From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XRIhQ-0005u4-8n for qemu-devel@nongnu.org; Tue, 09 Sep 2014 06:31:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XRIhI-0006VR-Q8 for qemu-devel@nongnu.org; Tue, 09 Sep 2014 06:31:00 -0400 Received: from mail.ispras.ru ([83.149.199.45]:58973) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XRIhI-0006V5-J4 for qemu-devel@nongnu.org; Tue, 09 Sep 2014 06:30:52 -0400 From: "Pavel Dovgaluk" 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> <53FDDB7A.8020604@redhat.com> In-Reply-To: <53FDDB7A.8020604@redhat.com> Date: Tue, 9 Sep 2014 14:30:54 +0400 Message-ID: <000e01cfcc19$2302aba0$690802e0$@Dovgaluk@ispras.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Content-Language: ru Subject: Re: [Qemu-devel] [PATCH 06/12] kvmvapic: fixing loading vmstate List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: 'Paolo Bonzini' , qemu-devel@nongnu.org Cc: zealot351@gmail.com, maria.klimushenkova@ispras.ru > From: Paolo Bonzini [mailto:pbonzini@redhat.com] > 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. > > 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); > } I've tried this one and it doesn't work. do_apic_enable_vapic runs on cpu, at the same time the VM state is loaded. APIC state still remains broken because of this. Pavel Dovgalyuk