qemu/accel
Emilio G. Cota cc689485ee translate-all: exit from tb_phys_invalidate if qht_remove fails
Two or more threads might race while invalidating the same TB. We currently
do not check for this at all despite taking tb_lock, which means we would
wrongly invalidate the same TB more than once. This bug has actually been
hit by users: I recently saw a report on IRC, although I have yet to see
the corresponding test case.

Fix this by using qht_remove as the synchronization point; if it fails,
that means the TB has already been invalidated, and therefore there
is nothing left to do in tb_phys_invalidate.

Note that this solution works now that we still have tb_lock, and will
continue working once we remove tb_lock.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1508445114-4717-1-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-24 13:53:42 -07:00
..
kvm kvm: simplify kvm_align_section() 2017-10-18 10:15:00 +02:00
stubs kvm: check KVM_CAP_SYNC_MMU with kvm_vm_check_extension() 2017-10-02 14:38:06 +02:00
tcg translate-all: exit from tb_phys_invalidate if qht_remove fails 2017-10-24 13:53:42 -07:00
Makefile.objs tcg: add the CONFIG_TCG into Makefiles 2017-07-05 09:12:44 +02:00
accel.c accel: cleanup error output 2017-08-01 17:27:33 +02:00