[Qemu-devel] [QEMU RFC PATCH 6/7] i386: topology & APIC ID utility functions

[Eduardo Habkost]

Signed-off-by: Eduardo Habkost <address@hidden>
---
 target-i386/topology.h |  138 ++++++++++++++++++++++++++++++++++++++++++++++++
 tests/.gitignore       |    1 +
 tests/Makefile         |    7 ++-
 tests/test-x86-cpuid.c |  108 +++++++++++++++++++++++++++++++++++++
 4 files changed, 253 insertions(+), 1 deletion(-)
 create mode 100644 target-i386/topology.h
 create mode 100644 tests/test-x86-cpuid.c

diff --git a/target-i386/topology.h b/target-i386/topology.h
new file mode 100644
index 0000000..de0f17a
--- /dev/null
+++ b/target-i386/topology.h
@@ -0,0 +1,138 @@
+/*
+ *  x86 CPU topology data structures and functions
+ *
+ *  Copyright (c) 2012 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to 
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef __QEMU_X86_TOPOLOGY_H__
+#define __QEMU_X86_TOPOLOGY_H__
+
+#include <stdint.h>
+#include <string.h>
+
+#include "bitops.h"
+
+/* Return the bit width needed for 'count' IDs
+ */
+static unsigned bits_for_count(unsigned count)
+{
+    g_assert(count >= 1);
+    if (count == 1) {
+        return 0;
+    }
+    return bitops_flsl(count - 1) + 1;
+}
+
+/* Bit width of the SMT_ID (thread ID) field on the APIC ID
+ */
+static inline unsigned apicid_smt_width(unsigned nr_cores, unsigned nr_threads)
+{
+    return bits_for_count(nr_threads);
+}
+
+/* Bit width of the Core_ID field
+ */
+static inline unsigned apicid_core_width(unsigned nr_cores, unsigned 
nr_threads)
+{
+    return bits_for_count(nr_cores);
+}
+
+/* Bit offset of the Core_ID field
+ */
+static inline unsigned apicid_core_offset(unsigned nr_cores,
+                                          unsigned nr_threads)
+{
+        return apicid_smt_width(nr_cores, nr_threads);
+}
+
+/* Bit offset of the Pkg_ID (socket ID) field
+ */
+static inline unsigned apicid_pkg_offset(unsigned nr_cores, unsigned 
nr_threads)
+{
+        return apicid_core_offset(nr_cores, nr_threads) + \
+               apicid_core_width(nr_cores, nr_threads);
+}
+
+/* Make APIC ID for the CPU based on Pkg_ID, Core_ID, SMT_ID
+ *
+ * The caller must make sure core_id < nr_cores and smt_id < nr_threads.
+ */
+static inline uint8_t __make_apicid(unsigned nr_cores, unsigned nr_threads,
+                                         unsigned pkg_id, unsigned core_id,
+                                         unsigned smt_id)
+{
+    return (pkg_id  << apicid_pkg_offset(nr_cores, nr_threads)) | \
+           (core_id << apicid_core_offset(nr_cores, nr_threads)) | \
+           smt_id;
+}
+
+/* Calculate thread/core/package IDs for a specific topology,
+ * based on (continguous) CPU index
+ */
+static inline void topo_ids_from_idx(unsigned nr_cores, unsigned nr_threads,
+                                     unsigned cpu_index,
+                                     unsigned *pkg_id, unsigned *core_id,
+                                     unsigned *smt_id)
+{
+    unsigned core_index = cpu_index / nr_threads;
+    *smt_id = cpu_index % nr_threads;
+    *core_id = core_index % nr_cores;
+    *pkg_id = core_index / nr_cores;
+}
+
+/* Get package ID from an APIC ID
+ */
+static inline unsigned apicid_pkg_id(unsigned nr_cores, unsigned nr_threads,
+                                     uint8_t apic_id)
+{
+    return apic_id >> apicid_pkg_offset(nr_cores, nr_threads);
+}
+
+/* Get core ID from an APIC ID
+ */
+static inline unsigned apicid_core_id(unsigned nr_cores, unsigned nr_threads,
+                                      uint8_t apic_id)
+{
+    return (apic_id >> apicid_core_offset(nr_cores, nr_threads)) & \
+           ((1 << apicid_core_width(nr_cores, nr_threads)) - 1);
+}
+
+/* Get SMT (thread) ID from an APIC ID
+ */
+static inline unsigned apicid_smt_id(unsigned nr_cores, unsigned nr_threads,
+                                     uint8_t apic_id)
+{
+    return apic_id & ((1 << apicid_smt_width(nr_cores, nr_threads)) - 1);
+}
+
+/* Make APIC ID for the CPU 'cpu_index'
+ *
+ * 'cpu_index' is a sequential, contiguous ID for the CPU.
+ */
+static inline uint8_t topo_make_apicid(unsigned nr_cores, unsigned nr_threads,
+                                       unsigned cpu_index)
+{
+    unsigned pkg_id, core_id, smt_id;
+    topo_ids_from_idx(nr_cores, nr_threads, cpu_index,
+                      &pkg_id, &core_id, &smt_id);
+    return __make_apicid(nr_cores, nr_threads, pkg_id, core_id, smt_id);
+}
+
+#endif /* __QMU_X86_TOPOLOGY_H__ */
diff --git a/tests/.gitignore b/tests/.gitignore
index f9041f3..38c94ef 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -10,4 +10,5 @@ test-qmp-commands.h
 test-qmp-commands
 test-qmp-input-strict
 test-qmp-marshal.c
+test-x86-cpuid
 *-test
diff --git a/tests/Makefile b/tests/Makefile
index b605e14..89bd890 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -15,6 +15,7 @@ check-unit-y += tests/test-string-output-visitor$(EXESUF)
 check-unit-y += tests/test-coroutine$(EXESUF)
 check-unit-y += tests/test-visitor-serialization$(EXESUF)
 check-unit-y += tests/test-iov$(EXESUF)
+check-unit-y += tests/test-x86-cpuid$(EXESUF)
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -33,7 +34,8 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o 
tests/check-qdict.o \
        tests/test-coroutine.o tests/test-string-output-visitor.o \
        tests/test-string-input-visitor.o tests/test-qmp-output-visitor.o \
        tests/test-qmp-input-visitor.o tests/test-qmp-input-strict.o \
-       tests/test-qmp-commands.o tests/test-visitor-serialization.o
+       tests/test-qmp-commands.o tests/test-visitor-serialization.o \
+       tests/test-x86-cpuid.o
 
 test-qapi-obj-y =  $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y)
 test-qapi-obj-y += tests/test-qapi-visit.o tests/test-qapi-types.o
@@ -41,6 +43,8 @@ test-qapi-obj-y += module.o
 
 $(test-obj-y): QEMU_INCLUDES += -Itests
 
+tests/test-x86-cpuid.o: QEMU_INCLUDES += -Itarget-i386
+
 tests/check-qint$(EXESUF): tests/check-qint.o qint.o $(tools-obj-y)
 tests/check-qstring$(EXESUF): tests/check-qstring.o qstring.o $(tools-obj-y)
 tests/check-qdict$(EXESUF): tests/check-qdict.o qdict.o qfloat.o qint.o 
qstring.o qbool.o qlist.o $(tools-obj-y)
@@ -49,6 +53,7 @@ tests/check-qfloat$(EXESUF): tests/check-qfloat.o qfloat.o 
$(tools-obj-y)
 tests/check-qjson$(EXESUF): tests/check-qjson.o $(qobject-obj-y) $(tools-obj-y)
 tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(coroutine-obj-y) 
$(tools-obj-y)
 tests/test-iov$(EXESUF): tests/test-iov.o iov.o
+tests/test-x86-cpuid$(EXESUF): tests/test-x86-cpuid.o
 
 tests/test-qapi-types.c tests/test-qapi-types.h :\
 $(SRC_PATH)/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py
diff --git a/tests/test-x86-cpuid.c b/tests/test-x86-cpuid.c
new file mode 100644
index 0000000..b27ed62
--- /dev/null
+++ b/tests/test-x86-cpuid.c
@@ -0,0 +1,108 @@
+/*
+ *  Test code for x86 CPUID and Topology functions
+ *
+ *  Copyright (c) 2012 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to 
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <glib.h>
+
+/*FIXME: this should be built inside the i386 target directory instead */
+#include "topology.h"
+
+static void test_topo_bits(void)
+{
+    /* simple tests for 1 thread per core, 1 core per socket */
+    g_assert_cmpuint(apicid_smt_width(1, 1), ==, 0);
+    g_assert_cmpuint(apicid_core_width(1, 1), ==, 0);
+
+    g_assert_cmpuint(topo_make_apicid(1, 1, 0), ==, 0);
+    g_assert_cmpuint(topo_make_apicid(1, 1, 1), ==, 1);
+    g_assert_cmpuint(topo_make_apicid(1, 1, 2), ==, 2);
+    g_assert_cmpuint(topo_make_apicid(1, 1, 3), ==, 3);
+
+
+    /* Test field width calculation for multiple values
+     */
+    g_assert_cmpuint(apicid_smt_width(1, 2), ==, 1);
+    g_assert_cmpuint(apicid_smt_width(1, 3), ==, 2);
+    g_assert_cmpuint(apicid_smt_width(1, 4), ==, 2);
+
+    g_assert_cmpuint(apicid_smt_width(1, 14), ==, 4);
+    g_assert_cmpuint(apicid_smt_width(1, 15), ==, 4);
+    g_assert_cmpuint(apicid_smt_width(1, 16), ==, 4);
+    g_assert_cmpuint(apicid_smt_width(1, 17), ==, 5);
+
+
+    g_assert_cmpuint(apicid_core_width(30, 2), ==, 5);
+    g_assert_cmpuint(apicid_core_width(31, 2), ==, 5);
+    g_assert_cmpuint(apicid_core_width(32, 2), ==, 5);
+    g_assert_cmpuint(apicid_core_width(33, 2), ==, 6);
+
+
+    /* build a weird topology and see if IDs are calculated correctly
+     */
+
+    /* This will use 2 bits for thread ID and 3 bits for core ID
+     */
+    g_assert_cmpuint(apicid_smt_width(6, 3), ==, 2);
+    g_assert_cmpuint(apicid_core_width(6, 3), ==, 3);
+    g_assert_cmpuint(apicid_pkg_offset(6, 3), ==, 5);
+
+    g_assert_cmpuint(topo_make_apicid(6, 3, 0), ==, 0);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 1), ==, 1);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 2), ==, 2);
+
+    g_assert_cmpuint(topo_make_apicid(6, 3, 1*3 + 0), ==, (1<<2) | 0);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 1*3 + 1), ==, (1<<2) | 1);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 1*3 + 2), ==, (1<<2) | 2);
+
+    g_assert_cmpuint(topo_make_apicid(6, 3, 2*3 + 0), ==, (2<<2) | 0);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 2*3 + 1), ==, (2<<2) | 1);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 2*3 + 2), ==, (2<<2) | 2);
+
+    g_assert_cmpuint(topo_make_apicid(6, 3, 5*3 + 0), ==, (5<<2) | 0);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 5*3 + 1), ==, (5<<2) | 1);
+    g_assert_cmpuint(topo_make_apicid(6, 3, 5*3 + 2), ==, (5<<2) | 2);
+
+    g_assert_cmpuint(topo_make_apicid(6, 3, 1*6*3 + 0*3 + 0), ==, (1<<5));
+    g_assert_cmpuint(topo_make_apicid(6, 3, 1*6*3 + 1*3 + 1), ==,
+                                      (1<<5) | (1<<2) | 1);
+
+    g_assert_cmpuint(topo_make_apicid(6, 3, 3*6*3 + 5*3 + 2), ==,
+                                      (3<<5) | (5<<2) | 2);
+
+
+    /* Check the APIC ID -> {pkg,core,thread} ID functions */
+    g_assert_cmpuint(apicid_pkg_id(6, 3, (3<<5) | (5<<2) | 2), ==, 3);
+    g_assert_cmpuint(apicid_core_id(6, 3, (3<<5) | (5<<2) | 2), ==, 5);
+    g_assert_cmpuint(apicid_smt_id(6, 3, (3<<5) | (5<<2) | 2), ==, 2);
+}
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+
+    g_test_add_func("/cpuid/topology/basic", test_topo_bits);
+
+    g_test_run();
+
+    return 0;
+}
-- 
1.7.10.4