Merge tag 'hyperv-fixes-signed-20211007' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Replace uuid.h with types.h in a header (Andy Shevchenko)

 - Avoid sleeping in atomic context in PCI driver (Long Li)

 - Avoid sending IPI to self when it shouldn't (Vitaly Kuznetsov)

* tag 'hyperv-fixes-signed-20211007' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Avoid erroneously sending IPI to 'self'
  hyper-v: Replace uuid.h with types.h
  PCI: hv: Fix sleep while in non-sleep context when removing child devices from the bus

Author: torvalds

arch/x86/hyperv/hv_apic.c

@@ -122,17 +122,27 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
 	ipi_arg->reserved = 0;
 	ipi_arg->vp_set.valid_bank_mask = 0;
 
-	if (!cpumask_equal(mask, cpu_present_mask)) {
+	/*
+	 * Use HV_GENERIC_SET_ALL and avoid converting cpumask to VP_SET
+	 * when the IPI is sent to all currently present CPUs.
+	 */
+	if (!cpumask_equal(mask, cpu_present_mask) || exclude_self) {
 		ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
 		if (exclude_self)
 			nr_bank = cpumask_to_vpset_noself(&(ipi_arg->vp_set), mask);
 		else
 			nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
-	}
-	if (nr_bank < 0)
-		goto ipi_mask_ex_done;
-	if (!nr_bank)
+
+		/*
+		 * 'nr_bank <= 0' means some CPUs in cpumask can't be
+		 * represented in VP_SET. Return an error and fall back to
+		 * native (architectural) method of sending IPIs.
+		 */
+		if (nr_bank <= 0)
+			goto ipi_mask_ex_done;
+	} else {
 		ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
+	}
 
 	status = hv_do_rep_hypercall(HVCALL_SEND_IPI_EX, 0, nr_bank,
 			      ipi_arg, NULL);

drivers/pci/controller/pci-hyperv.c

@@ -3301,17 +3301,24 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
 		return 0;
 
 	if (!keep_devs) {
-		/* Delete any children which might still exist. */
+		struct list_head removed;
+
+		/* Move all present children to the list on stack */
+		INIT_LIST_HEAD(&removed);
 		spin_lock_irqsave(&hbus->device_list_lock, flags);
-		list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry) {
+		list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry)
+			list_move_tail(&hpdev->list_entry, &removed);
+		spin_unlock_irqrestore(&hbus->device_list_lock, flags);
+
+		/* Remove all children in the list */
+		list_for_each_entry_safe(hpdev, tmp, &removed, list_entry) {
 			list_del(&hpdev->list_entry);
 			if (hpdev->pci_slot)
 				pci_destroy_slot(hpdev->pci_slot);
 			/* For the two refs got in new_pcichild_device() */
 			put_pcichild(hpdev);
 			put_pcichild(hpdev);
 		}
-		spin_unlock_irqrestore(&hbus->device_list_lock, flags);
 	}
 
 	ret = hv_send_resources_released(hdev);

include/uapi/linux/hyperv.h

@@ -26,7 +26,7 @@
 #ifndef _UAPI_HYPERV_H
 #define _UAPI_HYPERV_H
 
-#include <linux/uuid.h>
+#include <linux/types.h>
 
 /*
  * Framework version for util services.