From patchwork Fri Feb 4 15:47:22 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 81896 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 56FAEB70A3 for ; Sat, 5 Feb 2011 02:51:16 +1100 (EST) Received: from localhost ([127.0.0.1]:49990 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PlNwH-00061G-GT for incoming@patchwork.ozlabs.org; Fri, 04 Feb 2011 10:51:13 -0500 Received: from [140.186.70.92] (port=51571 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PlNus-00060Q-1b for qemu-devel@nongnu.org; Fri, 04 Feb 2011 10:49:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PlNuq-0007we-Cy for qemu-devel@nongnu.org; Fri, 04 Feb 2011 10:49:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64551) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PlNuq-0007wA-57 for qemu-devel@nongnu.org; Fri, 04 Feb 2011 10:49:44 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p14Fnhbo031898 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 4 Feb 2011 10:49:43 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p14Fnhsq020716; Fri, 4 Feb 2011 10:49:43 -0500 Received: from amt.cnet (vpn2-8-97.ams2.redhat.com [10.36.8.97]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p14FneCN002210; Fri, 4 Feb 2011 10:49:41 -0500 Received: from amt.cnet (localhost.localdomain [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 2A3C965214C; Fri, 4 Feb 2011 13:48:48 -0200 (BRST) Received: (from marcelo@localhost) by amt.cnet (8.14.4/8.14.4/Submit) id p14FmisE017699; Fri, 4 Feb 2011 13:48:44 -0200 From: Marcelo Tosatti To: Anthony Liguori Date: Fri, 4 Feb 2011 13:47:22 -0200 Message-Id: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: Jan Kiszka , Gleb Natapov , Marcelo Tosatti , qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: [Qemu-devel] [PATCH 19/23] kvm: Unconditionally reenter kernel after IO exits X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Jan Kiszka KVM requires to reenter the kernel after IO exits in order to complete instruction emulation. Failing to do so will leave the kernel state inconsistently behind. To ensure that we will get back ASAP, we issue a self-signal that will cause KVM_RUN to return once the pending operations are completed. We can move kvm_arch_process_irqchip_events out of the inner VCPU loop. The only state that mattered at its old place was a pending INIT request. Catch it in kvm_arch_pre_run and also trigger a self-signal to process the request on next kvm_cpu_exec. This patch also fixes the missing exit_request check in kvm_cpu_exec in the CONFIG_IOTHREAD case. Signed-off-by: Jan Kiszka CC: Gleb Natapov Signed-off-by: Marcelo Tosatti --- kvm-all.c | 31 +++++++++++++++++-------------- target-i386/kvm.c | 5 +++++ 2 files changed, 22 insertions(+), 14 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index a83aff2..0c20f9e 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -199,7 +199,6 @@ int kvm_pit_in_kernel(void) return kvm_state->pit_in_kernel; } - int kvm_init_vcpu(CPUState *env) { KVMState *s = kvm_state; @@ -896,29 +895,33 @@ int kvm_cpu_exec(CPUState *env) DPRINTF("kvm_cpu_exec()\n"); - do { -#ifndef CONFIG_IOTHREAD - if (env->exit_request) { - DPRINTF("interrupt exit requested\n"); - ret = 0; - break; - } -#endif - - if (kvm_arch_process_irqchip_events(env)) { - ret = 0; - break; - } + if (kvm_arch_process_irqchip_events(env)) { + env->exit_request = 0; + env->exception_index = EXCP_HLT; + return 0; + } + do { if (env->kvm_vcpu_dirty) { kvm_arch_put_registers(env, KVM_PUT_RUNTIME_STATE); env->kvm_vcpu_dirty = 0; } kvm_arch_pre_run(env, run); + if (env->exit_request) { + DPRINTF("interrupt exit requested\n"); + /* + * KVM requires us to reenter the kernel after IO exits to complete + * instruction emulation. This self-signal will ensure that we + * leave ASAP again. + */ + qemu_cpu_kick_self(); + } cpu_single_env = NULL; qemu_mutex_unlock_iothread(); + ret = kvm_vcpu_ioctl(env, KVM_RUN, 0); + qemu_mutex_lock_iothread(); cpu_single_env = env; kvm_arch_post_run(env, run); diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 9df8ff8..8a87244 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -1426,6 +1426,11 @@ int kvm_arch_get_registers(CPUState *env) int kvm_arch_pre_run(CPUState *env, struct kvm_run *run) { + /* Force the VCPU out of its inner loop to process the INIT request */ + if (env->interrupt_request & CPU_INTERRUPT_INIT) { + env->exit_request = 1; + } + /* Inject NMI */ if (env->interrupt_request & CPU_INTERRUPT_NMI) { env->interrupt_request &= ~CPU_INTERRUPT_NMI;