From 47cb2ed9df2789fc4a3fe1201e475078f93c4839 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 6 Nov 2008 13:48:24 -0800 Subject: x86, xen: fix use of pgd_page now that it really does return a page Impact: fix 32-bit Xen guest boot crash On 32-bit PAE, pud_page, for no good reason, didn't really return a struct page *. Since Jan Beulich's fix "i386/PAE: fix pud_page()", pud_page does return a struct page *. Because PAE has 3 pagetable levels, the pud level is folded into the pgd level, so pgd_page() is the same as pud_page(), and now returns a struct page *. Update the xen/mmu.c code which uses pgd_page() accordingly. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/xen/mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/xen/mmu.c') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index aba77b2b7d1..49697d86c6a 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -874,7 +874,7 @@ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) #else /* CONFIG_X86_32 */ #ifdef CONFIG_X86_PAE /* Need to make sure unshared kernel PMD is pinnable */ - xen_pin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), + xen_pin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]), PT_PMD); #endif xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd))); @@ -991,7 +991,7 @@ static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd) #ifdef CONFIG_X86_PAE /* Need to make sure unshared kernel PMD is unpinned */ - xen_unpin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), + xen_unpin_page(mm, pgd_page(pgd[pgd_index(TASK_SIZE)]), PT_PMD); #endif -- cgit v1.2.3 From d05fdf316067cd311d5e7add08da26ded8a58080 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 28 Oct 2008 19:23:06 +1100 Subject: xen: make sure stray alias mappings are gone before pinning Xen requires that all mappings of pagetable pages are read-only, so that they can't be updated illegally. As a result, if a page is being turned into a pagetable page, we need to make sure all its mappings are RO. If the page had been used for ioremap or vmalloc, it may still have left over mappings as a result of not having been lazily unmapped. This change makes sure we explicitly mop them all up before pinning the page. Unlike aliases created by kmap, the there can be vmalloc aliases even for non-high pages, so we must do the flush unconditionally. Signed-off-by: Jeremy Fitzhardinge Cc: Linux Memory Management List Cc: Nick Piggin Signed-off-by: Ingo Molnar --- arch/x86/xen/mmu.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/x86/xen/mmu.c') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index aba77b2b7d1..89f3b6edc65 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -850,13 +850,16 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page, read-only, and can be pinned. */ static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd) { + vm_unmap_aliases(); + xen_mc_batch(); - if (xen_pgd_walk(mm, xen_pin_page, USER_LIMIT)) { - /* re-enable interrupts for kmap_flush_unused */ + if (xen_pgd_walk(mm, xen_pin_page, USER_LIMIT)) { + /* re-enable interrupts for flushing */ xen_mc_issue(0); + kmap_flush_unused(); - vm_unmap_aliases(); + xen_mc_batch(); } -- cgit v1.2.3