Insert the appropriate UNWIND hint into the kvm_exc_entry assembly
function to guide the generation of correct ORC table entries, thereby
solving the timeout problem ("unreliable stack") while loading the
livepatch-sample module on a physical machine running virtual machines
with multiple vcpus.
Cc: stable@vger.kernel.org
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
If we directly compile the switch.S file into the kernel, the address of
the kvm_exc_entry function will definitely be within the DMW memory area.
Therefore, we will no longer need to perform a copy relocation of the
kvm_exc_entry.
So this patch compiles switch.S directly into the kernel, and then remove
the copy relocation execution logic for the kvm_exc_entry function.
Cc: stable@vger.kernel.org
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
PGD table for primary mmu keeps unchanged once VM is created, it is not
necessary to save PGD table pointer during VM context switch. And it can
be acquired when VM is created.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
PRMD register is only meaningful on the beginning stage of exception
entry, and it is overwritten with nested irq or exception.
When CPU runs in VM mode, interrupt need be enabled on host. And the
mode for host had better be kernel mode rather than random or user mode.
When VM is running, the running mode with top command comes from CRMD
register, and running mode should be kernel mode since kernel function
is executing with perf command. It needs be consistent with both top and
perf command.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
There exist some warnings when building kernel if CONFIG_CPU_HAS_LBT is
set but CONFIG_CPU_HAS_LSX and CONFIG_CPU_HAS_LASX are not set. In this
case, there are no definitions of _restore_lsx & _restore_lasx and there
are also no definitions of kvm_restore_lsx & kvm_restore_lasx in fpu.S
and switch.S respectively, just add some ifdefs to fix these warnings.
AS arch/loongarch/kernel/fpu.o
arch/loongarch/kernel/fpu.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0
arch/loongarch/kernel/fpu.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0
AS [M] arch/loongarch/kvm/switch.o
arch/loongarch/kvm/switch.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0
arch/loongarch/kvm/switch.o: warning: objtool: unexpected relocation symbol type in .rela.discard.func_stack_frame_non_standard: 0
MODPOST Module.symvers
ERROR: modpost: "kvm_restore_lsx" [arch/loongarch/kvm/kvm.ko] undefined!
ERROR: modpost: "kvm_restore_lasx" [arch/loongarch/kvm/kvm.ko] undefined!
Cc: stable@vger.kernel.org # 6.9+
Fixes: cb8a2ef084 ("LoongArch: Add ORC stack unwinder support")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408120955.qls5oNQY-lkp@intel.com/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
1, Add objtool support for LoongArch;
2, Add ORC stack unwinder support for LoongArch;
3, Add kernel livepatching support for LoongArch;
4, Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig;
5, Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig;
6, Some bug fixes and other small changes.
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Merge tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
Pull LoongArch updates from Huacai Chen:
- Add objtool support for LoongArch
- Add ORC stack unwinder support for LoongArch
- Add kernel livepatching support for LoongArch
- Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig
- Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig
- Some bug fixes and other small changes
* tag 'loongarch-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
LoongArch/crypto: Clean up useless assignment operations
LoongArch: Define the __io_aw() hook as mmiowb()
LoongArch: Remove superfluous flush_dcache_page() definition
LoongArch: Move {dmw,tlb}_virt_to_page() definition to page.h
LoongArch: Change __my_cpu_offset definition to avoid mis-optimization
LoongArch: Select HAVE_ARCH_USERFAULTFD_MINOR in Kconfig
LoongArch: Select ARCH_HAS_CURRENT_STACK_POINTER in Kconfig
LoongArch: Add kernel livepatching support
LoongArch: Add ORC stack unwinder support
objtool: Check local label in read_unwind_hints()
objtool: Check local label in add_dead_ends()
objtool/LoongArch: Enable orc to be built
objtool/x86: Separate arch-specific and generic parts
objtool/LoongArch: Implement instruction decoder
objtool/LoongArch: Enable objtool to be built
The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
similar in concept to a DWARF unwinder. The difference is that the format
of the ORC data is much simpler than DWARF, which in turn allows the ORC
unwinder to be much simpler and faster.
The ORC data consists of unwind tables which are generated by objtool.
After analyzing all the code paths of a .o file, it determines information
about the stack state at each instruction address in the file and outputs
that information to the .orc_unwind and .orc_unwind_ip sections.
The per-object ORC sections are combined at link time and are sorted and
post-processed at boot time. The unwinder uses the resulting data to
correlate instruction addresses with their stack states at run time.
Most of the logic are similar with x86, in order to get ra info before ra
is saved into stack, add ra_reg and ra_offset into orc_entry. At the same
time, modify some arch-specific code to silence the objtool warnings.
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Some CSR registers like CRMD/PRMD are saved during enter VM mode now.
However they are not restored for actual use, so saving for these CSR
registers can be removed.
Reviewed-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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>
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>
Implement LoongArch vcpu world switch, including vcpu enter guest and
vcpu exit from guest, both operations need to save or restore the host
and guest registers.
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
