From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58502) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XMdB5-0006lg-Eg for qemu-devel@nongnu.org; Wed, 27 Aug 2014 09:22:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XMdAx-0002g4-Vj for qemu-devel@nongnu.org; Wed, 27 Aug 2014 09:22:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10043) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XMdAx-0002fy-Nd for qemu-devel@nongnu.org; Wed, 27 Aug 2014 09:22:11 -0400 Message-ID: <53FDDB7A.8020604@redhat.com> Date: Wed, 27 Aug 2014 15:22:02 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <20140826071427.1672.48119.stgit@PASHA-ISP> <20140826071503.1672.32964.stgit@PASHA-ISP> <53FC5ADE.8030306@redhat.com> <002401cfc1f0$b5aefe50$210cfaf0$@Dovgaluk@ispras.ru> <53FDD09C.4040208@redhat.com> <002b01cfc1f7$4c954e90$e5bfebb0$@Dovgaluk@ispras.ru> In-Reply-To: <002b01cfc1f7$4c954e90$e5bfebb0$@Dovgaluk@ispras.ru> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 06/12] kvmvapic: fixing loading vmstate List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgaluk , qemu-devel@nongnu.org Cc: zealot351@gmail.com, maria.klimushenkova@ispras.ru Il 27/08/2014 15:03, Pavel Dovgaluk ha scritto: >> > Hmm, probably not. The bug would not be other timers accessing the >> > APIC, because that would also call apic_sync_vapic and the only effect >> > would be an extra useless synchronization. The bug would happen if the >> > APIC is accessed by the CPU before the timer has the occasion to run. > Sorry, but I don't understand which problem we will solve with apic_sync_vapic. In KVM mode, it is not a problem to call apic_enable_vapic before APIC state is loaded; all vapic processing is delayed anyway to after the VCPUs are started. In TCG mode, apic_enable_vapic calls apic_sync_vapic. Taking inspiration from what KVM does, the fix could be even simpler than a change state handler. run_on_cpu functions do not run while the VM is stopped, so the following should work: diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c index ce3d903..81d1ad7 100644 --- a/hw/intc/apic_common.c +++ b/hw/intc/apic_common.c @@ -91,13 +91,20 @@ void apic_enable_tpr_access_reporting(DeviceState *dev, bool enable) } } +static void do_apic_enable_vapic(void *data) +{ + APICCommonState *s = APIC_COMMON(data); + APICCommonClass *info = APIC_COMMON_GET_CLASS(s); + + info->vapic_base_update(s); +} + void apic_enable_vapic(DeviceState *dev, hwaddr paddr) { APICCommonState *s = APIC_COMMON(dev); - APICCommonClass *info = APIC_COMMON_GET_CLASS(s); s->vapic_paddr = paddr; - info->vapic_base_update(s); + run_on_cpu(CPU(s->cpu), do_apic_enable_vapic, s); } void apic_handle_tpr_access_report(DeviceState *dev, target_ulong ip, > All fields that were added to vmstate are not affected by this function. The sipi_vector and wait_for_sipi parts of this patch are okay. You should split those in a separate patch. Paolo