*/
struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
-/*
- * Flag to determine whether vcpu info placement is available on all
- * VCPUs. We assume it is to start with, and then set it to zero on
- * the first failure. This is because it can succeed on some VCPUs
- * and not others, since it can involve hypervisor memory allocation,
- * or because the guest failed to guarantee all the appropriate
- * constraints on all VCPUs (ie buffer can't cross a page boundary).
- *
- * Note that any particular CPU may be using a placed vcpu structure,
- * but we can only optimise if the all are.
- *
- * 0: not available, 1: available
- */
-int xen_have_vcpu_info_placement = 1;
-
static int xen_cpu_up_online(unsigned int cpu)
{
xen_init_lock_cpu(cpu);
return rc >= 0 ? 0 : rc;
}
-static int xen_vcpu_setup_restore(int cpu)
+static void xen_vcpu_setup_restore(int cpu)
{
- int rc = 0;
-
/* Any per_cpu(xen_vcpu) is stale, so reset it */
xen_vcpu_info_reset(cpu);
* be handled by hotplug.
*/
if (xen_pv_domain() ||
- (xen_hvm_domain() && cpu_online(cpu))) {
- rc = xen_vcpu_setup(cpu);
- }
-
- return rc;
+ (xen_hvm_domain() && cpu_online(cpu)))
+ xen_vcpu_setup(cpu);
}
/*
*/
void xen_vcpu_restore(void)
{
- int cpu, rc;
+ int cpu;
for_each_possible_cpu(cpu) {
bool other_cpu = (cpu != smp_processor_id());
if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
xen_setup_runstate_info(cpu);
- rc = xen_vcpu_setup_restore(cpu);
- if (rc)
- pr_emerg_once("vcpu restore failed for cpu=%d err=%d. "
- "System will hang.\n", cpu, rc);
- /*
- * In case xen_vcpu_setup_restore() fails, do not bring up the
- * VCPU. This helps us avoid the resulting OOPS when the VCPU
- * accesses pvclock_vcpu_time via xen_vcpu (which is NULL.)
- * Note that this does not improve the situation much -- now the
- * VM hangs instead of OOPSing -- with the VCPUs that did not
- * fail, spinning in stop_machine(), waiting for the failed
- * VCPUs to come up.
- */
- if (other_cpu && is_up && (rc == 0) &&
+ xen_vcpu_setup_restore(cpu);
+
+ if (other_cpu && is_up &&
HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
BUG();
}
}
}
-int xen_vcpu_setup(int cpu)
+void xen_vcpu_setup(int cpu)
{
struct vcpu_register_vcpu_info info;
int err;
*/
if (xen_hvm_domain()) {
if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
- return 0;
+ return;
}
- if (xen_have_vcpu_info_placement) {
- vcpup = &per_cpu(xen_vcpu_info, cpu);
- info.mfn = arbitrary_virt_to_mfn(vcpup);
- info.offset = offset_in_page(vcpup);
+ vcpup = &per_cpu(xen_vcpu_info, cpu);
+ info.mfn = arbitrary_virt_to_mfn(vcpup);
+ info.offset = offset_in_page(vcpup);
- /*
- * Check to see if the hypervisor will put the vcpu_info
- * structure where we want it, which allows direct access via
- * a percpu-variable.
- * N.B. This hypercall can _only_ be called once per CPU.
- * Subsequent calls will error out with -EINVAL. This is due to
- * the fact that hypervisor has no unregister variant and this
- * hypercall does not allow to over-write info.mfn and
- * info.offset.
- */
- err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info,
- xen_vcpu_nr(cpu), &info);
-
- if (err) {
- pr_warn_once("register_vcpu_info failed: cpu=%d err=%d\n",
- cpu, err);
- xen_have_vcpu_info_placement = 0;
- } else {
- /*
- * This cpu is using the registered vcpu info, even if
- * later ones fail to.
- */
- per_cpu(xen_vcpu, cpu) = vcpup;
- }
- }
-
- if (!xen_have_vcpu_info_placement)
- xen_vcpu_info_reset(cpu);
+ /*
+ * N.B. This hypercall can _only_ be called once per CPU.
+ * Subsequent calls will error out with -EINVAL. This is due to
+ * the fact that hypervisor has no unregister variant and this
+ * hypercall does not allow to over-write info.mfn and
+ * info.offset.
+ */
+ err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
+ &info);
+ if (err)
+ panic("register_vcpu_info failed: cpu=%d err=%d\n", cpu, err);
- return ((per_cpu(xen_vcpu, cpu) == NULL) ? -ENODEV : 0);
+ per_cpu(xen_vcpu, cpu) = vcpup;
}
void __init xen_banner(void)
for_each_possible_cpu(cpu) {
/* Set up direct vCPU id mapping for PV guests. */
per_cpu(xen_vcpu_id, cpu) = cpu;
-
- /*
- * xen_vcpu_setup(cpu) can fail -- in which case it
- * falls back to the shared_info version for cpus
- * where xen_vcpu_nr(cpu) < MAX_VIRT_CPUS.
- *
- * xen_cpu_up_prepare_pv() handles the rest by failing
- * them in hotplug.
- */
- (void) xen_vcpu_setup(cpu);
+ xen_vcpu_setup(cpu);
}
- /*
- * xen_vcpu_setup managed to place the vcpu_info within the
- * percpu area for all cpus, so make use of it.
- */
- if (xen_have_vcpu_info_placement) {
- pv_ops.irq.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
- pv_ops.irq.irq_disable =
- __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
- pv_ops.irq.irq_enable =
- __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
- pv_ops.mmu.read_cr2 =
- __PV_IS_CALLEE_SAVE(xen_read_cr2_direct);
- }
+ pv_ops.irq.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
+ pv_ops.irq.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
+ pv_ops.irq.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
+ pv_ops.mmu.read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2_direct);
}
static const struct pv_info xen_info __initconst = {