x86/mm: Fix dump_pagetables with Xen PV

Commit 2ae27137b2db89 ("x86: mm: convert dump_pagetables to use
walk_page_range") broke Xen PV guests as the hypervisor reserved hole in
the memory map was not taken into account.

Fix that by starting the kernel range only at GUARD_HOLE_END_ADDR.

Fixes: 2ae27137b2db89 ("x86: mm: convert dump_pagetables to use walk_page_range")
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Julien Grall <julien@xen.org>
Link: https://lkml.kernel.org/r/20200221103851.7855-1-jgross@suse.com

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 64229dad7eab6ce868957491431b62b51a2bee95..69309cd56fdf3fb28c8b7732297471ba69f46686 100644 (file)
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -363,13 +363,8 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m,
 {
        const struct ptdump_range ptdump_ranges[] = {
 #ifdef CONFIG_X86_64
-
-#define normalize_addr_shift (64 - (__VIRTUAL_MASK_SHIFT + 1))
-#define normalize_addr(u) ((signed long)((u) << normalize_addr_shift) >> \
-                          normalize_addr_shift)
-
        {0, PTRS_PER_PGD * PGD_LEVEL_MULT / 2},
-       {normalize_addr(PTRS_PER_PGD * PGD_LEVEL_MULT / 2), ~0UL},
+       {GUARD_HOLE_END_ADDR, ~0UL},
 #else
        {0, ~0UL},
 #endif