: coll_id=1, raw_cmd[2]=0x8000000000000001, parsed_target=0 kvm [20832]: MAPC: coll_id=1, vcpu_id=0 kvm [20832]: MAPC: coll_id=2, raw_cmd[2]=0x8000000000000002, parsed_target=0 kvm [20832]: MAPC: coll_id=2, vcpu_id=0 Note the last bit of the cmd string reflects the collection ID, but the rest of the cmd string reads 0. The handler parses out vCPU 0 for all 3 mapc calls. After the patch, the debug logs read: kvm [20019]: MAPC: coll_id=0, raw_cmd[2]=0x8000000000000000, parsed_target=0 kvm [20019]: MAPC: coll_id=0, vcpu_id=0 kvm [20019]: MAPC: coll_id=1, raw_cmd[2]=0x8000000000010001, parsed_target=1 kvm [20019]: MAPC: coll_id=1, vcpu_id=1 kvm [20019]: MAPC: coll_id=2, raw_cmd[2]=0x8000000000020002, parsed_target=2 kvm [20019]: MAPC: coll_id=2, vcpu_id=2 Note that the target vcpu and target collection are both visible in the cmd string. The handler parses out the correct vCPU for all 3 mapc calls. --- tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c b/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c index 09f270545646..23c46ad17221 100644 --- a/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c +++ b/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c @@ -15,6 +15,8 @@ #include "gic_v3.h" #include "processor.h" +#define GITS_COLLECTION_TARGET_SHIFT 16 + static u64 its_read_u64(unsigned long offset) { return readq_relaxed(GITS_BASE_GVA + offset); @@ -217,7 +219,7 @@ void its_send_mapc_cmd(void *cmdq_base, u32 vcpu_id, u32 collection_id, bool val its_encode_cmd(&cmd, GITS_CMD_MAPC); its_encode_collection(&cmd, collection_id); - its_encode_target(&cmd, vcpu_id); + its_encode_target(&cmd, vcpu_id << GITS_COLLECTION_TARGET_SHIFT); its_encode_valid(&cmd, valid); its_send_cmd(cmdq_base, &cmd); -- 2.50.1 (Apple Git-155) Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

1 week, 1 day

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[PATCH v2] KVM: selftests: fix MAPC RDbase target formatting in vgic_lpi_stress

by Maximilian Dittgen

Since GITS_TYPER.PTA == 0, the ITS MAPC command demands a CPU ID, rather than a physical redistributor address, for its RDbase command argument. As such, when MAPC-ing guest ITS collections, vgic_lpi_stress iterates over CPU IDs in the range [0, nr_cpus), passing them as the RDbase vcpu_id argument to its_send_mapc_cmd(). However, its_encode_target() in the its_send_mapc_cmd() selftest handler expects RDbase arguments to be formatted with a 16 bit offset, as shown by the 16-bit target_addr right shift its implementation: its_mask_encode(&cmd->raw_cmd[2], target_addr >> 16, 51, 16) At the moment, all CPU IDs passed into its_send_mapc_cmd() have no offset, therefore becoming 0x0 after the bit shift. Thus, when vgic_its_cmd_handle_mapc() receives the ITS command in vgic-its.c, it always interprets the RDbase target CPU as CPU 0. All interrupts sent to collections will be processed by vCPU 0, which defeats the purpose of this multi-vCPU test. Fix by creating procnum_to_rdbase() helper function, which left-shifts the vCPU parameter received by its_send_mapc_cmd 16 bits before passing it to its_encode_target for encoding. Signed-off-by: Maximilian Dittgen <mdittgen(a)amazon.de> --- v2: Refactor the vcpu_id left shift into procnum_to_rdbase() helper. Rename and rewrite commit to reflect root cause of bug which was improper RDbase formatting, not that MAPC expects a physical address as the RDbase parameter. To validate the patch, I added the following debug code at the top of vgic_its_cmd_handle_mapc: u64 raw_cmd2 = le64_to_cpu(its_cmd[2]); u32 target_addr = its_cmd_get_target_addr(its_cmd); kvm_info("MAPC: coll_id=%d, raw_cmd[2]=0x%llx, parsed_target=%u\n", coll_id, raw_cmd2, target_addr); vcpu = kvm_get_vcpu_by_id(kvm, its_cmd_get_target_addr(its_cmd)); kvm_info("MAPC: coll_id=%d, vcpu_id=%d\n", coll_id, vcpu ? vcpu->vcpu_id : -1); I then ran `./vgic_lpi_stress -v 3` to trigger the stress selftest with 3 vCPUs. Before the patch, the debug logs read: kvm [20832]: MAPC: coll_id=0, raw_cmd[2]=0x8000000000000000, parsed_target=0 kvm [20832]: MAPC: coll_id=0, vcpu_id=0 kvm [20832]: MAPC: coll_id=1, raw_cmd[2]=0x8000000000000001, parsed_target=0 kvm [20832]: MAPC: coll_id=1, vcpu_id=0 kvm [20832]: MAPC: coll_id=2, raw_cmd[2]=0x8000000000000002, parsed_target=0 kvm [20832]: MAPC: coll_id=2, vcpu_id=0 Note the last bit of the cmd string reflects the collection ID, but the rest of the cmd string reads 0. The handler parses out vCPU 0 for all 3 mapc calls. After the patch, the debug logs read: kvm [20019]: MAPC: coll_id=0, raw_cmd[2]=0x8000000000000000, parsed_target=0 kvm [20019]: MAPC: coll_id=0, vcpu_id=0 kvm [20019]: MAPC: coll_id=1, raw_cmd[2]=0x8000000000010001, parsed_target=1 kvm [20019]: MAPC: coll_id=1, vcpu_id=1 kvm [20019]: MAPC: coll_id=2, raw_cmd[2]=0x8000000000020002, parsed_target=2 kvm [20019]: MAPC: coll_id=2, vcpu_id=2 Note that the target vcpu and target collection are both visible in the cmd string. The handler parses out the correct vCPU for all 3 mapc calls. ___ tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c b/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c index 09f270545646..0e2f8ed90f30 100644 --- a/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c +++ b/tools/testing/selftests/kvm/lib/arm64/gic_v3_its.c @@ -15,6 +15,8 @@ #include "gic_v3.h" #include "processor.h" +#define GITS_COLLECTION_TARGET_SHIFT 16 + static u64 its_read_u64(unsigned long offset) { return readq_relaxed(GITS_BASE_GVA + offset); @@ -163,6 +165,11 @@ static void its_encode_collection(struct its_cmd_block *cmd, u16 col) its_mask_encode(&cmd->raw_cmd[2], col, 15, 0); } +static u64 procnum_to_rdbase(u32 vcpu_id) +{ + return vcpu_id << GITS_COLLECTION_TARGET_SHIFT; +} + #define GITS_CMDQ_POLL_ITERATIONS 0 static void its_send_cmd(void *cmdq_base, struct its_cmd_block *cmd) @@ -217,7 +224,7 @@ void its_send_mapc_cmd(void *cmdq_base, u32 vcpu_id, u32 collection_id, bool val its_encode_cmd(&cmd, GITS_CMD_MAPC); its_encode_collection(&cmd, collection_id); - its_encode_target(&cmd, vcpu_id); + its_encode_target(&cmd, procnum_to_rdbase(vcpu_id)); its_encode_valid(&cmd, valid); its_send_cmd(cmdq_base, &cmd); -- 2.50.1 (Apple Git-155) Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

1 week, 1 day

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[PATCH v3 00/12] Start porting UML to nolibc

by Benjamin Berg

From: Benjamin Berg <benjamin.berg(a)intel.com> This patchset is an attempt to start a nolibc port of UML. The goal is to port UML to use nolibc in smaller chunks to make the switch more manageable. Using nolibc has the advantage that it is a smaller runtime and it allows us to be in full control about all memory mappings that are done. Another libc on the other hand might map memory unaware of UML, causing collisions with the UML memory layout. Such mappings could even happen before UML has fully initialized (e.g. rseq being mapped into the physical or vmalloc memory areas). There are three parts to this patchset: * Two patches to use tools/include headers instead of kernel headers for userspace files. * A few nolibc fixes and a new NOLIBC_NO_RUNTIME compile flag for it * Finally nolibc build support for UML and switching two files while adding the appropriate support in nolibc itself. v1 of this patchset was https://lore.kernel.org/all/20250915071115.1429196-1-benjamin@sipsolutions.… v2: https://lore.kernel.org/all/20250919153420.727385-1-benjamin@sipsolutions.n… Changes in v3: - sys_ptrace is now not a varadic function - improve printf %m implementation - keep perror as function available with NOLIBC_IGNORE_ERRNO - change syscall guard and fix i386 build Changes in v2: - add sys/uio.h and sys/ptrace.h to nolibc - Use NOLIBC_NO_RUNTIME to disable nolibc startup code - Fix out-of-tree build - various small improvements and cleanups Benjamin Benjamin Berg (12): tools compiler.h: fix __used definition um: use tools/include for user files tools/nolibc/stdio: let perror work when NOLIBC_IGNORE_ERRNO is set tools/nolibc/dirent: avoid errno in readdir_r tools/nolibc: implement %m if errno is not defined tools/nolibc: use __fallthrough__ rather than fallthrough tools/nolibc: add option to disable runtime um: add infrastructure to build files using nolibc um: use nolibc for the --showconfig implementation tools/nolibc: add uio.h with readv and writev tools/nolibc: add ptrace support um: switch ptrace FP register access to nolibc arch/um/Makefile | 38 ++++++++++++--- arch/um/include/shared/init.h | 2 +- arch/um/include/shared/os.h | 2 + arch/um/include/shared/user.h | 6 --- arch/um/kernel/Makefile | 2 +- arch/um/kernel/skas/stub.c | 1 + arch/um/kernel/skas/stub_exe.c | 4 +- arch/um/os-Linux/skas/process.c | 6 +-- arch/um/os-Linux/start_up.c | 4 +- arch/um/scripts/Makefile.rules | 10 +++- arch/x86/um/Makefile | 6 ++- arch/x86/um/os-Linux/Makefile | 5 +- arch/x86/um/os-Linux/registers.c | 20 ++------ arch/x86/um/user-offsets.c | 1 - tools/include/linux/compiler.h | 2 +- tools/include/nolibc/Makefile | 2 + tools/include/nolibc/arch-arm.h | 2 + tools/include/nolibc/arch-arm64.h | 2 + tools/include/nolibc/arch-loongarch.h | 2 + tools/include/nolibc/arch-m68k.h | 2 + tools/include/nolibc/arch-mips.h | 2 + tools/include/nolibc/arch-powerpc.h | 2 + tools/include/nolibc/arch-riscv.h | 2 + tools/include/nolibc/arch-s390.h | 2 + tools/include/nolibc/arch-sh.h | 2 + tools/include/nolibc/arch-sparc.h | 2 + tools/include/nolibc/arch-x86.h | 4 ++ tools/include/nolibc/compiler.h | 4 +- tools/include/nolibc/crt.h | 3 ++ tools/include/nolibc/dirent.h | 6 +-- tools/include/nolibc/nolibc.h | 2 + tools/include/nolibc/stackprotector.h | 2 + tools/include/nolibc/stdio.h | 10 +++- tools/include/nolibc/stdlib.h | 2 + tools/include/nolibc/sys.h | 3 +- tools/include/nolibc/sys/auxv.h | 3 ++ tools/include/nolibc/sys/ptrace.h | 44 ++++++++++++++++++ tools/include/nolibc/sys/uio.h | 49 ++++++++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 11 +++++ 39 files changed, 221 insertions(+), 53 deletions(-) create mode 100644 tools/include/nolibc/sys/ptrace.h create mode 100644 tools/include/nolibc/sys/uio.h -- 2.51.0

1 week, 1 day

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[RFC PATCH 0/3] mm: Fix MF_DELAYED handling on memory failure

by Lisa Wang

Hello, This patch series addresses an issue in the memory failure handling path where MF_DELAYED is incorrectly treated as an error. This issue was revealed because guest_memfd’s .error_remove_folio() callback returns MF_DELAYED. Currently, when the .error_remove_folio() callback for guest_memfd returns MF_DELAYED, there are a few issues. 1. truncate_error_folio() maps this to MF_FAILED. This causes memory_failure() to return -EBUSY, which unconditionally triggers a SIGBUS. The process’ configured memory corruption kill policy is ignored - even if PR_MCE_KILL_LATE is set, the process will still get a SIGBUS on deferred memory failures. 2. “Failed to punch page” is printed, even though MF_DELAYED indicates that it was intentionally not punched. The first patch corrects this by updating truncate_error_folio() to propagate MF_DELAYED to its caller. This allows memory_failure() to return 0, indicating success, and lets the delayed handling proceed as designed. This patch also updates me_pagecache_clean() to account for the folio's refcount, which remains elevated during delayed handling, aligning its logic with me_swapcache_dirty(). The subsequent two patches add KVM selftests to validate the fix and the expected behavior of guest_memfd memory failure: The first test patch verifies that memory_failure() now returns 0 in the delayed case and confirms that SIGBUS signaling logic remains correct for other scenarios (e.g., madvise injection or PR_MCE_KILL_EARLY). The second test patch confirms that after a memory failure, the poisoned page is correctly unmapped from the KVM guest's stage 2 page tables and that a subsequent access by the guest correctly notifies the userspace VMM with EHWPOISON. This patch series is built upon kvm/next. In addition, to align with the change of INIT_SHARED and to use the macro wrapper in guest_memfd selftests, we put these patches behind Sean’s patches [1]. For ease of testing, this series is also available, stitched together, at https://github.com/googleprodkernel/linux-cc/tree/memory-failure-mf-delayed… [1]: https://lore.kernel.org/all/20251003232606.4070510-1-seanjc@google.com/T/ Thank you, Lisa Wang (3): mm: memory_failure: Fix MF_DELAYED handling on truncation during failure KVM: selftests: Add memory failure tests in guest_memfd_test KVM: selftests: Test guest_memfd behavior with respect to stage 2 page tables mm/memory-failure.c | 24 +- .../testing/selftests/kvm/guest_memfd_test.c | 233 ++++++++++++++++++ 2 files changed, 248 insertions(+), 9 deletions(-) -- 2.51.0.788.g6d19910ace-goog

1 week, 1 day

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[PATCH 0/4] PCI: Add support and tests for FIXUP quirks in modules

by Brian Norris

This series primarily adds support for DECLARE_PCI_FIXUP_*() in modules. There are a few drivers that already use this, and so they are presumably broken when built as modules. While at it, I wrote some unit tests that emulate a fake PCI device, and let the PCI framework match/not-match its vendor/device IDs. This test can be built into the kernel or built as a module. I also include some infrastructure changes (patch 3 and 4), so that ARCH=um (the default for kunit.py), ARCH=arm, and ARCH=arm64 will run these tests by default. These patches have different maintainers and are independent, so they can probably be picked up separately. I included them because otherwise the tests in patch 2 aren't so easy to run. Brian Norris (4): PCI: Support FIXUP quirks in modules PCI: Add KUnit tests for FIXUP quirks um: Select PCI_DOMAINS_GENERIC kunit: qemu_configs: Add PCI to arm, arm64 arch/um/Kconfig | 1 + drivers/pci/Kconfig | 11 ++ drivers/pci/Makefile | 1 + drivers/pci/fixup-test.c | 197 ++++++++++++++++++++++ drivers/pci/quirks.c | 62 +++++++ include/linux/module.h | 18 ++ kernel/module/main.c | 26 +++ tools/testing/kunit/qemu_configs/arm.py | 1 + tools/testing/kunit/qemu_configs/arm64.py | 1 + 9 files changed, 318 insertions(+) create mode 100644 drivers/pci/fixup-test.c -- 2.51.0.384.g4c02a37b29-goog

1 week, 2 days

6
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[PATCH v3 0/5] mm: VMA count limit fixes and improvements

by Kalesh Singh

Hi all, This series addresses an off-by-one bug in the VMA count limit check and introduces several improvements for clarity, test coverage, and observability around the VMA limit mechanism. The VMA count limit, controlled by sysctl_max_map_count, is a critical safeguard that prevents a single process from consuming excessive kernel memory by creating too many memory mappings. However, the checks in do_mmap() and do_brk_flags() used a strict inequality, allowing a process to exceed this limit by one VMA. This series begins by fixing this long-standing bug. The subsequent patches build on this by improving the surrounding code. A comprehensive selftest is added to validate VMA operations near the limit, preventing future regressions. The open-coded limit checks are replaced with a centralized helper, vma_count_remaining(), to improve readability. For better code clarity, mm_struct->map_count is renamed to the more apt vma_count. Finally, a trace event is added to provide observability for processes that fail allocations due to VMA exhaustion, which is valuable for debugging and profiling on production systems. The major changes in this version are: 1. Rebased on mm-new to resolve prior conflicts. 2. The patches to harden and add assertions for the VMA count have been dropped. David pointed out that these could be racy if sysctl_max_map_count is changed from userspace at just the wrong time. 3. The selftest has been completely rewritten per Lorenzo's feedback to make use of the kselftest harness and vm_util.h helpers. 4. The trace event has also been updated to contain more useful information and has been given a more fitting name, per feedback from Steve and Lorenzo. Tested on x86_64 and arm64: 1. Build test: allyesconfig for rename 2. Selftests: cd tools/testing/selftests/mm && \ make && \ ./run_vmtests.sh -t max_vma_count 3. vma tests: cd tools/testing/vma && \ make && \ ./vma Link to v2: https://lore.kernel.org/r/20250915163838.631445-1-kaleshsingh@google.com/ Thanks to everyone for their comments and feedback on the previous versions. --Kalesh Kalesh Singh (5): mm: fix off-by-one error in VMA count limit checks mm/selftests: add max_vma_count tests mm: introduce vma_count_remaining() mm: rename mm_struct::map_count to vma_count mm/tracing: introduce trace_mm_insufficient_vma_slots event MAINTAINERS | 2 + fs/binfmt_elf.c | 2 +- fs/coredump.c | 2 +- include/linux/mm.h | 2 - include/linux/mm_types.h | 2 +- include/trace/events/vma.h | 32 + kernel/fork.c | 2 +- mm/debug.c | 2 +- mm/internal.h | 3 + mm/mmap.c | 31 +- mm/mremap.c | 13 +- mm/nommu.c | 8 +- mm/util.c | 1 - mm/vma.c | 39 +- mm/vma_internal.h | 2 + tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 1 + .../selftests/mm/max_vma_count_tests.c | 672 ++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 5 + tools/testing/vma/vma.c | 32 +- tools/testing/vma/vma_internal.h | 16 +- 21 files changed, 818 insertions(+), 52 deletions(-) create mode 100644 include/trace/events/vma.h create mode 100644 tools/testing/selftests/mm/max_vma_count_tests.c base-commit: 4c4142c93fc19cd75a024e5c81b0532578a9e187 -- 2.51.0.760.g7b8bcc2412-goog

1 week, 2 days

5
16
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[PATCH bpf-next 0/5] selftests/bpf: convert test_tc_tunnel.sh to test_progs

by Alexis Lothoré (eBPF Foundation)

Hello, this series aims to convert another test to the test_progs framework to make sure that it is executed in CI for series sent on the mailing list. test_tc_tunnel.sh tests a variety of tunnels based on BPF: packets are encapsulated by a BPF program on the client egress. We then check that those packets can be decapsulated on server ingress side, either thanks to kernel-based or BPF-based decapsulation. Those tests are run thanks to two veths in two dedicated namespaces. - patches 1 to 3 are preparatory patches - patch 4 introduce tc_tunnel test into test_progs - patch 5 gets rid of the test_tc_tunnel.sh script The new test has been executed both in some x86 local qemu machine, as well as in CI: # ./test_progs -a tc_tunnel #454/1 tc_tunnel/ipip_none:OK #454/2 tc_tunnel/ipip6_none:OK #454/3 tc_tunnel/ip6tnl_none:OK #454/4 tc_tunnel/sit_none:OK #454/5 tc_tunnel/vxlan_eth:OK #454/6 tc_tunnel/ip6vxlan_eth:OK #454/7 tc_tunnel/gre_none:OK #454/8 tc_tunnel/gre_eth:OK #454/9 tc_tunnel/gre_mpls:OK #454/10 tc_tunnel/ip6gre_none:OK #454/11 tc_tunnel/ip6gre_eth:OK #454/12 tc_tunnel/ip6gre_mpls:OK #454/13 tc_tunnel/udp_none:OK #454/14 tc_tunnel/udp_eth:OK #454/15 tc_tunnel/udp_mpls:OK #454/16 tc_tunnel/ip6udp_none:OK #454/17 tc_tunnel/ip6udp_eth:OK #454/18 tc_tunnel/ip6udp_mpls:OK #454 tc_tunnel:OK Summary: 1/18 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore(a)bootlin.com> --- Alexis Lothoré (eBPF Foundation) (5): testing/selftests: rename tc_helpers.h to tcx_helpers.h selftests/bpf: add tc helpers selftests/bpf: make test_tc_tunnel.bpf.c compatible with big endian platforms selftests/bpf: integrate test_tc_tunnel.sh tests into test_progs selftests/bpf: remove test_tc_tunnel.sh tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/prog_tests/tc_links.c | 46 +- tools/testing/selftests/bpf/prog_tests/tc_netkit.c | 22 +- tools/testing/selftests/bpf/prog_tests/tc_opts.c | 40 +- .../bpf/prog_tests/{tc_helpers.h => tcx_helpers.h} | 6 +- .../selftests/bpf/prog_tests/test_tc_tunnel.c | 684 +++++++++++++++++++++ .../testing/selftests/bpf/prog_tests/test_tunnel.c | 80 +-- tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 99 ++- tools/testing/selftests/bpf/tc_helpers.c | 87 +++ tools/testing/selftests/bpf/tc_helpers.h | 9 + tools/testing/selftests/bpf/test_tc_tunnel.sh | 320 ---------- 11 files changed, 884 insertions(+), 511 deletions(-) --- base-commit: 22267893b8c7f2773896e814800bbe693f206e0c change-id: 20250811-tc_tunnel-c61342683f18 Best regards, -- Alexis Lothoré, Bootlin Embedded Linux and Kernel engineering https://bootlin.com

1 week, 2 days

3
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