On 20/9/26 04:36, Boden Randin wrote:
'p' does not call cpu_synchronize_state like 'g' does.
Accelerators may keep guest CPU state out of sync with QEMU while a
vCPU is running. After a vCPU is stopped, an individual 'p' register
read can therefore observe stale state until something updates the state.
Yeah, I mentioned that to Alex few months ago and have a similar
fix but put my work on hold to avoid clash with Richard series in
the same area, waiting his work to be merged:
https://lore.kernel.org/qemu-devel/[email protected]/
Signed-off-by: Boden Randin <[email protected]>
---
Notes:
I found this while investigating why LLDB was showing the RIP truncated to
32 bits under WHPX. LLDB appears to use individual p register reads by default,
while GDB primarily uses g, which is why I noticed the issue much more
consistently with LLDB.
This is my first open-source contribution, so please let me know if I missed anything in the patch or submission process.
Well done!
gdbstub/gdbstub.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 0a328b0dd4..31a845cfa7 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1246,7 +1246,7 @@ static void handle_get_reg(GArray *params, void *user_ctx)
gdb_put_packet("E14");
return;
}
-
+ cpu_synchronize_state(gdbserver_state.g_cpu);
reg_size = gdb_read_register(gdbserver_state.g_cpu,
gdbserver_state.mem_buf,
gdb_get_cmd_param(params, 0)->val_ull);
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
