CVS commit: src/sys/arch

["Manuel Bouyer" <bouyer%netbsd.org@localhost>]

Module Name:    src
Committed By:   bouyer
Date:           Thu Feb 23 18:59:22 UTC 2012

Modified Files:
        src/sys/arch/x86/x86: pmap.c
        src/sys/arch/xen/x86: x86_xpmap.c

Log Message:
On Xen, there is variable-sized Xen data after the kernel's text+data+bss
(this include the physical->machine table).
(vaddr_t)(KERNBASE + NKL2_KIMG_ENTRIES * NBPD_L2) is after text+data+bss but,
on a domU with lots of RAM (more than 4GB) (so large
xpmap_phys_to_machine_mapping table) this can point to some of Xen's data
setup at bootstrap (either the xpmap_phys_to_machine_mapping table,
some page shared with the hypervisor, or our kernel page table). Using it for
early_zerop will cause of these pages to be unmapped after bootstrap.
This will cause a kernel page fault for the domU, either immediatly or
eventually much later, depending on where early_zerop points to.
To fix this, account for early_zerop when building the bootstrap pages,
and its VA from here.

May fix PR port-xen/38699


To generate a diff of this commit:
cvs rdiff -u -r1.169 -r1.170 src/sys/arch/x86/x86/pmap.c
cvs rdiff -u -r1.39 -r1.40 src/sys/arch/xen/x86/x86_xpmap.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.