diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h index 608a79d5a466..e6911caf5bbf 100644 --- a/arch/x86/include/asm/xen/events.h +++ b/arch/x86/include/asm/xen/events.h @@ -20,4 +20,15 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) /* 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 */ diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 292ab0364a89..c4b3646bd04c 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -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 diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index ec1d5c46e58f..29b239025b57 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -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 int cpu) 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(void) 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; } diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 7ff2f1bfb7ec..4e6b65baf8e2 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -742,6 +742,8 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus) 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; diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 1e69956d7852..4535627cf532 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -432,6 +432,11 @@ static void xen_hvm_setup_cpu_clockevents(void) 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"); diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 6a53577772c9..42807ce11c42 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1312,6 +1312,9 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu) 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) {} diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c index 2a165cc8a43c..1c4deac9b0f8 100644 --- a/drivers/xen/platform-pci.c +++ b/drivers/xen/platform-pci.c @@ -67,7 +67,7 @@ static uint64_t get_callback_via(struct pci_dev *pdev) 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_dev *pdev) 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_dev *pdev, 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);