Re: [kvm-unit-tests PATCH 1/4] s390x: sie: Add sie lib validity handling

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Thu, 29 Jul 2021 13:48:00 +0000
Janosch Frank <frankja@linux.ibm.com> wrote:

> Let's start off the SIE lib with validity handling code since that has
> the least amount of dependencies to other files.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/sie.c  | 41 +++++++++++++++++++++++++++++++++++++++++
>  lib/s390x/sie.h  |  3 +++
>  s390x/Makefile   |  1 +
>  s390x/mvpg-sie.c |  2 +-
>  s390x/sie.c      |  7 +------
>  5 files changed, 47 insertions(+), 7 deletions(-)
>  create mode 100644 lib/s390x/sie.c
> 
> diff --git a/lib/s390x/sie.c b/lib/s390x/sie.c
> new file mode 100644
> index 00000000..9107519f
> --- /dev/null
> +++ b/lib/s390x/sie.c
> @@ -0,0 +1,41 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Virtualization library that speeds up managing guests.
> + *
> + * Copyright (c) 2021 IBM Corp
> + *
> + * Authors:
> + *  Janosch Frank <frankja@linux.ibm.com>
> + */
> +
> +#include <asm/barrier.h>
> +#include <libcflat.h>
> +#include <sie.h>
> +
> +static bool validity_expected;
> +static uint16_t vir;
> +
> +void sie_expect_validity(void)
> +{
> +	validity_expected = true;
> +	vir = 0;
> +}
> +
> +void sie_check_validity(uint16_t vir_exp)
> +{
> +	report(vir_exp == vir, "VALIDITY: %x", vir);
> +	mb();

why the barrier?

> +	vir = 0;
> +}
> +
> +void sie_handle_validity(struct vm *vm)
> +{
> +	if (vm->sblk->icptcode != ICPT_VALIDITY)
> +		return;
> +
> +	vir = vm->sblk->ipb >> 16;
> +
> +	if (!validity_expected)
> +		report_abort("VALIDITY: %x", vir);
> +	validity_expected = false;
> +}
> diff --git a/lib/s390x/sie.h b/lib/s390x/sie.h
> index 6ba858a2..7ff98d2d 100644
> --- a/lib/s390x/sie.h
> +++ b/lib/s390x/sie.h
> @@ -197,5 +197,8 @@ struct vm {
>  extern void sie_entry(void);
>  extern void sie_exit(void);
>  extern void sie64a(struct kvm_s390_sie_block *sblk, struct
> vm_save_area *save_area); +void sie_expect_validity(void);
> +void sie_check_validity(uint16_t vir_exp);
> +void sie_handle_validity(struct vm *vm);
>  
>  #endif /* _S390X_SIE_H_ */
> diff --git a/s390x/Makefile b/s390x/Makefile
> index 6565561b..ef8041a6 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -71,6 +71,7 @@ cflatobjs += lib/s390x/css_dump.o
>  cflatobjs += lib/s390x/css_lib.o
>  cflatobjs += lib/s390x/malloc_io.o
>  cflatobjs += lib/s390x/uv.o
> +cflatobjs += lib/s390x/sie.o
>  
>  OBJDIRS += lib/s390x
>  
> diff --git a/s390x/mvpg-sie.c b/s390x/mvpg-sie.c
> index 5e70f591..2ac91eec 100644
> --- a/s390x/mvpg-sie.c
> +++ b/s390x/mvpg-sie.c
> @@ -39,7 +39,7 @@ static void sie(struct vm *vm)
>  
>  	while (vm->sblk->icptcode == 0) {
>  		sie64a(vm->sblk, &vm->save_area);
> -		assert(vm->sblk->icptcode != ICPT_VALIDITY);
> +		sie_handle_validity(vm);
>  	}
>  	vm->save_area.guest.grs[14] = vm->sblk->gg14;
>  	vm->save_area.guest.grs[15] = vm->sblk->gg15;
> diff --git a/s390x/sie.c b/s390x/sie.c
> index 134d3c4f..5c798a9e 100644
> --- a/s390x/sie.c
> +++ b/s390x/sie.c
> @@ -24,17 +24,12 @@ static u8 *guest;
>  static u8 *guest_instr;
>  static struct vm vm;
>  
> -static void handle_validity(struct vm *vm)
> -{
> -	report(0, "VALIDITY: %x", vm->sblk->ipb >> 16);
> -}
>  
>  static void sie(struct vm *vm)
>  {
>  	while (vm->sblk->icptcode == 0) {
>  		sie64a(vm->sblk, &vm->save_area);
> -		if (vm->sblk->icptcode == ICPT_VALIDITY)
> -			handle_validity(vm);
> +		sie_handle_validity(vm);
>  	}
>  	vm->save_area.guest.grs[14] = vm->sblk->gg14;
>  	vm->save_area.guest.grs[15] = vm->sblk->gg15;