If CONFIG_SMP is disabled, xen_setup_vcpu_info_placement() is called from
xen_setup_shared_info(). This is fine as far as boot goes, but it means
that we also call it in the restore path. This results in an OOPS
because we assign to pv_mmu_ops.read_cr2 which is __ro_after_init.
Also, though less problematically, this means we call xen_vcpu_setup()
twice at restore -- once from the vcpu info placement call and the
second time from xen_vcpu_restore().
Fix by calling xen_setup_vcpu_info_placement() at boot only.
Reviewed-by: Boris Ostrovsky <boris.ostrov...@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.ar...@oracle.com>
---
arch/x86/xen/enlighten_pv.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index f51e48299692..29cad193db53 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -938,23 +938,27 @@ void xen_setup_shared_info(void)
HYPERVISOR_shared_info =
(struct shared_info *)__va(xen_start_info->shared_info);
-#ifndef CONFIG_SMP
- /* In UP this is as good a place as any to set up shared info */
- xen_setup_vcpu_info_placement();
-#endif
-
xen_setup_mfn_list_list();
- /*
- * Now that shared info is set up we can start using routines that
- * point to pvclock area.
- */
- if (system_state == SYSTEM_BOOTING)
+ if (system_state == SYSTEM_BOOTING) {
+#ifndef CONFIG_SMP
+ /*
+ * In UP this is as good a place as any to set up shared info.
+ * Limit this to boot only, at restore vcpu setup is done via
+ * xen_vcpu_restore().
+ */
+ xen_setup_vcpu_info_placement();
+#endif
+ /*
+ * Now that shared info is set up we can start using routines
+ * that point to pvclock area.
+ */
xen_init_time_ops();
+ }
}
/* This is called once we have the cpu_possible_mask */
-void xen_setup_vcpu_info_placement(void)
+void __ref xen_setup_vcpu_info_placement(void)
{
int cpu;
--
2.7.4
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