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Unbreak large mem support by removing kqemu

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kqemu introduces a number of restrictions on the i386 target.  The worst is that
it prevents large memory from working in the default build.

Furthermore, kqemu is fundamentally flawed in a number of ways.  It relies on
the TSC as a time source which will not be reliable on a multiple processor
system in userspace.  Since most modern processors are multicore, this severely
limits the utility of kqemu.

kvm is a viable alternative for people looking to accelerate qemu and has the
benefit of being supported by the upstream Linux kernel.  If someone can
implement work arounds to remove the restrictions introduced by kqemu, I'm
happy to avoid and/or revert this patch.

N.B. kqemu will still function in the 0.11 series but this patch removes it from
the 0.12 series.

Paul, please Ack or Nack this patch.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Anthony Liguori 2009-08-10 17:07:24 -05:00
parent 0953a80f04
commit 4a1418e07b
24 changed files with 8 additions and 1722 deletions
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38
cpu-exec.c
View file

@ -321,31 +321,6 @@ int cpu_exec(CPUState *env1)
}
env->exception_index = -1;
}
#ifdef CONFIG_KQEMU
if (kqemu_is_ok(env) && env->interrupt_request == 0 && env->exit_request == 0) {
int ret;
env->eflags = env->eflags | helper_cc_compute_all(CC_OP) | (DF & DF_MASK);
ret = kqemu_cpu_exec(env);
/* put eflags in CPU temporary format */
CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
DF = 1 - (2 * ((env->eflags >> 10) & 1));
CC_OP = CC_OP_EFLAGS;
env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
if (ret == 1) {
/* exception */
longjmp(env->jmp_env, 1);
} else if (ret == 2) {
/* softmmu execution needed */
} else {
if (env->interrupt_request != 0 || env->exit_request != 0) {
/* hardware interrupt will be executed just after */
} else {
/* otherwise, we restart */
longjmp(env->jmp_env, 1);
}
}
}
#endif
if (kvm_enabled()) {
kvm_cpu_exec(env);
@ -620,11 +595,7 @@ int cpu_exec(CPUState *env1)
spans two pages, we cannot safely do a direct
jump. */
{
if (next_tb != 0 &&
#ifdef CONFIG_KQEMU
(env->kqemu_enabled != 2) &&
#endif
tb->page_addr[1] == -1) {
if (next_tb != 0 && tb->page_addr[1] == -1) {
tb_add_jump((TranslationBlock *)(next_tb & ~3), next_tb & 3, tb);
}
}
@ -678,13 +649,6 @@ int cpu_exec(CPUState *env1)
}
/* reset soft MMU for next block (it can currently
only be set by a memory fault) */
#if defined(CONFIG_KQEMU)
#define MIN_CYCLE_BEFORE_SWITCH (100 * 1000)
if (kqemu_is_ok(env) &&
(cpu_get_time_fast() - env->last_io_time) >= MIN_CYCLE_BEFORE_SWITCH) {
cpu_loop_exit();
}
#endif
} /* for(;;) */
} else {
env_to_regs();