From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:59182)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <lersek@redhat.com>) id 1SyjQL-0002rm-7a
	for qemu-devel@nongnu.org; Tue, 07 Aug 2012 09:02:18 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <lersek@redhat.com>) id 1SyjQB-0001XR-1L
	for qemu-devel@nongnu.org; Tue, 07 Aug 2012 09:02:13 -0400
Received: from mx1.redhat.com ([209.132.183.28]:25509)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <lersek@redhat.com>) id 1SyjQA-0001Wq-QX
	for qemu-devel@nongnu.org; Tue, 07 Aug 2012 09:02:02 -0400
Received: from int-mx11.intmail.prod.int.phx2.redhat.com
	(int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24])
	by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q77D21c8013965
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK)
	for <qemu-devel@nongnu.org>; Tue, 7 Aug 2012 09:02:01 -0400
Message-ID: <50211212.5020909@redhat.com>
Date: Tue, 07 Aug 2012 15:03:14 +0200
From: Laszlo Ersek <lersek@redhat.com>
MIME-Version: 1.0
References: <20120807125203.GC3341@redhat.com>
In-Reply-To: <20120807125203.GC3341@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH] reset PMBA and PMREGMISC PIIX4 registers.
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Gleb Natapov <gleb@redhat.com>
Cc: qemu-devel@nongnu.org

On 08/07/12 14:52, Gleb Natapov wrote:
> The bug causes Windows + OVMF hang after reboot since OVMF
> checks PMREGMISC to see if IO space is enabled and skip
> configuration if it is. 
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
> index 0aace60..90b46b5 100644
> --- a/hw/acpi_piix4.c
> +++ b/hw/acpi_piix4.c
> @@ -353,6 +353,9 @@ static void piix4_reset(void *opaque)
>      pci_conf[0x5a] = 0;
>      pci_conf[0x5b] = 0;
>  
> +    pci_conf[0x40] = 0x01; /* PM io base read only bit */
> +    pci_conf[0x80] = 0;
> +
>      if (s->kvm_enabled) {
>          /* Mark SMM as already inited (until KVM supports SMM). */
>          pci_conf[0x5B] = 0x02;
> @@ -392,8 +395,6 @@ static int piix4_pm_initfn(PCIDevice *dev)
>      pci_conf[0x09] = 0x00;
>      pci_conf[0x3d] = 0x01; // interrupt pin 1
>  
> -    pci_conf[0x40] = 0x01; /* PM io base read only bit */
> -
>      /* APM */
>      apm_init(&s->apm, apm_ctrl_changed, s);
>  
> --
> 			Gleb.

Unless I'm missing something, the patch keeps the "PM io base read only
bit" set-up correctly the first time around too, since

piix4_pm_initfn()
  qemu_register_reset(piix4_reset, ...);

main()
  qemu_system_reset()

FWIW,

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks!
Laszlo