max_cpus needs to be an upper bound on the number of vCPUs initialized; otherwise TCG region initialization breaks.
Some boards initialize a hard-coded number of vCPUs, which is not captured by the global max_cpus. Fix it by adding the .min_cpus field to machine_class. This commit also changes some user-facing behaviour: we now die if -smp is below this hard-coded vCPU minimum instead of silently ignoring the passed -smp value (sometimes announcing this by printing a warning). However, the introduction of .default_cpus lessens the likelihood that users will notice this: if -smp isn't set, we now assign the value in .default_cpus to both smp_cpus and max_cpus. IOW, if a user does not set -smp, they always get a correct number of vCPUs. This change fixes 3468b59 ("tcg: enable multiple TCG contexts in softmmu", 2017-10-24), which broke TCG initialization for some ARM boards. Fixes: 3468b59e18b179bc63c7ce934de912dfa9596122 Reported-by: Thomas Huth <th...@redhat.com> Suggested-by: Peter Maydell <peter.mayd...@linaro.org> Signed-off-by: Emilio G. Cota <c...@braap.org> --- hw/arm/exynos4_boards.c | 12 ++++-------- hw/arm/raspi.c | 2 ++ hw/arm/xlnx-zcu102.c | 5 +++++ include/hw/boards.h | 5 +++++ vl.c | 28 +++++++++++++++++++++++++--- 5 files changed, 41 insertions(+), 11 deletions(-) diff --git a/hw/arm/exynos4_boards.c b/hw/arm/exynos4_boards.c index f1441ec..750162c 100644 --- a/hw/arm/exynos4_boards.c +++ b/hw/arm/exynos4_boards.c @@ -27,7 +27,6 @@ #include "qemu-common.h" #include "cpu.h" #include "sysemu/sysemu.h" -#include "sysemu/qtest.h" #include "hw/sysbus.h" #include "net/net.h" #include "hw/arm/arm.h" @@ -129,13 +128,6 @@ exynos4_boards_init_common(MachineState *machine, Exynos4BoardType board_type) { Exynos4BoardState *s = g_new(Exynos4BoardState, 1); - MachineClass *mc = MACHINE_GET_CLASS(machine); - - if (smp_cpus != EXYNOS4210_NCPUS && !qtest_enabled()) { - error_report("%s board supports only %d CPU cores, ignoring smp_cpus" - " value", - mc->name, EXYNOS4210_NCPUS); - } exynos4_board_binfo.ram_size = exynos4_board_ram_size[board_type]; exynos4_board_binfo.board_id = exynos4_board_id[board_type]; @@ -189,6 +181,8 @@ static void nuri_class_init(ObjectClass *oc, void *data) mc->desc = "Samsung NURI board (Exynos4210)"; mc->init = nuri_init; mc->max_cpus = EXYNOS4210_NCPUS; + mc->min_cpus = EXYNOS4210_NCPUS; + mc->default_cpus = EXYNOS4210_NCPUS; mc->ignore_memory_transaction_failures = true; } @@ -205,6 +199,8 @@ static void smdkc210_class_init(ObjectClass *oc, void *data) mc->desc = "Samsung SMDKC210 board (Exynos4210)"; mc->init = smdkc210_init; mc->max_cpus = EXYNOS4210_NCPUS; + mc->min_cpus = EXYNOS4210_NCPUS; + mc->default_cpus = EXYNOS4210_NCPUS; mc->ignore_memory_transaction_failures = true; } diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c index 5941c9f..cd5fa8c 100644 --- a/hw/arm/raspi.c +++ b/hw/arm/raspi.c @@ -167,6 +167,8 @@ static void raspi2_machine_init(MachineClass *mc) mc->no_floppy = 1; mc->no_cdrom = 1; mc->max_cpus = BCM2836_NCPUS; + mc->min_cpus = BCM2836_NCPUS; + mc->default_cpus = BCM2836_NCPUS; mc->default_ram_size = 1024 * 1024 * 1024; mc->ignore_memory_transaction_failures = true; }; diff --git a/hw/arm/xlnx-zcu102.c b/hw/arm/xlnx-zcu102.c index e2d15a1..395d1b5 100644 --- a/hw/arm/xlnx-zcu102.c +++ b/hw/arm/xlnx-zcu102.c @@ -185,6 +185,9 @@ static void xlnx_ep108_machine_class_init(ObjectClass *oc, void *data) mc->block_default_type = IF_IDE; mc->units_per_default_bus = 1; mc->ignore_memory_transaction_failures = true; + mc->max_cpus = XLNX_ZYNQMP_NUM_APU_CPUS + XLNX_ZYNQMP_NUM_RPU_CPUS; + mc->min_cpus = XLNX_ZYNQMP_NUM_APU_CPUS; + mc->default_cpus = XLNX_ZYNQMP_NUM_APU_CPUS; } static const TypeInfo xlnx_ep108_machine_init_typeinfo = { @@ -241,6 +244,8 @@ static void xlnx_zcu102_machine_class_init(ObjectClass *oc, void *data) mc->units_per_default_bus = 1; mc->ignore_memory_transaction_failures = true; mc->max_cpus = XLNX_ZYNQMP_NUM_APU_CPUS + XLNX_ZYNQMP_NUM_RPU_CPUS; + mc->min_cpus = XLNX_ZYNQMP_NUM_APU_CPUS; + mc->default_cpus = XLNX_ZYNQMP_NUM_APU_CPUS; } static const TypeInfo xlnx_zcu102_machine_init_typeinfo = { diff --git a/include/hw/boards.h b/include/hw/boards.h index 191a5b3..62f160e 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -102,6 +102,9 @@ typedef struct { /** * MachineClass: + * @max_cpus: maximum number of CPUs supported. Default: 1 + * @min_cpus: minimum number of CPUs supported. Default: 1 + * @default_cpus: number of CPUs instantiated if none are specified. Default: 1 * @get_hotplug_handler: this function is called during bus-less * device hotplug. If defined it returns pointer to an instance * of HotplugHandler object, which handles hotplug operation @@ -167,6 +170,8 @@ struct MachineClass { BlockInterfaceType block_default_type; int units_per_default_bus; int max_cpus; + int min_cpus; + int default_cpus; unsigned int no_serial:1, no_parallel:1, use_virtcon:1, diff --git a/vl.c b/vl.c index ec29909..3ca5ee8 100644 --- a/vl.c +++ b/vl.c @@ -160,8 +160,8 @@ Chardev *virtcon_hds[MAX_VIRTIO_CONSOLES]; Chardev *sclp_hds[MAX_SCLP_CONSOLES]; int win2k_install_hack = 0; int singlestep = 0; -int smp_cpus = 1; -unsigned int max_cpus = 1; +int smp_cpus; +unsigned int max_cpus; int smp_cores = 1; int smp_threads = 1; int acpi_enabled = 1; @@ -4330,12 +4330,34 @@ int main(int argc, char **argv, char **envp) smp_parse(qemu_opts_find(qemu_find_opts("smp-opts"), NULL)); machine_class->max_cpus = machine_class->max_cpus ?: 1; /* Default to UP */ + machine_class->min_cpus = machine_class->min_cpus ?: 1; + machine_class->default_cpus = machine_class->default_cpus ?: 1; + + /* if -smp is not set, default to mc->default_cpus */ + if (!smp_cpus) { + smp_cpus = machine_class->default_cpus; + max_cpus = machine_class->default_cpus; + } + + /* sanity-check smp_cpus and max_cpus */ + if (smp_cpus < machine_class->min_cpus) { + error_report("Invalid SMP CPUs %d. The min CPUs " + "supported by machine '%s' is %d", smp_cpus, + machine_class->name, machine_class->min_cpus); + exit(1); + } if (max_cpus > machine_class->max_cpus) { - error_report("Invalid SMP CPUs %d. The max CPUs " + error_report("Invalid max SMP CPUs %d. The max CPUs " "supported by machine '%s' is %d", max_cpus, machine_class->name, machine_class->max_cpus); exit(1); } + if (max_cpus < machine_class->min_cpus) { + error_report("Invalid max SMP CPUs %d. The min CPUs " + "supported by machine '%s' is %d", max_cpus, + machine_class->name, machine_class->min_cpus); + exit(1); + } /* * Get the default machine options from the machine if it is not already -- 2.7.4