From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60654) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xjm4R-0001HO-PF for qemu-devel@nongnu.org; Thu, 30 Oct 2014 05:31:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xjm4L-0005Z4-NA for qemu-devel@nongnu.org; Thu, 30 Oct 2014 05:31:07 -0400 Received: from mail.ispras.ru ([83.149.199.45]:36126) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xjm4L-0005Yn-GT for qemu-devel@nongnu.org; Thu, 30 Oct 2014 05:31:01 -0400 From: Pavel Dovgalyuk Date: Thu, 30 Oct 2014 12:31:00 +0300 Message-ID: <20141030093100.7176.716.stgit@PASHA-ISP> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH] kvmvapic: patch_instruction fix List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mark.burton@greensocs.com, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, pavel.dovgaluk@ispras.ru, pbonzini@redhat.com, zealot351@gmail.com, fred.konrad@greensocs.com When QEMU works in icount mode cpu_restore_state function performs two actions: restoring the program counter and updating icount to the correct value. kvmvapic's patch_instruction function is called by cpu_report_tpr_access function which also invokes cpu_restore_state. It results to calling cpu_restore_state twice - in cpu_report_tpr_access and in patch_instruction. When icount is disabled second call is safe. But when icount is enabled, cpu_restore_state modifies instructions counter twice, which leads to incorrect behavior. This patch removes useless cpu_restore_state call from kvmvapic. Signed-off-by: Pavel Dovgalyuk --- hw/i386/kvmvapic.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-) diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c index f9da050..28547a7 100644 --- a/hw/i386/kvmvapic.c +++ b/hw/i386/kvmvapic.c @@ -405,7 +405,6 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) } if (!kvm_enabled()) { - cpu_restore_state(cs, cs->mem_io_pc); cpu_get_tb_cpu_state(env, ¤t_pc, ¤t_cs_base, ¤t_flags); }