From: Alex Bennée Date: Wed, 22 Mar 2017 16:11:13 +0000 (+0000) Subject: ui/console: ensure do_safe_dpy_refresh holds BQL X-Git-Tag: v2.9.0-rc2~5^2~3 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=85390939190e4b7eeba57765e344947c328cd166;p=mirror_qemu.git ui/console: ensure do_safe_dpy_refresh holds BQL I missed the fact that when an exclusive work item runs it drops the BQL to ensure all no vCPUs are stuck waiting for it, hence causing a deadlock. However the actual helper needs to take the BQL especially as we'll be messing with device emulation bits during the update which all assume BQL is held. We make a minor cpu_reloading_memory_map which must try and unlock the RCU if we are actually outside the running context. Reported-by: Laurent Desnogues Signed-off-by: Alex Bennée Reviewed-by: Paolo Bonzini Reviewed-by: Gerd Hoffmann --- diff --git a/cpu-exec-common.c b/cpu-exec-common.c index 0504a9457b..e81da276bb 100644 --- a/cpu-exec-common.c +++ b/cpu-exec-common.c @@ -35,7 +35,7 @@ void cpu_loop_exit_noexc(CPUState *cpu) #if defined(CONFIG_SOFTMMU) void cpu_reloading_memory_map(void) { - if (qemu_in_vcpu_thread()) { + if (qemu_in_vcpu_thread() && current_cpu->running) { /* The guest can in theory prolong the RCU critical section as long * as it feels like. The major problem with this is that because it * can do multiple reconfigurations of the memory map within the diff --git a/ui/console.c b/ui/console.c index 937c950840..dd27c9501b 100644 --- a/ui/console.c +++ b/ui/console.c @@ -1586,7 +1586,9 @@ bool dpy_gfx_check_format(QemuConsole *con, static void do_safe_dpy_refresh(CPUState *cpu, run_on_cpu_data opaque) { DisplayChangeListener *dcl = opaque.host_ptr; + qemu_mutex_lock_iothread(); dcl->ops->dpy_refresh(dcl); + qemu_mutex_unlock_iothread(); } static void dpy_refresh(DisplayState *s)