xen/vcpu: Handle xen_vcpu_setup() failure at boot

On PVH, PVHVM, at failure in the VCPUOP_register_vcpu_info hypercall
we limit the number of cpus to to MAX_VIRT_CPUS. However, if this
failure had occurred for a cpu beyond MAX_VIRT_CPUS, we continue
to function with > MAX_VIRT_CPUS.

This leads to problems at the next save/restore cycle when there
are > MAX_VIRT_CPUS threads going into stop_machine() but coming
back up there's valid state for only the first MAX_VIRT_CPUS.

This patch pulls the excess CPUs down via cpu_down().

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 17:06:02 -07:00
committed by Juergen Gross
parent c9b5d98b25
commit ae03900105
4 changed files with 35 additions and 5 deletions

View File

@@ -14,6 +14,8 @@ extern void xen_smp_intr_free(unsigned int cpu);
int xen_smp_intr_init_pv(unsigned int cpu);
void xen_smp_intr_free_pv(unsigned int cpu);
void xen_smp_cpus_done(unsigned int max_cpus);
void xen_smp_send_reschedule(int cpu);
void xen_smp_send_call_function_ipi(const struct cpumask *mask);
void xen_smp_send_call_function_single_ipi(int cpu);