From: "Daniel P. Berrange" <berra...@redhat.com>
Several info commands rely on the 'mon_cpu' field in the Monitor
struct. This field can be updated using the 'cpu NN' command.
The processing for HMP passthrough commands, however, does not
use the global 'Monitor *' instance, instead creating a brand
new instance on the stack for HMP command executed. This breaks
anything setting/getting the current monitor CPU
$ ./x86_64-softmmu/qemu-system-x86_64 -cdrom ~/boot.iso -qmp stdio -smp 4
{"QMP": {"version": {"qemu": {"micro": 50, "minor": 15, "major": 0},
"package": ""}, "capabilities": []}}
{"execute":"qmp_capabilities"}
{"return": {}}
{"execute":"human-monitor-command","arguments":{"command-line":"info cpus"}}
{"return": "* CPU #0: pc=0x000000000010017c (halted) thread_id=2570 \r\n CPU
#1: pc=0x00000000000ff0a2 (halted) thread_id=2570 \r\n CPU #2:
pc=0x00000000000ff0a2 (halted) thread_id=2570 \r\n CPU #3:
pc=0x00000000000ff0a2 (halted) thread_id=2570 \r\n"}
{"execute":"human-monitor-command","arguments":{"command-line":"cpu 2"}}
{"return": {}}
{"execute":"human-monitor-command","arguments":{"command-line":"info cpus"}}
{"return": "* CPU #0: pc=0x000000000010017c (halted) thread_id=2570 \r\n CPU
#1: pc=0x00000000000ff0a2 (halted) thread_id=2570 \r\n CPU #2:
pc=0x00000000000ff0a2 (halted) thread_id=2570 \r\n CPU #3:
pc=0x00000000000ff0a2 (halted) thread_id=2570 \r\n"}
In that example, the '*' should have moved from CPU #0, to CPU #2
but it did not.
The simple fix is to just copy the existing 'mon_cpu' field into
the new temporary Monitor instance, before the HMP command is
run, and copy the updated value back to the global instance
afterwards.
* monitor.c: Track 'mon_cpu' when doing HMP passthrough
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
monitor.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/monitor.c b/monitor.c
index 421a65c..f99659d 100644
--- a/monitor.c
+++ b/monitor.c
@@ -513,6 +513,7 @@ static int do_hmp_passthrough(Monitor *mon, const QDict
*params,
memset(&hmp, 0, sizeof(hmp));
qemu_chr_init_mem(&mchar);
hmp.chr = &mchar;
+ hmp.mon_cpu = cur_mon->mon_cpu;
old_mon = cur_mon;
cur_mon = &hmp;
@@ -521,6 +522,7 @@ static int do_hmp_passthrough(Monitor *mon, const QDict
*params,
ret = mon_set_cpu(qdict_get_int(params, "cpu-index"));
if (ret < 0) {
cur_mon = old_mon;
+ cur_mon->mon_cpu = hmp.mon_cpu;
qerror_report(QERR_INVALID_PARAMETER_VALUE, "cpu-index", "a CPU
number");
goto out;
}
@@ -528,6 +530,7 @@ static int do_hmp_passthrough(Monitor *mon, const QDict
*params,
handle_user_command(&hmp, qdict_get_str(params, "command-line"));
cur_mon = old_mon;
+ cur_mon->mon_cpu = hmp.mon_cpu;
if (qemu_chr_mem_osize(hmp.chr) > 0) {
*ret_data = QOBJECT(qemu_chr_mem_to_qs(hmp.chr));
--
1.7.6
