From: Janosch Frank <frankja@xxxxxxxxxxxxx> When we leave SIE due to an exception, we'll still have guest values in registers 0 - 13 and that's not clearly portraied in our debug prints. So let's fix that. Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230112154548.163021-8-frankja@xxxxxxxxxxxxx Message-Id: <20230112154548.163021-8-frankja@xxxxxxxxxxxxx> --- lib/s390x/sie.h | 2 ++ lib/s390x/interrupt.c | 46 ++++++++++++++++++++++++++++++++++++++----- s390x/cpu.S | 6 ++++-- 3 files changed, 47 insertions(+), 7 deletions(-) diff --git a/lib/s390x/sie.h b/lib/s390x/sie.h index a27a8401..147cb0f2 100644 --- a/lib/s390x/sie.h +++ b/lib/s390x/sie.h @@ -273,6 +273,8 @@ struct vm { extern void sie_entry(void); extern void sie_exit(void); +extern void sie_entry_gregs(void); +extern void sie_exit_gregs(void); extern void sie64a(struct kvm_s390_sie_block *sblk, struct vm_save_area *save_area); void sie(struct vm *vm); void sie_expect_validity(struct vm *vm); diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c index dadb7415..3f993a36 100644 --- a/lib/s390x/interrupt.c +++ b/lib/s390x/interrupt.c @@ -9,6 +9,7 @@ */ #include <libcflat.h> #include <asm/barrier.h> +#include <asm/asm-offsets.h> #include <sclp.h> #include <interrupt.h> #include <sie.h> @@ -188,9 +189,12 @@ static void print_storage_exception_information(void) } } -static void print_int_regs(struct stack_frame_int *stack) +static void print_int_regs(struct stack_frame_int *stack, bool sie) { + struct kvm_s390_sie_block *sblk; + printf("\n"); + printf("%s\n", sie ? "Guest registers:" : "Host registers:"); printf("GPRS:\n"); printf("%016lx %016lx %016lx %016lx\n", stack->grs1[0], stack->grs1[1], stack->grs0[0], stack->grs0[1]); @@ -198,24 +202,56 @@ static void print_int_regs(struct stack_frame_int *stack) stack->grs0[2], stack->grs0[3], stack->grs0[4], stack->grs0[5]); printf("%016lx %016lx %016lx %016lx\n", stack->grs0[6], stack->grs0[7], stack->grs0[8], stack->grs0[9]); - printf("%016lx %016lx %016lx %016lx\n", - stack->grs0[10], stack->grs0[11], stack->grs0[12], stack->grs0[13]); + + if (sie) { + sblk = (struct kvm_s390_sie_block *)stack->grs0[12]; + printf("%016lx %016lx %016lx %016lx\n", + stack->grs0[10], stack->grs0[11], sblk->gg14, sblk->gg15); + } else { + printf("%016lx %016lx %016lx %016lx\n", + stack->grs0[10], stack->grs0[11], stack->grs0[12], stack->grs0[13]); + } + printf("\n"); } static void print_pgm_info(struct stack_frame_int *stack) { - bool in_sie; + bool in_sie, in_sie_gregs; + struct vm_save_area *vregs; in_sie = (lowcore.pgm_old_psw.addr >= (uintptr_t)sie_entry && lowcore.pgm_old_psw.addr <= (uintptr_t)sie_exit); + in_sie_gregs = (lowcore.pgm_old_psw.addr >= (uintptr_t)sie_entry_gregs && + lowcore.pgm_old_psw.addr < (uintptr_t)sie_exit_gregs); printf("\n"); printf("Unexpected program interrupt %s: %#x on cpu %d at %#lx, ilen %d\n", in_sie ? "in SIE" : "", lowcore.pgm_int_code, stap(), lowcore.pgm_old_psw.addr, lowcore.pgm_int_id); - print_int_regs(stack); + + /* + * If we fall out of SIE before loading the host registers, + * then we need to do it here so we print the host registers + * and not the guest registers. + * + * Back tracing is actually not a problem since SIE restores gr15. + */ + if (in_sie_gregs) { + print_int_regs(stack, true); + vregs = *((struct vm_save_area **)(stack->grs0[13] + __SF_SIE_SAVEAREA)); + + /* + * The grs are not linear on the interrupt stack frame. + * We copy 0 and 1 here and 2 - 15 with the memcopy below. + */ + stack->grs1[0] = vregs->host.grs[0]; + stack->grs1[1] = vregs->host.grs[1]; + /* 2 - 15 */ + memcpy(stack->grs0, &vregs->host.grs[2], sizeof(stack->grs0) - 8); + } + print_int_regs(stack, false); dump_stack(); /* Dump stack doesn't end with a \n so we add it here instead */ diff --git a/s390x/cpu.S b/s390x/cpu.S index 45bd551a..9155b044 100644 --- a/s390x/cpu.S +++ b/s390x/cpu.S @@ -82,7 +82,8 @@ sie64a: # Store scb and save_area pointer into stack frame stg %r2,__SF_SIE_CONTROL(%r15) # save control block pointer stg %r3,__SF_SIE_SAVEAREA(%r15) # save guest register save area - +.globl sie_entry_gregs +sie_entry_gregs: # Load guest's gprs, fprs and fpc .irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 ld \i, \i * 8 + SIE_SAVEAREA_GUEST_FPRS(%r3) @@ -121,7 +122,8 @@ sie_exit: .endr lfpc SIE_SAVEAREA_HOST_FPC(%r14) lmg %r0,%r14,SIE_SAVEAREA_HOST_GRS(%r14) # restore kernel registers - +.globl sie_exit_gregs +sie_exit_gregs: br %r14 .align 8 -- 2.39.1
