Messages in this thread | | | Date | Wed, 29 Oct 2014 06:30:18 +0100 | From | Juergen Gross <> | Subject | Re: [PATCH 1/2] Xen: Delay remapping memory of pv-domain |
| |
On 10/28/2014 06:34 PM, David Vrabel wrote: > Can these patches be split up? They're hard to review as-is. e.g., the > changes to page allocation look they could be split out. > > On 27/10/14 14:52, Juergen Gross wrote: >> Early in the boot process the memory layout of a pv-domain is changed >> to match the E820 map (either the host one for Dom0 or the Xen one) >> regarding placement of RAM and PCI holes. This requires removing memory >> pages initially located at positions not suitable for RAM and adding >> them later at higher addresses where no restrictions apply. > > How does this impact Matt Rushton's recent change to ensure the > relocated frames are contiguous?
It is simplifying it. :-)
The relocated frames are in the same sequence as before, just at another location. As the remapping is done later, I don't have to be careful not to cross a p2m leaf page boundary (allocating a new leaf page is no problem now).
> > The change was "xen/setup: Remap Xen Identity Mapped RAM" (4fbb67e3c87). > >> + /* Update kernel mapping */ >> + if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), >> + mfn_pte(mfn, PAGE_KERNEL), 0)) { >> + WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", >> + mfn, pfn); >> + return 0; > > I think you need to check if this is a PFN for a high page before > updating the mapping.
Really? I'm not aware of having removed such a check. If it is really necessary it must have been missing before...
Juergen
| |