From 0e4d583723487a975f66f0a8b346fdcb024fafa6 Mon Sep 17 00:00:00 2001 From: Ankur Arora Date: Fri, 2 Jun 2017 17:06:00 -0700 Subject: [PATCH] xen/pv: Fix OOPS on restore for a PV, !SMP domain 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 Signed-off-by: Ankur Arora Signed-off-by: Juergen Gross --- 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 3ec1c4632e12..9a0714dbddfa 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -931,23 +931,27 @@ void xen_setup_shared_info(void) HYPERVISOR_shared_info = (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); -#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; -- 2.20.1