From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35438) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f4Nmq-0002AJ-Gc for qemu-devel@nongnu.org; Fri, 06 Apr 2018 05:36:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f4Nmn-0004fH-Dh for qemu-devel@nongnu.org; Fri, 06 Apr 2018 05:36:00 -0400 From: David Hildenbrand Date: Fri, 6 Apr 2018 11:35:52 +0200 Message-Id: <20180406093552.13016-1-david@redhat.com> Subject: [Qemu-devel] [PATCH v1 for-2.12] s390x/kvm: call cpu_synchronize_state() on every kvm_arch_handle_exit() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-s390x@nongnu.org Cc: qemu-devel@nongnu.org, Richard Henderson , Alexander Graf , Cornelia Huck , Christian Borntraeger , Thomas Huth , David Hildenbrand Manually having to use cpu_synchronize_state() is error prone. And as Christian Borntraeger discovered, e.g. handle_diag() is currently missing a cpu_synchronize_state(), as decode_basedisp_s() uses a general purpose register value internally. So let's do an overall cpu_synchronize_state(), which fixes at least the one mentioned BUG. We will clean up the superfluous cpu_synchronize_state() calls later. We now also call it (although maybe not neded) for - KVM_EXIT_S390_RESET -> s390_reipl_request() - KVM_EXIT_DEBUG -> kvm_arch_handle_debug_exit() - unmanagable/unimplemented intercepts - ICPT_CPU_STOP -> do_stop_interrupt() -> cpu gets halted - Scenarios where we inject an operation exception - handle_stsi() I don't think any of these are performance critical. Especially as we have all information directly contained in kvm_run, there are no additional IOCTLs to issue on modern kernels. Signed-off-by: David Hildenbrand --- target/s390x/kvm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c index f570896dc1..fb59d92def 100644 --- a/target/s390x/kvm.c +++ b/target/s390x/kvm.c @@ -1778,6 +1778,8 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) qemu_mutex_lock_iothread(); + cpu_synchronize_state(cs); + switch (run->exit_reason) { case KVM_EXIT_S390_SIEIC: ret = handle_intercept(cpu); -- 2.14.3