The APIC ID topology is made of three elements:
smt, core and pkg id; bit width of first two is determined by the
actual number of hyperthreads/cores and pkg gets the rest.
Basic xAPIC unit tests are included.
Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
---
target-i386/topology.h | 13 +++++++++++++
tests/test-x86-cpuid.c | 9 +++++++++
2 files changed, 22 insertions(+)
diff --git a/target-i386/topology.h b/target-i386/topology.h
index 07a6c5f..e87a685 100644
--- a/target-i386/topology.h
+++ b/target-i386/topology.h
@@ -70,6 +70,19 @@ static inline unsigned apicid_core_width(unsigned nr_cores,
unsigned nr_threads)
return apicid_bitwidth_for_count(nr_cores);
}
+/* Bit width of the Pkg_ID field
+ */
+static inline unsigned apicid_pkg_width(unsigned nr_cores,
+ unsigned nr_threads,
+ unsigned apicid_limit)
+{
+ unsigned core_smt_width = apicid_core_width(nr_cores, nr_threads) +
+ apicid_smt_width(nr_cores, nr_threads);
+ unsigned apicid_width = apicid_bitwidth_for_count(apicid_limit);
+
+ return apicid_width > core_smt_width ? apicid_width - core_smt_width : 0;
+}
+
/* Bit offset of the Core_ID field
*/
static inline unsigned apicid_core_offset(unsigned nr_cores,
diff --git a/tests/test-x86-cpuid.c b/tests/test-x86-cpuid.c
index 8d9f96a..6b74f08 100644
--- a/tests/test-x86-cpuid.c
+++ b/tests/test-x86-cpuid.c
@@ -31,6 +31,8 @@ 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(apicid_pkg_width(1, 1, 255), ==, 8);
+ g_assert_cmpuint(apicid_pkg_width(1, 1, 256), ==, 8);
g_assert_cmpuint(x86_apicid_from_cpu_idx(1, 1, 0), ==, 0);
g_assert_cmpuint(x86_apicid_from_cpu_idx(1, 1, 1), ==, 1);
@@ -55,6 +57,13 @@ static void test_topo_bits(void)
g_assert_cmpuint(apicid_core_width(32, 2), ==, 5);
g_assert_cmpuint(apicid_core_width(33, 2), ==, 6);
+ g_assert_cmpuint(apicid_pkg_width( 2, 2, 255), ==, 6);
+ g_assert_cmpuint(apicid_pkg_width(16, 16, 255), ==, 0);
+ g_assert_cmpuint(apicid_pkg_width(99, 99, 255), ==, 0);
+ g_assert_cmpuint(apicid_pkg_width( 7, 3, 255), ==, 3);
+ g_assert_cmpuint(apicid_pkg_width( 8, 3, 255), ==, 3);
+ g_assert_cmpuint(apicid_pkg_width( 9, 3, 255), ==, 2);
+ g_assert_cmpuint(apicid_pkg_width(12, 6, 255), ==, 1);
/* build a weird topology and see if IDs are calculated correctly
*/
--
2.1.0
