On Wed, Nov 01, 2017 at 18:34:23 +0100, Thomas Huth wrote:
> Seems like something in this patch series broke a couple of ARM boards
> (smdkc210, nuri, raspi2, xlnx-ep108 and xlnx-zcu102). With current
> master branch, I just get this error:
>
> $ aarch64-softmmu/qemu-system-aarch64 -machine raspi2
> **
> ERROR:/home/thuth/devel/qemu/tcg/tcg.c:537:tcg_register_thread:
> assertion failed: (n < max_cpus)
> Aborted (core dumped)
>
> Could you please have a look at this?
Turns out some boards initialize a fixed number of vcpus, which
can be > max_cpus.
The below fixes the issue for me, although I'm not entirely happy
with it because if -{smp,max}_cpus < machine_class->max_cpus, some
TCG regions will be wasted. Not a huge deal (in most cases it will be
2MB per unused vCPU), but a better fix might be to just honour -max_cpus
for these boards. We might just not care enough though.
Emilio
---8<---
Subject: [PATCH] hw: define and use machine_class->max_cpus_override
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; mark this
with machine_class->max_cpus_override so that max_cpus is
set to machine_class->max_cpus when set.
Update the ARM boards that hard-code max_cpus, thereby letting
them boot again.
Reported-by: Thomas Huth <th...@redhat.com>
Signed-off-by: Emilio G. Cota <c...@braap.org>
---
hw/arm/exynos4_boards.c | 2 ++
hw/arm/raspi.c | 1 +
hw/arm/xlnx-zcu102.c | 3 +++
include/hw/boards.h | 3 ++-
vl.c | 4 ++++
5 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/hw/arm/exynos4_boards.c b/hw/arm/exynos4_boards.c
index f1441ec..7071505 100644
--- a/hw/arm/exynos4_boards.c
+++ b/hw/arm/exynos4_boards.c
@@ -189,6 +189,7 @@ 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->max_cpus_override = 1;
mc->ignore_memory_transaction_failures = true;
}
@@ -205,6 +206,7 @@ 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->max_cpus_override = 1;
mc->ignore_memory_transaction_failures = true;
}
diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
index 5941c9f..bf4eec3 100644
--- a/hw/arm/raspi.c
+++ b/hw/arm/raspi.c
@@ -167,6 +167,7 @@ static void raspi2_machine_init(MachineClass *mc)
mc->no_floppy = 1;
mc->no_cdrom = 1;
mc->max_cpus = BCM2836_NCPUS;
+ mc->max_cpus_override = 1;
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..f7e0004 100644
--- a/hw/arm/xlnx-zcu102.c
+++ b/hw/arm/xlnx-zcu102.c
@@ -185,6 +185,8 @@ 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->max_cpus_override = 1;
}
static const TypeInfo xlnx_ep108_machine_init_typeinfo = {
@@ -241,6 +243,7 @@ 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->max_cpus_override = 1;
}
static const TypeInfo xlnx_zcu102_machine_init_typeinfo = {
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 191a5b3..724be45 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -176,7 +176,8 @@ struct MachineClass {
no_sdcard:1,
has_dynamic_sysbus:1,
pci_allow_0_address:1,
- legacy_fw_cfg_order:1;
+ legacy_fw_cfg_order:1,
+ max_cpus_override:1;
int is_default;
const char *default_machine_opts;
const char *default_boot_order;
diff --git a/vl.c b/vl.c
index ec29909..b2f056a 100644
--- a/vl.c
+++ b/vl.c
@@ -4336,6 +4336,10 @@ int main(int argc, char **argv, char **envp)
machine_class->name, machine_class->max_cpus);
exit(1);
}
+ /* some machines initialize a hard-coded number of cpus */
+ if (machine_class->max_cpus_override) {
+ max_cpus = machine_class->max_cpus;
+ }
/*
* Get the default machine options from the machine if it is not already
--
2.7.4
