i8259: add -no-spurious-interrupt-hack option

This patch provides a way to optionally suppress spurious interrupts,
as a workaround for systems described below:

Some old operating systems do not handle spurious interrupts well,
and qemu tends to generate them significantly more often than
real hardware.

Examples:
  - Microport UNIX System V/386 v 2.1 (ca 1987)
    (The main problem I'm fixing: Without this patch, it panics
    sporadically when accessing the hard disk.)
  - AT&T UNIX System V/386 Release 4.0 Version 2.1a (ca 1991)
    See screenshot in "QEMU Official OS Support List":
    http://www.claunia.com/qemu/objectManager.php?sClass=application&iId=9
    (I don't have this system to test.)
  - A report about OS/2 boot lockup from 2004 by Hampa Hug:
    http://lists.nongnu.org/archive/html/qemu-devel/2004-09/msg00367.html
    (My patch was partially inspired by his.)
    Also: http://lists.nongnu.org/archive/html/qemu-devel/2005-06/msg00243.html
    (I don't have this system to test.)

Signed-off-by: Matthew Ogilvie <mmogilvi_qemu@miniinfo.net>
Signed-off-by: malc <av1474@comtv.ru>
This commit is contained in:
Matthew Ogilvie 2012-08-23 00:24:43 -06:00 committed by malc
parent 482f7bf86b
commit f278d4947f
5 changed files with 44 additions and 5 deletions

View file

@ -329,11 +329,15 @@ int cpu_exec(CPUArchState *env)
0);
env->interrupt_request &= ~(CPU_INTERRUPT_HARD | CPU_INTERRUPT_VIRQ);
intno = cpu_get_pic_interrupt(env);
qemu_log_mask(CPU_LOG_TB_IN_ASM, "Servicing hardware INT=0x%02x\n", intno);
do_interrupt_x86_hardirq(env, intno, 1);
/* ensure that no TB jump will be modified as
the program flow was changed */
next_tb = 0;
if (intno >= 0) {
qemu_log_mask(CPU_LOG_TB_IN_ASM,
"Servicing hardware INT=0x%02x\n",
intno);
do_interrupt_x86_hardirq(env, intno, 1);
/* ensure that no TB jump will be modified as
the program flow was changed */
next_tb = 0;
}
#if !defined(CONFIG_USER_ONLY)
} else if ((interrupt_request & CPU_INTERRUPT_VIRQ) &&
(env->eflags & IF_MASK) &&