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* LoongArch: KVM: Streamline kvm_check_cpucfg() and improve commentsWANG Xuerui2024-02-231-22/+20
| | | | | | | | | | | | | | | | | | All the checks currently done in kvm_check_cpucfg can be realized with early returns, so just do that to avoid extra cognitive burden related to the return value handling. While at it, clean up comments of _kvm_get_cpucfg_mask() and kvm_check_cpucfg(), by removing comments that are merely restatement of the code nearby, and paraphrasing the rest so they read more natural for English speakers (that likely are not familiar with the actual Chinese- influenced grammar). No functional changes intended. Reviewed-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: KVM: Rename _kvm_get_cpucfg() to _kvm_get_cpucfg_mask()WANG Xuerui2024-02-231-3/+3
| | | | | | | | | | The function is not actually a getter of guest CPUCFG, but rather validation of the input CPUCFG ID plus information about the supported bit flags of that CPUCFG leaf. So rename it to avoid confusion. Reviewed-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: KVM: Fix input validation of _kvm_get_cpucfg() & kvm_check_cpucfg()WANG Xuerui2024-02-231-17/+18
| | | | | | | | | | | | | | | | | | | | | | | | | The range check for the CPUCFG ID is wrong (should have been a || instead of &&) and useless in effect, so fix the obvious mistake. Furthermore, the juggling of the temp return value is unnecessary, because it is semantically equivalent and more readable to just return at every switch case's end. This is done too to avoid potential bugs in the future related to the unwanted complexity. Also, the return value of _kvm_get_cpucfg is meant to be checked, but this was not done, so bad CPUCFG IDs wrongly fall back to the default case and 0 is incorrectly returned; check the return value to fix the UAPI behavior. While at it, also remove the redundant range check in kvm_check_cpucfg, because out-of-range CPUCFG IDs are already rejected by the -EINVAL as returned by _kvm_get_cpucfg(). Fixes: db1ecca22edf ("LoongArch: KVM: Add LSX (128bit SIMD) support") Fixes: 118e10cd893d ("LoongArch: KVM: Add LASX (256bit SIMD) support") Reviewed-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: dts: Minor whitespace cleanupKrzysztof Kozlowski2024-02-232-2/+2
| | | | | | | | The DTS code coding style expects exactly one space before '{' character. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Call early_init_fdt_scan_reserved_mem() earlierHuacai Chen2024-02-231-2/+2
| | | | | | | | | | | | | | | | | | The unflatten_and_copy_device_tree() function contains a call to memblock_alloc(). This means that memblock is allocating memory before any of the reserved memory regions are set aside in the arch_mem_init() function which calls early_init_fdt_scan_reserved_mem(). Therefore, there is a possibility for memblock to allocate from any of the reserved memory regions. Hence, move the call to early_init_fdt_scan_reserved_mem() to be earlier in the init sequence, so that the reserved memory regions are set aside before any allocations are done using memblock. Cc: stable@vger.kernel.org Fixes: 88d4d957edc707e ("LoongArch: Add FDT booting support from efi system table") Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Update cpu_sibling_map when disabling nonboot CPUsHuacai Chen2024-02-231-53/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update cpu_sibling_map when disabling nonboot CPUs by defining & calling clear_cpu_sibling_map(), otherwise we get such errors on SMT systems: jump label: negative count! WARNING: CPU: 6 PID: 45 at kernel/jump_label.c:263 __static_key_slow_dec_cpuslocked+0xec/0x100 CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 pc 90000000004c302c ra 90000000004c302c tp 90000001005bc000 sp 90000001005bfd20 a0 000000000000001b a1 900000000224c278 a2 90000001005bfb58 a3 900000000224c280 a4 900000000224c278 a5 90000001005bfb50 a6 0000000000000001 a7 0000000000000001 t0 ce87a4763eb5234a t1 ce87a4763eb5234a t2 0000000000000000 t3 0000000000000000 t4 0000000000000006 t5 0000000000000000 t6 0000000000000064 t7 0000000000001964 t8 000000000009ebf6 u0 9000000001f2a068 s9 0000000000000000 s0 900000000246a2d8 s1 ffffffffffffffff s2 ffffffffffffffff s3 90000000021518c0 s4 0000000000000040 s5 9000000002151058 s6 9000000009828e40 s7 00000000000000b4 s8 0000000000000006 ra: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 ERA: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1c (LIE=2-4,10-12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014d000 (Loongson-64bit, Loongson-3A6000-HV) CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 Stack : 0000000000000000 900000000203f258 900000000179afc8 90000001005bc000 90000001005bf980 0000000000000000 90000001005bf988 9000000001fe0be0 900000000224c280 900000000224c278 90000001005bf8c0 0000000000000001 0000000000000001 ce87a4763eb5234a 0000000007f38000 90000001003f8cc0 0000000000000000 0000000000000006 0000000000000000 4c206e6f73676e6f 6f4c203a656d616e 000000000009ec99 0000000007f38000 0000000000000000 900000000214b000 9000000001fe0be0 0000000000000004 0000000000000000 0000000000000107 0000000000000009 ffffffffffafdabe 00000000000000b4 0000000000000006 90000000004c302c 9000000000224528 00005555939a0c7c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c ... Call Trace: [<9000000000224528>] show_stack+0x48/0x1a0 [<900000000179afc8>] dump_stack_lvl+0x78/0xa0 [<9000000000263ed0>] __warn+0x90/0x1a0 [<90000000017419b8>] report_bug+0x1b8/0x280 [<900000000179c564>] do_bp+0x264/0x420 [<90000000004c302c>] __static_key_slow_dec_cpuslocked+0xec/0x100 [<90000000002b4d7c>] sched_cpu_deactivate+0x2fc/0x300 [<9000000000266498>] cpuhp_invoke_callback+0x178/0x8a0 [<9000000000267f70>] cpuhp_thread_fun+0xf0/0x240 [<90000000002a117c>] smpboot_thread_fn+0x1dc/0x2e0 [<900000000029a720>] kthread+0x140/0x160 [<9000000000222288>] ret_from_kernel_thread+0xc/0xa4 Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Disable IRQ before init_fn() for nonboot CPUsHuacai Chen2024-02-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Disable IRQ before init_fn() for nonboot CPUs when hotplug, in order to silence such warnings (and also avoid potential errors due to unexpected interrupts): WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:4503 rcu_cpu_starting+0x214/0x280 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.17+ #1198 pc 90000000048e3334 ra 90000000047bd56c tp 900000010039c000 sp 900000010039fdd0 a0 0000000000000001 a1 0000000000000006 a2 900000000802c040 a3 0000000000000000 a4 0000000000000001 a5 0000000000000004 a6 0000000000000000 a7 90000000048e3f4c t0 0000000000000001 t1 9000000005c70968 t2 0000000004000000 t3 000000000005e56e t4 00000000000002e4 t5 0000000000001000 t6 ffffffff80000000 t7 0000000000040000 t8 9000000007931638 u0 0000000000000006 s9 0000000000000004 s0 0000000000000001 s1 9000000006356ac0 s2 9000000007244000 s3 0000000000000001 s4 0000000000000001 s5 900000000636f000 s6 7fffffffffffffff s7 9000000002123940 s8 9000000001ca55f8 ra: 90000000047bd56c tlb_init+0x24c/0x528 ERA: 90000000048e3334 rcu_cpu_starting+0x214/0x280 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000000 (PPLV0 -PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071000 (LIE=12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.17+ #1198 Stack : 0000000000000000 9000000006375000 9000000005b61878 900000010039c000 900000010039fa30 0000000000000000 900000010039fa38 900000000619a140 9000000006456888 9000000006456880 900000010039f950 0000000000000001 0000000000000001 cb0cb028ec7e52e1 0000000002b90000 9000000100348700 0000000000000000 0000000000000001 ffffffff916d12f1 0000000000000003 0000000000040000 9000000007930370 0000000002b90000 0000000000000004 9000000006366000 900000000619a140 0000000000000000 0000000000000004 0000000000000000 0000000000000009 ffffffffffc681f2 9000000002123940 9000000001ca55f8 9000000006366000 90000000047a4828 00007ffff057ded8 00000000000000b0 0000000000000000 0000000000000000 0000000000071000 ... Call Trace: [<90000000047a4828>] show_stack+0x48/0x1a0 [<9000000005b61874>] dump_stack_lvl+0x84/0xcc [<90000000047f60ac>] __warn+0x8c/0x1e0 [<9000000005b0ab34>] report_bug+0x1b4/0x280 [<9000000005b63110>] do_bp+0x2d0/0x480 [<90000000047a2e20>] handle_bp+0x120/0x1c0 [<90000000048e3334>] rcu_cpu_starting+0x214/0x280 [<90000000047bd568>] tlb_init+0x248/0x528 [<90000000047a4c44>] per_cpu_trap_init+0x124/0x160 [<90000000047a19f4>] cpu_probe+0x494/0xa00 [<90000000047b551c>] start_secondary+0x3c/0xc0 [<9000000005b66134>] smpboot_entry+0x50/0x58 Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* work around gcc bugs with 'asm goto' with outputsLinus Torvalds2024-02-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've had issues with gcc and 'asm goto' before, and we created a 'asm_volatile_goto()' macro for that in the past: see commits 3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation bug") and a9f180345f53 ("compiler/gcc4: Make quirk for asm_volatile_goto() unconditional"). Then, much later, we ended up removing the workaround in commit 43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR 58670") because we no longer supported building the kernel with the affected gcc versions, but we left the macro uses around. Now, Sean Christopherson reports a new version of a very similar problem, which is fixed by re-applying that ancient workaround. But the problem in question is limited to only the 'asm goto with outputs' cases, so instead of re-introducing the old workaround as-is, let's rename and limit the workaround to just that much less common case. It looks like there are at least two separate issues that all hit in this area: (a) some versions of gcc don't mark the asm goto as 'volatile' when it has outputs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 which is easy to work around by just adding the 'volatile' by hand. (b) Internal compiler errors: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 which are worked around by adding the extra empty 'asm' as a barrier, as in the original workaround. but the problem Sean sees may be a third thing since it involves bad code generation (not an ICE) even with the manually added 'volatile'. but the same old workaround works for this case, even if this feels a bit like voodoo programming and may only be hiding the issue. Reported-and-tested-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Andrew Pinski <quic_apinski@quicinc.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* LoongArch: vDSO: Disable UBSAN instrumentationKees Cook2024-02-061-0/+1
| | | | | | | | | | | | | | | | | | | | The vDSO executes in userspace, so the kernel's UBSAN should not instrument it. Solves these kind of build errors: loongarch64-linux-ld: arch/loongarch/vdso/vgettimeofday.o: in function `vdso_shift_ns': lib/vdso/gettimeofday.c:23:(.text+0x3f8): undefined reference to `__ubsan_handle_shift_out_of_bounds' Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202401310530.lZHCj1Zl-lkp@intel.com/ Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Fangrui Song <maskray@google.com> Cc: loongarch@lists.linux.dev Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Fix earlycon parameter if KASAN enabledHuacai Chen2024-02-061-0/+3
| | | | | | | | | | | The earlycon parameter is based on fixmap, and fixmap addresses are not supposed to be shadowed by KASAN. So return the kasan_early_shadow_page in kasan_mem_to_shadow() if the input address is above FIXADDR_START. Otherwise earlycon cannot work after kasan_init(). Cc: stable@vger.kernel.org Fixes: 5aa4ac64e6add3e ("LoongArch: Add KASAN (Kernel Address Sanitizer) support") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Change acpi_core_pic[NR_CPUS] to acpi_core_pic[MAX_CORE_PIC]Huacai Chen2024-02-062-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With default config, the value of NR_CPUS is 64. When HW platform has more then 64 cpus, system will crash on these platforms. MAX_CORE_PIC is the maximum cpu number in MADT table (max physical number) which can exceed the supported maximum cpu number (NR_CPUS, max logical number), but kernel should not crash. Kernel should boot cpus with NR_CPUS, let the remainder cpus stay in BIOS. The potential crash reason is that the array acpi_core_pic[NR_CPUS] can be overflowed when parsing MADT table, and it is obvious that CORE_PIC should be corresponding to physical core rather than logical core, so it is better to define the array as acpi_core_pic[MAX_CORE_PIC]. With the patch, system can boot up 64 vcpus with qemu parameter -smp 128, otherwise system will crash with the following message. [ 0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000420000004259, era == 90000000037a5f0c, ra == 90000000037a46ec [ 0.000000] Oops[#1]: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-rc2+ #192 [ 0.000000] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 [ 0.000000] pc 90000000037a5f0c ra 90000000037a46ec tp 9000000003c90000 sp 9000000003c93d60 [ 0.000000] a0 0000000000000019 a1 9000000003d93bc0 a2 0000000000000000 a3 9000000003c93bd8 [ 0.000000] a4 9000000003c93a74 a5 9000000083c93a67 a6 9000000003c938f0 a7 0000000000000005 [ 0.000000] t0 0000420000004201 t1 0000000000000000 t2 0000000000000001 t3 0000000000000001 [ 0.000000] t4 0000000000000003 t5 0000000000000000 t6 0000000000000030 t7 0000000000000063 [ 0.000000] t8 0000000000000014 u0 ffffffffffffffff s9 0000000000000000 s0 9000000003caee98 [ 0.000000] s1 90000000041b0480 s2 9000000003c93da0 s3 9000000003c93d98 s4 9000000003c93d90 [ 0.000000] s5 9000000003caa000 s6 000000000a7fd000 s7 000000000f556b60 s8 000000000e0a4330 [ 0.000000] ra: 90000000037a46ec platform_init+0x214/0x250 [ 0.000000] ERA: 90000000037a5f0c efi_runtime_init+0x30/0x94 [ 0.000000] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) [ 0.000000] PRMD: 00000000 (PPLV0 -PIE -PWE) [ 0.000000] EUEN: 00000000 (-FPE -SXE -ASXE -BTE) [ 0.000000] ECFG: 00070800 (LIE=11 VS=7) [ 0.000000] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) [ 0.000000] BADV: 0000420000004259 [ 0.000000] PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) [ 0.000000] Modules linked in: [ 0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____)) [ 0.000000] Stack : 9000000003c93a14 9000000003800898 90000000041844f8 90000000037a46ec [ 0.000000] 000000000a7fd000 0000000008290000 0000000000000000 0000000000000000 [ 0.000000] 0000000000000000 0000000000000000 00000000019d8000 000000000f556b60 [ 0.000000] 000000000a7fd000 000000000f556b08 9000000003ca7700 9000000003800000 [ 0.000000] 9000000003c93e50 9000000003800898 9000000003800108 90000000037a484c [ 0.000000] 000000000e0a4330 000000000f556b60 000000000a7fd000 000000000f556b08 [ 0.000000] 9000000003ca7700 9000000004184000 0000000000200000 000000000e02b018 [ 0.000000] 000000000a7fd000 90000000037a0790 9000000003800108 0000000000000000 [ 0.000000] 0000000000000000 000000000e0a4330 000000000f556b60 000000000a7fd000 [ 0.000000] 000000000f556b08 000000000eaae298 000000000eaa5040 0000000000200000 [ 0.000000] ... [ 0.000000] Call Trace: [ 0.000000] [<90000000037a5f0c>] efi_runtime_init+0x30/0x94 [ 0.000000] [<90000000037a46ec>] platform_init+0x214/0x250 [ 0.000000] [<90000000037a484c>] setup_arch+0x124/0x45c [ 0.000000] [<90000000037a0790>] start_kernel+0x90/0x670 [ 0.000000] [<900000000378b0d8>] kernel_entry+0xd8/0xdc Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Select HAVE_ARCH_SECCOMP to use the common SECCOMP menuMasahiro Yamada2024-02-061-17/+1
| | | | | | | | | | | | LoongArch missed the refactoring made by commit 282a181b1a0d ("seccomp: Move config option SECCOMP to arch/Kconfig") because LoongArch was not mainlined at that time. The 'depends on PROC_FS' statement is stale as described in that commit. Select HAVE_ARCH_SECCOMP, and remove the duplicated config entry. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: Select ARCH_ENABLE_THP_MIGRATION instead of redefining itMasahiro Yamada2024-02-061-4/+1
| | | | | | | ARCH_ENABLE_THP_MIGRATION is supposed to be selected by arch Kconfig. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: KVM: Add returns to SIMD stubsRandy Dunlap2024-01-261-2/+2
| | | | | | | | | | | | | | | | | | The stubs for kvm_own/lsx()/kvm_own_lasx() when CONFIG_CPU_HAS_LSX or CONFIG_CPU_HAS_LASX is not defined should have a return value since they return an int, so add "return -EINVAL;" to the stubs. Fixes the build error: In file included from ../arch/loongarch/include/asm/kvm_csr.h:12, from ../arch/loongarch/kvm/interrupt.c:8: ../arch/loongarch/include/asm/kvm_vcpu.h: In function 'kvm_own_lasx': ../arch/loongarch/include/asm/kvm_vcpu.h:73:39: error: no return statement in function returning non-void [-Werror=return-type] 73 | static inline int kvm_own_lasx(struct kvm_vcpu *vcpu) { } Fixes: db1ecca22edf ("LoongArch: KVM: Add LSX (128bit SIMD) support") Fixes: 118e10cd893d ("LoongArch: KVM: Add LASX (256bit SIMD) support") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch: KVM: Fix build due to API changesHuacai Chen2024-01-261-2/+2
| | | | | | | | | Commit 8569992d64b8f750e34b7858eac ("KVM: Use gfn instead of hva for mmu_notifier_retry") replaces mmu_invalidate_retry_hva() usage with mmu_invalidate_retry_gfn() for X86, LoongArch also need similar changes to fix build. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* LoongArch/smp: Call rcutree_report_cpu_starting() at tlb_init()Huacai Chen2024-01-262-7/+10
| | | | | | | | | | | | | | | | | Machines which have more than 8 nodes fail to boot SMP after commit a2ccf46333d7b2cf96 ("LoongArch/smp: Call rcutree_report_cpu_starting() earlier"). Because such machines use tlb-based per-cpu base address rather than dmw-based per-cpu base address, resulting per-cpu variables can only be accessed after tlb_init(). But rcutree_report_cpu_starting() is now called before tlb_init() and accesses per-cpu variables indeed. Since the original patch want to avoid the lockdep warning caused by page allocation in tlb_init(), we can move rcutree_report_cpu_starting() to tlb_init() where after tlb exception configuration but before page allocation. Fixes: a2ccf46333d7b2cf96 ("LoongArch/smp: Call rcutree_report_cpu_starting() earlier") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* Merge tag 'loongarch-6.8' of ↵Linus Torvalds2024-01-1925-77/+1575
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson Pull LoongArch updates from Huacai Chen: - Raise minimum clang version to 18.0.0 - Enable initial Rust support for LoongArch - Add built-in dtb support for LoongArch - Use generic interface to support crashkernel=X,[high,low] - Some bug fixes and other small changes - Update the default config file. * tag 'loongarch-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (22 commits) MAINTAINERS: Add BPF JIT for LOONGARCH entry LoongArch: Update Loongson-3 default config file LoongArch: BPF: Prevent out-of-bounds memory access LoongArch: BPF: Support 64-bit pointers to kfuncs LoongArch: Fix definition of ftrace_regs_set_instruction_pointer() LoongArch: Use generic interface to support crashkernel=X,[high,low] LoongArch: Fix and simplify fcsr initialization on execve() LoongArch: Let cores_io_master cover the largest NR_CPUS LoongArch: Change SHMLBA from SZ_64K to PAGE_SIZE LoongArch: Add a missing call to efi_esrt_init() LoongArch: Parsing CPU-related information from DTS LoongArch: dts: DeviceTree for Loongson-2K2000 LoongArch: dts: DeviceTree for Loongson-2K1000 LoongArch: dts: DeviceTree for Loongson-2K0500 LoongArch: Allow device trees be built into the kernel dt-bindings: interrupt-controller: loongson,liointc: Fix dtbs_check warning for interrupt-names dt-bindings: interrupt-controller: loongson,liointc: Fix dtbs_check warning for reg-names dt-bindings: loongarch: Add Loongson SoC boards compatibles dt-bindings: loongarch: Add CPU bindings for LoongArch LoongArch: Enable initial Rust support ...
| * LoongArch: Update Loongson-3 default config fileHuacai Chen2024-01-171-8/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1, Increase NR_CPUS to 256. 2, Enable some cgroup options. 3, Enable some PREEMPT_DYNAMIC/SCHED_CORE options. 4, Enable some CMA/DMA_CMA options. 5, Enable some F2FS options. 6, Enable some DMABUF/UDMABUF options. 7, Enable some USB4 and NTB options. 8, Enable some networking options (MPTCP). 9, Enable Loongson-specific drivers: APB DMA, ASoC. 10, Enable PCI_HOST_GENERIC and SND_VIRTIO for virtual machine. 11, Remove obsolete SECURITY_SELINUX_DISABLE. 12, Regenerate the whole file to keep the order of options be the same as the latest source code. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: BPF: Prevent out-of-bounds memory accessHengqi Chen2024-01-171-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The test_tag test triggers an unhandled page fault: # ./test_tag [ 130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70 [ 130.640501] Oops[#3]: [ 130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G D O 6.7.0-rc4-loong-devel-gb62ab1a397cf #47 61985c1d94084daa2432f771daa45b56b10d8d2a [ 130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 [ 130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40 [ 130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000 [ 130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000 [ 130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70 [ 130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0 [ 130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0 [ 130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000 [ 130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000 [ 130.641900] ra: 9000000003139e70 build_body+0x1fcc/0x4988 [ 130.642007] ERA: 9000000003137f7c build_body+0xd8/0x4988 [ 130.642112] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) [ 130.642261] PRMD: 00000004 (PPLV0 +PIE -PWE) [ 130.642353] EUEN: 00000003 (+FPE +SXE -ASXE -BTE) [ 130.642458] ECFG: 00071c1c (LIE=2-4,10-12 VS=7) [ 130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) [ 130.642658] BADV: ffff80001b898004 [ 130.642719] PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) [ 130.642815] Modules linked in: [last unloaded: bpf_testmod(O)] [ 130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd) [ 130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8 [ 130.643213] 0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0 [ 130.643378] 0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000 [ 130.643538] 0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000 [ 130.643685] 00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000 [ 130.643831] ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000 [ 130.643983] 0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558 [ 130.644131] 0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000 [ 130.644276] 9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc [ 130.644423] ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0 [ 130.644572] ... [ 130.644629] Call Trace: [ 130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988 [ 130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec [ 130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0 [ 130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44 [ 130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588 [ 130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c [ 130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94 [ 130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158 [ 130.645507] [ 130.645539] Code: 380839f6 380831f9 28412bae <24000ca6> 004081ad 0014cb50 004083e8 02bff34c 58008e91 [ 130.645729] [ 130.646418] ---[ end trace 0000000000000000 ]--- On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at loading a BPF prog with 2039 instructions: prog = (struct bpf_prog *)ffff80001b894000 insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048 insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page In the build_insn() function, we are trying to access next instruction unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next page and can be not owned by the current process, thus an page fault is inevitable and then segfault. So, let's access next instruction only under `dst = imm64` context. With this fix, we have: # ./test_tag test_tag: OK (40945 tests) Fixes: bbfddb904df6f82 ("LoongArch: BPF: Avoid declare variables in switch-case") Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: BPF: Support 64-bit pointers to kfuncsHengqi Chen2024-01-171-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like commit 1cf3bfc60f9836f ("bpf: Support 64-bit pointers to kfuncs") for s390x, add support for 64-bit pointers to kfuncs for LoongArch. Since the infrastructure is already implemented in BPF core, the only thing need to be done is to override bpf_jit_supports_far_kfunc_call(). Before this change, several test_verifier tests failed: # ./test_verifier | grep # | grep FAIL #119/p calls: invalid kfunc call: ptr_to_mem to struct with non-scalar FAIL #120/p calls: invalid kfunc call: ptr_to_mem to struct with nesting depth > 4 FAIL #121/p calls: invalid kfunc call: ptr_to_mem to struct with FAM FAIL #122/p calls: invalid kfunc call: reg->type != PTR_TO_CTX FAIL #123/p calls: invalid kfunc call: void * not allowed in func proto without mem size arg FAIL #124/p calls: trigger reg2btf_ids[reg->type] for reg->type > __BPF_REG_TYPE_MAX FAIL #125/p calls: invalid kfunc call: reg->off must be zero when passed to release kfunc FAIL #126/p calls: invalid kfunc call: don't match first member type when passed to release kfunc FAIL #127/p calls: invalid kfunc call: PTR_TO_BTF_ID with negative offset FAIL #128/p calls: invalid kfunc call: PTR_TO_BTF_ID with variable offset FAIL #129/p calls: invalid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID FAIL #130/p calls: valid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID FAIL #486/p map_kptr: ref: reference state created and released on xchg FAIL This is because the kfuncs in the loaded module are far away from __bpf_call_base: ffff800002009440 t bpf_kfunc_call_test_fail1 [bpf_testmod] 9000000002e128d8 T __bpf_call_base The offset relative to __bpf_call_base does NOT fit in s32, which breaks the assumption in BPF core. Enable bpf_jit_supports_far_kfunc_call() lifts this limit. Note that to reproduce the above result, tools/testing/selftests/bpf/config should be applied, and run the test with JIT enabled, unpriv BPF enabled. With this change, the test_verifier tests now all passed: # ./test_verifier ... Summary: 777 PASSED, 0 SKIPPED, 0 FAILED Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Fix definition of ftrace_regs_set_instruction_pointer()Tiezhu Yang2024-01-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current definition of ftrace_regs_set_instruction_pointer() is not correct. Obviously, this function is used to set instruction pointer but not return value, so it should call instruction_pointer_set() instead of regs_set_return_value(). There is no side effect by now because it is only used for kernel live- patching which is not supported, so fix it to avoid failure when testing livepatch in the future. Fixes: 6fbff14a6382 ("LoongArch: ftrace: Abstract DYNAMIC_FTRACE_WITH_ARGS accesses") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Use generic interface to support crashkernel=X,[high,low]Youling Tang2024-01-173-34/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LoongArch already supports two crashkernel regions in kexec-tools, so we can directly use the common interface to support crashkernel=X,[high,low] after commit 0ab97169aa0517079b ("crash_core: add generic function to do reservation"). With the help of newly changed function parse_crashkernel() and generic reserve_crashkernel_generic(), crashkernel reservation can be simplified by steps: 1) Add a new header file <asm/crash_core.h>, then define CRASH_ALIGN, CRASH_ADDR_LOW_MAX and CRASH_ADDR_HIGH_MAX and in <asm/crash_core.h>; 2) Add arch_reserve_crashkernel() to call parse_crashkernel() and reserve_crashkernel_generic(); 3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in arch/loongarch/Kconfig. One can reserve the crash kernel from high memory above DMA zone range by explicitly passing "crashkernel=X,high"; or reserve a memory range below 4G with "crashkernel=X,low". Besides, there are few rules need to take notice: 1) "crashkernel=X,[high,low]" will be ignored if "crashkernel=size" is specified. 2) "crashkernel=X,low" is valid only when "crashkernel=X,high" is passed and there is enough memory to be allocated under 4G. 3) When allocating crashkernel above 4G and no "crashkernel=X,low" is specified, a 128M low memory will be allocated automatically for swiotlb bounce buffer. See Documentation/admin-guide/kernel-parameters.txt for more information. Following test cases have been performed as expected: 1) crashkernel=256M //low=256M 2) crashkernel=1G //low=1G 3) crashkernel=4G //high=4G, low=128M(default) 4) crashkernel=4G crashkernel=256M,high //high=4G, low=128M(default), high is ignored 5) crashkernel=4G crashkernel=256M,low //high=4G, low=128M(default), low is ignored 6) crashkernel=4G,high //high=4G, low=128M(default) 7) crashkernel=256M,low //low=0M, invalid 8) crashkernel=4G,high crashkernel=256M,low //high=4G, low=256M 9) crashkernel=4G,high crashkernel=4G,low //high=0M, low=0M, invalid 10) crashkernel=512M@2560M //low=512M 11) crashkernel=1G,high crashkernel=0M,low //high=1G, low=0M Recommended usage in general: 1) In the case of small memory: crashkernel=512M 2) In the case of large memory: crashkernel=1024M,high crashkernel=128M,low Signed-off-by: Youling Tang <tangyouling@kylinos.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Fix and simplify fcsr initialization on execve()Xi Ruoyao2024-01-173-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There has been a lingering bug in LoongArch Linux systems causing some GCC tests to intermittently fail (see Closes link). I've made a minimal reproducer: zsh% cat measure.s .align 4 .globl _start _start: movfcsr2gr $a0, $fcsr0 bstrpick.w $a0, $a0, 16, 16 beqz $a0, .ok break 0 .ok: li.w $a7, 93 syscall 0 zsh% cc mesaure.s -o measure -nostdlib zsh% echo $((1.0/3)) 0.33333333333333331 zsh% while ./measure; do ; done This while loop should not stop as POSIX is clear that execve must set fenv to the default, where FCSR should be zero. But in fact it will just stop after running for a while (normally less than 30 seconds). Note that "$((1.0/3))" is needed to reproduce this issue because it raises FE_INVALID and makes fcsr0 non-zero. The problem is we are currently relying on SET_PERSONALITY2() to reset current->thread.fpu.fcsr. But SET_PERSONALITY2() is executed before start_thread which calls lose_fpu(0). We can see if kernel preempt is enabled, we may switch to another thread after SET_PERSONALITY2() but before lose_fpu(0). Then bad thing happens: during the thread switch the value of the fcsr0 register is stored into current->thread.fpu.fcsr, making it dirty again. The issue can be fixed by setting current->thread.fpu.fcsr after lose_fpu(0) because lose_fpu() clears TIF_USEDFPU, then the thread switch won't touch current->thread.fpu.fcsr. The only other architecture setting FCSR in SET_PERSONALITY2() is MIPS. I've ran a similar test on MIPS with mainline kernel and it turns out MIPS is buggy, too. Anyway MIPS do this for supporting different FP flavors (NaN encodings, etc.) which do not exist on LoongArch. So for LoongArch, we can simply remove the current->thread.fpu.fcsr setting from SET_PERSONALITY2() and do it in start_thread(), after lose_fpu(0). The while loop failing with the mainline kernel has survived one hour after this change on LoongArch. Fixes: 803b0fc5c3f2baa ("LoongArch: Add process management") Closes: https://github.com/loongson-community/discussions/issues/7 Link: https://lore.kernel.org/linux-mips/7a6aa1bbdbbe2e63ae96ff163fab0349f58f1b9e.camel@xry111.site/ Cc: stable@vger.kernel.org Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Let cores_io_master cover the largest NR_CPUSHuacai Chen2024-01-173-4/+6
| | | | | | | | | | | | | | | | Now loongson_system_configuration::cores_io_master only covers 64 cpus, if NR_CPUS > 64 there will be memory corruption. So let cores_io_master cover the largest NR_CPUS (256). Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Change SHMLBA from SZ_64K to PAGE_SIZEHuacai Chen2024-01-172-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LoongArch has hardware page coloring for L1 Cache, so we don't have cache aliases. But SFB (Store Fill Buffer) still has aliases. So we define SHMLBA to SZ_64K previously. But there are losts of applications use PAGE_SIZE rather than SHMLBA to mmap() file pages and shared pages. Of course we can fix them one by one, but not easy. On the other hand, we can simply disable SFB for 4KB page size to fix cache alias (there will be performance decrease, but acceptable), and in future we will fix SFB in hardware. So we can safely define SHMLBA to PAGE_SIZE (use the generic shmparam.h) to make life easier. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Add a missing call to efi_esrt_init()Huacai Chen2024-01-171-0/+2
| | | | | | | | | | | | | | | | ESRT (EFI System Resource Table) is needed for UEFI's "Capsule Update" feature. But ESRT initialization is missing on LoongArch now, so add a call to efi_esrt_init() at the end of efi_init(). Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Parsing CPU-related information from DTSBinbin Zhou2024-01-172-1/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | Generally, we can get cpu-related information, such as model name, from /proc/cpuinfo. For FDT-based systems, we need to parse the relevant information from DTS. BTW, set loongson_sysconf.cores_per_package to num_processors if SMBIOS doesn't provide a valid number (usually FDT-based systems). Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: dts: DeviceTree for Loongson-2K2000Binbin Zhou2024-01-173-1/+373
| | | | | | | | | | | | | | | | Add DeviceTree file for Loongson-2K2000 processor, which integrates two 64-bit 3-issue superscalar LA364 processor cores. Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: dts: DeviceTree for Loongson-2K1000Binbin Zhou2024-01-173-1/+676
| | | | | | | | | | | | | | | | Add DeviceTree file for Loongson-2K1000 processor, which integrates two 64-bit 2-issue superscalar LA264 processor cores. Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: dts: DeviceTree for Loongson-2K0500Binbin Zhou2024-01-173-0/+356
| | | | | | | | | | | | | | | | Add DeviceTree file for Loongson-2K0500 processor, which integrates one 64-bit 2-issue superscalar LA264 processor core. Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Allow device trees be built into the kernelBinbin Zhou2024-01-175-6/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During the upstream progress of those DT-based drivers, DT properties are changed a lot so very different from those in existing bootloaders. It is inevitably that some existing systems do not provide a standard, canonical device tree to the kernel at boot time. So let's provide a device tree table in the kernel, keyed by the dts filename, containing the relevant DTBs. We can use the built-in dts files as references. Each SoC has only one built-in dts file which describes all possible device information of that SoC, so the dts files are good examples during development. And as a reference, our built-in dts file only enables the most basic bootable combinations (so it is generic enough), acts as an alternative in case the dts in the bootloader is unexpected. Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * LoongArch: Enable initial Rust supportWANG Rui2024-01-172-0/+4
| | | | | | | | | | | | | | | | Enable initial Rust support for LoongArch. Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: WANG Rui <wangrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
* | Merge tag 'driver-core-6.8-rc1' of ↵Linus Torvalds2024-01-182-40/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here are the set of driver core and kernfs changes for 6.8-rc1. Nothing major in here this release cycle, just lots of small cleanups and some tweaks on kernfs that in the very end, got reverted and will come back in a safer way next release cycle. Included in here are: - more driver core 'const' cleanups and fixes - fw_devlink=rpm is now the default behavior - kernfs tiny changes to remove some string functions - cpu handling in the driver core is updated to work better on many systems that add topologies and cpus after booting - other minor changes and cleanups All of the cpu handling patches have been acked by the respective maintainers and are coming in here in one series. Everything has been in linux-next for a while with no reported issues" * tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (51 commits) Revert "kernfs: convert kernfs_idr_lock to an irq safe raw spinlock" kernfs: convert kernfs_idr_lock to an irq safe raw spinlock class: fix use-after-free in class_register() PM: clk: make pm_clk_add_notifier() take a const pointer EDAC: constantify the struct bus_type usage kernfs: fix reference to renamed function driver core: device.h: fix Excess kernel-doc description warning driver core: class: fix Excess kernel-doc description warning driver core: mark remaining local bus_type variables as const driver core: container: make container_subsys const driver core: bus: constantify subsys_register() calls driver core: bus: make bus_sort_breadthfirst() take a const pointer kernfs: d_obtain_alias(NULL) will do the right thing... driver core: Better advertise dev_err_probe() kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy() kernfs: Convert kernfs_name_locked() from strlcpy() to strscpy() kernfs: Convert kernfs_walk_ns() from strlcpy() to strscpy() initramfs: Expose retained initrd as sysfs file fs/kernfs/dir: obey S_ISGID kernel/cgroup: use kernfs_create_dir_ns() ...
| * | LoongArch: convert to use arch_cpu_is_hotpluggable()Russell King (Oracle)2023-12-061-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert loongarch to use the arch_cpu_is_hotpluggable() helper rather than arch_register_cpu(). Also remove the export as nothing should be using arch_register_cpu() outside of the core kernel/acpi code. Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/E1r5R4B-00Ct0G-Kk@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | LoongArch: Use the __weak version of arch_unregister_cpu()James Morse2023-12-061-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LoongArch provides its own arch_unregister_cpu(). This clears the hotpluggable flag, then unregisters the CPU. It isn't necessary to clear the hotpluggable flag when unregistering a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices pointer, meaning cpu_is_hotpluggable() will return false, as get_cpu_device() has returned NULL. Remove arch_unregister_cpu() and use the __weak version. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/E1r5R46-00Ct0A-GJ@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | LoongArch: Switch over to GENERIC_CPU_DEVICESJames Morse2023-12-062-27/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be overridden by the arch code, switch over to this to allow common code to choose when the register_cpu() call is made. This allows topology_init() to be removed. This is an intermediate step to the logic being moved to drivers/acpi, where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. This is a subtle change. Originally: - on boot, topology_init() would have marked present CPUs that io_master() is true for as hotplug-incapable. - if a CPU is hotplugged that is an io_master(), it can later be hot-unplugged. The new behaviour is that any CPU that io_master() is true for will now always be marked as hotplug-incapable, thus even if it was hotplugged, it can no longer be hot-unplugged. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/E1r5R41-00Ct04-Bg@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | ACPI: Move ACPI_HOTPLUG_CPU to be disabled on arm64 and riscvJames Morse2023-12-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Neither arm64 nor riscv support physical hotadd of CPUs that were not present at boot. For arm64 much of the platform description is in static tables which do not have update methods. arm64 does support HOTPLUG_CPU, which is backed by a firmware interface to turn CPUs on and off. acpi_processor_hotadd_init() and acpi_processor_remove() are for adding and removing CPUs that were not present at boot. arm64 systems that do this are not supported as there is currently insufficient information in the platform description. (e.g. did the GICR get removed too?) arm64 currently relies on the MADT enabled flag check in map_gicc_mpidr() to prevent CPUs that were not described as present at boot from being added to the system. Similarly, riscv relies on the same check in map_rintc_hartid(). Both architectures also rely on the weak 'always fails' definitions of acpi_map_cpu() and arch_register_cpu(). Subsequent changes will redefine ACPI_HOTPLUG_CPU as making possible CPUs present. Neither arm64 nor riscv support this. Disable ACPI_HOTPLUG_CPU for arm64 and riscv by removing 'default y' and selecting it on the other three ACPI architectures. This allows the weak definitions of some symbols to be removed. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/E1r5R31-00Csyt-Jq@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | Loongarch: remove arch_*register_cpu() exportsRussell King (Oracle)2023-12-061-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_register_cpu() and arch_unregister_cpu() are not used by anything that can be a module - they are used by drivers/base/cpu.c and drivers/acpi/acpi_processor.c, neither of which can be a module. Remove the exports. Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/E1r5R2w-00Csyn-E2@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2024-01-1712-149/+553
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm updates from Paolo Bonzini: "Generic: - Use memdup_array_user() to harden against overflow. - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all architectures. - Clean up Kconfigs that all KVM architectures were selecting - New functionality around "guest_memfd", a new userspace API that creates an anonymous file and returns a file descriptor that refers to it. guest_memfd files are bound to their owning virtual machine, cannot be mapped, read, or written by userspace, and cannot be resized. guest_memfd files do however support PUNCH_HOLE, which can be used to switch a memory area between guest_memfd and regular anonymous memory. - New ioctl KVM_SET_MEMORY_ATTRIBUTES allowing userspace to specify per-page attributes for a given page of guest memory; right now the only attribute is whether the guest expects to access memory via guest_memfd or not, which in Confidential SVMs backed by SEV-SNP, TDX or ARM64 pKVM is checked by firmware or hypervisor that guarantees confidentiality (AMD PSP, Intel TDX module, or EL2 in the case of pKVM). x86: - Support for "software-protected VMs" that can use the new guest_memfd and page attributes infrastructure. This is mostly useful for testing, since there is no pKVM-like infrastructure to provide a meaningfully reduced TCB. - Fix a relatively benign off-by-one error when splitting huge pages during CLEAR_DIRTY_LOG. - Fix a bug where KVM could incorrectly test-and-clear dirty bits in non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with a non-huge SPTE. - Use more generic lockdep assertions in paths that don't actually care about whether the caller is a reader or a writer. - let Xen guests opt out of having PV clock reported as "based on a stable TSC", because some of them don't expect the "TSC stable" bit (added to the pvclock ABI by KVM, but never set by Xen) to be set. - Revert a bogus, made-up nested SVM consistency check for TLB_CONTROL. - Advertise flush-by-ASID support for nSVM unconditionally, as KVM always flushes on nested transitions, i.e. always satisfies flush requests. This allows running bleeding edge versions of VMware Workstation on top of KVM. - Sanity check that the CPU supports flush-by-ASID when enabling SEV support. - On AMD machines with vNMI, always rely on hardware instead of intercepting IRET in some cases to detect unmasking of NMIs - Support for virtualizing Linear Address Masking (LAM) - Fix a variety of vPMU bugs where KVM fail to stop/reset counters and other state prior to refreshing the vPMU model. - Fix a double-overflow PMU bug by tracking emulated counter events using a dedicated field instead of snapshotting the "previous" counter. If the hardware PMC count triggers overflow that is recognized in the same VM-Exit that KVM manually bumps an event count, KVM would pend PMIs for both the hardware-triggered overflow and for KVM-triggered overflow. - Turn off KVM_WERROR by default for all configs so that it's not inadvertantly enabled by non-KVM developers, which can be problematic for subsystems that require no regressions for W=1 builds. - Advertise all of the host-supported CPUID bits that enumerate IA32_SPEC_CTRL "features". - Don't force a masterclock update when a vCPU synchronizes to the current TSC generation, as updating the masterclock can cause kvmclock's time to "jump" unexpectedly, e.g. when userspace hotplugs a pre-created vCPU. - Use RIP-relative address to read kvm_rebooting in the VM-Enter fault paths, partly as a super minor optimization, but mostly to make KVM play nice with position independent executable builds. - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on CONFIG_HYPERV as a minor optimization, and to self-document the code. - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV "emulation" at build time. ARM64: - LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB base granule sizes. Branch shared with the arm64 tree. - Large Fine-Grained Trap rework, bringing some sanity to the feature, although there is more to come. This comes with a prefix branch shared with the arm64 tree. - Some additional Nested Virtualization groundwork, mostly introducing the NV2 VNCR support and retargetting the NV support to that version of the architecture. - A small set of vgic fixes and associated cleanups. Loongarch: - Optimization for memslot hugepage checking - Cleanup and fix some HW/SW timer issues - Add LSX/LASX (128bit/256bit SIMD) support RISC-V: - KVM_GET_REG_LIST improvement for vector registers - Generate ISA extension reg_list using macros in get-reg-list selftest - Support for reporting steal time along with selftest s390: - Bugfixes Selftests: - Fix an annoying goof where the NX hugepage test prints out garbage instead of the magic token needed to run the test. - Fix build errors when a header is delete/moved due to a missing flag in the Makefile. - Detect if KVM bugged/killed a selftest's VM and print out a helpful message instead of complaining that a random ioctl() failed. - Annotate the guest printf/assert helpers with __printf(), and fix the various bugs that were lurking due to lack of said annotation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (185 commits) x86/kvm: Do not try to disable kvmclock if it was not enabled KVM: x86: add missing "depends on KVM" KVM: fix direction of dependency on MMU notifiers KVM: introduce CONFIG_KVM_COMMON KVM: arm64: Add missing memory barriers when switching to pKVM's hyp pgd KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache RISC-V: KVM: selftests: Add get-reg-list test for STA registers RISC-V: KVM: selftests: Add steal_time test support RISC-V: KVM: selftests: Add guest_sbi_probe_extension RISC-V: KVM: selftests: Move sbi_ecall to processor.c RISC-V: KVM: Implement SBI STA extension RISC-V: KVM: Add support for SBI STA registers RISC-V: KVM: Add support for SBI extension registers RISC-V: KVM: Add SBI STA info to vcpu_arch RISC-V: KVM: Add steal-update vcpu request RISC-V: KVM: Add SBI STA extension skeleton RISC-V: paravirt: Implement steal-time support RISC-V: Add SBI STA extension definitions RISC-V: paravirt: Add skeleton for pv-time support RISC-V: KVM: Fix indentation in kvm_riscv_vcpu_set_reg_csr() ...
| * | | KVM: introduce CONFIG_KVM_COMMONPaolo Bonzini2024-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_HAVE_KVM is currently used by some architectures to either enabled the KVM config proper, or to enable host-side code that is not part of the KVM module. However, CONFIG_KVM's "select" statement in virt/kvm/Kconfig corresponds to a third meaning, namely to enable common Kconfigs required by all architectures that support KVM. These three meanings can be replaced respectively by an architecture-specific Kconfig, by IS_ENABLED(CONFIG_KVM), or by a new Kconfig symbol that is in turn selected by the architecture-specific "config KVM". Start by introducing such a new Kconfig symbol, CONFIG_KVM_COMMON. Unlike CONFIG_HAVE_KVM, it is selected by CONFIG_KVM, not by architecture code, and it brings in all dependencies of common KVM code. In particular, INTERVAL_TREE was missing in loongarch and riscv, so that is another thing that is fixed. Fixes: 8132d887a702 ("KVM: remove CONFIG_HAVE_KVM_EVENTFD", 2023-12-08) Reported-by: Randy Dunlap <rdunlap@infradead.org> Closes: https://lore.kernel.org/all/44907c6b-c5bd-4e4a-a921-e4d3825539d8@infradead.org/ Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | Merge tag 'loongarch-kvm-6.8' of ↵Paolo Bonzini2024-01-0226-193/+595
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.8 1. Optimization for memslot hugepage checking. 2. Cleanup and fix some HW/SW timer issues. 3. Add LSX/LASX (128bit/256bit SIMD) support.
| | * | | LoongArch: KVM: Add LASX (256bit SIMD) supportTianrui Zhao2023-12-197-4/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds LASX (256bit SIMD) support for LoongArch KVM. There will be LASX exception in KVM when guest use the LASX instructions. KVM will enable LASX and restore the vector registers for guest and then return to guest to continue running. Reviewed-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| | * | | LoongArch: KVM: Add LSX (128bit SIMD) supportTianrui Zhao2023-12-198-8/+280
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds LSX (128bit SIMD) support for LoongArch KVM. There will be LSX exception in KVM when guest use the LSX instructions. KVM will enable LSX and restore the vector registers for guest and then return to guest to continue running. Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| | * | | LoongArch: KVM: Fix timer emulation with oneshot modeBibo Mao2023-12-191-13/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When timer is fired in oneshot mode, CSR TVAL will be -1 rather than 0. There needs special handing for this situation. There are two scenarios when oneshot timer is fired. One scenario is that time is fired after exiting to host, CSR TVAL is set with 0 in order to inject hw interrupt, and -1 will assigned to CSR TVAL soon. The other situation is that timer is fired in VM and guest kernel is hanlding timer IRQ, IRQ is acked and is ready to set next expired timer value, then vm exits to host. Timer interrupt should not be inject at this point, else there will be spurious timer interrupt. Here hw timer irq status in CSR ESTAT is used to judge these two scenarios. If CSR TVAL is -1, the oneshot timer is fired; and if timer hw irq is on in CSR ESTAT register, it happens after exiting to host; else if timer hw irq is off, we think that it happens in vm and timer IRQ handler has already acked IRQ. With this patch, runltp with version ltp20230516 passes to run in vm. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| | * | | LoongArch: KVM: Remove kvm_acquire_timer() before entering guestBibo Mao2023-12-193-46/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Timer emulation method in VM is switch to SW timer, there are two places where timer emulation is needed. One is during vcpu thread context switch, the other is halt-polling with idle instruction emulation. SW timer switching is removed during halt-polling mode, so it is not necessary to disable SW timer before entering to guest. This patch removes SW timer handling before entering guest mode, and put it in HW timer restoring flow when vcpu thread is sched-in. With this patch, vm timer emulation is simpler, there is SW/HW timer switch only in vcpu thread context switch scenario. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| | * | | LoongArch: KVM: Allow to access HW timer CSR registers alwaysBibo Mao2023-12-192-22/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently HW timer CSR registers are allowed to access before entering to vm and disabled if switch to SW timer in host mode, instead it is not necessary to do so. HW timer CSR registers can be accessed always, it is nothing to do with whether it is in vm mode or host mode. This patch removes the limitation. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| | * | | LoongArch: KVM: Remove SW timer switch when vcpu is halt pollingBibo Mao2023-12-193-15/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With halt-polling supported, there is checking for pending events or interrupts when vcpu executes idle instruction. Pending interrupts include injected SW interrupts and passthrough HW interrupts, such as HW timer interrupts, since HW timer works still even if vcpu exists from VM mode. Since HW timer pending interrupt can be set directly with CSR status register, and pending HW timer interrupt checking is used in vcpu block checking function, it is not necessary to switch to SW timer during halt-polling. This patch adds preemption disabling in function kvm_cpu_has_pending_timer(), and removes SW timer switching in idle instruction emulation function. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| | * | | LoongArch: KVM: Optimization for memslot hugepage checkingBibo Mao2023-12-192-41/+86
| | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During shadow mmu page fault, there is checking for huge page for specified memslot. Page fault is hot path, check logic can be done when memslot is created. Here two flags are added for huge page checking, KVM_MEM_HUGEPAGE_CAPABLE and KVM_MEM_HUGEPAGE_INCAPABLE. Indeed for an optimized qemu, memslot for DRAM is always huge page aligned. The flag is firstly checked during hot page fault path. Now only huge page flag is supported, there is a long way for super page support in LoongArch system. Since super page size is 64G for 16K pagesize and 1G for 4K pagesize, 64G physical address is rarely used and LoongArch kernel needs support super page for 4K. Also memory layout of LoongArch qemu VM should be 1G aligned. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| * | | KVM: remove CONFIG_HAVE_KVM_EVENTFDPaolo Bonzini2023-12-081-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | virt/kvm/eventfd.c is compiled unconditionally, meaning that the ioeventfds member of struct kvm is accessed unconditionally. CONFIG_HAVE_KVM_EVENTFD therefore must be defined for KVM common code to compile successfully, remove it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | Merge branch 'kvm-guestmemfd' into HEADPaolo Bonzini2023-11-142-2/+1
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce several new KVM uAPIs to ultimately create a guest-first memory subsystem within KVM, a.k.a. guest_memfd. Guest-first memory allows KVM to provide features, enhancements, and optimizations that are kludgly or outright impossible to implement in a generic memory subsystem. The core KVM ioctl() for guest_memfd is KVM_CREATE_GUEST_MEMFD, which similar to the generic memfd_create(), creates an anonymous file and returns a file descriptor that refers to it. Again like "regular" memfd files, guest_memfd files live in RAM, have volatile storage, and are automatically released when the last reference is dropped. The key differences between memfd files (and every other memory subystem) is that guest_memfd files are bound to their owning virtual machine, cannot be mapped, read, or written by userspace, and cannot be resized. guest_memfd files do however support PUNCH_HOLE, which can be used to convert a guest memory area between the shared and guest-private states. A second KVM ioctl(), KVM_SET_MEMORY_ATTRIBUTES, allows userspace to specify attributes for a given page of guest memory. In the long term, it will likely be extended to allow userspace to specify per-gfn RWX protections, including allowing memory to be writable in the guest without it also being writable in host userspace. The immediate and driving use case for guest_memfd are Confidential (CoCo) VMs, specifically AMD's SEV-SNP, Intel's TDX, and KVM's own pKVM. For such use cases, being able to map memory into KVM guests without requiring said memory to be mapped into the host is a hard requirement. While SEV+ and TDX prevent untrusted software from reading guest private data by encrypting guest memory, pKVM provides confidentiality and integrity *without* relying on memory encryption. In addition, with SEV-SNP and especially TDX, accessing guest private memory can be fatal to the host, i.e. KVM must be prevent host userspace from accessing guest memory irrespective of hardware behavior. Long term, guest_memfd may be useful for use cases beyond CoCo VMs, for example hardening userspace against unintentional accesses to guest memory. As mentioned earlier, KVM's ABI uses userspace VMA protections to define the allow guest protection (with an exception granted to mapping guest memory executable), and similarly KVM currently requires the guest mapping size to be a strict subset of the host userspace mapping size. Decoupling the mappings sizes would allow userspace to precisely map only what is needed and with the required permissions, without impacting guest performance. A guest-first memory subsystem also provides clearer line of sight to things like a dedicated memory pool (for slice-of-hardware VMs) and elimination of "struct page" (for offload setups where userspace _never_ needs to DMA from or into guest memory). guest_memfd is the result of 3+ years of development and exploration; taking on memory management responsibilities in KVM was not the first, second, or even third choice for supporting CoCo VMs. But after many failed attempts to avoid KVM-specific backing memory, and looking at where things ended up, it is quite clear that of all approaches tried, guest_memfd is the simplest, most robust, and most extensible, and the right thing to do for KVM and the kernel at-large. The "development cycle" for this version is going to be very short; ideally, next week I will merge it as is in kvm/next, taking this through the KVM tree for 6.8 immediately after the end of the merge window. The series is still based on 6.6 (plus KVM changes for 6.7) so it will require a small fixup for changes to get_file_rcu() introduced in 6.7 by commit 0ede61d8589c ("file: convert to SLAB_TYPESAFE_BY_RCU"). The fixup will be done as part of the merge commit, and most of the text above will become the commit message for the merge. Pending post-merge work includes: - hugepage support - looking into using the restrictedmem framework for guest memory - introducing a testing mechanism to poison memory, possibly using the same memory attributes introduced here - SNP and TDX support There are two non-KVM patches buried in the middle of this series: fs: Rename anon_inode_getfile_secure() and anon_inode_getfd_secure() mm: Add AS_UNMOVABLE to mark mapping as completely unmovable The first is small and mostly suggested-by Christian Brauner; the second a bit less so but it was written by an mm person (Vlastimil Babka).
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