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xen/pv: Fix OOPS on restore for a PV, !SMP domain

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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.ostrovsky@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Ankur Arora 2017-06-02 17:06:00 -07:00 committed by Juergen Gross
parent 0b64ffb8db
commit 0e4d583723
1 changed files with 15 additions and 11 deletions
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26
arch/x86/xen/enlighten_pv.c
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@ -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;