| Message ID | 20231106163738.1116942-6-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: Add support for running guests without MSO/MSL | expand |
On 11/6/23 17:37, Nico Boehr wrote: > At the moment, when a PGM int occurs while in SIE, we will just reenter > SIE after the interrupt handler was called. > > This is because sie() has a loop which checks icptcode and re-enters SIE > if it is zero. > > However, this behaviour is quite undesirable for SIE tests, since it > doesn't give the host the chance to assert on the PGM int. Instead, we > will just re-enter SIE, on nullifing conditions even causing the > exception again. > > In sie(), check whether a pgm int code is set in lowcore. If it has, > exit the loop so the test can react to the interrupt. Add a new function > read_pgm_int_code() to obtain the interrupt code. > > Note that this introduces a slight oddity with sie and pgm int in > certain cases: If a PGM int occurs between a expect_pgm_int() and sie(), > we will now never enter SIE until the pgm_int_code is cleared by e.g. > clear_pgm_int(). > > Also add missing include of facility.h to mem.h. > > Signed-off-by: Nico Boehr <nrb@linux.ibm.com> > Reviewed-by: Thomas Huth <thuth@redhat.com> > Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h index d01f8a89641a..39b43b64ea07 100644 --- a/lib/s390x/asm/interrupt.h +++ b/lib/s390x/asm/interrupt.h @@ -97,4 +97,18 @@ static inline void low_prot_disable(void) ctl_clear_bit(0, CTL0_LOW_ADDR_PROT); } +/** + * read_pgm_int_code - Get the program interruption code of the last pgm int + * on the current CPU. + * + * This is similar to clear_pgm_int(), except that it doesn't clear the + * interruption information from lowcore. + * + * Return: 0 when none occurred. + */ +static inline uint16_t read_pgm_int_code(void) +{ + return lowcore.pgm_int_code; +} + #endif diff --git a/lib/s390x/asm/mem.h b/lib/s390x/asm/mem.h index 64ef59b546a4..94d58c34f53f 100644 --- a/lib/s390x/asm/mem.h +++ b/lib/s390x/asm/mem.h @@ -8,6 +8,7 @@ #ifndef _ASMS390X_MEM_H_ #define _ASMS390X_MEM_H_ #include <asm/arch_def.h> +#include <asm/facility.h> /* create pointer while avoiding compiler warnings */ #define OPAQUE_PTR(x) ((void *)(((uint64_t)&lowcore) + (x))) diff --git a/lib/s390x/sie.c b/lib/s390x/sie.c index 7f4474555ff7..2530ff09ddcd 100644 --- a/lib/s390x/sie.c +++ b/lib/s390x/sie.c @@ -13,6 +13,7 @@ #include <libcflat.h> #include <sie.h> #include <asm/page.h> +#include <asm/interrupt.h> #include <libcflat.h> #include <alloc_page.h> @@ -54,6 +55,9 @@ void sie(struct vm *vm) { uint64_t old_cr13; + /* When a pgm int code is set, we'll never enter SIE below. */ + assert(!read_pgm_int_code()); + if (vm->sblk->sdf == 2) memcpy(vm->sblk->pv_grregs, vm->save_area.guest.grs, sizeof(vm->save_area.guest.grs)); @@ -79,7 +83,8 @@ void sie(struct vm *vm) /* also handle all interruptions in home space while in SIE */ irq_set_dat_mode(true, AS_HOME); - while (vm->sblk->icptcode == 0) { + /* leave SIE when we have an intercept or an interrupt so the test can react to it */ + while (vm->sblk->icptcode == 0 && !read_pgm_int_code()) { sie64a(vm->sblk, &vm->save_area); sie_handle_validity(vm); }