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2023-09-17x86/boot: Set EFI handover offset directly in header asmArd Biesheuvel
The offsets of the EFI handover entrypoints are available to the assembler when constructing the header, so there is no need to set them from the build tool afterwards. This change has no impact on the resulting bzImage binary. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230915171623.655440-12-ardb@google.com
2023-09-17x86/boot: Grab kernel_info offset from zoffset header directlyArd Biesheuvel
Instead of parsing zoffset.h and poking the kernel_info offset value into the header from the build tool, just grab the value directly in the asm file that describes this header. This change has no impact on the resulting bzImage binary. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230915171623.655440-11-ardb@google.com
2023-09-17Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== The following pull-request contains BPF updates for your *net-next* tree. We've added 73 non-merge commits during the last 9 day(s) which contain a total of 79 files changed, 5275 insertions(+), 600 deletions(-). The main changes are: 1) Basic BTF validation in libbpf, from Andrii Nakryiko. 2) bpf_assert(), bpf_throw(), exceptions in bpf progs, from Kumar Kartikeya Dwivedi. 3) next_thread cleanups, from Oleg Nesterov. 4) Add mcpu=v4 support to arm32, from Puranjay Mohan. 5) Add support for __percpu pointers in bpf progs, from Yonghong Song. 6) Fix bpf tailcall interaction with bpf trampoline, from Leon Hwang. 7) Raise irq_work in bpf_mem_alloc while irqs are disabled to improve refill probabablity, from Hou Tao. Please consider pulling these changes from: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git Thanks a lot! Also thanks to reporters, reviewers and testers of commits in this pull-request: Alan Maguire, Andrey Konovalov, Dave Marchevsky, "Eric W. Biederman", Jiri Olsa, Maciej Fijalkowski, Quentin Monnet, Russell King (Oracle), Song Liu, Stanislav Fomichev, Yonghong Song ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-17x86/platform/uv: Rework NMI "action" modparam handlingHans de Goede
Rework NMI "action" modparam handling: - Replace the uv_nmi_action string with an enum; and - Use sysfs_match_string() for string parsing in param_set_action() No change in functionality intended. Suggested-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Steve Wahl <steve.wahl@hpe.com> Reviewed-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Steve Wahl <steve.wahl@hpe.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20230916130653.243532-1-hdegoede@redhat.com
2023-09-17x86/purgatory: Remove LTO flagsSong Liu
-flto* implies -ffunction-sections. With LTO enabled, ld.lld generates multiple .text sections for purgatory.ro: $ readelf -S purgatory.ro | grep " .text" [ 1] .text PROGBITS 0000000000000000 00000040 [ 7] .text.purgatory PROGBITS 0000000000000000 000020e0 [ 9] .text.warn PROGBITS 0000000000000000 000021c0 [13] .text.sha256_upda PROGBITS 0000000000000000 000022f0 [15] .text.sha224_upda PROGBITS 0000000000000000 00002be0 [17] .text.sha256_fina PROGBITS 0000000000000000 00002bf0 [19] .text.sha224_fina PROGBITS 0000000000000000 00002cc0 This causes WARNING from kexec_purgatory_setup_sechdrs(): WARNING: CPU: 26 PID: 110894 at kernel/kexec_file.c:919 kexec_load_purgatory+0x37f/0x390 Fix this by disabling LTO for purgatory. [ AFAICT, x86 is the only arch that supports LTO and purgatory. ] We could also fix this with an explicit linker script to rejoin .text.* sections back into .text. However, given the benefit of LTOing purgatory is small, simply disable the production of more .text.* sections for now. Fixes: b33fff07e3e3 ("x86, build: allow LTO to be selected") Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20230914170138.995606-1-song@kernel.org
2023-09-17x86/boot/compressed: Reserve more memory for page tablesKirill A. Shutemov
The decompressor has a hard limit on the number of page tables it can allocate. This limit is defined at compile-time and will cause boot failure if it is reached. The kernel is very strict and calculates the limit precisely for the worst-case scenario based on the current configuration. However, it is easy to forget to adjust the limit when a new use-case arises. The worst-case scenario is rarely encountered during sanity checks. In the case of enabling 5-level paging, a use-case was overlooked. The limit needs to be increased by one to accommodate the additional level. This oversight went unnoticed until Aaron attempted to run the kernel via kexec with 5-level paging and unaccepted memory enabled. Update wost-case calculations to include 5-level paging. To address this issue, let's allocate some extra space for page tables. 128K should be sufficient for any use-case. The logic can be simplified by using a single value for all kernel configurations. [ Also add a warning, should this memory run low - by Dave Hansen. ] Fixes: 34bbb0009f3b ("x86/boot/compressed: Enable 5-level paging during decompression stage") Reported-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230915070221.10266-1-kirill.shutemov@linux.intel.com
2023-09-16bpf: Implement BPF exceptionsKumar Kartikeya Dwivedi
This patch implements BPF exceptions, and introduces a bpf_throw kfunc to allow programs to throw exceptions during their execution at runtime. A bpf_throw invocation is treated as an immediate termination of the program, returning back to its caller within the kernel, unwinding all stack frames. This allows the program to simplify its implementation, by testing for runtime conditions which the verifier has no visibility into, and assert that they are true. In case they are not, the program can simply throw an exception from the other branch. BPF exceptions are explicitly *NOT* an unlikely slowpath error handling primitive, and this objective has guided design choices of the implementation of the them within the kernel (with the bulk of the cost for unwinding the stack offloaded to the bpf_throw kfunc). The implementation of this mechanism requires use of add_hidden_subprog mechanism introduced in the previous patch, which generates a couple of instructions to move R1 to R0 and exit. The JIT then rewrites the prologue of this subprog to take the stack pointer and frame pointer as inputs and reset the stack frame, popping all callee-saved registers saved by the main subprog. The bpf_throw function then walks the stack at runtime, and invokes this exception subprog with the stack and frame pointers as parameters. Reviewers must take note that currently the main program is made to save all callee-saved registers on x86_64 during entry into the program. This is because we must do an equivalent of a lightweight context switch when unwinding the stack, therefore we need the callee-saved registers of the caller of the BPF program to be able to return with a sane state. Note that we have to additionally handle r12, even though it is not used by the program, because when throwing the exception the program makes an entry into the kernel which could clobber r12 after saving it on the stack. To be able to preserve the value we received on program entry, we push r12 and restore it from the generated subprogram when unwinding the stack. For now, bpf_throw invocation fails when lingering resources or locks exist in that path of the program. In a future followup, bpf_throw will be extended to perform frame-by-frame unwinding to release lingering resources for each stack frame, removing this limitation. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16arch/x86: Implement arch_bpf_stack_walkKumar Kartikeya Dwivedi
The plumbing for offline unwinding when we throw an exception in programs would require walking the stack, hence introduce a new arch_bpf_stack_walk function. This is provided when the JIT supports exceptions, i.e. bpf_jit_supports_exceptions is true. The arch-specific code is really minimal, hence it should be straightforward to extend this support to other architectures as well, as it reuses the logic of arch_stack_walk, but allowing access to unwind_state data. Once the stack pointer and frame pointer are known for the main subprog during the unwinding, we know the stack layout and location of any callee-saved registers which must be restored before we return back to the kernel. This handling will be added in the subsequent patches. Note that while we primarily unwind through BPF frames, which are effectively CONFIG_UNWINDER_FRAME_POINTER, we still need one of this or CONFIG_UNWINDER_ORC to be able to unwind through the bpf_throw frame from which we begin walking the stack. We also require both sp and bp (stack and frame pointers) from the unwind_state structure, which are only available when one of these two options are enabled. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16bpf: Use bpf_is_subprog to check for subprogsKumar Kartikeya Dwivedi
We would like to know whether a bpf_prog corresponds to the main prog or one of the subprogs. The current JIT implementations simply check this using the func_idx in bpf_prog->aux->func_idx. When the index is 0, it belongs to the main program, otherwise it corresponds to some subprogram. This will also be necessary to halt exception propagation while walking the stack when an exception is thrown, so we add a simple helper function to check this, named bpf_is_subprog, and convert existing JIT implementations to also make use of it. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-15x86/percpu: Use raw_cpu_try_cmpxchg() in preempt_count_set()Uros Bizjak
Use raw_cpu_try_cmpxchg() instead of raw_cpu_cmpxchg(*ptr, old, new) == old. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after CMPXCHG (and related MOV instruction in front of CMPXCHG). Also, raw_cpu_try_cmpxchg() implicitly assigns old *ptr value to "old" when cmpxchg fails. There is no need to re-read the value in the loop. No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230830151623.3900-2-ubizjak@gmail.com
2023-09-15x86/percpu: Define raw_cpu_try_cmpxchg and this_cpu_try_cmpxchg()Uros Bizjak
Define target-specific raw_cpu_try_cmpxchg_N() and this_cpu_try_cmpxchg_N() macros. These definitions override the generic fallback definitions and enable target-specific optimized implementations. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230830151623.3900-1-ubizjak@gmail.com
2023-09-15x86/percpu: Define {raw,this}_cpu_try_cmpxchg{64,128}Uros Bizjak
Define target-specific {raw,this}_cpu_try_cmpxchg64() and {raw,this}_cpu_try_cmpxchg128() macros. These definitions override the generic fallback definitions and enable target-specific optimized implementations. Several places in mm/slub.o improve from e.g.: 53bc: 48 8d 4f 40 lea 0x40(%rdi),%rcx 53c0: 48 89 fa mov %rdi,%rdx 53c3: 49 8b 5c 05 00 mov 0x0(%r13,%rax,1),%rbx 53c8: 4c 89 e8 mov %r13,%rax 53cb: 49 8d 30 lea (%r8),%rsi 53ce: e8 00 00 00 00 call 53d3 <...> 53cf: R_X86_64_PLT32 this_cpu_cmpxchg16b_emu-0x4 53d3: 48 31 d7 xor %rdx,%rdi 53d6: 4c 31 e8 xor %r13,%rax 53d9: 48 09 c7 or %rax,%rdi 53dc: 75 ae jne 538c <...> to: 53bc: 48 8d 4a 40 lea 0x40(%rdx),%rcx 53c0: 49 8b 1c 07 mov (%r15,%rax,1),%rbx 53c4: 4c 89 f8 mov %r15,%rax 53c7: 48 8d 37 lea (%rdi),%rsi 53ca: e8 00 00 00 00 call 53cf <...> 53cb: R_X86_64_PLT32 this_cpu_cmpxchg16b_emu-0x4 53cf: 75 bb jne 538c <...> reducing the size of mm/slub.o by 80 bytes: text data bss dec hex filename 39758 5337 4208 49303 c097 slub-new.o 39838 5337 4208 49383 c0e7 slub-old.o Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230906185941.53527-1-ubizjak@gmail.com
2023-09-15x86/boot: Drop references to startup_64Ard Biesheuvel
The x86 boot image generation tool assign a default value to startup_64 and subsequently parses the actual value from zoffset.h but it never actually uses the value anywhere. So remove this code. This change has no impact on the resulting bzImage binary. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230912090051.4014114-25-ardb@google.com
2023-09-15x86/boot: Drop redundant code setting the root deviceArd Biesheuvel
The root device defaults to 0,0 and is no longer configurable at build time [0], so there is no need for the build tool to ever write to this field. [0] 079f85e624189292 ("x86, build: Do not set the root_dev field in bzImage") This change has no impact on the resulting bzImage binary. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230912090051.4014114-23-ardb@google.com
2023-09-15x86/boot: Omit compression buffer from PE/COFF image memory footprintArd Biesheuvel
Now that the EFI stub decompresses the kernel and hands over to the decompressed image directly, there is no longer a need to provide a decompression buffer as part of the .BSS allocation of the PE/COFF image. It also means the PE/COFF image can be loaded anywhere in memory, and setting the preferred image base is unnecessary. So drop the handling of this from the header and from the build tool. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230912090051.4014114-22-ardb@google.com
2023-09-15x86/boot: Remove the 'bugger off' messageArd Biesheuvel
Ancient (pre-2003) x86 kernels could boot from a floppy disk straight from the BIOS, using a small real mode boot stub at the start of the image where the BIOS would expect the boot record (or boot block) to appear. Due to its limitations (kernel size < 1 MiB, no support for IDE, USB or El Torito floppy emulation), this support was dropped, and a Linux aware bootloader is now always required to boot the kernel from a legacy BIOS. To smoothen this transition, the boot stub was not removed entirely, but replaced with one that just prints an error message telling the user to install a bootloader. As it is unlikely that anyone doing direct floppy boot with such an ancient kernel is going to upgrade to v6.5+ and expect that this boot method still works, printing this message is kind of pointless, and so it should be possible to remove the logic that emits it. Let's free up this space so it can be used to expand the PE header in a subsequent patch. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com> Link: https://lore.kernel.org/r/20230912090051.4014114-21-ardb@google.com
2023-09-15x86/efi: Drop alignment flags from PE section headersArd Biesheuvel
The section header flags for alignment are documented in the PE/COFF spec as being applicable to PE object files only, not to PE executables such as the Linux bzImage, so let's drop them from the PE header. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230912090051.4014114-20-ardb@google.com
2023-09-15x86/efi: Drop EFI stub .bss from .data sectionArd Biesheuvel
Now that the EFI stub always zero inits its BSS section upon entry, there is no longer a need to place the BSS symbols carried by the stub into the .data section. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230912090051.4014114-18-ardb@google.com
2023-09-14x86: Make IA32_EMULATION boot time configurableNikolay Borisov
Distributions would like to reduce their attack surface as much as possible but at the same time they'd want to retain flexibility to cater to a variety of legacy software. This stems from the conjecture that compat layer is likely rarely tested and could have latent security bugs. Ideally distributions will set their default policy and also give users the ability to override it as appropriate. To enable this use case, introduce CONFIG_IA32_EMULATION_DEFAULT_DISABLED compile time option, which controls whether 32bit processes/syscalls should be allowed or not. This option is aimed mainly at distributions to set their preferred default behavior in their kernels. To allow users to override the distro's policy, introduce the 'ia32_emulation' parameter which allows overriding CONFIG_IA32_EMULATION_DEFAULT_DISABLED state at boot time. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230623111409.3047467-7-nik.borisov@suse.com
2023-09-14x86/entry: Make IA32 syscalls' availability depend on ia32_enabled()Nikolay Borisov
Another major aspect of supporting running of 32bit processes is the ability to access 32bit syscalls. Such syscalls can be invoked by using the legacy int 0x80 handler and sysenter/syscall instructions. If IA32 emulation is disabled ensure that each of those 3 distinct mechanisms are also disabled. For int 0x80 a #GP exception would be generated since the respective descriptor is not going to be loaded at all. Invoking sysenter will also result in a #GP since IA32_SYSENTER_CS contains an invalid segment. Finally, syscall instruction cannot really be disabled so it's configured to execute a minimal handler. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230623111409.3047467-6-nik.borisov@suse.com
2023-09-14x86/elf: Make loading of 32bit processes depend on ia32_enabled()Nikolay Borisov
Major aspect of ia32 emulation is the ability to load 32bit processes. That's currently decided (among others) by compat_elf_check_arch(). Make the macro use ia32_enabled() to decide if IA32 compat is enabled before loading a 32bit process. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230623111409.3047467-5-nik.borisov@suse.com
2023-09-14x86/entry: Compile entry_SYSCALL32_ignore() unconditionallyNikolay Borisov
To limit the IA32 exposure on 64bit kernels while keeping the flexibility for the user to enable it when required, the compile time enable/disable via CONFIG_IA32_EMULATION is not good enough and will be complemented with a kernel command line option. Right now entry_SYSCALL32_ignore() is only compiled when CONFIG_IA32_EMULATION=n, but boot-time enable- / disablement obviously requires it to be unconditionally available. Remove the #ifndef CONFIG_IA32_EMULATION guard. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230623111409.3047467-4-nik.borisov@suse.com
2023-09-14x86/entry: Rename ignore_sysret()Nikolay Borisov
The SYSCALL instruction cannot really be disabled in compatibility mode. The best that can be done is to configure the CSTAR msr to point to a minimal handler. Currently this handler has a rather misleading name - ignore_sysret() as it's not really doing anything with sysret. Give it a more descriptive name. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230623111409.3047467-3-nik.borisov@suse.com
2023-09-14x86: Introduce ia32_enabled()Nikolay Borisov
IA32 support on 64bit kernels depends on whether CONFIG_IA32_EMULATION is selected or not. As it is a compile time option it doesn't provide the flexibility to have distributions set their own policy for IA32 support and give the user the flexibility to override it. As a first step introduce ia32_enabled() which abstracts whether IA32 compat is turned on or off. Upcoming patches will implement the ability to set IA32 compat state at boot time. Signed-off-by: Nikolay Borisov <nik.borisov@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230623111409.3047467-2-nik.borisov@suse.com
2023-09-13x86/sched: Restore the SD_ASYM_PACKING flag in the DIE domainRicardo Neri
Commit 8f2d6c41e5a6 ("x86/sched: Rewrite topology setup") dropped the SD_ASYM_PACKING flag in the DIE domain added in commit 044f0e27dec6 ("x86/sched: Add the SD_ASYM_PACKING flag to the die domain of hybrid processors"). Restore it on hybrid processors. The die-level domain does not depend on any build configuration and now x86_sched_itmt_flags() is always needed. Remove the build dependency on CONFIG_SCHED_[SMT|CLUSTER|MC]. Fixes: 8f2d6c41e5a6 ("x86/sched: Rewrite topology setup") Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Caleb Callaway <caleb.callaway@intel.com> Link: https://lkml.kernel.org/r/20230815035747.11529-1-ricardo.neri-calderon@linux.intel.com
2023-09-12x86/virt/tdx: Make TDX_MODULE_CALL handle SEAMCALL #UD and #GPKai Huang
SEAMCALL instruction causes #UD if the CPU isn't in VMX operation. Currently the TDX_MODULE_CALL assembly doesn't handle #UD, thus making SEAMCALL when VMX is disabled would cause Oops. Unfortunately, there are legal cases that SEAMCALL can be made when VMX is disabled. For instance, VMX can be disabled due to emergency reboot while there are still TDX guests running. Extend the TDX_MODULE_CALL assembly to return an error code for #UD to handle this case gracefully, e.g., KVM can then quietly eat all SEAMCALL errors caused by emergency reboot. SEAMCALL instruction also causes #GP when TDX isn't enabled by the BIOS. Use _ASM_EXTABLE_FAULT() to catch both exceptions with the trap number recorded, and define two new error codes by XORing the trap number to the TDX_SW_ERROR. This opportunistically handles #GP too while using the same simple assembly code. A bonus is when kernel mistakenly calls SEAMCALL when CPU isn't in VMX operation, or when TDX isn't enabled by the BIOS, or when the BIOS is buggy, the kernel can get a nicer error code rather than a less understandable Oops. This is basically based on Peter's code. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/de975832a367f476aab2d0eb0d9de66019a16b54.1692096753.git.kai.huang%40intel.com
2023-09-12x86/virt/tdx: Wire up basic SEAMCALL functionsKai Huang
Intel Trust Domain Extensions (TDX) protects guest VMs from malicious host and certain physical attacks. A CPU-attested software module called 'the TDX module' runs inside a new isolated memory range as a trusted hypervisor to manage and run protected VMs. TDX introduces a new CPU mode: Secure Arbitration Mode (SEAM). This mode runs only the TDX module itself or other code to load the TDX module. The host kernel communicates with SEAM software via a new SEAMCALL instruction. This is conceptually similar to a guest->host hypercall, except it is made from the host to SEAM software instead. The TDX module establishes a new SEAMCALL ABI which allows the host to initialize the module and to manage VMs. The SEAMCALL ABI is very similar to the TDCALL ABI and leverages much TDCALL infrastructure. Wire up basic functions to make SEAMCALLs for the basic support of running TDX guests: __seamcall(), __seamcall_ret(), and __seamcall_saved_ret() for TDH.VP.ENTER. All SEAMCALLs involved in the basic TDX support don't use "callee-saved" registers as input and output, except the TDH.VP.ENTER. To start to support TDX, create a new arch/x86/virt/vmx/tdx/tdx.c for TDX host kernel support. Add a new Kconfig option CONFIG_INTEL_TDX_HOST to opt-in TDX host kernel support (to distinguish with TDX guest kernel support). So far only KVM uses TDX. Make the new config option depend on KVM_INTEL. Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Isaku Yamahata <isaku.yamahata@intel.com> Link: https://lore.kernel.org/all/4db7c3fc085e6af12acc2932294254ddb3d320b3.1692096753.git.kai.huang%40intel.com
2023-09-12x86/tdx: Remove 'struct tdx_hypercall_args'Kai Huang
Now 'struct tdx_hypercall_args' is basically 'struct tdx_module_args' minus RCX. Although from __tdx_hypercall()'s perspective RCX isn't used as shared register thus not part of input/output registers, it's not worth to have a separate structure just due to one register. Remove the 'struct tdx_hypercall_args' and use 'struct tdx_module_args' instead in __tdx_hypercall() related code. This also saves the memory copy between the two structures within __tdx_hypercall(). Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/798dad5ce24e9d745cf0e16825b75ccc433ad065.1692096753.git.kai.huang%40intel.com
2023-09-12x86/tdx: Reimplement __tdx_hypercall() using TDX_MODULE_CALL asmKai Huang
Now the TDX_HYPERCALL asm is basically identical to the TDX_MODULE_CALL with both '\saved' and '\ret' enabled, with two minor things though: 1) The way to restore the structure pointer is different The TDX_HYPERCALL uses RCX as spare to restore the structure pointer, but the TDX_MODULE_CALL assumes no spare register can be used. In other words, TDX_MODULE_CALL already covers what TDX_HYPERCALL does. 2) TDX_MODULE_CALL only clears shared registers for TDH.VP.ENTER For this just need to make that code available for the non-host case. Thus, remove the TDX_HYPERCALL and reimplement the __tdx_hypercall() using the TDX_MODULE_CALL. Extend the TDX_MODULE_CALL to cover "clear shared registers" for TDG.VP.VMCALL. Introduce a new __tdcall_saved_ret() to replace the temporary __tdcall_hypercall(). The __tdcall_saved_ret() can also be used for those new TDCALLs which require more input/output registers than the basic TDCALLs do. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/e68a2473fb6f5bcd78b078cae7510e9d0753b3df.1692096753.git.kai.huang%40intel.com
2023-09-12x86/tdx: Make TDX_HYPERCALL asm similar to TDX_MODULE_CALLKai Huang
Now the 'struct tdx_hypercall_args' and 'struct tdx_module_args' are almost the same, and the TDX_HYPERCALL and TDX_MODULE_CALL asm macro share similar code pattern too. The __tdx_hypercall() and __tdcall() should be unified to use the same assembly code. As a preparation to unify them, simplify the TDX_HYPERCALL to make it more like the TDX_MODULE_CALL. The TDX_HYPERCALL takes the pointer of 'struct tdx_hypercall_args' as function call argument, and does below extra things comparing to the TDX_MODULE_CALL: 1) It sets RAX to 0 (TDG.VP.VMCALL leaf) internally; 2) It sets RCX to the (fixed) bitmap of shared registers internally; 3) It calls __tdx_hypercall_failed() internally (and panics) when the TDCALL instruction itself fails; 4) After TDCALL, it moves R10 to RAX to return the return code of the VMCALL leaf, regardless the '\ret' asm macro argument; Firstly, change the TDX_HYPERCALL to take the same function call arguments as the TDX_MODULE_CALL does: TDCALL leaf ID, and the pointer to 'struct tdx_module_args'. Then 1) and 2) can be moved to the caller: - TDG.VP.VMCALL leaf ID can be passed via the function call argument; - 'struct tdx_module_args' is 'struct tdx_hypercall_args' + RCX, thus the bitmap of shared registers can be passed via RCX in the structure. Secondly, to move 3) and 4) out of assembly, make the TDX_HYPERCALL always save output registers to the structure. The caller then can: - Call __tdx_hypercall_failed() when TDX_HYPERCALL returns error; - Return R10 in the structure as the return code of the VMCALL leaf; With above changes, change the asm function from __tdx_hypercall() to __tdcall_hypercall(), and reimplement __tdx_hypercall() as the C wrapper of it. This avoids having to add another wrapper of __tdx_hypercall() (_tdx_hypercall() is already taken). The __tdcall_hypercall() will be replaced with a __tdcall() variant using TDX_MODULE_CALL in a later commit as the final goal is to have one assembly to handle both TDCALL and TDVMCALL. Currently, the __tdx_hypercall() asm is in '.noinstr.text'. To keep this unchanged, annotate __tdx_hypercall(), which is a C function now, as 'noinstr'. Remove the __tdx_hypercall_ret() as __tdx_hypercall() already does so. Implement __tdx_hypercall() in tdx-shared.c so it can be shared with the compressed code. Opportunistically fix a checkpatch error complaining using space around parenthesis '(' and ')' while moving the bitmap of shared registers to <asm/shared/tdx.h>. [ dhansen: quash new calls of __tdx_hypercall_ret() that showed up ] Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/0cbf25e7aee3256288045023a31f65f0cef90af4.1692096753.git.kai.huang%40intel.com
2023-09-12x86/numa: Introduce numa_fill_memblks()Alison Schofield
numa_fill_memblks() fills in the gaps in numa_meminfo memblks over an physical address range. The ACPI driver will use numa_fill_memblks() to implement a new Linux policy that prescribes extending proximity domains in a portion of a CFMWS window to the entire window. Dan Williams offered this explanation of the policy: A CFWMS is an ACPI data structure that indicates *potential* locations where CXL memory can be placed. It is the playground where the CXL driver has free reign to establish regions. That space can be populated by BIOS created regions, or driver created regions, after hotplug or other reconfiguration. When BIOS creates a region in a CXL Window it additionally describes that subset of the Window range in the other typical ACPI tables SRAT, SLIT, and HMAT. The rationale for BIOS not pre-describing the entire CXL Window in SRAT, SLIT, and HMAT is that it can not predict the future. I.e. there is nothing stopping higher or lower performance devices being placed in the same Window. Compare that to ACPI memory hotplug that just onlines additional capacity in the proximity domain with little freedom for dynamic performance differentiation. That leaves the OS with a choice, should unpopulated window capacity match the proximity domain of an existing region, or should it allocate a new one? This patch takes the simple position of minimizing proximity domain proliferation by reusing any proximity domain intersection for the entire Window. If the Window has no intersections then allocate a new proximity domain. Note that SRAT, SLIT and HMAT information can be enumerated dynamically in a standard way from device provided data. Think of CXL as the end of ACPI needing to describe memory attributes, CXL offers a standard discovery model for performance attributes, but Linux still needs to interoperate with the old regime. Reported-by: Derick Marks <derick.w.marks@intel.com> Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alison Schofield <alison.schofield@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Derick Marks <derick.w.marks@intel.com> Link: https://lore.kernel.org/all/ef078a6f056ca974e5af85997013c0fda9e3326d.1689018477.git.alison.schofield%40intel.com
2023-09-12bpf, x64: Fix tailcall infinite loopLeon Hwang
From commit ebf7d1f508a73871 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT"), the tailcall on x64 works better than before. From commit e411901c0b775a3a ("bpf: allow for tailcalls in BPF subprograms for x64 JIT"), tailcall is able to run in BPF subprograms on x64. From commit 5b92a28aae4dd0f8 ("bpf: Support attaching tracing BPF program to other BPF programs"), BPF program is able to trace other BPF programs. How about combining them all together? 1. FENTRY/FEXIT on a BPF subprogram. 2. A tailcall runs in the BPF subprogram. 3. The tailcall calls the subprogram's caller. As a result, a tailcall infinite loop comes up. And the loop would halt the machine. As we know, in tail call context, the tail_call_cnt propagates by stack and rax register between BPF subprograms. So do in trampolines. Fixes: ebf7d1f508a7 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT") Fixes: e411901c0b77 ("bpf: allow for tailcalls in BPF subprograms for x64 JIT") Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Leon Hwang <hffilwlqm@gmail.com> Link: https://lore.kernel.org/r/20230912150442.2009-3-hffilwlqm@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12bpf, x64: Comment tail_call_cnt initialisationLeon Hwang
Without understanding emit_prologue(), it is really hard to figure out where does tail_call_cnt come from, even though searching tail_call_cnt in the whole kernel repo. By adding these comments, it is a little bit easier to understand tail_call_cnt initialisation. Signed-off-by: Leon Hwang <hffilwlqm@gmail.com> Link: https://lore.kernel.org/r/20230912150442.2009-2-hffilwlqm@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12x86/ibt: Avoid duplicate ENDBR in __put_user_nocheck*()Peter Zijlstra
Commit cb855971d717 ("x86/putuser: Provide room for padding") changed __put_user_nocheck_*() into proper functions but failed to note that SYM_FUNC_START() already provides ENDBR, rendering the explicit ENDBR superfluous. Fixes: cb855971d717 ("x86/putuser: Provide room for padding") Reported-by: David Kaplan <David.Kaplan@amd.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230802110323.086971726@infradead.org
2023-09-12x86/ibt: Suppress spurious ENDBRPeter Zijlstra
It was reported that under certain circumstances GCC emits ENDBR instructions for _THIS_IP_ usage. Specifically, when it appears at the start of a basic block -- but not elsewhere. Since _THIS_IP_ is never used for control flow, these ENDBR instructions are completely superfluous. Override the _THIS_IP_ definition for x86_64 to avoid this. Less ENDBR instructions is better. Fixes: 156ff4a544ae ("x86/ibt: Base IBT bits") Reported-by: David Kaplan <David.Kaplan@amd.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230802110323.016197440@infradead.org
2023-09-12perf/x86/intel: Extend the ref-cycles event to GP countersKan Liang
The current ref-cycles event is only available on the fixed counter 2. Starting from the GLC and GRT core, the architectural UnHalted Reference Cycles event (0x013c) which is available on general-purpose counters can collect the exact same events as the fixed counter 2. Update the mapping of ref-cycles to 0x013c. So the ref-cycles can be available on both fixed counter 2 and general-purpose counters. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230911144139.2354015-1-kan.liang@linux.intel.com
2023-09-12perf/x86/intel: Fix broken fixed event constraints extensionKan Liang
Unnecessary multiplexing is triggered when running an "instructions" event on an MTL. perf stat -e cpu_core/instructions/,cpu_core/instructions/ -a sleep 1 Performance counter stats for 'system wide': 115,489,000 cpu_core/instructions/ (50.02%) 127,433,777 cpu_core/instructions/ (49.98%) 1.002294504 seconds time elapsed Linux architectural perf events, e.g., cycles and instructions, usually have dedicated fixed counters. These events also have equivalent events which can be used in the general-purpose counters. The counters are precious. In the intel_pmu_check_event_constraints(), perf check/extend the event constraints of these events. So these events can utilize both fixed counters and general-purpose counters. The following cleanup commit: 97588df87b56 ("perf/x86/intel: Add common intel_pmu_init_hybrid()") forgot adding the intel_pmu_check_event_constraints() into update_pmu_cap(). The architectural perf events cannot utilize the general-purpose counters. The code to check and update the counters, event constraints and extra_regs is the same among hybrid systems. Move intel_pmu_check_hybrid_pmus() to init_hybrid_pmu(), and emove the duplicate check in update_pmu_cap(). Fixes: 97588df87b56 ("perf/x86/intel: Add common intel_pmu_init_hybrid()") Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230911135128.2322833-1-kan.liang@linux.intel.com
2023-09-11x86/tdx: Extend TDX_MODULE_CALL to support more TDCALL/SEAMCALL leafsKai Huang
The TDX guest live migration support (TDX 1.5) adds new TDCALL/SEAMCALL leaf functions. Those new TDCALLs/SEAMCALLs take additional registers for input (R10-R13) and output (R12-R13). TDG.SERVTD.RD is an example. Also, the current TDX_MODULE_CALL doesn't aim to handle TDH.VP.ENTER SEAMCALL, which monitors the TDG.VP.VMCALL in input/output registers when it returns in case of VMCALL from TDX guest. With those new TDCALLs/SEAMCALLs and the TDH.VP.ENTER covered, the TDX_MODULE_CALL macro basically needs to handle the same input/output registers as the TDX_HYPERCALL does. And as a result, they also share similar logic in the assembly, thus should be unified to use one common assembly. Extend the TDX_MODULE_CALL asm to support the new TDCALLs/SEAMCALLs and also the TDH.VP.ENTER SEAMCALL. Eventually it will be unified with the TDX_HYPERCALL. The new input/output registers fit with the "callee-saved" registers in the x86 calling convention. Add a new "saved" parameter to support those new TDCALLs/SEAMCALLs and TDH.VP.ENTER and keep the existing TDCALLs/SEAMCALLs minimally impacted. For TDH.VP.ENTER, after it returns the registers shared by the guest contain guest's values. Explicitly clear them to prevent speculative use of guest's values. Note most TDX live migration related SEAMCALLs may also clobber AVX* state ("AVX, AVX2 and AVX512 state: may be reset to the architectural INIT state" -- see TDH.EXPORT.MEM for example). And TDH.VP.ENTER also clobbers XMM0-XMM15 when the corresponding bit is set in RCX. Don't handle them in the TDX_MODULE_CALL macro but let the caller save and restore when needed. This is basically based on Peter's code. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/d4785de7c392f7c5684407f6c24a73b92148ec49.1692096753.git.kai.huang%40intel.com
2023-09-11x86/tdx: Pass TDCALL/SEAMCALL input/output registers via a structureKai Huang
Currently, the TDX_MODULE_CALL asm macro, which handles both TDCALL and SEAMCALL, takes one parameter for each input register and an optional 'struct tdx_module_output' (a collection of output registers) as output. This is different from the TDX_HYPERCALL macro which uses a single 'struct tdx_hypercall_args' to carry all input/output registers. The newer TDX versions introduce more TDCALLs/SEAMCALLs which use more input/output registers. Also, the TDH.VP.ENTER (which isn't covered by the current TDX_MODULE_CALL macro) basically can use all registers that the TDX_HYPERCALL does. The current TDX_MODULE_CALL macro isn't extendible to cover those cases. Similar to the TDX_HYPERCALL macro, simplify the TDX_MODULE_CALL macro to use a single structure 'struct tdx_module_args' to carry all the input/output registers. Currently, R10/R11 are only used as output register but not as input by any TDCALL/SEAMCALL. Change to also use R10/R11 as input register to make input/output registers symmetric. Currently, the TDX_MODULE_CALL macro depends on the caller to pass a non-NULL 'struct tdx_module_output' to get additional output registers. Similar to the TDX_HYPERCALL macro, change the TDX_MODULE_CALL macro to take a new 'ret' macro argument to indicate whether to save the output registers to the 'struct tdx_module_args'. Also introduce a new __tdcall_ret() for that purpose, similar to the __tdx_hypercall_ret(). Note the tdcall(), which is a wrapper of __tdcall(), is called by three callers: tdx_parse_tdinfo(), tdx_get_ve_info() and tdx_early_init(). The former two need the additional output but the last one doesn't. For simplicity, make tdcall() always call __tdcall_ret() to avoid another "_ret()" wrapper. The last caller tdx_early_init() isn't performance critical anyway. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/483616c1762d85eb3a3c3035a7de061cfacf2f14.1692096753.git.kai.huang%40intel.com
2023-09-11x86/tdx: Rename __tdx_module_call() to __tdcall()Kai Huang
__tdx_module_call() is only used by the TDX guest to issue TDCALL to the TDX module. Rename it to __tdcall() to match its behaviour, e.g., it cannot be used to make host-side SEAMCALL. Also rename tdx_module_call() which is a wrapper of __tdx_module_call() to tdcall(). No functional change intended. Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/785d20d99fbcd0db8262c94da6423375422d8c75.1692096753.git.kai.huang%40intel.com
2023-09-11x86/tdx: Make macros of TDCALLs consistent with the specKai Huang
The TDX spec names all TDCALLs with prefix "TDG". Currently, the kernel doesn't follow such convention for the macros of those TDCALLs but uses prefix "TDX_" for all of them. Although it's arguable whether the TDX spec names those TDCALLs properly, it's better for the kernel to follow the spec when naming those macros. Change all macros of TDCALLs to make them consistent with the spec. As a bonus, they get distinguished easily from the host-side SEAMCALLs, which all have prefix "TDH". No functional change intended. Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/516dccd0bd8fb9a0b6af30d25bb2d971aa03d598.1692096753.git.kai.huang%40intel.com
2023-09-11x86/tdx: Skip saving output regs when SEAMCALL fails with VMFailInvalidKai Huang
If SEAMCALL fails with VMFailInvalid, the SEAM software (e.g., the TDX module) won't have chance to set any output register. Skip saving the output registers to the structure in this case. Also, as '.Lno_output_struct' is the very last symbol before RET, rename it to '.Lout' to make it short. Opportunistically make the asm directives unindented. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/704088f5b4d72c7e24084f7f15bd1ac5005b7213.1692096753.git.kai.huang%40intel.com
2023-09-11x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macroKai Huang
In the TDX_HYPERCALL asm, after the TDCALL instruction returns from the untrusted VMM, the registers that the TDX guest shares to the VMM need to be cleared to avoid speculative execution of VMM-provided values. RSI is specified in the bitmap of those registers, but it is missing when zeroing out those registers in the current TDX_HYPERCALL. It was there when it was originally added in commit 752d13305c78 ("x86/tdx: Expand __tdx_hypercall() to handle more arguments"), but was later removed in commit 1e70c680375a ("x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall()"), which was correct because %rsi is later restored in the "pop %rsi". However a later commit 7a3a401874be ("x86/tdx: Drop flags from __tdx_hypercall()") removed that "pop %rsi" but forgot to add the "xor %rsi, %rsi" back. Fix by adding it back. Fixes: 7a3a401874be ("x86/tdx: Drop flags from __tdx_hypercall()") Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/e7d1157074a0b45d34564d5f17f3e0ffee8115e9.1692096753.git.kai.huang%40intel.com
2023-09-11x86/tdx: Retry partially-completed page conversion hypercallsDexuan Cui
TDX guest memory is private by default and the VMM may not access it. However, in cases where the guest needs to share data with the VMM, the guest and the VMM can coordinate to make memory shared between them. The guest side of this protocol includes the "MapGPA" hypercall. This call takes a guest physical address range. The hypercall spec (aka. the GHCI) says that the MapGPA call is allowed to return partial progress in mapping this range and indicate that fact with a special error code. A guest that sees such partial progress is expected to retry the operation for the portion of the address range that was not completed. Hyper-V does this partial completion dance when set_memory_decrypted() is called to "decrypt" swiotlb bounce buffers that can be up to 1GB in size. It is evidently the only VMM that does this, which is why nobody noticed this until now. [ dhansen: rewrite changelog ] Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: https://lore.kernel.org/all/20230811021246.821-2-decui%40microsoft.com
2023-09-11x86/platform/uv: Use alternate source for socket to node dataSteve Wahl
The UV code attempts to build a set of tables to allow it to do bidirectional socket<=>node lookups. But when nr_cpus is set to a smaller number than actually present, the cpu_to_node() mapping information for unused CPUs is not available to build_socket_tables(). This results in skipping some nodes or sockets when creating the tables and leaving some -1's for later code to trip. over, causing oopses. The problem is that the socket<=>node lookups are created by doing a loop over all CPUs, then looking up the CPU's APICID and socket. But if a CPU is not present, there is no way to start this lookup. Instead of looping over all CPUs, take CPUs out of the equation entirely. Loop over all APICIDs which are mapped to a valid NUMA node. Then just extract the socket-id from the APICID. This avoid tripping over disabled CPUs. Fixes: 8a50c5851927 ("x86/platform/uv: UV support for sub-NUMA clustering") Signed-off-by: Steve Wahl <steve.wahl@hpe.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20230807141730.1117278-1-steve.wahl%40hpe.com
2023-09-11efi/x86: Ensure that EFI_RUNTIME_MAP is enabled for kexecArd Biesheuvel
CONFIG_EFI_RUNTIME_MAP needs to be enabled in order for kexec to be able to provide the required information about the EFI runtime mappings to the incoming kernel, regardless of whether kexec_load() or kexec_file_load() is being used. Without this information, kexec boot in EFI mode is not possible. The CONFIG_EFI_RUNTIME_MAP option is currently directly configurable if CONFIG_EXPERT is enabled, so that it can be turned on for debugging purposes even if KEXEC is not enabled. However, the upshot of this is that it can also be disabled even when it shouldn't. So tweak the Kconfig declarations to avoid this situation. Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-11efi/x86: Move EFI runtime call setup/teardown helpers out of lineArd Biesheuvel
Only the arch_efi_call_virt() macro that some architectures override needs to be a macro, given that it is variadic and encapsulates calls via function pointers that have different prototypes. The associated setup and teardown code are not special in this regard, and don't need to be instantiated at each call site. So turn them into ordinary C functions and move them out of line. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-10Merge tag 'x86-urgent-2023-09-10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code, fix a ld.lld linker (in)compatibility quirk and make the x86 SMP init code a bit more conservative to fix kexec() lockups" * tag 'x86-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Break up long non-preemptible delays in sgx_vepc_release() x86: Remove the arch_calc_vm_prot_bits() macro from the UAPI x86/build: Fix linker fill bytes quirk/incompatibility for ld.lld x86/smp: Don't send INIT to non-present and non-booted CPUs
2023-09-10Merge tag 'perf-urgent-2023-09-10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf event fix from Ingo Molnar: "Work around a firmware bug in the uncore PMU driver, affecting certain Intel systems" * tag 'perf-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/uncore: Correct the number of CHAs on EMR
2023-09-07Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Clean up vCPU targets, always returning generic v8 as the preferred target - Trap forwarding infrastructure for nested virtualization (used for traps that are taken from an L2 guest and are needed by the L1 hypervisor) - FEAT_TLBIRANGE support to only invalidate specific ranges of addresses when collapsing a table PTE to a block PTE. This avoids that the guest refills the TLBs again for addresses that aren't covered by the table PTE. - Fix vPMU issues related to handling of PMUver. - Don't unnecessary align non-stack allocations in the EL2 VA space - Drop HCR_VIRT_EXCP_MASK, which was never used... - Don't use smp_processor_id() in kvm_arch_vcpu_load(), but the cpu parameter instead - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort() - Remove prototypes without implementations RISC-V: - Zba, Zbs, Zicntr, Zicsr, Zifencei, and Zihpm support for guest - Added ONE_REG interface for SATP mode - Added ONE_REG interface to enable/disable multiple ISA extensions - Improved error codes returned by ONE_REG interfaces - Added KVM_GET_REG_LIST ioctl() implementation for KVM RISC-V - Added get-reg-list selftest for KVM RISC-V s390: - PV crypto passthrough enablement (Tony, Steffen, Viktor, Janosch) Allows a PV guest to use crypto cards. Card access is governed by the firmware and once a crypto queue is "bound" to a PV VM every other entity (PV or not) looses access until it is not bound anymore. Enablement is done via flags when creating the PV VM. - Guest debug fixes (Ilya) x86: - Clean up KVM's handling of Intel architectural events - Intel bugfixes - Add support for SEV-ES DebugSwap, allowing SEV-ES guests to use debug registers and generate/handle #DBs - Clean up LBR virtualization code - Fix a bug where KVM fails to set the target pCPU during an IRTE update - Fix fatal bugs in SEV-ES intrahost migration - Fix a bug where the recent (architecturally correct) change to reinject #BP and skip INT3 broke SEV guests (can't decode INT3 to skip it) - Retry APIC map recalculation if a vCPU is added/enabled - Overhaul emergency reboot code to bring SVM up to par with VMX, tie the "emergency disabling" behavior to KVM actually being loaded, and move all of the logic within KVM - Fix user triggerable WARNs in SVM where KVM incorrectly assumes the TSC ratio MSR cannot diverge from the default when TSC scaling is disabled up related code - Add a framework to allow "caching" feature flags so that KVM can check if the guest can use a feature without needing to search guest CPUID - Rip out the ancient MMU_DEBUG crud and replace the useful bits with CONFIG_KVM_PROVE_MMU - Fix KVM's handling of !visible guest roots to avoid premature triple fault injection - Overhaul KVM's page-track APIs, and KVMGT's usage, to reduce the API surface that is needed by external users (currently only KVMGT), and fix a variety of issues in the process Generic: - Wrap kvm_{gfn,hva}_range.pte in a union to allow mmu_notifier events to pass action specific data without needing to constantly update the main handlers. - Drop unused function declarations Selftests: - Add testcases to x86's sync_regs_test for detecting KVM TOCTOU bugs - Add support for printf() in guest code and covert all guest asserts to use printf-based reporting - Clean up the PMU event filter test and add new testcases - Include x86 selftests in the KVM x86 MAINTAINERS entry" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (279 commits) KVM: x86/mmu: Include mmu.h in spte.h KVM: x86/mmu: Use dummy root, backed by zero page, for !visible guest roots KVM: x86/mmu: Disallow guest from using !visible slots for page tables KVM: x86/mmu: Harden TDP MMU iteration against root w/o shadow page KVM: x86/mmu: Harden new PGD against roots without shadow pages KVM: x86/mmu: Add helper to convert root hpa to shadow page drm/i915/gvt: Drop final dependencies on KVM internal details KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers KVM: x86/mmu: Drop @slot param from exported/external page-track APIs KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled KVM: x86/mmu: Assert that correct locks are held for page write-tracking KVM: x86/mmu: Rename page-track APIs to reflect the new reality KVM: x86/mmu: Drop infrastructure for multiple page-track modes KVM: x86/mmu: Use page-track notifiers iff there are external users KVM: x86/mmu: Move KVM-only page-track declarations to internal header KVM: x86: Remove the unused page-track hook track_flush_slot() drm/i915/gvt: switch from ->track_flush_slot() to ->track_remove_region() KVM: x86: Add a new page-track hook to handle memslot deletion drm/i915/gvt: Don't bother removing write-protection on to-be-deleted slot KVM: x86: Reject memslot MOVE operations if KVMGT is attached ...