diff options
| -rw-r--r-- | cpus.c | 1 | ||||
| -rw-r--r-- | target/i386/hax-all.c | 36 |
2 files changed, 34 insertions, 3 deletions
@@ -1594,7 +1594,6 @@ static void *qemu_hax_cpu_thread_fn(void *arg) cpu->thread_id = qemu_get_thread_id(); cpu->created = true; - cpu->halted = 0; current_cpu = cpu; hax_init_vcpu(cpu); diff --git a/target/i386/hax-all.c b/target/i386/hax-all.c index 64fd51a..9e7b779 100644 --- a/target/i386/hax-all.c +++ b/target/i386/hax-all.c @@ -471,13 +471,35 @@ static int hax_vcpu_hax_exec(CPUArchState *env) return 0; } - cpu->halted = 0; - if (cpu->interrupt_request & CPU_INTERRUPT_POLL) { cpu->interrupt_request &= ~CPU_INTERRUPT_POLL; apic_poll_irq(x86_cpu->apic_state); } + /* After a vcpu is halted (either because it is an AP and has just been + * reset, or because it has executed the HLT instruction), it will not be + * run (hax_vcpu_run()) until it is unhalted. The next few if blocks check + * for events that may change the halted state of this vcpu: + * a) Maskable interrupt, when RFLAGS.IF is 1; + * Note: env->eflags may not reflect the current RFLAGS state, because + * it is not updated after each hax_vcpu_run(). We cannot afford + * to fail to recognize any unhalt-by-maskable-interrupt event + * (in which case the vcpu will halt forever), and yet we cannot + * afford the overhead of hax_vcpu_sync_state(). The current + * solution is to err on the side of caution and have the HLT + * handler (see case HAX_EXIT_HLT below) unconditionally set the + * IF_MASK bit in env->eflags, which, in effect, disables the + * RFLAGS.IF check. + * b) NMI; + * c) INIT signal; + * d) SIPI signal. + */ + if (((cpu->interrupt_request & CPU_INTERRUPT_HARD) && + (env->eflags & IF_MASK)) || + (cpu->interrupt_request & CPU_INTERRUPT_NMI)) { + cpu->halted = 0; + } + if (cpu->interrupt_request & CPU_INTERRUPT_INIT) { DPRINTF("\nhax_vcpu_hax_exec: handling INIT for %d\n", cpu->cpu_index); @@ -493,6 +515,16 @@ static int hax_vcpu_hax_exec(CPUArchState *env) hax_vcpu_sync_state(env, 1); } + if (cpu->halted) { + /* If this vcpu is halted, we must not ask HAXM to run it. Instead, we + * break out of hax_smp_cpu_exec() as if this vcpu had executed HLT. + * That way, this vcpu thread will be trapped in qemu_wait_io_event(), + * until the vcpu is unhalted. + */ + cpu->exception_index = EXCP_HLT; + return 0; + } + do { int hax_ret; |