@@ -20,4 +20,15 @@ static inline int xen_irqs_disabled(stru
/* No need for a barrier -- XCHG is a barrier on x86. */
#define xchg_xen_ulong(ptr, val) xchg((ptr), (val))
+extern int xen_have_vector_callback;
+
+/*
+ * Events delivered via platform PCI interrupts are always
+ * routed to vcpu 0 and hence cannot be rebound.
+ */
+static inline bool xen_support_evtchn_rebind(void)
+{
+ return (!xen_hvm_domain() || xen_have_vector_callback);
+}
+
#endif /* _ASM_X86_XEN_EVENTS_H */
@@ -447,7 +447,7 @@ void __init xen_msi_init(void)
int __init pci_xen_hvm_init(void)
{
- if (!xen_feature(XENFEAT_hvm_pirqs))
+ if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
return 0;
#ifdef CONFIG_ACPI
@@ -138,6 +138,8 @@ struct shared_info xen_dummy_shared_info
void *xen_initial_gdt;
RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
+__read_mostly int xen_have_vector_callback;
+EXPORT_SYMBOL_GPL(xen_have_vector_callback);
static int xen_cpu_up_prepare(unsigned int cpu);
static int xen_cpu_up_online(unsigned int cpu);
@@ -1861,7 +1863,9 @@ static int xen_cpu_up_prepare(unsigned i
xen_vcpu_setup(cpu);
}
- if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
+ if (xen_pv_domain() ||
+ (xen_have_vector_callback &&
+ xen_feature(XENFEAT_hvm_safe_pvclock)))
xen_setup_timer(cpu);
rc = xen_smp_intr_init(cpu);
@@ -1877,7 +1881,9 @@ static int xen_cpu_dead(unsigned int cpu
{
xen_smp_intr_free(cpu);
- if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
+ if (xen_pv_domain() ||
+ (xen_have_vector_callback &&
+ xen_feature(XENFEAT_hvm_safe_pvclock)))
xen_teardown_timer(cpu);
return 0;
@@ -1916,8 +1922,8 @@ static void __init xen_hvm_guest_init(vo
xen_panic_handler_init();
- BUG_ON(!xen_feature(XENFEAT_hvm_callback_vector));
-
+ if (xen_feature(XENFEAT_hvm_callback_vector))
+ xen_have_vector_callback = 1;
xen_hvm_smp_init();
WARN_ON(xen_cpuhp_setup());
xen_unplug_emulated_devices();
@@ -1958,7 +1964,7 @@ bool xen_hvm_need_lapic(void)
return false;
if (!xen_hvm_domain())
return false;
- if (xen_feature(XENFEAT_hvm_pirqs))
+ if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
return false;
return true;
}
@@ -742,6 +742,8 @@ static void __init xen_hvm_smp_prepare_c
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_cpu_die;
@@ -432,6 +432,11 @@ static void xen_hvm_setup_cpu_clockevent
void __init xen_hvm_init_time_ops(void)
{
+ /* vector callback is needed otherwise we cannot receive interrupts
+ * on cpu > 0 and at this point we don't know how many cpus are
+ * available */
+ if (!xen_have_vector_callback)
+ return;
if (!xen_feature(XENFEAT_hvm_safe_pvclock)) {
printk(KERN_INFO "Xen doesn't support pvclock on HVM,"
"disable pv timer\n");
@@ -1312,6 +1312,9 @@ static int rebind_irq_to_cpu(unsigned ir
if (!VALID_EVTCHN(evtchn))
return -1;
+ if (!xen_support_evtchn_rebind())
+ return -1;
+
/* Send future instances of this interrupt to other vcpu. */
bind_vcpu.port = evtchn;
bind_vcpu.vcpu = xen_vcpu_nr(tcpu);
@@ -1645,15 +1648,20 @@ void xen_callback_vector(void)
{
int rc;
uint64_t callback_via;
-
- callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
- rc = xen_set_callback_via(callback_via);
- BUG_ON(rc);
- pr_info("Xen HVM callback vector for event delivery is enabled\n");
- /* in the restore case the vector has already been allocated */
- if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
- alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
- xen_hvm_callback_vector);
+ if (xen_have_vector_callback) {
+ callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
+ rc = xen_set_callback_via(callback_via);
+ if (rc) {
+ pr_err("Request for Xen HVM callback vector failed\n");
+ xen_have_vector_callback = 0;
+ return;
+ }
+ pr_info("Xen HVM callback vector for event delivery is enabled\n");
+ /* in the restore case the vector has already been allocated */
+ if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
+ xen_hvm_callback_vector);
+ }
}
#else
void xen_callback_vector(void) {}
@@ -67,7 +67,7 @@ static uint64_t get_callback_via(struct
pin = pdev->pin;
/* We don't know the GSI. Specify the PCI INTx line instead. */
- return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */
+ return ((uint64_t)0x01 << 56) | /* PCI INTx identifier */
((uint64_t)pci_domain_nr(pdev->bus) << 32) |
((uint64_t)pdev->bus->number << 16) |
((uint64_t)(pdev->devfn & 0xff) << 8) |
@@ -90,7 +90,7 @@ static int xen_allocate_irq(struct pci_d
static int platform_pci_resume(struct pci_dev *pdev)
{
int err;
- if (!xen_pv_domain())
+ if (xen_have_vector_callback)
return 0;
err = xen_set_callback_via(callback_via);
if (err) {
@@ -138,14 +138,7 @@ static int platform_pci_probe(struct pci
platform_mmio = mmio_addr;
platform_mmiolen = mmio_len;
- /*
- * Xen HVM guests always use the vector callback mechanism.
- * L1 Dom0 in a nested Xen environment is a PV guest inside in an
- * HVM environment. It needs the platform-pci driver to get
- * notifications from L0 Xen, but it cannot use the vector callback
- * as it is not exported by L1 Xen.
- */
- if (xen_pv_domain()) {
+ if (!xen_have_vector_callback) {
ret = xen_allocate_irq(pdev);
if (ret) {
dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);