From patchwork Tue Jan 25 16:49:05 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Berger X-Patchwork-Id: 80387 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 0D454B6EF1 for ; Wed, 26 Jan 2011 04:07:08 +1100 (EST) Received: from localhost ([127.0.0.1]:43163 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PhmM2-0005ff-VI for incoming@patchwork.ozlabs.org; Tue, 25 Jan 2011 12:06:55 -0500 Received: from [140.186.70.92] (port=59755 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Phm5T-0005OK-Uf for qemu-devel@nongnu.org; Tue, 25 Jan 2011 11:50:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Phm4s-00054A-OK for qemu-devel@nongnu.org; Tue, 25 Jan 2011 11:49:47 -0500 Received: from e9.ny.us.ibm.com ([32.97.182.139]:46360) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Phm4s-00053V-II for qemu-devel@nongnu.org; Tue, 25 Jan 2011 11:49:10 -0500 Received: from d01dlp02.pok.ibm.com (d01dlp02.pok.ibm.com [9.56.224.85]) by e9.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p0PGOTJ2002068 for ; Tue, 25 Jan 2011 11:24:32 -0500 Received: from d01relay01.pok.ibm.com (d01relay01.pok.ibm.com [9.56.227.233]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 8DA804DE803B for ; Tue, 25 Jan 2011 11:45:36 -0500 (EST) Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay01.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p0PGn5qM406322 for ; Tue, 25 Jan 2011 11:49:05 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p0PGn5MY016749 for ; Tue, 25 Jan 2011 11:49:05 -0500 Received: from [9.59.241.154] (d941e-10.watson.ibm.com [9.59.241.154]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p0PGn5KB016738; Tue, 25 Jan 2011 11:49:05 -0500 Message-ID: <4D3EFF01.9080608@linux.vnet.ibm.com> Date: Tue, 25 Jan 2011 11:49:05 -0500 From: Stefan Berger User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101027 Fedora/3.1.6-1.fc14 Lightning/1.0b3pre Thunderbird/3.1.6 MIME-Version: 1.0 To: Jan Kiszka Subject: Re: [Qemu-devel] Re: Errors on MMIO read access on VM suspend / resume operations References: <4D2C8305.2090609@linux.vnet.ibm.com> <4D2ED260.4010801@redhat.com> <4D30A38F.3030002@linux.vnet.ibm.com> <4D3303FD.8020509@redhat.com> <4D35030E.4080406@linux.vnet.ibm.com> <4D3554F4.6080405@siemens.com> <4D3DC49E.2000100@linux.vnet.ibm.com> <4D3DFE5A.802@web.de> <4D3E3FDE.80805@linux.vnet.ibm.com> <4D3E7B13.5000303@web.de> In-Reply-To: <4D3E7B13.5000303@web.de> X-Content-Scanned: Fidelis XPS MAILER X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) Cc: Avi Kivity , kvm@vger.kernel.org, qemu-devel@nongnu.org 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 On 01/25/2011 02:26 AM, Jan Kiszka wrote: > > Do you see a chance to look closer at the issue yourself? E.g. > instrument the kernel's irqchip models and dump their states once your > guest is stuck? The device runs on iRQ 3. So I applied this patch here. While it's still working I see this here with the levels changing 0-1-0. Though then it stops and levels are only at '1'. [ 1773.833824] kvm_pic_set_irq [ 1773.833827] pic_set_irq1 131: level=0, irr = 5b [ 1773.834161] kvm_pic_set_irq [ 1773.834163] pic_set_irq1 131: level=1, irr = 5b [ 1773.834193] kvm_pic_set_irq [ 1773.834195] pic_set_irq1 131: level=0, irr = 5b [ 1773.835028] kvm_pic_set_irq [ 1773.835031] pic_set_irq1 131: level=1, irr = 5b [ 1773.835542] kvm_pic_set_irq [ 1773.835545] pic_set_irq1 131: level=1, irr = 5b [ 1773.889892] kvm_pic_set_irq [ 1773.889894] pic_set_irq1 131: level=1, irr = 5b [ 1791.258793] pic_set_irq1 119: level=1, irr = d9 [ 1791.258824] pic_set_irq1 119: level=0, irr = d1 [ 1791.402476] pic_set_irq1 119: level=1, irr = d9 [ 1791.402534] pic_set_irq1 119: level=0, irr = d1 [ 1791.402538] pic_set_irq1 119: level=1, irr = d9 [...] I believe the last 5 shown calls can be ignored. After that the interrupts don't go through anymore. In the device model I see interrupts being raised and cleared. After the last one was cleared in 'my' device model, only interrupts are raised. This looks like as if the interrupt handler in the guest Linux was never run, thus the IRQ is never cleared and we're stuck. Regards, Stefan diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 3cece05..8f4f94c 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -106,7 +106,7 @@ static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level) { int mask, ret = 1; mask = 1<< irq; - if (s->elcr& mask) /* level triggered */ + if (s->elcr& mask) /* level triggered */ { if (level) { ret = !(s->irr& mask); s->irr |= mask; @@ -115,7 +115,10 @@ static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level) s->irr&= ~mask; s->last_irr&= ~mask; } - else /* edge triggered */ +if (irq == 3) + printk("%s %d: level=%d, irr = %x\n", __FUNCTION__,__LINE__,level, s->irr); + } + else /* edge triggered */ { if (level) { if ((s->last_irr& mask) == 0) { ret = !(s->irr& mask); @@ -124,7 +127,9 @@ static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level) s->last_irr |= mask; } else s->last_irr&= ~mask; - +if (irq == 3) + printk("%s %d: level=%d, irr = %x\n", __FUNCTION__,__LINE__,level, s->irr); + } return (s->imr& mask) ? -1 : ret; } @@ -206,6 +211,8 @@ int kvm_pic_set_irq(void *opaque, int irq, int level) pic_lock(s); if (irq>= 0&& irq< PIC_NUM_PINS) { +if (irq == 3) +printk("%s\n", __FUNCTION__); ret = pic_set_irq1(&s->pics[irq>> 3], irq& 7, level); pic_update_irq(s); trace_kvm_pic_set_irq(irq>> 3, irq& 7, s->pics[irq>> 3].elcr,