[PATCH 2/4] tools/tests: Unit test for paging mempool size

[Andrew Cooper <andrew.cooper3@citrix.com>]

Exercise some basic functionality of the new
xc_{get,set}_paging_mempool_size() hypercalls.

This passes on x86, but fails currently on ARM.  ARM will be fixed up in
future patches.

This is part of XSA-409 / CVE-2022-33747.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Wei Liu <wl@xen.org>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Bertrand Marquis <bertrand.marquis@arm.com>
CC: Henry Wang <Henry.Wang@arm.com>
CC: Anthony PERARD <anthony.perard@citrix.com>

x86 Shadow is complicated because of how it behaves for PV guests, and because
of how it forms a simultaneous equation with tot_pages.  This will require
more work to untangle.

v2:
 * s/p2m/paging/
 * Fix CFLAGS_libxenforeginmemory typo
---
 tools/tests/Makefile                             |   1 +
 tools/tests/paging-mempool/.gitignore            |   1 +
 tools/tests/paging-mempool/Makefile              |  42 ++++++
 tools/tests/paging-mempool/test-paging-mempool.c | 181 +++++++++++++++++++++++
 4 files changed, 225 insertions(+)
 create mode 100644 tools/tests/paging-mempool/.gitignore
 create mode 100644 tools/tests/paging-mempool/Makefile
 create mode 100644 tools/tests/paging-mempool/test-paging-mempool.c

diff --git a/tools/tests/Makefile b/tools/tests/Makefile
index d99146d56a64..1319c3a9d88c 100644
--- a/tools/tests/Makefile
+++ b/tools/tests/Makefile
@@ -11,6 +11,7 @@ endif
 SUBDIRS-y += xenstore
 SUBDIRS-y += depriv
 SUBDIRS-y += vpci
+SUBDIRS-y += paging-mempool
 
 .PHONY: all clean install distclean uninstall
 all clean distclean install uninstall: %: subdirs-%
diff --git a/tools/tests/paging-mempool/.gitignore b/tools/tests/paging-mempool/.gitignore
new file mode 100644
index 000000000000..2f9305b7cc07
--- /dev/null
+++ b/tools/tests/paging-mempool/.gitignore
@@ -0,0 +1 @@
+test-paging-mempool
diff --git a/tools/tests/paging-mempool/Makefile b/tools/tests/paging-mempool/Makefile
new file mode 100644
index 000000000000..5d49497710e0
--- /dev/null
+++ b/tools/tests/paging-mempool/Makefile
@@ -0,0 +1,42 @@
+XEN_ROOT = $(CURDIR)/../../..
+include $(XEN_ROOT)/tools/Rules.mk
+
+TARGET := test-paging-mempool
+
+.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_libxenforeignmemory)
+CFLAGS += $(CFLAGS_libxengnttab)
+CFLAGS += $(APPEND_CFLAGS)
+
+LDFLAGS += $(LDLIBS_libxenctrl)
+LDFLAGS += $(LDLIBS_libxenforeignmemory)
+LDFLAGS += $(LDLIBS_libxengnttab)
+LDFLAGS += $(APPEND_LDFLAGS)
+
+%.o: Makefile
+
+$(TARGET): test-paging-mempool.o
+	$(CC) -o $@ $< $(LDFLAGS)
+
+-include $(DEPS_INCLUDE)
diff --git a/tools/tests/paging-mempool/test-paging-mempool.c b/tools/tests/paging-mempool/test-paging-mempool.c
new file mode 100644
index 000000000000..942a2fde19c7
--- /dev/null
+++ b/tools/tests/paging-mempool/test-paging-mempool.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_mempool_size_bytes =
+#if defined(__x86_64__) || defined(__i386__)
+    256 << 12; /* Only x86 HAP for now.  x86 Shadow needs more work. */
+#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 mempool size\n");
+
+    rc = xc_get_paging_mempool_size(xch, domid, &size_bytes);
+    if ( rc )
+        return fail("  Fail: get mempool size: %d - %s\n",
+                    errno, strerror(errno));
+
+    printf("mempool 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_mempool_size_bytes )
+        return fail("  Fail: size %"PRIu64" != expected size %"PRIu64"\n",
+                    size_bytes, default_mempool_size_bytes);
+
+
+    printf("Test that allocate doesn't alter pool size\n");
+
+    /*
+     * Populate the domain with some RAM.  This will cause more of the mempool
+     * 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_paging_mempool_size(xch, domid, &size_bytes);
+    if ( rc )
+        return fail("  Fail: get mempool size: %d - %s\n",
+                    errno, strerror(errno));
+
+    if ( old_size_bytes != size_bytes )
+        return fail("  Fail: 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_paging_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_paging_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_paging_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("Paging mempool tests\n");
+
+    xch = xc_interface_open(NULL, NULL, 0);
+
+    if ( !xch )
+        err(1, "xc_interface_open");
+
+    rc = xc_domain_create(xch, &domid, &create);
+    if ( rc )
+    {
+        if ( errno == EINVAL || errno == EOPNOTSUPP )
+            printf("  Skip: %d - %s\n", errno, strerror(errno));
+        else
+            fail("  Domain create failure: %d - %s\n",
+                 errno, strerror(errno));
+        goto out;
+    }
+
+    printf("  Created d%u\n", domid);
+
+    run_tests();
+
+    rc = xc_domain_destroy(xch, domid);
+    if ( rc )
+        fail("  Failed to destroy domain: %d - %s\n",
+             errno, strerror(errno));
+ out:
+    return !!nr_failures;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.11.0