Prevent guests from booting with CPU topologies that have partially
filled CPU cores or can result in partially filled CPU cores after
CPU hotplug like
-smp 15,sockets=1,cores=4,threads=4,maxcpus=16 or
-smp 15,sockets=1,cores=4,threads=4,maxcpus=17.
This is enforced by introducing MachineClass::validate_smp_config()
that gets called from generic SMP parsing code. Machine type versions
that don't want to enforce this can override this method.
TODO: Only sPAPR and PC changes are done in this patch, other archs
will be touched after there is agreement on this approach.
Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com>
---
hw/core/machine.c | 20 ++++++++++++++++++++
hw/i386/pc_piix.c | 7 +++++++
hw/i386/pc_q35.c | 7 +++++++
hw/ppc/spapr.c | 7 +++++++
include/hw/boards.h | 1 +
vl.c | 4 ++++
6 files changed, 46 insertions(+)
diff --git a/hw/core/machine.c b/hw/core/machine.c
index c46ddc7..b66c101 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -336,6 +336,25 @@ static void machine_init_notify(Notifier *notifier, void
*data)
foreach_dynamic_sysbus_device(error_on_sysbus_device, NULL);
}
+static int validate_smp_config_generic(int smp_cpus, int max_cpus,
+ int smp_threads)
+{
+ if (smp_cpus % smp_threads) {
+ error_report("cpu topology: "
+ "smp_cpus (%u) should be multiple of threads (%u) ",
+ smp_cpus, smp_threads);
+ return 1;
+ }
+
+ if (max_cpus % smp_threads) {
+ error_report("cpu topology: "
+ "max_cpus (%u) should be multiple of threads (%u) ",
+ max_cpus, smp_threads);
+ return 1;
+ }
+ return 0;
+}
+
static void machine_class_init(ObjectClass *oc, void *data)
{
MachineClass *mc = MACHINE_CLASS(oc);
@@ -343,6 +362,7 @@ static void machine_class_init(ObjectClass *oc, void *data)
/* Default 128 MB as guest ram size */
mc->default_ram_size = 128 * M_BYTE;
mc->rom_file_has_mr = true;
+ mc->validate_smp_config = validate_smp_config_generic;
}
static void machine_class_base_init(ObjectClass *oc, void *data)
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 438cdae..dd4bba1 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -397,6 +397,12 @@ static void pc_xen_hvm_init(MachineState *machine)
}
#endif
+static int pc_validate_smp_config_default(int smp_cpus, int max_cpus,
+ int smp_threads)
+{
+ return 0;
+}
+
#define DEFINE_I440FX_MACHINE(suffix, name, compatfn, optionfn) \
static void pc_init_##suffix(MachineState *machine) \
{ \
@@ -434,6 +440,7 @@ static void pc_i440fx_2_5_machine_options(MachineClass *m)
pc_i440fx_2_6_machine_options(m);
m->alias = NULL;
m->is_default = 0;
+ m->validate_smp_config = pc_validate_smp_config_default;
SET_MACHINE_COMPAT(m, PC_COMPAT_2_5);
}
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 412b3cd..80ce9e8 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -325,6 +325,12 @@ static void pc_compat_1_4(MachineState *machine)
pc_compat_1_5(machine);
}
+static int pc_q35_validate_smp_config_default(int smp_cpus, int max_cpus,
+ int smp_threads)
+{
+ return 0;
+}
+
#define DEFINE_Q35_MACHINE(suffix, name, compatfn, optionfn) \
static void pc_init_##suffix(MachineState *machine) \
{ \
@@ -362,6 +368,7 @@ static void pc_q35_2_5_machine_options(MachineClass *m)
{
pc_q35_2_6_machine_options(m);
m->alias = NULL;
+ m->validate_smp_config = pc_q35_validate_smp_config_default;
SET_MACHINE_COMPAT(m, PC_COMPAT_2_5);
}
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 414e0f9b..a330169 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2320,6 +2320,12 @@ static const TypeInfo spapr_machine_info = {
},
};
+static int spapr_validate_smp_config_default(int smp_cpus, int max_cpus,
+ int smp_threads)
+{
+ return 0;
+}
+
#define DEFINE_SPAPR_MACHINE(suffix, verstr, latest) \
static void spapr_machine_##suffix##_class_init(ObjectClass *oc, \
void *data) \
@@ -2379,6 +2385,7 @@ static void spapr_machine_2_5_class_options(MachineClass
*mc)
spapr_machine_2_6_class_options(mc);
smc->use_ohci_by_default = true;
SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_5);
+ mc->validate_smp_config = spapr_validate_smp_config_default;
}
DEFINE_SPAPR_MACHINE(2_5, "2.5", false);
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 0f30959..39091bf 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -99,6 +99,7 @@ struct MachineClass {
HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
DeviceState *dev);
unsigned (*cpu_index_to_socket_id)(unsigned cpu_index);
+ int (*validate_smp_config)(int smp_cpus, int max_cpus, int smp_threads);
};
/**
diff --git a/vl.c b/vl.c
index 5aaea77..4b36a49 100644
--- a/vl.c
+++ b/vl.c
@@ -4132,6 +4132,10 @@ int main(int argc, char **argv, char **envp)
smp_parse(qemu_opts_find(qemu_find_opts("smp-opts"), NULL));
+ if (machine_class->validate_smp_config(smp_cpus, max_cpus, smp_threads)) {
+ exit(1);
+ }
+
machine_class->max_cpus = machine_class->max_cpus ?: 1; /* Default to UP */
if (max_cpus > machine_class->max_cpus) {
error_report("Number of SMP CPUs requested (%d) exceeds max CPUs "
--
2.1.0
