Merge tag 'for-linus-6.7a-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - A fix for the Xen event driver setting the correct return value when
   experiencing an allocation failure

 - A fix for allocating space for a struct in the percpu area to not
   cross page boundaries (this one is for x86, a similar one for Arm was
   already in the pull request for rc3)

* tag 'for-linus-6.7a-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/events: fix error code in xen_bind_pirq_msi_to_irq()
  x86/xen: fix percpu vcpu_info allocation

Author: torvalds

arch/x86/xen/enlighten.c

@@ -33,9 +33,12 @@ EXPORT_SYMBOL_GPL(hypercall_page);
  * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
  * but during boot it is switched to point to xen_vcpu_info.
  * The pointer is used in xen_evtchn_do_upcall to acknowledge pending events.
+ * Make sure that xen_vcpu_info doesn't cross a page boundary by making it
+ * cache-line aligned (the struct is guaranteed to have a size of 64 bytes,
+ * which matches the cache line size of 64-bit x86 processors).
  */
 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
-DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
+DEFINE_PER_CPU_ALIGNED(struct vcpu_info, xen_vcpu_info);
 
 /* Linux <-> Xen vCPU id mapping */
 DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
@@ -160,6 +163,7 @@ void xen_vcpu_setup(int cpu)
 	int err;
 	struct vcpu_info *vcpup;
 
+	BUILD_BUG_ON(sizeof(*vcpup) > SMP_CACHE_BYTES);
 	BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
 
 	/*

arch/x86/xen/xen-ops.h

@@ -21,7 +21,7 @@ extern void *xen_initial_gdt;
 struct trap_info;
 void xen_copy_trap_info(struct trap_info *traps);
 
-DECLARE_PER_CPU(struct vcpu_info, xen_vcpu_info);
+DECLARE_PER_CPU_ALIGNED(struct vcpu_info, xen_vcpu_info);
 DECLARE_PER_CPU(unsigned long, xen_cr3);
 DECLARE_PER_CPU(unsigned long, xen_current_cr3);
 

drivers/xen/events/events_base.c

@@ -1110,8 +1110,10 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 
 	for (i = 0; i < nvec; i++) {
 		info = xen_irq_init(irq + i);
-		if (!info)
+		if (!info) {
+			ret = -ENOMEM;
 			goto error_irq;
+		}
 
 		irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);