motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-06 17:23:56 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

Handle CPU interrupts by inline checking of a flag

Browse source 
Fix some of the nasty TCG race conditions and crashes by implementing
cpu_exit() as setting a flag which is checked at the start of each TB.
This avoids crashes if a thread or signal handler calls cpu_exit()
while the execution thread is itself modifying the TB graph (which
may happen in system emulation mode as well as in linux-user mode
with a multithreaded guest binary).

This fixes the crashes seen in LP:668799; however there are another
class of crashes described in LP:1098729 which stem from the fact
that in linux-user with a multithreaded guest all threads will
use and modify the same global TCG date structures (including the
generated code buffer) without any kind of locking. This means that
multithreaded guest binaries are still in the "unsupported"
category.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Peter Maydell 2013-02-22 18:10:03 +00:00 • committed by Blue Swirl
parent 77211379d7
commit 378df4b237
6 changed files with 47 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

3
include/qom/cpu.h
View file

@ -71,6 +71,8 @@ struct kvm_run;
* @created: Indicates whether the CPU thread has been successfully created.
* @stop: Indicates a pending stop request.
* @stopped: Indicates the CPU has been artificially stopped.
* @tcg_exit_req: Set to force TCG to stop executing linked TBs for this
* CPU and return to its top level loop.
* @env_ptr: Pointer to subclass-specific CPUArchState field.
* @current_tb: Currently executing TB.
* @kvm_fd: vCPU file descriptor for KVM.
@ -100,6 +102,7 @@ struct CPUState {
bool stop;
bool stopped;
volatile sig_atomic_t exit_request;
volatile sig_atomic_t tcg_exit_req;
void *env_ptr; /* CPUArchState */
struct TranslationBlock *current_tb;