Deer Eduardo,
At 10/26/2017 04:02 PM, Eduardo Habkost wrote:
Hi,
Sorry for taking so long to review it:
Not matter. It's my honor!
On Mon, Oct 23, 2017 at 09:33:42AM +0800, Dou Liyang wrote:
[...]
+ */
+ if (ram_slots > 0 && QTAILQ_EMPTY(&numa_opts->head)) {
+ if (mc->auto_enable_numa_with_memhp) {
If you move the code after qemu_opts_foreach(), you could just
check if nb_numa_nodes is 0 instead of peeking at
numa_opts->head.
+ qemu_opts_parse_noisily(numa_opts, "node", true);
+ }
+ }
Calling qemu_opts_parse*() has additional user-visible side
effects (it can make -writeconfig include the new option,
depending on the initialization ordering). Affecting QemuOpts
depending on the machine-type breaks the separation between
machine configuration from machine initialization, so I would
like to avoid it.
Yes, Indeed. Thank you so much for kind explanation!
We could simply call parse_numa_node() (after making it increment
nb_numa_nodes automatically).
Yes, I will use it in the next version.
e.g.:
diff --git a/numa.c b/numa.c
index 8d78d959f6..da18e42ce7 100644
--- a/numa.c
+++ b/numa.c
@@ -216,6 +216,7 @@ static void parse_numa_node(MachineState *ms,
NumaNodeOptions *node,
}
numa_info[nodenr].present = true;
max_numa_nodeid = MAX(max_numa_nodeid, nodenr + 1);
+ nb_numa_nodes++;
}
static void parse_numa_distance(NumaDistOptions *dist, Error **errp)
@@ -282,7 +283,6 @@ static int parse_numa(void *opaque, QemuOpts *opts, Error
**errp)
if (err) {
goto end;
}
- nb_numa_nodes++;
break;
case NUMA_OPTIONS_TYPE_DIST:
parse_numa_distance(&object->u.dist, &err);
@@ -433,6 +433,26 @@ void parse_numa_opts(MachineState *ms)
exit(1);
}
+ /*
+ * If memory hotplug is enabled (slots > 0) but without '-numa'
+ * options explicitly on CLI, guestes will break.
+ *
+ * Windows: won't enable memory hotplug without SRAT table at all
+ *
+ * Linux: if QEMU is started with initial memory all below 4Gb
+ * and no SRAT table present, guest kernel will use nommu DMA ops,
+ * which breaks 32bit hw drivers when memory is hotplugged and
+ * guest tries to use it with that drivers.
+ *
+ * Enable NUMA implicitly by adding a new NUMA node automatically.
+ */
+ if (ms->ram_slots > 0 && nb_numa_nodes == 0 &&
+ mc->auto_enable_numa_with_memhp) {
+ NumaNodeOptions node = { };
+ parse_numa_node(ms, &node, &error_abort);
+ }
+
+
assert(max_numa_nodeid <= MAX_NODES);
/* No support for sparse NUMA node IDs yet: */
+
+ if (qemu_opts_foreach(numa_opts, parse_numa, ms, NULL)) {
exit(1);
}
diff --git a/vl.c b/vl.c
index 0723835..516d0c9 100644
--- a/vl.c
+++ b/vl.c
@@ -4677,8 +4677,6 @@ int main(int argc, char **argv, char **envp)
default_drive(default_floppy, snapshot, IF_FLOPPY, 0, FD_OPTS);
default_drive(default_sdcard, snapshot, IF_SD, 0, SD_OPTS);
- parse_numa_opts(current_machine);
-
if (qemu_opts_foreach(qemu_find_opts("mon"),
mon_init_func, NULL, NULL)) {
exit(1);
@@ -4728,6 +4726,7 @@ int main(int argc, char **argv, char **envp)
current_machine->boot_order = boot_order;
current_machine->cpu_model = cpu_model;
+ parse_numa_opts(current_machine, ram_slots);
Why did you add a ram_slots argument if it's already present at
current_machine->ram_slots?
Oops, Forgot to update it after moving it behind the setup of
current_machine. will remove the redundant ram_slots argument.
Thanks,
dou
/* parse features once if machine provides default cpu_type */
if (machine_class->default_cpu_type) {
--
2.5.5
