Re: [kvm-unit-tests PATCH 1/8] lib: s390x: sie: Add sca allocation and freeing

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

On Tue, 23 Nov 2021 10:39:49 +0000
Janosch Frank <frankja@linux.ibm.com> wrote:

> For protected guests we always need a ESCA so let's add functions to
> create and destroy SCAs on demand. We don't have scheduling and I
> don't expect multiple VCPU SIE in the next few months so SCA content
> handling is not added.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

> ---
>  lib/s390x/sie.c | 12 ++++++++++++
>  lib/s390x/sie.h |  2 ++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/lib/s390x/sie.c b/lib/s390x/sie.c
> index b965b314..51d3b94e 100644
> --- a/lib/s390x/sie.c
> +++ b/lib/s390x/sie.c
> @@ -55,6 +55,16 @@ void sie(struct vm *vm)
>  	vm->save_area.guest.grs[15] = vm->sblk->gg15;
>  }
>  
> +void sie_guest_sca_create(struct vm *vm)
> +{
> +	vm->sca = (struct esca_block *)alloc_page();
> +
> +	/* Let's start out with one page of ESCA for now */
> +	vm->sblk->scaoh = ((uint64_t)vm->sca >> 32);
> +	vm->sblk->scaol = (uint64_t)vm->sca & ~0x3fU;
> +	vm->sblk->ecb2 |= ECB2_ESCA;
> +}
> +
>  /* Initializes the struct vm members like the SIE control block. */
>  void sie_guest_create(struct vm *vm, uint64_t guest_mem, uint64_t guest_mem_len)
>  {
> @@ -80,4 +90,6 @@ void sie_guest_destroy(struct vm *vm)
>  {
>  	free_page(vm->crycb);
>  	free_page(vm->sblk);
> +	if (vm->sblk->ecb2 & ECB2_ESCA)
> +		free_page(vm->sca);
>  }
> diff --git a/lib/s390x/sie.h b/lib/s390x/sie.h
> index 7ef7251b..f34e3c80 100644
> --- a/lib/s390x/sie.h
> +++ b/lib/s390x/sie.h
> @@ -191,6 +191,7 @@ struct vm_save_area {
>  struct vm {
>  	struct kvm_s390_sie_block *sblk;
>  	struct vm_save_area save_area;
> +	void *sca;				/* System Control Area */
>  	uint8_t *crycb;				/* Crypto Control Block */
>  	/* Ptr to first guest page */
>  	uint8_t *guest_mem;
> @@ -203,6 +204,7 @@ void sie(struct vm *vm);
>  void sie_expect_validity(void);
>  void sie_check_validity(uint16_t vir_exp);
>  void sie_handle_validity(struct vm *vm);
> +void sie_guest_sca_create(struct vm *vm);
>  void sie_guest_create(struct vm *vm, uint64_t guest_mem, uint64_t guest_mem_len);
>  void sie_guest_destroy(struct vm *vm);
>