Re: QEMU, MCE, unpoison memory address across reboot

Marcelo Tosatti
2010-12-27T21:30:05Z

On Fri, Dec 24, 2010 at 11:30:37AM +0800, Huang Ying wrote:
> On Thu, 2010-12-23 at 22:28 +0800, Marcelo Tosatti wrote:
> > Can't you free and reallocate all guest memory instead, on reboot, if
> > there's a hwpoisoned page? Then you don't need this interface.
>
> Consider about this method. It seems that some guest RAMs are not
> allocated in qemu_ram_alloc_from_ptr(), that is, host parameter is
> allocated elsewhere and passed in. I found two:
>
> - assigned_dev_register_regions() in hw/device-assignment.c
> - create_shared_memory_BAR() and ivshmem_read() in hw/ivshmem.c
>
> There is no general method to reallocate these memory so far. We may
> need a flag in struct RAMBlock to track these memory, and ignore them
> during reallocation. But if there are hwpoisoned pages in these memory,
> we can not recover. Do you think that is OK?

Yes, these are not guest RAM so there should be no MCE for them.