Re: [kvm-unit-tests PATCH 3/4] s390x: lib: sie: Add struct vm (de)initialization functions

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

On Thu, 29 Jul 2021 13:48:02 +0000
Janosch Frank <frankja@linux.ibm.com> wrote:

> Before I start copying the same code over and over lets move this into
> the library.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  lib/s390x/sie.c  | 30 ++++++++++++++++++++++++++++++
>  lib/s390x/sie.h  |  3 +++
>  s390x/mvpg-sie.c | 18 ++----------------
>  s390x/sie.c      | 19 +++----------------
>  4 files changed, 38 insertions(+), 32 deletions(-)
> 
> diff --git a/lib/s390x/sie.c b/lib/s390x/sie.c
> index 9107519f..ec0c4867 100644
> --- a/lib/s390x/sie.c
> +++ b/lib/s390x/sie.c
> @@ -11,6 +11,9 @@
>  #include <asm/barrier.h>
>  #include <libcflat.h>
>  #include <sie.h>
> +#include <asm/page.h>
> +#include <libcflat.h>
> +#include <alloc_page.h>
>  
>  static bool validity_expected;
>  static uint16_t vir;
> @@ -39,3 +42,30 @@ void sie_handle_validity(struct vm *vm)
>  		report_abort("VALIDITY: %x", vir);
>  	validity_expected = false;
>  }
> +
> +/* 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) +{
> +	vm->sblk = alloc_page();
> +	memset(vm->sblk, 0, PAGE_SIZE);

you can skip the memset, the page allocator always zeroes the page,
unless you explicitly pass FLAG_DONTZERO

regardless of that:

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

> +	vm->sblk->cpuflags = CPUSTAT_ZARCH | CPUSTAT_RUNNING;
> +	vm->sblk->ihcpu = 0xffff;
> +	vm->sblk->prefix = 0;
> +
> +	/* Guest memory chunks are always 1MB */
> +	assert(!(guest_mem_len & ~HPAGE_MASK));
> +	/* Currently MSO/MSL is the easiest option */
> +	vm->sblk->mso = (uint64_t)guest_mem;
> +	vm->sblk->msl = (uint64_t)guest_mem + ((guest_mem_len - 1) &
> HPAGE_MASK); +
> +	/* CRYCB needs to be in the first 2GB */
> +	vm->crycb = alloc_pages_flags(0, AREA_DMA31);
> +	vm->sblk->crycbd = (uint32_t)(uintptr_t)vm->crycb;
> +}
> +
> +/* Frees the memory that was gathered on initialization */
> +void sie_guest_destroy(struct vm *vm)
> +{
> +	free_page(vm->crycb);
> +	free_page(vm->sblk);
> +}
> diff --git a/lib/s390x/sie.h b/lib/s390x/sie.h
> index 7ff98d2d..946bd164 100644
> --- a/lib/s390x/sie.h
> +++ b/lib/s390x/sie.h
> @@ -190,6 +190,7 @@ struct vm_save_area {
>  struct vm {
>  	struct kvm_s390_sie_block *sblk;
>  	struct vm_save_area save_area;
> +	uint8_t *crycb;				/* Crypto
> Control Block */ /* Ptr to first guest page */
>  	uint8_t *guest_mem;
>  };
> @@ -200,5 +201,7 @@ extern void sie64a(struct kvm_s390_sie_block
> *sblk, struct vm_save_area *save_ar void sie_expect_validity(void);
>  void sie_check_validity(uint16_t vir_exp);
>  void sie_handle_validity(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);
>  
>  #endif /* _S390X_SIE_H_ */
> diff --git a/s390x/mvpg-sie.c b/s390x/mvpg-sie.c
> index 2ac91eec..71ae4f88 100644
> --- a/s390x/mvpg-sie.c
> +++ b/s390x/mvpg-sie.c
> @@ -110,22 +110,7 @@ static void setup_guest(void)
>  	/* The first two pages are the lowcore */
>  	guest_instr = guest + PAGE_SIZE * 2;
>  
> -	vm.sblk = alloc_page();
> -
> -	vm.sblk->cpuflags = CPUSTAT_ZARCH | CPUSTAT_RUNNING;
> -	vm.sblk->prefix = 0;
> -	/*
> -	 * Pageable guest with the same ASCE as the test programm,
> but
> -	 * the guest memory 0x0 is offset to start at the allocated
> -	 * guest pages and end after 1MB.
> -	 *
> -	 * It's not pretty but faster and easier than managing guest
> ASCEs.
> -	 */
> -	vm.sblk->mso = (u64)guest;
> -	vm.sblk->msl = (u64)guest;
> -	vm.sblk->ihcpu = 0xffff;
> -
> -	vm.sblk->crycbd = (uint64_t)alloc_page();
> +	sie_guest_create(&vm, (uint64_t)guest, HPAGE_SIZE);
>  
>  	vm.sblk->gpsw.addr = PAGE_SIZE * 4;
>  	vm.sblk->gpsw.mask = 0x0000000180000000ULL;
> @@ -150,6 +135,7 @@ int main(void)
>  	setup_guest();
>  	test_mvpg();
>  	test_mvpg_pei();
> +	sie_guest_destroy(&vm);
>  
>  done:
>  	report_prefix_pop();
> diff --git a/s390x/sie.c b/s390x/sie.c
> index 5c798a9e..9cb9b055 100644
> --- a/s390x/sie.c
> +++ b/s390x/sie.c
> @@ -84,22 +84,7 @@ static void setup_guest(void)
>  	/* The first two pages are the lowcore */
>  	guest_instr = guest + PAGE_SIZE * 2;
>  
> -	vm.sblk = alloc_page();
> -
> -	vm.sblk->cpuflags = CPUSTAT_ZARCH | CPUSTAT_RUNNING;
> -	vm.sblk->prefix = 0;
> -	/*
> -	 * Pageable guest with the same ASCE as the test programm,
> but
> -	 * the guest memory 0x0 is offset to start at the allocated
> -	 * guest pages and end after 1MB.
> -	 *
> -	 * It's not pretty but faster and easier than managing guest
> ASCEs.
> -	 */
> -	vm.sblk->mso = (u64)guest;
> -	vm.sblk->msl = (u64)guest;
> -	vm.sblk->ihcpu = 0xffff;
> -
> -	vm.sblk->crycbd = (uint64_t)alloc_page();
> +	sie_guest_create(&vm, (uint64_t)guest, HPAGE_SIZE);
>  }
>  
>  int main(void)
> @@ -112,6 +97,8 @@ int main(void)
>  
>  	setup_guest();
>  	test_diags();
> +	sie_guest_destroy(&vm);
> +
>  done:
>  	report_prefix_pop();
>  	return report_summary();