linux_dsm_epyc7002/arch/x86/xen/smp_hvm.c
Ankur Arora ae03900105 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>
2017-06-13 16:10:58 +02:00

76 lines
1.7 KiB
C

#include <asm/smp.h>
#include <xen/events.h>
#include "xen-ops.h"
#include "smp.h"
static void __init xen_hvm_smp_prepare_boot_cpu(void)
{
BUG_ON(smp_processor_id() != 0);
native_smp_prepare_boot_cpu();
/*
* Setup vcpu_info for boot CPU. Secondary CPUs get their vcpu_info
* in xen_cpu_up_prepare_hvm().
*/
xen_vcpu_setup(0);
/*
* The alternative logic (which patches the unlock/lock) runs before
* the smp bootup up code is activated. Hence we need to set this up
* the core kernel is being patched. Otherwise we will have only
* modules patched but not core code.
*/
xen_init_spinlocks();
}
static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
{
int cpu;
native_smp_prepare_cpus(max_cpus);
WARN_ON(xen_smp_intr_init(0));
xen_init_lock_cpu(0);
for_each_possible_cpu(cpu) {
if (cpu == 0)
continue;
/* Set default vcpu_id to make sure that we don't use cpu-0's */
per_cpu(xen_vcpu_id, cpu) = XEN_VCPU_ID_INVALID;
}
}
#ifdef CONFIG_HOTPLUG_CPU
static void xen_hvm_cpu_die(unsigned int cpu)
{
if (common_cpu_die(cpu) == 0) {
xen_smp_intr_free(cpu);
xen_uninit_lock_cpu(cpu);
xen_teardown_timer(cpu);
}
}
#else
static void xen_hvm_cpu_die(unsigned int cpu)
{
BUG();
}
#endif
void __init xen_hvm_smp_init(void)
{
if (!xen_have_vector_callback)
return;
smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
smp_ops.cpu_die = xen_hvm_cpu_die;
smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
smp_ops.smp_cpus_done = xen_smp_cpus_done;
}