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Date: Mon, 10 Sep 2012 11:25:38 +0200
From: Jan Kiszka <jan.kiszka@siemens.com>
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Subject: Re: [Qemu-devel] [PATCH 3/3] support readonly memory feature in qemu
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To: Avi Kivity <avi@redhat.com>
Cc: "aliguori@us.ibm.com" <aliguori@us.ibm.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "mtosatti@redhat.com" <mtosatti@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "xiaoguangrong@linux.vnet.ibm.com" <xiaoguangrong@linux.vnet.ibm.com>, Liu Sheng <liusheng@linux.vnet.ibm.com>

On 2012-09-09 17:45, Avi Kivity wrote:
> On 09/07/2012 11:50 AM, Jan Kiszka wrote:
>>
>>> +            } else {
>>> +                cpu_physical_memory_rw(run->mmio.phys_addr,
>>> +                                       run->mmio.data,
>>> +                                       run->mmio.len,
>>> +                                       run->mmio.is_write);
>>> +            }
>>> +
>>>              ret = 0;
>>>              break;
>>>          case KVM_EXIT_IRQ_WINDOW_OPEN:
>>>
>>
>> Great to see this feature for KVM finally! I'm just afraid that this
>> will finally break good old isapc - due to broken Seabios. KVM used to
>> "unbreak" it as it didn't respect write protections. ;)
> 
> Can you describe the breakage?

Try "qemu -machine isapc [-enable-kvm]". Seabios is writing to some
read-only marked area. Don't recall where precisely.

Jan

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