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

[Janosch Frank <frankja@linux.ibm.com>]

On 7/5/21 11:52 AM, Thomas Huth wrote:
> 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>
> 

Thanks, I'll fix this up and queue the series