VFIO fixes for v5.10-rc3

- Remove code by using existing helper (Zenghui Yu)
 
  - fsl-mc copy-user return and underflow fixes (Dan Carpenter)
 
  - fsl-mc static function declaration (Diana Craciun)
 
  - Fix ioeventfd sleeping under spinlock (Alex Williamson)
 
  - Fix pm reference count leak in vfio-platform (Zhang Qilong)
 
  - Allow opening IGD device w/o OpRegion support (Fred Gao)
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Merge tag 'vfio-v5.10-rc3' of git://github.com/awilliam/linux-vfio

Pull VFIO fixes from Alex Williamson:

 - Remove code by using existing helper (Zenghui Yu)

 - fsl-mc copy-user return and underflow fixes (Dan Carpenter)

 - fsl-mc static function declaration (Diana Craciun)

 - Fix ioeventfd sleeping under spinlock (Alex Williamson)

 - Fix pm reference count leak in vfio-platform (Zhang Qilong)

 - Allow opening IGD device w/o OpRegion support (Fred Gao)

* tag 'vfio-v5.10-rc3' of git://github.com/awilliam/linux-vfio:
  vfio/pci: Bypass IGD init in case of -ENODEV
  vfio: platform: fix reference leak in vfio_platform_open
  vfio/pci: Implement ioeventfd thread handler for contended memory lock
  vfio/fsl-mc: Make vfio_fsl_mc_irqs_allocate static
  vfio/fsl-mc: prevent underflow in vfio_fsl_mc_mmap()
  vfio/fsl-mc: return -EFAULT if copy_to_user() fails
  vfio/type1: Use the new helper to find vfio_group

drivers/vfio/fsl-mc/vfio_fsl_mc.c

@@ -248,7 +248,9 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
 		info.size = vdev->regions[info.index].size;
 		info.flags = vdev->regions[info.index].flags;
 
-		return copy_to_user((void __user *)arg, &info, minsz);
+		if (copy_to_user((void __user *)arg, &info, minsz))
+			return -EFAULT;
+		return 0;
 	}
 	case VFIO_DEVICE_GET_IRQ_INFO:
 	{
@@ -267,7 +269,9 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
 		info.flags = VFIO_IRQ_INFO_EVENTFD;
 		info.count = 1;
 
-		return copy_to_user((void __user *)arg, &info, minsz);
+		if (copy_to_user((void __user *)arg, &info, minsz))
+			return -EFAULT;
+		return 0;
 	}
 	case VFIO_DEVICE_SET_IRQS:
 	{
@@ -468,7 +472,7 @@ static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma)
 {
 	struct vfio_fsl_mc_device *vdev = device_data;
 	struct fsl_mc_device *mc_dev = vdev->mc_dev;
-	int index;
+	unsigned int index;
 
 	index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT);
 

drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

@@ -13,7 +13,7 @@
 #include "linux/fsl/mc.h"
 #include "vfio_fsl_mc_private.h"
 
-int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
+static int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
 {
 	struct fsl_mc_device *mc_dev = vdev->mc_dev;
 	struct vfio_fsl_mc_irq *mc_irq;

drivers/vfio/pci/vfio_pci.c

@@ -385,7 +385,7 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
 	    pdev->vendor == PCI_VENDOR_ID_INTEL &&
 	    IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
 		ret = vfio_pci_igd_init(vdev);
-		if (ret) {
+		if (ret && ret != -ENODEV) {
 			pci_warn(pdev, "Failed to setup Intel IGD regions\n");
 			goto disable_exit;
 		}

drivers/vfio/pci/vfio_pci_rdwr.c

@@ -356,34 +356,60 @@ ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
 	return done;
 }
 
-static int vfio_pci_ioeventfd_handler(void *opaque, void *unused)
+static void vfio_pci_ioeventfd_do_write(struct vfio_pci_ioeventfd *ioeventfd,
+					bool test_mem)
 {
-	struct vfio_pci_ioeventfd *ioeventfd = opaque;
-
 	switch (ioeventfd->count) {
 	case 1:
-		vfio_pci_iowrite8(ioeventfd->vdev, ioeventfd->test_mem,
+		vfio_pci_iowrite8(ioeventfd->vdev, test_mem,
 				  ioeventfd->data, ioeventfd->addr);
 		break;
 	case 2:
-		vfio_pci_iowrite16(ioeventfd->vdev, ioeventfd->test_mem,
+		vfio_pci_iowrite16(ioeventfd->vdev, test_mem,
 				   ioeventfd->data, ioeventfd->addr);
 		break;
 	case 4:
-		vfio_pci_iowrite32(ioeventfd->vdev, ioeventfd->test_mem,
+		vfio_pci_iowrite32(ioeventfd->vdev, test_mem,
 				   ioeventfd->data, ioeventfd->addr);
 		break;
 #ifdef iowrite64
 	case 8:
-		vfio_pci_iowrite64(ioeventfd->vdev, ioeventfd->test_mem,
+		vfio_pci_iowrite64(ioeventfd->vdev, test_mem,
 				   ioeventfd->data, ioeventfd->addr);
 		break;
 #endif
 	}
+}
+
+static int vfio_pci_ioeventfd_handler(void *opaque, void *unused)
+{
+	struct vfio_pci_ioeventfd *ioeventfd = opaque;
+	struct vfio_pci_device *vdev = ioeventfd->vdev;
+
+	if (ioeventfd->test_mem) {
+		if (!down_read_trylock(&vdev->memory_lock))
+			return 1; /* Lock contended, use thread */
+		if (!__vfio_pci_memory_enabled(vdev)) {
+			up_read(&vdev->memory_lock);
+			return 0;
+		}
+	}
+
+	vfio_pci_ioeventfd_do_write(ioeventfd, false);
+
+	if (ioeventfd->test_mem)
+		up_read(&vdev->memory_lock);
 
 	return 0;
 }
 
+static void vfio_pci_ioeventfd_thread(void *opaque, void *unused)
+{
+	struct vfio_pci_ioeventfd *ioeventfd = opaque;
+
+	vfio_pci_ioeventfd_do_write(ioeventfd, ioeventfd->test_mem);
+}
+
 long vfio_pci_ioeventfd(struct vfio_pci_device *vdev, loff_t offset,
 			uint64_t data, int count, int fd)
 {
@@ -457,7 +483,8 @@ long vfio_pci_ioeventfd(struct vfio_pci_device *vdev, loff_t offset,
 	ioeventfd->test_mem = vdev->pdev->resource[bar].flags & IORESOURCE_MEM;
 
 	ret = vfio_virqfd_enable(ioeventfd, vfio_pci_ioeventfd_handler,
-				 NULL, NULL, &ioeventfd->virqfd, fd);
+				 vfio_pci_ioeventfd_thread, NULL,
+				 &ioeventfd->virqfd, fd);
 	if (ret) {
 		kfree(ioeventfd);
 		goto out_unlock;

drivers/vfio/platform/vfio_platform_common.c

@@ -267,7 +267,7 @@ static int vfio_platform_open(void *device_data)
 
 		ret = pm_runtime_get_sync(vdev->device);
 		if (ret < 0)
-			goto err_pm;
+			goto err_rst;
 
 		ret = vfio_platform_call_reset(vdev, &extra_dbg);
 		if (ret && vdev->reset_required) {
@@ -284,7 +284,6 @@ static int vfio_platform_open(void *device_data)
 
 err_rst:
 	pm_runtime_put(vdev->device);
-err_pm:
 	vfio_platform_irq_cleanup(vdev);
 err_irq:
 	vfio_platform_regions_cleanup(vdev);

drivers/vfio/vfio_iommu_type1.c

@@ -1993,6 +1993,7 @@ static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu,
 
 	list_splice_tail(iova_copy, iova);
 }
+
 static int vfio_iommu_type1_attach_group(void *iommu_data,
 					 struct iommu_group *iommu_group)
 {
@@ -2009,18 +2010,10 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 
 	mutex_lock(&iommu->lock);
 
-	list_for_each_entry(d, &iommu->domain_list, next) {
-		if (find_iommu_group(d, iommu_group)) {
-			mutex_unlock(&iommu->lock);
-			return -EINVAL;
-		}
-	}
-
-	if (iommu->external_domain) {
-		if (find_iommu_group(iommu->external_domain, iommu_group)) {
-			mutex_unlock(&iommu->lock);
-			return -EINVAL;
-		}
+	/* Check for duplicates */
+	if (vfio_iommu_find_iommu_group(iommu, iommu_group)) {
+		mutex_unlock(&iommu->lock);
+		return -EINVAL;
 	}
 
 	group = kzalloc(sizeof(*group), GFP_KERNEL);