Patchwork [RFC,14/15] i386: topology & APIC ID utility functions (v2)

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Submitter Eduardo Habkost
Date Aug. 7, 2012, 7:56 p.m.
Message ID <1344369413-9053-15-git-send-email-ehabkost@redhat.com>
Download mbox | patch
Permalink /patch/175785/
State New
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Comments

Eduardo Habkost - Aug. 7, 2012, 7:56 p.m.
Changes v1 -> v2:
 - Support 32-bit APIC IDs (in case x2APIC is going to be used)
 - Coding style changes
 - Use TARGET_I386_TOPOLOGY_H instead of __QEMU_X86_TOPOLOGY_H__
 - Rename topo_make_apic_id() to topo_apicid_for_cpu()
 - Rename __make_apicid() to topo_make_apicid()
 - Spaces around operators on test-x86-cpuid.c, as requested by
   Blue Swirl
 - Make test-x86-cpuid a target-specific test

Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 target-i386/topology.h | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
 tests/.gitignore       |   1 +
 tests/Makefile         |   3 ++
 tests/test-x86-cpuid.c | 108 +++++++++++++++++++++++++++++++++++++
 4 files changed, 256 insertions(+)
 create mode 100644 target-i386/topology.h
 create mode 100644 tests/test-x86-cpuid.c
Blue Swirl - Aug. 8, 2012, 6:57 p.m.
On Tue, Aug 7, 2012 at 7:56 PM, Eduardo Habkost <ehabkost@redhat.com> wrote:
> Changes v1 -> v2:
>  - Support 32-bit APIC IDs (in case x2APIC is going to be used)
>  - Coding style changes
>  - Use TARGET_I386_TOPOLOGY_H instead of __QEMU_X86_TOPOLOGY_H__
>  - Rename topo_make_apic_id() to topo_apicid_for_cpu()
>  - Rename __make_apicid() to topo_make_apicid()
>  - Spaces around operators on test-x86-cpuid.c, as requested by
>    Blue Swirl
>  - Make test-x86-cpuid a target-specific test
>
> Cc: Blue Swirl <blauwirbel@gmail.com>

Looks OK.

Would it make sense to add a quick fuzzing test (call the functions
with changing random parameters a large number of times, see other
tests) later?

> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  target-i386/topology.h | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/.gitignore       |   1 +
>  tests/Makefile         |   3 ++
>  tests/test-x86-cpuid.c | 108 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 256 insertions(+)
>  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..35d9817
> --- /dev/null
> +++ b/target-i386/topology.h
> @@ -0,0 +1,144 @@
> +/*
> + *  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 TARGET_I386_TOPOLOGY_H
> +#define TARGET_I386_TOPOLOGY_H
> +
> +#include <stdint.h>
> +#include <string.h>
> +
> +#include "bitops.h"
> +
> +/* APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
> + */
> +typedef uint32_t apic_id_t;
> +
> +/* 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 apic_id_t topo_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,
> +                                     apic_id_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,
> +                                      apic_id_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,
> +                                     apic_id_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 apic_id_t topo_apicid_for_cpu(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 topo_make_apicid(nr_cores, nr_threads, pkg_id, core_id, smt_id);
> +}
> +
> +#endif /* TARGET_I386_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 79796aa..e74efdd 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-i386-y += tests/test-x86-cpuid$(EXESUF)
>
>  check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
>
> @@ -35,6 +36,7 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.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
> +test-obj-i386-y = tests/test-x86-cpuid.o
>
>  test-qapi-obj-y =  $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y)
>  test-qapi-obj-y += tests/test-qapi-visit.o tests/test-qapi-types.o
> @@ -48,6 +50,7 @@ tests/check-qfloat$(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..d782c9c
> --- /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_apicid_for_cpu(1, 1, 0), ==, 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 1), ==, 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 2), ==, 2);
> +    g_assert_cmpuint(topo_apicid_for_cpu(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_apicid_for_cpu(6, 3, 0), ==, 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1), ==, 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2), ==, 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 0), ==, (1 << 2) | 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 1), ==, (1 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 2), ==, (1 << 2) | 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 0), ==, (2 << 2) | 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 1), ==, (2 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 2), ==, (2 << 2) | 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 0), ==, (5 << 2) | 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 1), ==, (5 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 2), ==, (5 << 2) | 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 0 * 3 + 0), ==,
> +                                         (1 << 5));
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 1 * 3 + 1), ==,
> +                                         (1 << 5) | (1 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(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;
> +}
> --
> 1.7.11.2
>
Eduardo Habkost - Aug. 8, 2012, 7:06 p.m.
On Wed, Aug 08, 2012 at 06:57:30PM +0000, Blue Swirl wrote:
> On Tue, Aug 7, 2012 at 7:56 PM, Eduardo Habkost <ehabkost@redhat.com> wrote:
> > Changes v1 -> v2:
> >  - Support 32-bit APIC IDs (in case x2APIC is going to be used)
> >  - Coding style changes
> >  - Use TARGET_I386_TOPOLOGY_H instead of __QEMU_X86_TOPOLOGY_H__
> >  - Rename topo_make_apic_id() to topo_apicid_for_cpu()
> >  - Rename __make_apicid() to topo_make_apicid()
> >  - Spaces around operators on test-x86-cpuid.c, as requested by
> >    Blue Swirl
> >  - Make test-x86-cpuid a target-specific test
> >
> > Cc: Blue Swirl <blauwirbel@gmail.com>
> 
> Looks OK.
> 
> Would it make sense to add a quick fuzzing test (call the functions
> with changing random parameters a large number of times, see other
> tests) later?

I think the functions are simple enough to not need that. But a fuzzing
black-box qtest test with lots of weird topology and CPU feature
configurations would be interesting.

> 
> > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> > ---
> >  target-i386/topology.h | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/.gitignore       |   1 +
> >  tests/Makefile         |   3 ++
> >  tests/test-x86-cpuid.c | 108 +++++++++++++++++++++++++++++++++++++
> >  4 files changed, 256 insertions(+)
> >  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..35d9817
> > --- /dev/null
> > +++ b/target-i386/topology.h
> > @@ -0,0 +1,144 @@
> > +/*
> > + *  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 TARGET_I386_TOPOLOGY_H
> > +#define TARGET_I386_TOPOLOGY_H
> > +
> > +#include <stdint.h>
> > +#include <string.h>
> > +
> > +#include "bitops.h"
> > +
> > +/* APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
> > + */
> > +typedef uint32_t apic_id_t;
> > +
> > +/* 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 apic_id_t topo_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,
> > +                                     apic_id_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,
> > +                                      apic_id_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,
> > +                                     apic_id_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 apic_id_t topo_apicid_for_cpu(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 topo_make_apicid(nr_cores, nr_threads, pkg_id, core_id, smt_id);
> > +}
> > +
> > +#endif /* TARGET_I386_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 79796aa..e74efdd 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-i386-y += tests/test-x86-cpuid$(EXESUF)
> >
> >  check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
> >
> > @@ -35,6 +36,7 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.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
> > +test-obj-i386-y = tests/test-x86-cpuid.o
> >
> >  test-qapi-obj-y =  $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y)
> >  test-qapi-obj-y += tests/test-qapi-visit.o tests/test-qapi-types.o
> > @@ -48,6 +50,7 @@ tests/check-qfloat$(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..d782c9c
> > --- /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_apicid_for_cpu(1, 1, 0), ==, 0);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 1), ==, 1);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 2), ==, 2);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(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_apicid_for_cpu(6, 3, 0), ==, 0);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1), ==, 1);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2), ==, 2);
> > +
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 0), ==, (1 << 2) | 0);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 1), ==, (1 << 2) | 1);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 2), ==, (1 << 2) | 2);
> > +
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 0), ==, (2 << 2) | 0);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 1), ==, (2 << 2) | 1);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 2), ==, (2 << 2) | 2);
> > +
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 0), ==, (5 << 2) | 0);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 1), ==, (5 << 2) | 1);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 2), ==, (5 << 2) | 2);
> > +
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 0 * 3 + 0), ==,
> > +                                         (1 << 5));
> > +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 1 * 3 + 1), ==,
> > +                                         (1 << 5) | (1 << 2) | 1);
> > +    g_assert_cmpuint(topo_apicid_for_cpu(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;
> > +}
> > --
> > 1.7.11.2
> >
Igor Mammedov - Aug. 14, 2012, 5:03 p.m.
On Tue,  7 Aug 2012 16:56:52 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> Changes v1 -> v2:
>  - Support 32-bit APIC IDs (in case x2APIC is going to be used)
>  - Coding style changes
>  - Use TARGET_I386_TOPOLOGY_H instead of __QEMU_X86_TOPOLOGY_H__
>  - Rename topo_make_apic_id() to topo_apicid_for_cpu()
>  - Rename __make_apicid() to topo_make_apicid()
>  - Spaces around operators on test-x86-cpuid.c, as requested by
>    Blue Swirl
>  - Make test-x86-cpuid a target-specific test

adding to commit description ref to intel(& maybe amd) spec or/and short
description how apicid is structured/constructed would be nice

> Cc: Blue Swirl <blauwirbel@gmail.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  target-i386/topology.h | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/.gitignore       |   1 +
>  tests/Makefile         |   3 ++
>  tests/test-x86-cpuid.c | 108 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 256 insertions(+)
>  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..35d9817
> --- /dev/null
> +++ b/target-i386/topology.h
> @@ -0,0 +1,144 @@
> +/*
> + *  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 TARGET_I386_TOPOLOGY_H
> +#define TARGET_I386_TOPOLOGY_H
> +
> +#include <stdint.h>
> +#include <string.h>
> +
> +#include "bitops.h"
> +
> +/* APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
> + */
> +typedef uint32_t apic_id_t;
> +
> +/* Return the bit width needed for 'count' IDs
> + */
> +static unsigned bits_for_count(unsigned count)
bitwidth_for_count(...) perhaps would be clearer?
and you could drop apicid_*_width/apicid_*_offset () funcs and use
it directly in topo_make_apicid() to make code more concise

> +{
> +    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 apic_id_t topo_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;
> +}
Looks like it considers only Intel spec, would it be correct for AMD case?
see support.amd.com/us/Embedded_TechDocs/25481.pdf "3.2 Extended Method"

AMD doesn't have SMT, perhaps nr_threads should be enforced to 1 when VCPU is
AMD?

> +
> +/* 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,
> +                                     apic_id_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,
> +                                      apic_id_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,
> +                                     apic_id_t apic_id)
> +{
> +    return apic_id & ((1 << apicid_smt_width(nr_cores, nr_threads)) - 1);
> +}
Are above getters necessary for fix to work or are there plans to use them?

> +
> +/* Make APIC ID for the CPU 'cpu_index'
> + *
> + * 'cpu_index' is a sequential, contiguous ID for the CPU.
> + */
> +static inline apic_id_t topo_apicid_for_cpu(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 topo_make_apicid(nr_cores, nr_threads, pkg_id, core_id, smt_id);
> +}
> +
> +#endif /* TARGET_I386_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 79796aa..e74efdd 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-i386-y += tests/test-x86-cpuid$(EXESUF)
>  
>  check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
>  
> @@ -35,6 +36,7 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.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
> +test-obj-i386-y = tests/test-x86-cpuid.o
>  
>  test-qapi-obj-y =  $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y)
>  test-qapi-obj-y += tests/test-qapi-visit.o tests/test-qapi-types.o
> @@ -48,6 +50,7 @@ tests/check-qfloat$(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..d782c9c
> --- /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_apicid_for_cpu(1, 1, 0), ==, 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 1), ==, 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 2), ==, 2);
> +    g_assert_cmpuint(topo_apicid_for_cpu(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_apicid_for_cpu(6, 3, 0), ==, 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1), ==, 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2), ==, 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 0), ==, (1 << 2) | 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 1), ==, (1 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 2), ==, (1 << 2) | 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 0), ==, (2 << 2) | 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 1), ==, (2 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 2), ==, (2 << 2) | 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 0), ==, (5 << 2) | 0);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 1), ==, (5 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 2), ==, (5 << 2) | 2);
> +
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 0 * 3 + 0), ==,
> +                                         (1 << 5));
> +    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 1 * 3 + 1), ==,
> +                                         (1 << 5) | (1 << 2) | 1);
> +    g_assert_cmpuint(topo_apicid_for_cpu(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;
> +}
> -- 
> 1.7.11.2
> 
>

Patch

diff --git a/target-i386/topology.h b/target-i386/topology.h
new file mode 100644
index 0000000..35d9817
--- /dev/null
+++ b/target-i386/topology.h
@@ -0,0 +1,144 @@ 
+/*
+ *  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 TARGET_I386_TOPOLOGY_H
+#define TARGET_I386_TOPOLOGY_H
+
+#include <stdint.h>
+#include <string.h>
+
+#include "bitops.h"
+
+/* APIC IDs can be 32-bit, but beware: APIC IDs > 255 require x2APIC support
+ */
+typedef uint32_t apic_id_t;
+
+/* 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 apic_id_t topo_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,
+                                     apic_id_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,
+                                      apic_id_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,
+                                     apic_id_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 apic_id_t topo_apicid_for_cpu(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 topo_make_apicid(nr_cores, nr_threads, pkg_id, core_id, smt_id);
+}
+
+#endif /* TARGET_I386_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 79796aa..e74efdd 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-i386-y += tests/test-x86-cpuid$(EXESUF)
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -35,6 +36,7 @@  test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.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
+test-obj-i386-y = tests/test-x86-cpuid.o
 
 test-qapi-obj-y =  $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y)
 test-qapi-obj-y += tests/test-qapi-visit.o tests/test-qapi-types.o
@@ -48,6 +50,7 @@  tests/check-qfloat$(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..d782c9c
--- /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_apicid_for_cpu(1, 1, 0), ==, 0);
+    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 1), ==, 1);
+    g_assert_cmpuint(topo_apicid_for_cpu(1, 1, 2), ==, 2);
+    g_assert_cmpuint(topo_apicid_for_cpu(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_apicid_for_cpu(6, 3, 0), ==, 0);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1), ==, 1);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2), ==, 2);
+
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 0), ==, (1 << 2) | 0);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 1), ==, (1 << 2) | 1);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 3 + 2), ==, (1 << 2) | 2);
+
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 0), ==, (2 << 2) | 0);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 1), ==, (2 << 2) | 1);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 2 * 3 + 2), ==, (2 << 2) | 2);
+
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 0), ==, (5 << 2) | 0);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 1), ==, (5 << 2) | 1);
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 5 * 3 + 2), ==, (5 << 2) | 2);
+
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 0 * 3 + 0), ==,
+                                         (1 << 5));
+    g_assert_cmpuint(topo_apicid_for_cpu(6, 3, 1 * 6 * 3 + 1 * 3 + 1), ==,
+                                         (1 << 5) | (1 << 2) | 1);
+    g_assert_cmpuint(topo_apicid_for_cpu(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;
+}