On Mon, Dec 21, 2015 at 09:41:32AM +0000, Gonglei (Arei) wrote:
When the gurb of OS is booting, then the softirq and C function send_disk_op() may use extra stack of SeaBIOS. If we inject a NMI, romlayout.S: irqentry_extrastack is invoked, and the extra stack will be used again. And the stack of first calling will be broken, so that the SeaBIOS stuck.
You can easily reproduce the problem.
- start on guest
- reset the guest
- inject a NMI when the guest show the grub surface
- then the guest stuck
Does the SeaBIOS patch below help? I'm not familiar with how to "inject a NMI" - can you describe the process in more detail?
-Kevin
--- a/src/romlayout.S +++ b/src/romlayout.S @@ -548,7 +548,9 @@ entry_post: ENTRY_INTO32 _cfunc32flat_handle_post // Normal entry point
ORG 0xe2c3 - IRQ_ENTRY 02 + .global entry_02 +entry_02: + ENTRY handle_02 // NMI handler does not switch onto extra stack
ORG 0xe3fe .global entry_13_official