Re: [PATCH 2/4] tools/tests: Unit test for p2m pool size

[Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>]

On 26/10/2022 15:24, Jan Beulich wrote:
> On 26.10.2022 12:20, Andrew Cooper wrote:
>> --- /dev/null
>> +++ b/tools/tests/p2m-pool/Makefile
>> @@ -0,0 +1,42 @@
>> +XEN_ROOT = $(CURDIR)/../../..
>> +include $(XEN_ROOT)/tools/Rules.mk
>> +
>> +TARGET := test-p2m-pool
>> +
>> +.PHONY: all
>> +all: $(TARGET)
>> +
>> +.PHONY: clean
>> +clean:
>> +    $(RM) -- *.o $(TARGET) $(DEPS_RM)
>> +
>> +.PHONY: distclean
>> +distclean: clean
>> +    $(RM) -- *~
>> +
>> +.PHONY: install
>> +install: all
>> +    $(INSTALL_DIR) $(DESTDIR)$(LIBEXEC_BIN)
>> +    $(INSTALL_PROG) $(TARGET) $(DESTDIR)$(LIBEXEC_BIN)
>> +
>> +.PHONY: uninstall
>> +uninstall:
>> +    $(RM) -- $(DESTDIR)$(LIBEXEC_BIN)/$(TARGET)
>> +
>> +CFLAGS += $(CFLAGS_xeninclude)
>> +CFLAGS += $(CFLAGS_libxenctrl)
>> +CFLAGS += $(CFLAGS_libxenforeginmemory)
> Typo here or typo also elsewhere: CFLAGS_libxenforeignmemory? I
> have to admit that I can't really spot where these variables are
> populated. The place in Rules.mk that I could spot uses
>
>  CFLAGS_libxen$(1) = $$(CFLAGS_xeninclude)
>
> i.e. the expansion doesn't really depend on the library.

Hmm.  It was copy&paste from test-resource and I forgot to trim
foreignmemory, but I guess I'll need to go and fix the typo everywhere.

>
> Apart from this looks okay to me, maybe apart from ...
>
>> --- /dev/null
>> +++ b/tools/tests/p2m-pool/test-p2m-pool.c
>> @@ -0,0 +1,181 @@
>> +#include <err.h>
>> +#include <errno.h>
>> +#include <inttypes.h>
>> +#include <stdio.h>
>> +#include <string.h>
>> +#include <sys/mman.h>
>> +
>> +#include <xenctrl.h>
>> +#include <xenforeignmemory.h>
>> +#include <xengnttab.h>
>> +#include <xen-tools/libs.h>
>> +
>> +static unsigned int nr_failures;
>> +#define fail(fmt, ...)                          \
>> +({                                              \
>> +    nr_failures++;                              \
>> +    (void)printf(fmt, ##__VA_ARGS__);           \
>> +})
>> +
>> +static xc_interface *xch;
>> +static uint32_t domid;
>> +
>> +static struct xen_domctl_createdomain create = {
>> +    .flags = XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap,
>> +    .max_vcpus = 1,
>> +    .max_grant_frames = 1,
>> +    .grant_opts = XEN_DOMCTL_GRANT_version(1),
>> +
>> +    .arch = {
>> +#if defined(__x86_64__) || defined(__i386__)
>> +        .emulation_flags = XEN_X86_EMU_LAPIC,
>> +#endif
>> +    },
>> +};
>> +
>> +static uint64_t default_p2m_size_bytes =
>> +#if defined(__x86_64__) || defined(__i386__)
>> +    256 << 12; /* Only x86 HAP for now.  x86 Shadow broken. */
> ... this shadow related comment (the commit message could at least
> say what's wrong there, to give a hint at what would need fixing to
> remove this restriction) and ...

That was in reference to the PV issue.  Will follow it up on patch 1
where there's more context.

>
>> +#elif defined (__arm__) || defined(__aarch64__)
>> +    16 << 12;
>> +#endif
>> +
>> +static void run_tests(void)
>> +{
>> +    xen_pfn_t physmap[] = { 0 };
>> +    uint64_t size_bytes, old_size_bytes;
>> +    int rc;
>> +
>> +    printf("Test default p2m mempool size\n");
>> +
>> +    rc = xc_get_p2m_mempool_size(xch, domid, &size_bytes);
>> +    if ( rc )
>> +        return fail("  Fail: get p2m mempool size: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    printf("P2M pool size %"PRIu64" bytes (%"PRIu64"kB, %"PRIu64"MB)\n",
>> +           size_bytes, size_bytes >> 10, size_bytes >> 20);
>> +
>> +
>> +    /*
>> +     * Check that the domain has the expected default allocation size.  This
>> +     * will fail if the logic in Xen is altered without an equivelent
>> +     * adjustment here.
>> +     */
>> +    if ( size_bytes != default_p2m_size_bytes )
>> +        return fail("  Fail: size %"PRIu64" != expected size %"PRIu64"\n",
>> +                    size_bytes, default_p2m_size_bytes);
>> +
>> +
>> +    printf("Test that allocate doesn't alter pool size\n");
>> +
>> +    /*
>> +     * Populate the domain with some RAM.  This will cause more of the p2m
>> +     * pool to be used.
>> +     */
>> +    old_size_bytes = size_bytes;
>> +
>> +    rc = xc_domain_setmaxmem(xch, domid, -1);
>> +    if ( rc )
>> +        return fail("  Fail: setmaxmem: : %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    rc = xc_domain_populate_physmap_exact(xch, domid, 1, 0, 0, physmap);
>> +    if ( rc )
>> +        return fail("  Fail: populate physmap: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    /*
>> +     * Re-get the p2m size.  Should not have changed as a consequence of
>> +     * populate physmap.
>> +     */
>> +    rc = xc_get_p2m_mempool_size(xch, domid, &size_bytes);
>> +    if ( rc )
>> +        return fail("  Fail: get p2m mempool size: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    if ( old_size_bytes != size_bytes )
>> +        return fail("  Fail: p2m mempool size changed %"PRIu64" => 
>> %"PRIu64"\n",
>> +                    old_size_bytes, size_bytes);
>> +
>> +
>> +
>> +    printf("Test bad set size\n");
>> +
>> +    /*
>> +     * Check that setting a non-page size results in failure.
>> +     */
>> +    rc = xc_set_p2m_mempool_size(xch, domid, size_bytes + 1);
>> +    if ( rc != -1 || errno != EINVAL )
>> +        return fail("  Fail: Bad set size: expected -1/EINVAL, got %d/%d - 
>> %s\n",
>> +                    rc, errno, strerror(errno));
>> +
>> +
>> +    printf("Test very large set size\n");
>> +
>> +    /*
>> +     * Check that setting a large P2M size succeeds.  This is expecting to
>> +     * trigger continuations.
>> +     */
>> +    rc = xc_set_p2m_mempool_size(xch, domid, 64 << 20);
>> +    if ( rc )
>> +        return fail("  Fail: Set size 64MB: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +
>> +    /*
>> +     * Check that the reported size matches what set consumed.
>> +     */
>> +    rc = xc_get_p2m_mempool_size(xch, domid, &size_bytes);
>> +    if ( rc )
>> +        return fail("  Fail: get p2m mempool size: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    if ( size_bytes != 64 << 20 )
>> +        return fail("  Fail: expected mempool size %u, got %"PRIu64"\n",
>> +                    64 << 20, size_bytes);
>> +}
>> +
>> +int main(int argc, char **argv)
>> +{
>> +    int rc;
>> +
>> +    printf("P2M Shadow memory pool tests\n");
> ... the question of why "Shadow" here.

Hmm, stale, but even the name of this test (p2m-pool) is subject to a
resolution of the naming question on patch 1.

~Andrew