Re: [Qemu-devel] [PATCH] linux-user: elfload: Still use TARGET_PAGE_SIZE for i386 guest

[Alexander Graf]

> Am 13.08.2015 um 04:45 schrieb gchen gchen <address@hidden>:
> 
>> On 2015年08月12日 23:06, Richard Henderson wrote:
>> On 08/12/2015 12:59 AM, gchen gchen wrote:
>>>> Nack.  There's 99 problems with host page size> guest page size.  This
>>>> solves none of them, and in the hackiest way possible.
>>> 
>>> Under alpha virtual machine, if set i386 guest page size 8KB, it will
>>> cause failure directly (any dynamically linked binaries can not work).
>> 
>> Yes, I know.  The same thing happens when running i386 guests on other
>> (non-virtual) hosts.  E.g. Sparc64's 8kB page, PowerPC64's 64kB page.
> 
> Yes. The reason why I am only focus on Alpha is "the machine which I am
> working for is almost the same as Alpha. But this machine is very slow,
> its performance maybe like 10 years ago's x86_64 laptop".

What does "Almost the same as Alpha" mean? Does it use 8k or 4k page size?

> 
>>> Do you have any other ideas for solving this issue?
>> 
>> The only complete solution that I see is to use softmmu with linux-user, so
>> that we properly emulate the guest pages.  Yes, it will cause quite some
>> slow-down in emulation, but I believe it's the only reliable way.
> 
> I have tried softmmu, for me, the performance is not acceptable, we can
> not use this way.

Softmmu but without system emulation. Performance should be about half of 
today's linux-user.


Alex