Commit 5d5791af authored Aug 03, 2011 by Andy Lutomirski Committed by H. Peter Anvin Aug 04, 2011

x86-64, xen: Enable the vvar mapping



Xen needs to handle VVAR_PAGE, introduced in git commit:
9fd67b4e
x86-64: Give vvars their own page

Otherwise we die during bootup with a message like:

(XEN) mm.c:940:d10 Error getting mfn 1888 (pfn 1e3e48) from L1 entry
      8000000001888465 for l1e_owner=10, pg_owner=10
(XEN) mm.c:5049:d10 ptwr_emulate: could not get_page_from_l1e()
[    0.000000] BUG: unable to handle kernel NULL pointer dereference at (null)
[    0.000000] IP: [<ffffffff8103a930>] xen_set_pte+0x20/0xe0

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/4659478ed2f3480938f96491c2ecbe2b2e113a23.1312378163.git.luto@mit.edu


Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

parent f670bb76

arch/x86/xen/mmu.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1829,6 +1829,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
		# endif
		#else
		case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
		case VVAR_PAGE:
		#endif
		case FIX_TEXT_POKE0:
		case FIX_TEXT_POKE1:
		@@ -1869,7 +1870,8 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
		#ifdef CONFIG_X86_64
		/* Replicate changes to map the vsyscall page into the user
		pagetable vsyscall mapping. */
		if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
		if ((idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) \|\|
		idx == VVAR_PAGE) {
		unsigned long vaddr = __fix_to_virt(idx);
		set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
		}