Date: Sat, 9 Sep 2023 08:21:15 GMT From: Zhenlei Huang <zlei@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 110113bc086f - main - sysctl(9): Enable vnet sysctl variables to be loader tunable Message-ID: <202309090821.3898LFsx046730@gitrepo.freebsd.org>
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The branch main has been updated by zlei: URL: https://cgit.FreeBSD.org/src/commit/?id=110113bc086f5df1a9b6547edb1ab0cec698c55c commit 110113bc086f5df1a9b6547edb1ab0cec698c55c Author: Zhenlei Huang <zlei@FreeBSD.org> AuthorDate: 2023-09-09 08:06:23 +0000 Commit: Zhenlei Huang <zlei@FreeBSD.org> CommitDate: 2023-09-09 08:06:23 +0000 sysctl(9): Enable vnet sysctl variables to be loader tunable Complete phase two of 3da1cf1e88f8. In 3da1cf1e88f8, the meaning of the flag CTLFLAG_TUN is extended to automatically check if there is a kernel environment variable which shall initialize the SYSCTL during early boot. It works for all SYSCTL types both statically and dynamically created ones, except for the SYSCTLs which belong to VNETs. This change extends the meaning further, to allow it also works for the SYSCTLs which belong to VNETs. A typical usage is ``` VNET_DEFINE_STATIC(int, foo) = 0; SYSCTL_INT(_net, OID_AUTO, foo, CTLFLAG_RWTUN | CTLFLAG_VNET, &VNET_NAME(foo), 0, "Description of the foo loader tunable"); ``` Note that the implementation has a limitation. It behaves the same way as that of non-vnet loader tunables. That is, after the kernel or modules being initialized, any changes (e.g. via kenv) to kernel environment variable will not affect the corresponding vnet variable of subsequently created VNETs. To overcome it, we can use TUNABLE_XXX_FETCH to fetch the kernel environment variable into those vnet variables during vnet constructing. This change will fix the following SYSCTLs those belong to VNETs and have CTLFLAG_TUN flag: ``` net.add_addr_allfibs net.bpf.optimize_writers net.inet.tcp.fastopen.ccache_buckets net.link.bridge.inherit_mac net.link.bridge.ipfw_arp net.link.bridge.log_stp net.link.bridge.pfil_bridge net.link.bridge.pfil_local_phys net.link.bridge.pfil_member net.link.bridge.pfil_onlyip net.link.lagg.default_use_flowid net.link.lagg.default_use_numa net.link.lagg.default_flowid_shift net.link.lagg.lacp.debug net.link.lagg.lacp.default_strict_mode ``` Although the following vnet SYSCTLs have CTLFLAG_TUN flag, theirs values are re-fetched via TUNABLE_XXX_FETCH, thus are not affected by this change. ``` net.inet.ip.reass_hashsize net.inet.tcp.hostcache.cachelimit net.inet.tcp.hostcache.hashsize net.inet.tcp.hostcache.bucketlimit net.inet.tcp.syncache.bucketlimit net.inet.tcp.syncache.cachelimit net.inet.tcp.syncache.hashsize net.key.spdcache.maxentries net.key.spdcache.threshold ``` In memoriam: hselasky Discussed with: hselasky, glebius Fixes: 3da1cf1e88f8 Extend the meaning of the CTLFLAG_TUN flag ... MFC after: 2 weeks Relnotes: yes Differential Revision: https://reviews.freebsd.org/D39638 --- sys/kern/kern_linker.c | 3 +++ sys/kern/kern_sysctl.c | 3 --- sys/kern/link_elf.c | 20 ++++++++++++++++++++ sys/kern/link_elf_obj.c | 30 +++++++++++++++++++++++++++++- sys/kern/linker_if.m | 9 +++++++++ 5 files changed, 61 insertions(+), 4 deletions(-) diff --git a/sys/kern/kern_linker.c b/sys/kern/kern_linker.c index a1073512e856..2367bf35da76 100644 --- a/sys/kern/kern_linker.c +++ b/sys/kern/kern_linker.c @@ -471,6 +471,9 @@ linker_load_file(const char *filename, linker_file_t *result) } modules = !TAILQ_EMPTY(&lf->modules); linker_file_register_sysctls(lf, false); +#ifdef VIMAGE + LINKER_PROPAGATE_VNETS(lf); +#endif linker_file_sysinit(lf); lf->flags |= LINKER_FILE_LINKED; diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index 814579a80f5a..a1d502d58bff 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -510,9 +510,6 @@ sysctl_register_oid(struct sysctl_oid *oidp) RB_INSERT(sysctl_oid_list, parent, oidp); if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE && -#ifdef VIMAGE - (oidp->oid_kind & CTLFLAG_VNET) == 0 && -#endif (oidp->oid_kind & CTLFLAG_TUN) != 0 && (oidp->oid_kind & CTLFLAG_NOFETCH) == 0) { /* only fetch value once */ diff --git a/sys/kern/link_elf.c b/sys/kern/link_elf.c index 5be2db9d32bf..3e9998f27baa 100644 --- a/sys/kern/link_elf.c +++ b/sys/kern/link_elf.c @@ -160,6 +160,9 @@ static int link_elf_each_function_nameval(linker_file_t, static void link_elf_reloc_local(linker_file_t); static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); static long link_elf_strtab_get(linker_file_t, caddr_t *); +#ifdef VIMAGE +static void link_elf_propagate_vnets(linker_file_t); +#endif static int elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *); static kobj_method_t link_elf_methods[] = { @@ -178,6 +181,9 @@ static kobj_method_t link_elf_methods[] = { KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), +#ifdef VIMAGE + KOBJMETHOD(linker_propagate_vnets, link_elf_propagate_vnets), +#endif KOBJMETHOD_END }; @@ -1923,6 +1929,20 @@ link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) return (ef->ddbstrcnt); } +#ifdef VIMAGE +static void +link_elf_propagate_vnets(linker_file_t lf) +{ + elf_file_t ef = (elf_file_t)lf; + int size; + + if (ef->vnet_base != 0) { + size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start; + vnet_data_copy((void *)ef->vnet_base, size); + } +} +#endif + #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) || defined(__powerpc__) /* * Use this lookup routine when performing relocations early during boot. diff --git a/sys/kern/link_elf_obj.c b/sys/kern/link_elf_obj.c index b853ca284f7d..768808d2102e 100644 --- a/sys/kern/link_elf_obj.c +++ b/sys/kern/link_elf_obj.c @@ -150,6 +150,9 @@ static int link_elf_each_function_nameval(linker_file_t, static int link_elf_reloc_local(linker_file_t, bool); static long link_elf_symtab_get(linker_file_t, const Elf_Sym **); static long link_elf_strtab_get(linker_file_t, caddr_t *); +#ifdef VIMAGE +static void link_elf_propagate_vnets(linker_file_t); +#endif static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *); @@ -170,6 +173,9 @@ static kobj_method_t link_elf_methods[] = { KOBJMETHOD(linker_ctf_get, link_elf_ctf_get), KOBJMETHOD(linker_symtab_get, link_elf_symtab_get), KOBJMETHOD(linker_strtab_get, link_elf_strtab_get), +#ifdef VIMAGE + KOBJMETHOD(linker_propagate_vnets, link_elf_propagate_vnets), +#endif KOBJMETHOD_END }; @@ -1848,7 +1854,7 @@ link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab) return (0); return (ef->ddbsymcnt); } - + static long link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) { @@ -1859,3 +1865,25 @@ link_elf_strtab_get(linker_file_t lf, caddr_t *strtab) return (0); return (ef->ddbstrcnt); } + +#ifdef VIMAGE +static void +link_elf_propagate_vnets(linker_file_t lf) +{ + elf_file_t ef = (elf_file_t) lf; + + if (ef->progtab) { + for (int i = 0; i < ef->nprogtab; i++) { + if (ef->progtab[i].size == 0) + continue; + if (ef->progtab[i].name == NULL) + continue; + if (strcmp(ef->progtab[i].name, VNET_SETNAME) == 0) { + vnet_data_copy(ef->progtab[i].addr, + ef->progtab[i].size); + break; + } + } + } +} +#endif diff --git a/sys/kern/linker_if.m b/sys/kern/linker_if.m index 0722390d4e20..a50ed1ea84a3 100644 --- a/sys/kern/linker_if.m +++ b/sys/kern/linker_if.m @@ -154,3 +154,12 @@ STATICMETHOD int link_preload { METHOD int link_preload_finish { linker_file_t file; }; + +#ifdef VIMAGE +# +# Propagate system tunable values to all vnets. +# +METHOD void propagate_vnets { + linker_file_t file; +}; +#endif
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