From 3c638d0690a0b21c6acef7ce3132f821d8c1e25d Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Fri, 25 Jun 2010 16:56:56 +0200 Subject: [PATCH] Rework debug exception processing for gdb use Guest debugging is currently broken under CONFIG_IOTHREAD. The reason is inconsistent or even lacking signaling the debug events from the source VCPU to the main loop and the gdbstub. This patch addresses the issue by pushing this signaling into a CPUDebugExcpHandler: cpu_debug_handler is registered as first handler, thus will be executed last after potential breakpoint emulation handlers. It sets informs the gdbstub about the debug event source, requests a debug exit of the main loop and stops the current VCPU. This mechanism works both for TCG and KVM, with and without IO-thread. Signed-off-by: Jan Kiszka Acked-by: Paolo Bonzini Reviewed-by: Marcelo Tosatti Signed-off-by: Aurelien Jarno --- cpus.c | 26 ++++++++++++++++---------- kvm-all.c | 2 -- 2 files changed, 16 insertions(+), 12 deletions(-) diff --git a/cpus.c b/cpus.c index 03ebcb0c6..b09f5e3b5 100644 --- a/cpus.c +++ b/cpus.c @@ -141,6 +141,13 @@ static int any_cpu_has_work(void) return 0; } +static void cpu_debug_handler(CPUState *env) +{ + gdb_set_stop_cpu(env); + debug_requested = EXCP_DEBUG; + vm_stop(EXCP_DEBUG); +} + #ifndef _WIN32 static int io_thread_fd = -1; @@ -236,6 +243,8 @@ static void qemu_event_increment(void) #ifndef CONFIG_IOTHREAD int qemu_init_main_loop(void) { + cpu_set_debug_excp_handler(cpu_debug_handler); + return qemu_event_init(); } @@ -326,6 +335,8 @@ int qemu_init_main_loop(void) { int ret; + cpu_set_debug_excp_handler(cpu_debug_handler); + ret = qemu_event_init(); if (ret) return ret; @@ -770,8 +781,6 @@ static int qemu_cpu_exec(CPUState *env) bool cpu_exec_all(void) { - int ret = 0; - if (next_cpu == NULL) next_cpu = first_cpu; for (; next_cpu != NULL && !exit_request; next_cpu = next_cpu->next_cpu) { @@ -782,14 +791,11 @@ bool cpu_exec_all(void) if (qemu_alarm_pending()) break; - if (cpu_can_run(env)) - ret = qemu_cpu_exec(env); - else if (env->stop) - break; - - if (ret == EXCP_DEBUG) { - gdb_set_stop_cpu(env); - debug_requested = EXCP_DEBUG; + if (cpu_can_run(env)) { + if (qemu_cpu_exec(env) == EXCP_DEBUG) { + break; + } + } else if (env->stop) { break; } } diff --git a/kvm-all.c b/kvm-all.c index 938030230..7635f2f89 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -924,8 +924,6 @@ int kvm_cpu_exec(CPUState *env) DPRINTF("kvm_exit_debug\n"); #ifdef KVM_CAP_SET_GUEST_DEBUG if (kvm_arch_debug(&run->debug.arch)) { - gdb_set_stop_cpu(env); - vm_stop(EXCP_DEBUG); env->exception_index = EXCP_DEBUG; return 0; } -- 2.39.2