| Message ID | 20200326032420.27220-16-pasha.tatashin@soleen.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: MMU enabled kexec relocation | expand |
On 2020-03-26 03:24, Pavel Tatashin wrote: > If we have a EL2 mode without VHE, the EL2 vectors are needed in order > to switch to EL2 and jump to new world with hyperivsor privileges. > > Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> > --- > arch/arm64/include/asm/kexec.h | 5 +++++ > arch/arm64/kernel/asm-offsets.c | 1 + > arch/arm64/kernel/machine_kexec.c | 5 +++++ > arch/arm64/kernel/relocate_kernel.S | 35 +++++++++++++++++++++++++++++ > 4 files changed, 46 insertions(+) > > diff --git a/arch/arm64/include/asm/kexec.h > b/arch/arm64/include/asm/kexec.h > index d944c2e289b2..0f758fd51518 100644 > --- a/arch/arm64/include/asm/kexec.h > +++ b/arch/arm64/include/asm/kexec.h > @@ -95,6 +95,7 @@ static inline void crash_post_resume(void) {} > extern const unsigned long kexec_relocate_code_size; > extern const unsigned char kexec_relocate_code_start[]; > extern const unsigned long kexec_kern_reloc_offset; > +extern const unsigned long kexec_el2_vectors_offset; > #endif > > /* > @@ -104,6 +105,9 @@ extern const unsigned long kexec_kern_reloc_offset; > * kernel, or purgatory entry address). > * kern_arg0 first argument to kernel is its dtb address. The other > * arguments are currently unused, and must be set to 0 > + * el2_vector If present means that relocation routine will go to EL1 > + * from EL2 to do the copy, and then back to EL2 to do the jump > + * to new world. > */ > struct kern_reloc_arg { > phys_addr_t head; > @@ -112,6 +116,7 @@ struct kern_reloc_arg { > phys_addr_t kern_arg1; > phys_addr_t kern_arg2; > phys_addr_t kern_arg3; > + phys_addr_t el2_vector; > }; > > #define ARCH_HAS_KIMAGE_ARCH > diff --git a/arch/arm64/kernel/asm-offsets.c > b/arch/arm64/kernel/asm-offsets.c > index 448230684749..ff974b648347 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -136,6 +136,7 @@ int main(void) > DEFINE(KEXEC_KRELOC_KERN_ARG1, offsetof(struct kern_reloc_arg, > kern_arg1)); > DEFINE(KEXEC_KRELOC_KERN_ARG2, offsetof(struct kern_reloc_arg, > kern_arg2)); > DEFINE(KEXEC_KRELOC_KERN_ARG3, offsetof(struct kern_reloc_arg, > kern_arg3)); > + DEFINE(KEXEC_KRELOC_EL2_VECTOR, offsetof(struct kern_reloc_arg, > el2_vector)); > #endif > return 0; > } > diff --git a/arch/arm64/kernel/machine_kexec.c > b/arch/arm64/kernel/machine_kexec.c > index ab571fca9bd1..bd398def7627 100644 > --- a/arch/arm64/kernel/machine_kexec.c > +++ b/arch/arm64/kernel/machine_kexec.c > @@ -84,6 +84,11 @@ int machine_kexec_post_load(struct kimage *kimage) > kern_reloc_arg->head = kimage->head; > kern_reloc_arg->entry_addr = kimage->start; > kern_reloc_arg->kern_arg0 = kimage->arch.dtb_mem; > + /* Setup vector table only when EL2 is available, but no VHE */ > + if (is_hyp_mode_available() && !is_kernel_in_hyp_mode()) { > + kern_reloc_arg->el2_vector = __pa(reloc_code) > + + kexec_el2_vectors_offset; > + } > kexec_image_info(kimage); > > return 0; > diff --git a/arch/arm64/kernel/relocate_kernel.S > b/arch/arm64/kernel/relocate_kernel.S > index aa9f2b2cd77c..6fd2fc0ef373 100644 > --- a/arch/arm64/kernel/relocate_kernel.S > +++ b/arch/arm64/kernel/relocate_kernel.S > @@ -89,6 +89,38 @@ ENTRY(arm64_relocate_new_kernel) > .ltorg > END(arm64_relocate_new_kernel) > > +.macro el1_sync_64 > + br x4 /* Jump to new world from el2 */ > + .fill 31, 4, 0 /* Set other 31 instr to zeroes */ > +.endm The common idiom to write this is to align the beginning of the macro, and not to bother about what follows: .macro whatever .align 7 br x4 .endm Specially given that 0 is an undefined instruction, and I really hate to see those in the actual text. On the contrary, .align generates NOPs. > + > +.macro invalid_vector label > +\label: > + b \label > + .fill 31, 4, 0 /* Set other 31 instr to zeroes */ > +.endm > + > +/* el2 vectors - switch el2 here while we restore the memory image. */ > + .align 11 > +ENTRY(kexec_el2_vectors) Please see commit 617a2f392c92 ("arm64: kvm: Annotate assembly using modern annoations"), and follow the same pattern. > + invalid_vector el2_sync_invalid_sp0 /* Synchronous EL2t */ > + invalid_vector el2_irq_invalid_sp0 /* IRQ EL2t */ > + invalid_vector el2_fiq_invalid_sp0 /* FIQ EL2t */ > + invalid_vector el2_error_invalid_sp0 /* Error EL2t */ > + invalid_vector el2_sync_invalid_spx /* Synchronous EL2h */ > + invalid_vector el2_irq_invalid_spx /* IRQ EL2h */ > + invalid_vector el2_fiq_invalid_spx /* FIQ EL2h */ > + invalid_vector el2_error_invalid_spx /* Error EL2h */ > + el1_sync_64 /* Synchronous 64-bit EL1 */ > + invalid_vector el1_irq_invalid_64 /* IRQ 64-bit EL1 */ > + invalid_vector el1_fiq_invalid_64 /* FIQ 64-bit EL1 */ > + invalid_vector el1_error_invalid_64 /* Error 64-bit EL1 */ > + invalid_vector el1_sync_invalid_32 /* Synchronous 32-bit EL1 */ > + invalid_vector el1_irq_invalid_32 /* IRQ 32-bit EL1 */ > + invalid_vector el1_fiq_invalid_32 /* FIQ 32-bit EL1 */ > + invalid_vector el1_error_invalid_32 /* Error 32-bit EL1 */ > +END(kexec_el2_vectors) Please write the vectors in 4 groups of 4, as this makes it a lot easier to follow what is what. > + > .Lkexec_relocate_code_end: > .org KEXEC_CONTROL_PAGE_SIZE > .align 3 /* To keep the 64-bit values below naturally aligned. */ > @@ -102,3 +134,6 @@ kexec_relocate_code_size: > .globl kexec_kern_reloc_offset > kexec_kern_reloc_offset: > .quad arm64_relocate_new_kernel - kexec_relocate_code_start > +.globl kexec_el2_vectors_offset > +kexec_el2_vectors_offset: > + .quad kexec_el2_vectors - kexec_relocate_code_start Thanks, M.
Hi Pavel, What happened to the subject? (it really needs a verb to make any sense) On 26/03/2020 03:24, Pavel Tatashin wrote: > If we have a EL2 mode without VHE, the EL2 vectors are needed in order > to switch to EL2 and jump to new world with hyperivsor privileges. Yes, but the hyp-stub has an API to let you do this... but you need your own version. Could you explain why in the commit message? (spelling: hyperivsor) > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > index ab571fca9bd1..bd398def7627 100644 > --- a/arch/arm64/kernel/machine_kexec.c > +++ b/arch/arm64/kernel/machine_kexec.c > @@ -84,6 +84,11 @@ int machine_kexec_post_load(struct kimage *kimage) > kern_reloc_arg->head = kimage->head; > kern_reloc_arg->entry_addr = kimage->start; > kern_reloc_arg->kern_arg0 = kimage->arch.dtb_mem; > + /* Setup vector table only when EL2 is available, but no VHE */ > + if (is_hyp_mode_available() && !is_kernel_in_hyp_mode()) { > + kern_reloc_arg->el2_vector = __pa(reloc_code) > + + kexec_el2_vectors_offset; > + } Why does the asm relocation code need to know where the vector is? It must access it via HVC. Thanks, James
> > +.macro el1_sync_64 > > + br x4 /* Jump to new world from el2 */ > > + .fill 31, 4, 0 /* Set other 31 instr to zeroes */ > > +.endm > > The common idiom to write this is to align the beginning of the > macro, and not to bother about what follows: > > .macro whatever > .align 7 > br x4 > .endm > > Specially given that 0 is an undefined instruction, and I really hate to > see > those in the actual text. On the contrary, .align generates NOPs. Fixed that. > > > + > > +.macro invalid_vector label > > +\label: > > + b \label > > + .fill 31, 4, 0 /* Set other 31 instr to zeroes */ > > +.endm > > + > > +/* el2 vectors - switch el2 here while we restore the memory image. */ > > + .align 11 > > +ENTRY(kexec_el2_vectors) > > Please see commit 617a2f392c92 ("arm64: kvm: Annotate assembly using > modern > annoations"), and follow the same pattern. Fixed that as well. Thank you, Pasha
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index d944c2e289b2..0f758fd51518 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -95,6 +95,7 @@ static inline void crash_post_resume(void) {} extern const unsigned long kexec_relocate_code_size; extern const unsigned char kexec_relocate_code_start[]; extern const unsigned long kexec_kern_reloc_offset; +extern const unsigned long kexec_el2_vectors_offset; #endif /* @@ -104,6 +105,9 @@ extern const unsigned long kexec_kern_reloc_offset; * kernel, or purgatory entry address). * kern_arg0 first argument to kernel is its dtb address. The other * arguments are currently unused, and must be set to 0 + * el2_vector If present means that relocation routine will go to EL1 + * from EL2 to do the copy, and then back to EL2 to do the jump + * to new world. */ struct kern_reloc_arg { phys_addr_t head; @@ -112,6 +116,7 @@ struct kern_reloc_arg { phys_addr_t kern_arg1; phys_addr_t kern_arg2; phys_addr_t kern_arg3; + phys_addr_t el2_vector; }; #define ARCH_HAS_KIMAGE_ARCH diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 448230684749..ff974b648347 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -136,6 +136,7 @@ int main(void) DEFINE(KEXEC_KRELOC_KERN_ARG1, offsetof(struct kern_reloc_arg, kern_arg1)); DEFINE(KEXEC_KRELOC_KERN_ARG2, offsetof(struct kern_reloc_arg, kern_arg2)); DEFINE(KEXEC_KRELOC_KERN_ARG3, offsetof(struct kern_reloc_arg, kern_arg3)); + DEFINE(KEXEC_KRELOC_EL2_VECTOR, offsetof(struct kern_reloc_arg, el2_vector)); #endif return 0; } diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index ab571fca9bd1..bd398def7627 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -84,6 +84,11 @@ int machine_kexec_post_load(struct kimage *kimage) kern_reloc_arg->head = kimage->head; kern_reloc_arg->entry_addr = kimage->start; kern_reloc_arg->kern_arg0 = kimage->arch.dtb_mem; + /* Setup vector table only when EL2 is available, but no VHE */ + if (is_hyp_mode_available() && !is_kernel_in_hyp_mode()) { + kern_reloc_arg->el2_vector = __pa(reloc_code) + + kexec_el2_vectors_offset; + } kexec_image_info(kimage); return 0; diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S index aa9f2b2cd77c..6fd2fc0ef373 100644 --- a/arch/arm64/kernel/relocate_kernel.S +++ b/arch/arm64/kernel/relocate_kernel.S @@ -89,6 +89,38 @@ ENTRY(arm64_relocate_new_kernel) .ltorg END(arm64_relocate_new_kernel) +.macro el1_sync_64 + br x4 /* Jump to new world from el2 */ + .fill 31, 4, 0 /* Set other 31 instr to zeroes */ +.endm + +.macro invalid_vector label +\label: + b \label + .fill 31, 4, 0 /* Set other 31 instr to zeroes */ +.endm + +/* el2 vectors - switch el2 here while we restore the memory image. */ + .align 11 +ENTRY(kexec_el2_vectors) + invalid_vector el2_sync_invalid_sp0 /* Synchronous EL2t */ + invalid_vector el2_irq_invalid_sp0 /* IRQ EL2t */ + invalid_vector el2_fiq_invalid_sp0 /* FIQ EL2t */ + invalid_vector el2_error_invalid_sp0 /* Error EL2t */ + invalid_vector el2_sync_invalid_spx /* Synchronous EL2h */ + invalid_vector el2_irq_invalid_spx /* IRQ EL2h */ + invalid_vector el2_fiq_invalid_spx /* FIQ EL2h */ + invalid_vector el2_error_invalid_spx /* Error EL2h */ + el1_sync_64 /* Synchronous 64-bit EL1 */ + invalid_vector el1_irq_invalid_64 /* IRQ 64-bit EL1 */ + invalid_vector el1_fiq_invalid_64 /* FIQ 64-bit EL1 */ + invalid_vector el1_error_invalid_64 /* Error 64-bit EL1 */ + invalid_vector el1_sync_invalid_32 /* Synchronous 32-bit EL1 */ + invalid_vector el1_irq_invalid_32 /* IRQ 32-bit EL1 */ + invalid_vector el1_fiq_invalid_32 /* FIQ 32-bit EL1 */ + invalid_vector el1_error_invalid_32 /* Error 32-bit EL1 */ +END(kexec_el2_vectors) + .Lkexec_relocate_code_end: .org KEXEC_CONTROL_PAGE_SIZE .align 3 /* To keep the 64-bit values below naturally aligned. */ @@ -102,3 +134,6 @@ kexec_relocate_code_size: .globl kexec_kern_reloc_offset kexec_kern_reloc_offset: .quad arm64_relocate_new_kernel - kexec_relocate_code_start +.globl kexec_el2_vectors_offset +kexec_el2_vectors_offset: + .quad kexec_el2_vectors - kexec_relocate_code_start
If we have a EL2 mode without VHE, the EL2 vectors are needed in order to switch to EL2 and jump to new world with hyperivsor privileges. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> --- arch/arm64/include/asm/kexec.h | 5 +++++ arch/arm64/kernel/asm-offsets.c | 1 + arch/arm64/kernel/machine_kexec.c | 5 +++++ arch/arm64/kernel/relocate_kernel.S | 35 +++++++++++++++++++++++++++++ 4 files changed, 46 insertions(+)