[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [Xen-devel] [PATCH] support HVM guests with more than 3.75G memory
>My previous response: Oops, I missed your previous response :-( > >Hi Xin, > >This patch seems to mess with the e820 logic quite a bit, in particular >adding some extra entries. What's going on there -- is it all >just a 'clean >up' or are there real changes going on in that section of the patch? > It's "real changes" and the issue here is, in current HVM guest memory layout, we don't reserve any guest physical address space for PCI MMIO uses. On the other hand, qemu-dm PCI BIOS allocates PCI MMIO from 0xF0000000, that's meaning the last 256M physical address space (below 4G) can not be regarded as normal RAM address space. But current e820 table is blind to this :-(, and we already encountered a bug that windows 2003 VMX guest only saw 1G RAM while we gave 5G RAM to it. On a real platform with 8G RAM, it's e820 table is like this: (XEN) 0000000000000000 - 000000000009dc00 (usable) (XEN) 000000000009dc00 - 00000000000a0000 (reserved) (XEN) 00000000000e4000 - 0000000000100000 (reserved) (XEN) 0000000000100000 - 00000000bff60000 (usable) (XEN) 00000000bff60000 - 00000000bff69000 (ACPI data) (XEN) 00000000bff69000 - 00000000bff80000 (ACPI NVS) (XEN) 00000000bff80000 - 00000000c0000000 (reserved) (XEN) 00000000e0000000 - 00000000f0000000 (reserved) (XEN) 00000000fec00000 - 00000000fec10000 (reserved) (XEN) 00000000fee00000 - 00000000fee01000 (reserved) (XEN) 00000000ff000000 - 0000000100000000 (reserved) (XEN) 0000000100000000 - 0000000240000000 (usable) 8G is split into 2 parts: 3G and 5G: 1) 0 - 3G 2) 4G - 9G So our HVM e820 table should also comply to this, and the 256M RAM that falls into that range should be moved to 4G above, that's the "real changes" in my patch. -Xin _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |