Add some basic testing of the memory claims mechainsm.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Anthony PERARD <anthony.perard@vates.tech>
CC: Michal Orzel <michal.orzel@amd.com>
CC: Jan Beulich <jbeulich@suse.com>
CC: Julien Grall <julien@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
---
 tools/tests/Makefile                   |   1 +
 tools/tests/mem-claim/.gitignore       |   1 +
 tools/tests/mem-claim/Makefile         |  38 +++++
 tools/tests/mem-claim/test-mem-claim.c | 190 +++++++++++++++++++++++++
 4 files changed, 230 insertions(+)
 create mode 100644 tools/tests/mem-claim/.gitignore
 create mode 100644 tools/tests/mem-claim/Makefile
 create mode 100644 tools/tests/mem-claim/test-mem-claim.c

diff --git a/tools/tests/Makefile b/tools/tests/Makefile
index e566bd169952..6477a4386dda 100644
--- a/tools/tests/Makefile
+++ b/tools/tests/Makefile
@@ -3,6 +3,7 @@ include $(XEN_ROOT)/tools/Rules.mk
 
 SUBDIRS-y :=
 SUBDIRS-y += domid
+SUBDIRS-y += mem-claim
 SUBDIRS-y += paging-mempool
 SUBDIRS-y += pdx
 SUBDIRS-y += rangeset
diff --git a/tools/tests/mem-claim/.gitignore b/tools/tests/mem-claim/.gitignore
new file mode 100644
index 000000000000..cfcee00b819b
--- /dev/null
+++ b/tools/tests/mem-claim/.gitignore
@@ -0,0 +1 @@
+test-mem-claim
diff --git a/tools/tests/mem-claim/Makefile b/tools/tests/mem-claim/Makefile
new file mode 100644
index 000000000000..76ba3e3c8bef
--- /dev/null
+++ b/tools/tests/mem-claim/Makefile
@@ -0,0 +1,38 @@
+XEN_ROOT = $(CURDIR)/../../..
+include $(XEN_ROOT)/tools/Rules.mk
+
+TARGET := test-mem-claim
+
+.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)/tests
+	$(INSTALL_PROG) $(TARGET) $(DESTDIR)$(LIBEXEC)/tests
+
+.PHONY: uninstall
+uninstall:
+	$(RM) -- $(DESTDIR)$(LIBEXEC)/tests/$(TARGET)
+
+CFLAGS += $(CFLAGS_xeninclude)
+CFLAGS += $(CFLAGS_libxenctrl)
+CFLAGS += $(APPEND_CFLAGS)
+
+LDFLAGS += $(LDLIBS_libxenctrl)
+LDFLAGS += $(APPEND_LDFLAGS)
+
+%.o: Makefile
+
+$(TARGET): test-mem-claim.o
+	$(CC) -o $@ $< $(LDFLAGS)
+
+-include $(DEPS_INCLUDE)
diff --git a/tools/tests/mem-claim/test-mem-claim.c b/tools/tests/mem-claim/test-mem-claim.c
new file mode 100644
index 000000000000..78eae9091f52
--- /dev/null
+++ b/tools/tests/mem-claim/test-mem-claim.c
@@ -0,0 +1,190 @@
+#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/common-macros.h>
+
+static unsigned int nr_failures;
+#define fail(fmt, ...)                          \
+({                                              \
+    nr_failures++;                              \
+    (void)printf(fmt, ##__VA_ARGS__);           \
+})
+
+static xc_interface *xch;
+static uint32_t domid = -1;
+
+static xc_physinfo_t physinfo;
+
+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 void run_tests(void)
+{
+    int rc;
+
+    /*
+     * Check that the system is quiescent.  Outstanding claims is a global
+     * field.
+     */
+    rc = xc_physinfo(xch, &physinfo);
+    if ( rc )
+        return fail("Failed to obtain physinfo: %d - %s\n",
+                    errno, strerror(errno));
+
+    printf("Free pages: %"PRIu64", Oustanding claims: %"PRIu64"\n",
+           physinfo.free_pages, physinfo.outstanding_pages);
+
+    if ( physinfo.outstanding_pages )
+        return fail("  Test needs running on a quiescent system\n");
+
+    /*
+     * We want any arbitrary domain.  Start with HVM/HAP, falling back to
+     * HVM/Shadow and then to PV.  The dom0 running this test case is one of
+     * these modes.
+     */
+#if defined(__x86_64__) || defined(__i386__)
+    if ( !(physinfo.capabilities & XEN_SYSCTL_PHYSCAP_hap) )
+        create.flags &= ~XEN_DOMCTL_CDF_hap;
+
+    if ( !(physinfo.capabilities & (XEN_SYSCTL_PHYSCAP_hap|XEN_SYSCTL_PHYSCAP_shadow)) ||
+         !(physinfo.capabilities & XEN_SYSCTL_PHYSCAP_hvm) )
+    {
+        create.flags &= ~XEN_DOMCTL_CDF_hvm;
+        create.arch.emulation_flags = 0;
+    }
+#endif
+
+    rc = xc_domain_create(xch, &domid, &create);
+    if ( rc )
+        return fail("  Domain create failure: %d - %s\n",
+                    errno, strerror(errno));
+
+    rc = xc_domain_setmaxmem(xch, domid, -1);
+    if ( rc )
+        return fail("  Failed to set maxmem: %d - %s\n",
+                    errno, strerror(errno));
+
+    printf("  Created d%u\n", domid);
+
+    /*
+     * Creating a domain shouldn't change the claim.  Check it's still 0.
+     */
+    rc = xc_physinfo(xch, &physinfo);
+    if ( rc )
+        return fail("  Failed to obtain physinfo: %d - %s\n",
+                    errno, strerror(errno));
+
+    if ( physinfo.outstanding_pages )
+        return fail("  Unexpected outstanding claim of %"PRIu64" pages\n",
+                    physinfo.outstanding_pages);
+
+    /*
+     * Set a claim for 4M.  This should be the only claim in the system, and
+     * show up globally.
+     */
+    rc = xc_domain_claim_pages(xch, domid, 4*1024*1024/4096);
+    if ( rc )
+        return fail("  Failed to claim 4M of RAM: %d - %s\n",
+                    errno, strerror(errno));
+
+    rc = xc_physinfo(xch, &physinfo);
+    if ( rc )
+        return fail("  Failed to obtain physinfo: %d - %s\n",
+                    errno, strerror(errno));
+
+    if ( physinfo.outstanding_pages != 4*1024*1024/4096 )
+        return fail("  Expected claim to be 4M, got %"PRIu64" pages\n",
+                    physinfo.outstanding_pages);
+
+    /*
+     * Allocate 2M of RAM to the domain.  This should be deducted from global
+     * claim.
+     */
+    xen_pfn_t ram[] = { 0 };
+    rc = xc_domain_populate_physmap_exact(
+        xch, domid, ARRAY_SIZE(ram), 9, 0, ram);
+    if ( rc )
+        return fail("  Failed to populate physmap domain: %d - %s\n",
+                    errno, strerror(errno));
+
+    rc = xc_physinfo(xch, &physinfo);
+    if ( rc )
+        return fail("  Failed to obtain physinfo: %d - %s\n",
+                    errno, strerror(errno));
+
+    if ( physinfo.outstanding_pages != 2*1024*1024/4096 )
+        return fail("  Expected claim to be 2M, got %"PRIu64" pages\n",
+                    physinfo.outstanding_pages);
+
+    /*
+     * Destroying the domain should release the outstanding 2M claim.
+     */
+    rc = xc_domain_destroy(xch, domid);
+
+    /* Cancel the cleanup path, even in the case of an error. */
+    domid = -1;
+
+    if ( rc )
+        return fail("  Failed to destroy domain: %d - %s\n",
+                    errno, strerror(errno));
+
+    rc = xc_physinfo(xch, &physinfo);
+    if ( rc )
+        return fail("  Failed to obtain physinfo: %d - %s\n",
+                    errno, strerror(errno));
+
+    if ( physinfo.outstanding_pages )
+        return fail("  Expected no outstanding claim, got %"PRIu64" pages\n",
+                    physinfo.outstanding_pages);
+}
+
+int main(int argc, char **argv)
+{
+    int rc;
+
+    printf("Memory claims tests\n");
+
+    xch = xc_interface_open(NULL, NULL, 0);
+
+    if ( !xch )
+        err(1, "xc_interface_open");
+
+    run_tests();
+
+    if ( (int)domid >= 0 )
+    {
+        rc = xc_domain_destroy(xch, domid);
+        if ( rc )
+            fail("  Failed to destroy domain: %d - %s\n",
+                 errno, strerror(errno));
+    }
+
+    return !!nr_failures;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.39.5

On Tue, Dec 16, 2025 at 04:32:30PM +0000, Andrew Cooper wrote:
> Add some basic testing of the memory claims mechainsm.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Some nits below.

> ---
> CC: Anthony PERARD <anthony.perard@vates.tech>
> CC: Michal Orzel <michal.orzel@amd.com>
> CC: Jan Beulich <jbeulich@suse.com>
> CC: Julien Grall <julien@xen.org>
> CC: Roger Pau Monné <roger.pau@citrix.com>
> CC: Stefano Stabellini <sstabellini@kernel.org>
> ---
>  tools/tests/Makefile                   |   1 +
>  tools/tests/mem-claim/.gitignore       |   1 +
>  tools/tests/mem-claim/Makefile         |  38 +++++
>  tools/tests/mem-claim/test-mem-claim.c | 190 +++++++++++++++++++++++++
>  4 files changed, 230 insertions(+)
>  create mode 100644 tools/tests/mem-claim/.gitignore
>  create mode 100644 tools/tests/mem-claim/Makefile
>  create mode 100644 tools/tests/mem-claim/test-mem-claim.c
> 
> diff --git a/tools/tests/Makefile b/tools/tests/Makefile
> index e566bd169952..6477a4386dda 100644
> --- a/tools/tests/Makefile
> +++ b/tools/tests/Makefile
> @@ -3,6 +3,7 @@ include $(XEN_ROOT)/tools/Rules.mk
>  
>  SUBDIRS-y :=
>  SUBDIRS-y += domid
> +SUBDIRS-y += mem-claim
>  SUBDIRS-y += paging-mempool
>  SUBDIRS-y += pdx
>  SUBDIRS-y += rangeset
> diff --git a/tools/tests/mem-claim/.gitignore b/tools/tests/mem-claim/.gitignore
> new file mode 100644
> index 000000000000..cfcee00b819b
> --- /dev/null
> +++ b/tools/tests/mem-claim/.gitignore
> @@ -0,0 +1 @@
> +test-mem-claim
> diff --git a/tools/tests/mem-claim/Makefile b/tools/tests/mem-claim/Makefile
> new file mode 100644
> index 000000000000..76ba3e3c8bef
> --- /dev/null
> +++ b/tools/tests/mem-claim/Makefile
> @@ -0,0 +1,38 @@
> +XEN_ROOT = $(CURDIR)/../../..
> +include $(XEN_ROOT)/tools/Rules.mk
> +
> +TARGET := test-mem-claim
> +
> +.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)/tests
> +	$(INSTALL_PROG) $(TARGET) $(DESTDIR)$(LIBEXEC)/tests
> +
> +.PHONY: uninstall
> +uninstall:
> +	$(RM) -- $(DESTDIR)$(LIBEXEC)/tests/$(TARGET)
> +
> +CFLAGS += $(CFLAGS_xeninclude)
> +CFLAGS += $(CFLAGS_libxenctrl)
> +CFLAGS += $(APPEND_CFLAGS)
> +
> +LDFLAGS += $(LDLIBS_libxenctrl)
> +LDFLAGS += $(APPEND_LDFLAGS)
> +
> +%.o: Makefile
> +
> +$(TARGET): test-mem-claim.o
> +	$(CC) -o $@ $< $(LDFLAGS)
> +
> +-include $(DEPS_INCLUDE)
> diff --git a/tools/tests/mem-claim/test-mem-claim.c b/tools/tests/mem-claim/test-mem-claim.c
> new file mode 100644
> index 000000000000..78eae9091f52
> --- /dev/null
> +++ b/tools/tests/mem-claim/test-mem-claim.c
> @@ -0,0 +1,190 @@

SPDX header comment?

> +#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/common-macros.h>
> +
> +static unsigned int nr_failures;
> +#define fail(fmt, ...)                          \
> +({                                              \
> +    nr_failures++;                              \
> +    (void)printf(fmt, ##__VA_ARGS__);           \
> +})
> +
> +static xc_interface *xch;
> +static uint32_t domid = -1;

I think you could use domid_t and DOMID_INVALID as the default value?

And then you could avoid the casting and just use domid <
DOMID_FIRST_RESERVED as the check for whether the cleanup is needed?

> +
> +static xc_physinfo_t physinfo;
> +
> +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 void run_tests(void)
> +{
> +    int rc;
> +
> +    /*
> +     * Check that the system is quiescent.  Outstanding claims is a global
> +     * field.
> +     */
> +    rc = xc_physinfo(xch, &physinfo);
> +    if ( rc )
> +        return fail("Failed to obtain physinfo: %d - %s\n",
> +                    errno, strerror(errno));
> +
> +    printf("Free pages: %"PRIu64", Oustanding claims: %"PRIu64"\n",
> +           physinfo.free_pages, physinfo.outstanding_pages);
> +
> +    if ( physinfo.outstanding_pages )
> +        return fail("  Test needs running on a quiescent system\n");
> +
> +    /*
> +     * We want any arbitrary domain.  Start with HVM/HAP, falling back to
> +     * HVM/Shadow and then to PV.  The dom0 running this test case is one of
> +     * these modes.
> +     */
> +#if defined(__x86_64__) || defined(__i386__)
> +    if ( !(physinfo.capabilities & XEN_SYSCTL_PHYSCAP_hap) )
> +        create.flags &= ~XEN_DOMCTL_CDF_hap;
> +
> +    if ( !(physinfo.capabilities & (XEN_SYSCTL_PHYSCAP_hap|XEN_SYSCTL_PHYSCAP_shadow)) ||
> +         !(physinfo.capabilities & XEN_SYSCTL_PHYSCAP_hvm) )
> +    {
> +        create.flags &= ~XEN_DOMCTL_CDF_hvm;
> +        create.arch.emulation_flags = 0;
> +    }
> +#endif
> +
> +    rc = xc_domain_create(xch, &domid, &create);
> +    if ( rc )
> +        return fail("  Domain create failure: %d - %s\n",
> +                    errno, strerror(errno));
> +
> +    rc = xc_domain_setmaxmem(xch, domid, -1);
> +    if ( rc )
> +        return fail("  Failed to set maxmem: %d - %s\n",
> +                    errno, strerror(errno));
> +
> +    printf("  Created d%u\n", domid);
> +
> +    /*
> +     * Creating a domain shouldn't change the claim.  Check it's still 0.
> +     */
> +    rc = xc_physinfo(xch, &physinfo);
> +    if ( rc )
> +        return fail("  Failed to obtain physinfo: %d - %s\n",
> +                    errno, strerror(errno));
> +
> +    if ( physinfo.outstanding_pages )
> +        return fail("  Unexpected outstanding claim of %"PRIu64" pages\n",
> +                    physinfo.outstanding_pages);
> +
> +    /*
> +     * Set a claim for 4M.  This should be the only claim in the system, and
> +     * show up globally.
> +     */
> +    rc = xc_domain_claim_pages(xch, domid, 4*1024*1024/4096);

You can use MB(4) (macro is in tools/common-macros.h) I think for
clarity?  Same below with MB(2).

Thanks, Roger.

On 17/12/2025 5:01 pm, Roger Pau Monné wrote:
> On Tue, Dec 16, 2025 at 04:32:30PM +0000, Andrew Cooper wrote:
>> Add some basic testing of the memory claims mechainsm.
>>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks.

> Some nits below.
>
>> ---
>> CC: Anthony PERARD <anthony.perard@vates.tech>
>> CC: Michal Orzel <michal.orzel@amd.com>
>> CC: Jan Beulich <jbeulich@suse.com>
>> CC: Julien Grall <julien@xen.org>
>> CC: Roger Pau Monné <roger.pau@citrix.com>
>> CC: Stefano Stabellini <sstabellini@kernel.org>
>> ---
>>  tools/tests/Makefile                   |   1 +
>>  tools/tests/mem-claim/.gitignore       |   1 +
>>  tools/tests/mem-claim/Makefile         |  38 +++++
>>  tools/tests/mem-claim/test-mem-claim.c | 190 +++++++++++++++++++++++++
>>  4 files changed, 230 insertions(+)
>>  create mode 100644 tools/tests/mem-claim/.gitignore
>>  create mode 100644 tools/tests/mem-claim/Makefile
>>  create mode 100644 tools/tests/mem-claim/test-mem-claim.c
>>
>> diff --git a/tools/tests/Makefile b/tools/tests/Makefile
>> index e566bd169952..6477a4386dda 100644
>> --- a/tools/tests/Makefile
>> +++ b/tools/tests/Makefile
>> @@ -3,6 +3,7 @@ include $(XEN_ROOT)/tools/Rules.mk
>>  
>>  SUBDIRS-y :=
>>  SUBDIRS-y += domid
>> +SUBDIRS-y += mem-claim
>>  SUBDIRS-y += paging-mempool
>>  SUBDIRS-y += pdx
>>  SUBDIRS-y += rangeset
>> diff --git a/tools/tests/mem-claim/.gitignore b/tools/tests/mem-claim/.gitignore
>> new file mode 100644
>> index 000000000000..cfcee00b819b
>> --- /dev/null
>> +++ b/tools/tests/mem-claim/.gitignore
>> @@ -0,0 +1 @@
>> +test-mem-claim
>> diff --git a/tools/tests/mem-claim/Makefile b/tools/tests/mem-claim/Makefile
>> new file mode 100644
>> index 000000000000..76ba3e3c8bef
>> --- /dev/null
>> +++ b/tools/tests/mem-claim/Makefile
>> @@ -0,0 +1,38 @@
>> +XEN_ROOT = $(CURDIR)/../../..
>> +include $(XEN_ROOT)/tools/Rules.mk
>> +
>> +TARGET := test-mem-claim
>> +
>> +.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)/tests
>> +	$(INSTALL_PROG) $(TARGET) $(DESTDIR)$(LIBEXEC)/tests
>> +
>> +.PHONY: uninstall
>> +uninstall:
>> +	$(RM) -- $(DESTDIR)$(LIBEXEC)/tests/$(TARGET)
>> +
>> +CFLAGS += $(CFLAGS_xeninclude)
>> +CFLAGS += $(CFLAGS_libxenctrl)
>> +CFLAGS += $(APPEND_CFLAGS)
>> +
>> +LDFLAGS += $(LDLIBS_libxenctrl)
>> +LDFLAGS += $(APPEND_LDFLAGS)
>> +
>> +%.o: Makefile
>> +
>> +$(TARGET): test-mem-claim.o
>> +	$(CC) -o $@ $< $(LDFLAGS)
>> +
>> +-include $(DEPS_INCLUDE)
>> diff --git a/tools/tests/mem-claim/test-mem-claim.c b/tools/tests/mem-claim/test-mem-claim.c
>> new file mode 100644
>> index 000000000000..78eae9091f52
>> --- /dev/null
>> +++ b/tools/tests/mem-claim/test-mem-claim.c
>> @@ -0,0 +1,190 @@
> SPDX header comment?

Will do.

>
>> +#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/common-macros.h>
>> +
>> +static unsigned int nr_failures;
>> +#define fail(fmt, ...)                          \
>> +({                                              \
>> +    nr_failures++;                              \
>> +    (void)printf(fmt, ##__VA_ARGS__);           \
>> +})
>> +
>> +static xc_interface *xch;
>> +static uint32_t domid = -1;
> I think you could use domid_t and DOMID_INVALID as the default value?

Sadly can't.  Domid's are strictly uint32_t due to xc_domain_create()
taking it by pointer.

> And then you could avoid the casting and just use domid <
> DOMID_FIRST_RESERVED as the check for whether the cleanup is needed?

Hmm.  The DOMID_INVALID part of that is nice-ish, but having the
boundary check be a different constant isn't.

Maybe I can just do != DOMID_INVALID for the cleanup.

>
>> +
>> +static xc_physinfo_t physinfo;
>> +
>> +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 void run_tests(void)
>> +{
>> +    int rc;
>> +
>> +    /*
>> +     * Check that the system is quiescent.  Outstanding claims is a global
>> +     * field.
>> +     */
>> +    rc = xc_physinfo(xch, &physinfo);
>> +    if ( rc )
>> +        return fail("Failed to obtain physinfo: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    printf("Free pages: %"PRIu64", Oustanding claims: %"PRIu64"\n",
>> +           physinfo.free_pages, physinfo.outstanding_pages);
>> +
>> +    if ( physinfo.outstanding_pages )
>> +        return fail("  Test needs running on a quiescent system\n");
>> +
>> +    /*
>> +     * We want any arbitrary domain.  Start with HVM/HAP, falling back to
>> +     * HVM/Shadow and then to PV.  The dom0 running this test case is one of
>> +     * these modes.
>> +     */
>> +#if defined(__x86_64__) || defined(__i386__)
>> +    if ( !(physinfo.capabilities & XEN_SYSCTL_PHYSCAP_hap) )
>> +        create.flags &= ~XEN_DOMCTL_CDF_hap;
>> +
>> +    if ( !(physinfo.capabilities & (XEN_SYSCTL_PHYSCAP_hap|XEN_SYSCTL_PHYSCAP_shadow)) ||
>> +         !(physinfo.capabilities & XEN_SYSCTL_PHYSCAP_hvm) )
>> +    {
>> +        create.flags &= ~XEN_DOMCTL_CDF_hvm;
>> +        create.arch.emulation_flags = 0;
>> +    }
>> +#endif
>> +
>> +    rc = xc_domain_create(xch, &domid, &create);
>> +    if ( rc )
>> +        return fail("  Domain create failure: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    rc = xc_domain_setmaxmem(xch, domid, -1);
>> +    if ( rc )
>> +        return fail("  Failed to set maxmem: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    printf("  Created d%u\n", domid);
>> +
>> +    /*
>> +     * Creating a domain shouldn't change the claim.  Check it's still 0.
>> +     */
>> +    rc = xc_physinfo(xch, &physinfo);
>> +    if ( rc )
>> +        return fail("  Failed to obtain physinfo: %d - %s\n",
>> +                    errno, strerror(errno));
>> +
>> +    if ( physinfo.outstanding_pages )
>> +        return fail("  Unexpected outstanding claim of %"PRIu64" pages\n",
>> +                    physinfo.outstanding_pages);
>> +
>> +    /*
>> +     * Set a claim for 4M.  This should be the only claim in the system, and
>> +     * show up globally.
>> +     */
>> +    rc = xc_domain_claim_pages(xch, domid, 4*1024*1024/4096);
> You can use MB(4) (macro is in tools/common-macros.h) I think for
> clarity?  Same below with MB(2).

I'll wrap it as MB_TO_PAGES() to hide the divide by 4k.

~Andrew