summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-08-14 14:34:00 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-08-23 11:52:15 -0400
commit3aca7fbc8ede0dd194317b2e3144815128ffb232 (patch)
treea46417408998d0952947891122ea4cd555f2f65a
parent7f9140626c757b773624b97865cb53c2a8348a69 (diff)
downloadop-kernel-dev-3aca7fbc8ede0dd194317b2e3144815128ffb232.zip
op-kernel-dev-3aca7fbc8ede0dd194317b2e3144815128ffb232.tar.gz
xen/mmu: Remove from __ka space PMD entries for pagetables.
Please first read the description in "xen/mmu: Copy and revector the P2M tree." At this stage, the __ka address space (which is what the old P2M tree was using) is partially disassembled. The cleanup_highmap has removed the PMD entries from 0-16MB and anything past _brk_end up to the max_pfn_mapped (which is the end of the ramdisk). The xen_remove_p2m_tree and code around has ripped out the __ka for the old P2M array. Here we continue on doing it to where the Xen page-tables were. It is safe to do it, as the page-tables are addressed using __va. For good measure we delete anything that is within MODULES_VADDR and up to the end of the PMD. At this point the __ka only contains PMD entries for the start of the kernel up to __brk. [v1: Per Stefano's suggestion wrapped the MODULES_VADDR in debug] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
-rw-r--r--arch/x86/xen/mmu.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index a640949..3f8e963 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1240,6 +1240,25 @@ static void __init xen_pagetable_setup_done(pgd_t *base)
xen_start_info->mfn_list = new_mfn_list;
}
}
+ /* At this stage, cleanup_highmap has already cleaned __ka space
+ * from _brk_limit way up to the max_pfn_mapped (which is the end of
+ * the ramdisk). We continue on, erasing PMD entries that point to page
+ * tables - do note that they are accessible at this stage via __va.
+ * For good measure we also round up to the PMD - which means that if
+ * anybody is using __ka address to the initial boot-stack - and try
+ * to use it - they are going to crash. The xen_start_info has been
+ * taken care of already in xen_setup_kernel_pagetable. */
+ addr = xen_start_info->pt_base;
+ size = roundup(xen_start_info->nr_pt_frames * PAGE_SIZE, PMD_SIZE);
+
+ xen_cleanhighmap(addr, addr + size);
+ xen_start_info->pt_base = (unsigned long)__va(__pa(xen_start_info->pt_base));
+#ifdef DEBUG
+ /* This is superflous and is not neccessary, but you know what
+ * lets do it. The MODULES_VADDR -> MODULES_END should be clear of
+ * anything at this stage. */
+ xen_cleanhighmap(MODULES_VADDR, roundup(MODULES_VADDR, PUD_SIZE) - 1);
+#endif
#endif
xen_post_allocator_init();
}
OpenPOWER on IntegriCloud