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Date: Wed, 27 Aug 2014 11:50:35 +0200
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Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH 3/5] target-ppc: Build error log
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To: Aravinda Prasad <aravinda@linux.vnet.ibm.com>, aik@au1.ibm.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org
Cc: benh@au1.ibm.com, paulus@samba.org



On 25.08.14 15:45, Aravinda Prasad wrote:
> Whenever there is a physical memory error due to bit
> flips, which cannot be corrected by hardware, the error
> is passed on to the kernel. If the memory address in
> error belongs to guest address space then guest kernel
> is responsible to take action. Hence the error is passed
> on to guest via KVM by invoking 0x200 NMI vector.
> 
> However, guest OS, as per PAPR, expects an error log
> upon such error. This patch registers a new hcall
> which is issued from 0x200 interrupt vector and builds
> the error log, copies the error log to rtas space and
> passes the address of the error log to guest
> 
> Enhancement to KVM to perform above functionality is
> already in upstream kernel.
> 
> Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>

Why do we have to maintain the error log inside the rtas blob? Can't we
just create a fixed MMIO region that is backed by an error log device in
QEMU?

Then this call would just always return that specific address and we'd
also have a single file that deals with all of the error reporting.


Alex