Re: [kvm-unit-tests PATCH v2 3/3] s390x: mvpg: Add SIE mvpg test

[Thomas Huth <thuth@redhat.com>]

On 05/07/2021 11.37, Janosch Frank wrote:
> On 7/5/21 9:24 AM, Thomas Huth wrote:
>> On 29/06/2021 15.18, Janosch Frank wrote:
>>> Let's also check the PEI values to make sure our VSIE implementation
>>> is correct.
>>>
>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>> ---
>>>    s390x/Makefile                  |   2 +
>>>    s390x/mvpg-sie.c                | 151 ++++++++++++++++++++++++++++++++
>>>    s390x/snippets/c/mvpg-snippet.c |  33 +++++++
>>>    s390x/unittests.cfg             |   3 +
>>>    4 files changed, 189 insertions(+)
>>>    create mode 100644 s390x/mvpg-sie.c
>>>    create mode 100644 s390x/snippets/c/mvpg-snippet.c
>>>
>>> diff --git a/s390x/Makefile b/s390x/Makefile
>>> index ba32f4c..07af26d 100644
>>> --- a/s390x/Makefile
>>> +++ b/s390x/Makefile
>>> @@ -23,6 +23,7 @@ tests += $(TEST_DIR)/sie.elf
>>>    tests += $(TEST_DIR)/mvpg.elf
>>>    tests += $(TEST_DIR)/uv-host.elf
>>>    tests += $(TEST_DIR)/edat.elf
>>> +tests += $(TEST_DIR)/mvpg-sie.elf
>>>    
>>>    tests_binary = $(patsubst %.elf,%.bin,$(tests))
>>>    ifneq ($(HOST_KEY_DOCUMENT),)
>>> @@ -82,6 +83,7 @@ snippet_asmlib = $(SNIPPET_DIR)/c/cstart.o
>>>    
>>>    # perquisites (=guests) for the snippet hosts.
>>>    # $(TEST_DIR)/<snippet-host>.elf: snippets = $(SNIPPET_DIR)/<c/asm>/<snippet>.gbin
>>> +$(TEST_DIR)/mvpg-sie.elf: snippets = $(SNIPPET_DIR)/c/mvpg-snippet.gbin
>>>    
>>>    $(SNIPPET_DIR)/asm/%.gbin: $(SNIPPET_DIR)/asm/%.o $(FLATLIBS)
>>>    	$(OBJCOPY) -O binary $(patsubst %.gbin,%.o,$@) $@
>>> diff --git a/s390x/mvpg-sie.c b/s390x/mvpg-sie.c
>>> new file mode 100644
>>> index 0000000..3536c6a
>>> --- /dev/null
>>> +++ b/s390x/mvpg-sie.c
>>> @@ -0,0 +1,151 @@
>>> +#include <libcflat.h>
>>> +#include <asm/asm-offsets.h>
>>> +#include <asm-generic/barrier.h>
>>> +#include <asm/pgtable.h>
>>> +#include <mmu.h>
>>> +#include <asm/page.h>
>>> +#include <asm/facility.h>
>>> +#include <asm/mem.h>
>>> +#include <alloc_page.h>
>>> +#include <vm.h>
>>> +#include <sclp.h>
>>> +#include <sie.h>
>>> +
>>> +static u8 *guest;
>>> +static u8 *guest_instr;
>>> +static struct vm vm;
>>> +
>>> +static uint8_t *src;
>>> +static uint8_t *dst;
>>> +static uint8_t *cmp;
>>> +
>>> +extern const char _binary_s390x_snippets_c_mvpg_snippet_gbin_start[];
>>> +extern const char _binary_s390x_snippets_c_mvpg_snippet_gbin_end[];
>>> +int binary_size;
>>> +
>>> +static void sie(struct vm *vm)
>>> +{
>>> +	/* Reset icptcode so we don't trip over it below */
>>> +	vm->sblk->icptcode = 0;
>>> +
>>> +	while (vm->sblk->icptcode == 0) {
>>> +		sie64a(vm->sblk, &vm->save_area);
>>> +		if (vm->sblk->icptcode == ICPT_VALIDITY)
>>> +			assert(0);
>>
>> Please replace the above two lines with:
>>
>> 		assert(vm->sblk->icptcode != ICPT_VALIDITY);
> 
> Sure
> 
>>
>>> +	}
>>> +	vm->save_area.guest.grs[14] = vm->sblk->gg14;
>>> +	vm->save_area.guest.grs[15] = vm->sblk->gg15;
>>> +}
>>> +
>>> +static void test_mvpg_pei(void)
>>> +{
>>> +	uint64_t **pei_dst = (uint64_t **)((uintptr_t) vm.sblk + 0xc0);
>>> +	uint64_t **pei_src = (uint64_t **)((uintptr_t) vm.sblk + 0xc8);
>>> +
>>> +	report_prefix_push("pei");
>>> +
>>> +	report_prefix_push("src");
>>> +	memset(dst, 0, PAGE_SIZE);
>>> +	protect_page(src, PAGE_ENTRY_I);
>>> +	sie(&vm);
>>> +	report(vm.sblk->icptcode == ICPT_PARTEXEC, "Partial execution");
>>> +	report((uintptr_t)**pei_src == (uintptr_t)src + PAGE_ENTRY_I, "PEI_SRC correct");
>>> +	report((uintptr_t)**pei_dst == (uintptr_t)dst, "PEI_DST correct");
>>> +	unprotect_page(src, PAGE_ENTRY_I);
>>> +	report(!memcmp(cmp, dst, PAGE_SIZE), "Destination intact");
>>> +	/*
>>> +	 * We need to execute the diag44 which is used as a blocker
>>> +	 * behind the mvpg. It makes sure we fail the tests above if
>>> +	 * the mvpg wouldn't have intercepted.
>>> +	 */
>>> +	sie(&vm);
>>> +	/* Make sure we intercepted for the diag44 and nothing else */
>>> +	assert(vm.sblk->icptcode == ICPT_INST &&
>>> +	       vm.sblk->ipa == 0x8300 && vm.sblk->ipb == 0x440000);
>>> +	report_prefix_pop();
>>> +
>>> +	/* Clear PEI data for next check */
>>> +	report_prefix_push("dst");
>>> +	memset((uint64_t *)((uintptr_t) vm.sblk + 0xc0), 0, 16);
>>> +	memset(dst, 0, PAGE_SIZE);
>>> +	protect_page(dst, PAGE_ENTRY_I);
>>> +	sie(&vm);
>>> +	report(vm.sblk->icptcode == ICPT_PARTEXEC, "Partial execution");
>>> +	report((uintptr_t)**pei_src == (uintptr_t)src, "PEI_SRC correct");
>>> +	report((uintptr_t)**pei_dst == (uintptr_t)dst + PAGE_ENTRY_I, "PEI_DST correct");
>>> +	/* Needed for the memcmp and general cleanup */
>>> +	unprotect_page(dst, PAGE_ENTRY_I);
>>> +	report(!memcmp(cmp, dst, PAGE_SIZE), "Destination intact");
>>> +	report_prefix_pop();
>>> +
>>> +	report_prefix_pop();
>>> +}
>>
>> Still quite a lot of magic values in above code ... any chance to introduce
>> some #defines finally?
> 
> Currently not really.
> I added a comment for the diag 44 which should be enough right now. If
> needed I can add a comment to the pei variables as well.

Ok, fine for me, we can still clean up later if necessary. Thus with the 
assert() fixed and the mb() removed:

Acked-by: Thomas Huth <thuth@redhat.com>