On Mon, Jul 19 2021, Yanan Wang <wangyana...@huawei.com> wrote: > Hi, > > This is v2 of the series [1] that I have posted to introduce some smp parsing > fixes and improvement, much more work has been processed compared to RFC v1. > > [1] https://lists.gnu.org/archive/html/qemu-devel/2021-07/msg00259.html > > The purpose of this series is to improve/fix the parsing logic. Explicitly > specifying a CPU topology parameter as zero is not allowed any more, and > maxcpus is now uniformly used to calculate the omitted parameters. It's also > suggested that we should start to prefer cores over sockets over threads on > the newer machine types, which will make the computed virtual topology more > reflective of the real hardware. > > In order to reduce code duplication and ease the code maintenance, smp_parse > in now converted into a parser generic enough for all arches, so that the PC > specific one can be removed. It's also convenient to introduce more topology > members (e.g. cluster) to the generic parser in the future.
Cc:ing Pierre, as he also had been looking at the smp parsing code (for s390x) recently. Also, please keep me on cc: for patches that touch s390x. > > Finally, a QEMU unit test for the parsing of given SMP configuration is added. > Since all the parsing logic is in generic function smp_parse(), this test > passes diffenent SMP configurations to the function and compare the parsing > result with what is expected. In the test, all possible collections of the > topology parameters and the corressponding expected results are listed, > including the valid and invalid ones. The preference of sockets over cores > and the preference of cores over sockets, and the support of multi-dies are > also taken into consideration. > > --- > > Changelogs: > > v1->v2: > - disallow "anything=0" in the smp configuration (Andrew) > - make function smp_parse() a generic helper for all arches > - improve the error reporting in the parser > - start to prefer cores over sockets since 6.2 (Daniel) > - add a unit test for the smp parsing (Daniel) > > --- > > Yanan Wang (11): > machine: Disallow specifying topology parameters as zero > machine: Make smp_parse generic enough for all arches > machine: Uniformly use maxcpus to calculate the omitted parameters > machine: Use the computed parameters to calculate omitted cpus > machine: Improve the error reporting of smp parsing > hw: Add compat machines for 6.2 > machine: Prefer cores over sockets in smp parsing since 6.2 > machine: Use ms instead of global current_machine in sanity-check > machine: Tweak the order of topology members in struct CpuTopology > machine: Split out the smp parsing code > tests/unit: Add a unit test for smp parsing > > MAINTAINERS | 2 + > hw/arm/virt.c | 10 +- > hw/core/machine-smp.c | 124 ++++ > hw/core/machine.c | 68 +-- > hw/core/meson.build | 1 + > hw/i386/pc.c | 66 +-- > hw/i386/pc_piix.c | 15 +- > hw/i386/pc_q35.c | 14 +- > hw/ppc/spapr.c | 16 +- > hw/s390x/s390-virtio-ccw.c | 15 +- > include/hw/boards.h | 13 +- > include/hw/i386/pc.h | 3 + > qapi/machine.json | 6 +- > qemu-options.hx | 4 +- > tests/unit/meson.build | 1 + > tests/unit/test-smp-parse.c | 1117 +++++++++++++++++++++++++++++++++++ > 16 files changed, 1338 insertions(+), 137 deletions(-) > create mode 100644 hw/core/machine-smp.c > create mode 100644 tests/unit/test-smp-parse.c > > -- > 2.19.1
