Re: [SeaBIOS] seabios hangs when injecting an MSI-X interrupt in early booting.

[Kevin O'Connor]

On Tue, Mar 27, 2018 at 10:08:20AM +0800, Zhe Liu wrote:
  Dear Kevin,
     Thanks for getting back to me. Your replay helps me a lot. And there
 are two things I want to make clear.
     1. > The real-mode handlers installed at 0x60-0x66 are intended for
 software interrupts.
 During the booting of the vm seabios, which modules will raise the software
 interrupts? (Qemu? KVM? VirtualMachine?)
Software interrupts are for guest software to raise and interally
catch.  Some old DOS-era software does this.

      2. In src/post.c: init_ivt, the handlers for
0x60-0x66 is set to none
 as below.
     for (i=0x60; i<=0x66; i++)
         SET_IVT(i, SEGOFF(0, 0));
     If I change the handlers of 0x60-0x66 to default handler, which is
 "iret" directly, is there some side effects?
It might break some old DOS-era software.

Notably, though, if something external is raising random interrupts,
it's likely going to cause havoc with both modern and old software.

-Kevin