Re: [PATCH v2 4/6] x86-64/xen: Enable the vvar mapping
From: Konrad Rzeszutek Wilk <hidden>
Date: 2011-08-03 13:49:34
On Wed, Aug 03, 2011 at 09:31:52AM -0400, Andy Lutomirski wrote:
Xen needs to handle VVAR_PAGE, introduced in git commit:
9fd67b4ed0714ab718f1f9bd14c344af336a6df7
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 <redacted>
Reported-by: Konrad Rzeszutek Wilk <redacted>Reviewed-by: Konrad Rzeszutek Wilk <redacted>
quoted hunk
--- arch/x86/xen/mmu.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index f987bde..8cce339 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c@@ -1916,6 +1916,7 @@ 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:@@ -1956,7 +1957,8 @@ 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); }-- 1.7.6