Merge tag 'vfio-v5.7-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - vfio-pci SR-IOV support (Alex Williamson)

 - vfio DMA read/write interface (Yan Zhao)

 - Fix vfio-platform erroneous IRQ error log (Eric Auger)

 - Fix shared ATSD support for NVLink on POWER (Sam Bobroff)

 - Fix init error without CONFIG_IOMMU_DMA (Andre Przywara)

* tag 'vfio-v5.7-rc1' of git://github.com/awilliam/linux-vfio:
  vfio: Ignore -ENODEV when getting MSI cookie
  vfio-pci/nvlink2: Allow fallback to ibm,mmio-atsd[0]
  vfio/pci: Cleanup .probe() exit paths
  vfio/pci: Remove dev_fmt definition
  vfio/pci: Add sriov_configure support
  vfio: Introduce VFIO_DEVICE_FEATURE ioctl and first user
  vfio/pci: Introduce VF token
  vfio/pci: Implement match ops
  vfio: Include optional device match in vfio_device_ops callbacks
  vfio: avoid inefficient operations on VFIO group in vfio_pin/unpin_pages
  vfio: introduce vfio_dma_rw to read/write a range of IOVAs
  vfio: allow external user to get vfio group from device
  vfio: platform: Switch to platform_get_irq_optional()

Author: torvalds

drivers/vfio/pci/vfio_pci.c

@@ -422,8 +422,14 @@ int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev)
 
 	if (of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", nvlink_index,
 			&mmio_atsd)) {
-		dev_warn(&vdev->pdev->dev, "No available ATSD found\n");
-		mmio_atsd = 0;
+		if (of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", 0,
+				&mmio_atsd)) {
+			dev_warn(&vdev->pdev->dev, "No available ATSD found\n");
+			mmio_atsd = 0;
+		} else {
+			dev_warn(&vdev->pdev->dev,
+				 "Using fallback ibm,mmio-atsd[0] for ATSD.\n");
+		}
 	}
 
 	if (of_property_read_u64(npu_node, "ibm,device-tgt-addr", &tgt)) {

drivers/vfio/pci/vfio_pci_nvlink2.c

@@ -12,6 +12,8 @@
 #include <linux/pci.h>
 #include <linux/irqbypass.h>
 #include <linux/types.h>
+#include <linux/uuid.h>
+#include <linux/notifier.h>
 
 #ifndef VFIO_PCI_PRIVATE_H
 #define VFIO_PCI_PRIVATE_H
@@ -84,6 +86,12 @@ struct vfio_pci_reflck {
 	struct mutex		lock;
 };
 
+struct vfio_pci_vf_token {
+	struct mutex		lock;
+	uuid_t			uuid;
+	int			users;
+};
+
 struct vfio_pci_device {
 	struct pci_dev		*pdev;
 	void __iomem		*barmap[PCI_STD_NUM_BARS];
@@ -122,6 +130,8 @@ struct vfio_pci_device {
 	struct list_head	dummy_resources_list;
 	struct mutex		ioeventfds_lock;
 	struct list_head	ioeventfds_list;
+	struct vfio_pci_vf_token	*vf_token;
+	struct notifier_block	nb;
 };
 
 #define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)

drivers/vfio/pci/vfio_pci_private.h

@@ -44,7 +44,7 @@ static int get_platform_irq(struct vfio_platform_device *vdev, int i)
 {
 	struct platform_device *pdev = (struct platform_device *) vdev->opaque;
 
-	return platform_get_irq(pdev, i);
+	return platform_get_irq_optional(pdev, i);
 }
 
 static int vfio_platform_probe(struct platform_device *pdev)

drivers/vfio/platform/vfio_platform.c

@@ -875,11 +875,23 @@ EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
 static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
 						     char *buf)
 {
-	struct vfio_device *it, *device = NULL;
+	struct vfio_device *it, *device = ERR_PTR(-ENODEV);
 
 	mutex_lock(&group->device_lock);
 	list_for_each_entry(it, &group->device_list, group_next) {
-		if (!strcmp(dev_name(it->dev), buf)) {
+		int ret;
+
+		if (it->ops->match) {
+			ret = it->ops->match(it->device_data, buf);
+			if (ret < 0) {
+				device = ERR_PTR(ret);
+				break;
+			}
+		} else {
+			ret = !strcmp(dev_name(it->dev), buf);
+		}
+
+		if (ret) {
 			device = it;
 			vfio_device_get(device);
 			break;
@@ -1430,8 +1442,8 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
 		return -EPERM;
 
 	device = vfio_device_get_from_name(group, buf);
-	if (!device)
-		return -ENODEV;
+	if (IS_ERR(device))
+		return PTR_ERR(device);
 
 	ret = device->ops->open(device->device_data);
 	if (ret) {
@@ -1720,6 +1732,44 @@ struct vfio_group *vfio_group_get_external_user(struct file *filep)
 }
 EXPORT_SYMBOL_GPL(vfio_group_get_external_user);
 
+/**
+ * External user API, exported by symbols to be linked dynamically.
+ * The external user passes in a device pointer
+ * to verify that:
+ *	- A VFIO group is assiciated with the device;
+ *	- IOMMU is set for the group.
+ * If both checks passed, vfio_group_get_external_user_from_dev()
+ * increments the container user counter to prevent the VFIO group
+ * from disposal before external user exits and returns the pointer
+ * to the VFIO group.
+ *
+ * When the external user finishes using the VFIO group, it calls
+ * vfio_group_put_external_user() to release the VFIO group and
+ * decrement the container user counter.
+ *
+ * @dev [in]	: device
+ * Return error PTR or pointer to VFIO group.
+ */
+
+struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev)
+{
+	struct vfio_group *group;
+	int ret;
+
+	group = vfio_group_get_from_dev(dev);
+	if (!group)
+		return ERR_PTR(-ENODEV);
+
+	ret = vfio_group_add_container_user(group);
+	if (ret) {
+		vfio_group_put(group);
+		return ERR_PTR(ret);
+	}
+
+	return group;
+}
+EXPORT_SYMBOL_GPL(vfio_group_get_external_user_from_dev);
+
 void vfio_group_put_external_user(struct vfio_group *group)
 {
 	vfio_group_try_dissolve_container(group);
@@ -1961,6 +2011,146 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
 }
 EXPORT_SYMBOL(vfio_unpin_pages);
 
+/*
+ * Pin a set of guest IOVA PFNs and return their associated host PFNs for a
+ * VFIO group.
+ *
+ * The caller needs to call vfio_group_get_external_user() or
+ * vfio_group_get_external_user_from_dev() prior to calling this interface,
+ * so as to prevent the VFIO group from disposal in the middle of the call.
+ * But it can keep the reference to the VFIO group for several calls into
+ * this interface.
+ * After finishing using of the VFIO group, the caller needs to release the
+ * VFIO group by calling vfio_group_put_external_user().
+ *
+ * @group [in]		: VFIO group
+ * @user_iova_pfn [in]	: array of user/guest IOVA PFNs to be pinned.
+ * @npage [in]		: count of elements in user_iova_pfn array.
+ *			  This count should not be greater
+ *			  VFIO_PIN_PAGES_MAX_ENTRIES.
+ * @prot [in]		: protection flags
+ * @phys_pfn [out]	: array of host PFNs
+ * Return error or number of pages pinned.
+ */
+int vfio_group_pin_pages(struct vfio_group *group,
+			 unsigned long *user_iova_pfn, int npage,
+			 int prot, unsigned long *phys_pfn)
+{
+	struct vfio_container *container;
+	struct vfio_iommu_driver *driver;
+	int ret;
+
+	if (!group || !user_iova_pfn || !phys_pfn || !npage)
+		return -EINVAL;
+
+	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
+		return -E2BIG;
+
+	container = group->container;
+	driver = container->iommu_driver;
+	if (likely(driver && driver->ops->pin_pages))
+		ret = driver->ops->pin_pages(container->iommu_data,
+					     user_iova_pfn, npage,
+					     prot, phys_pfn);
+	else
+		ret = -ENOTTY;
+
+	return ret;
+}
+EXPORT_SYMBOL(vfio_group_pin_pages);
+
+/*
+ * Unpin a set of guest IOVA PFNs for a VFIO group.
+ *
+ * The caller needs to call vfio_group_get_external_user() or
+ * vfio_group_get_external_user_from_dev() prior to calling this interface,
+ * so as to prevent the VFIO group from disposal in the middle of the call.
+ * But it can keep the reference to the VFIO group for several calls into
+ * this interface.
+ * After finishing using of the VFIO group, the caller needs to release the
+ * VFIO group by calling vfio_group_put_external_user().
+ *
+ * @group [in]		: vfio group
+ * @user_iova_pfn [in]	: array of user/guest IOVA PFNs to be unpinned.
+ * @npage [in]		: count of elements in user_iova_pfn array.
+ *			  This count should not be greater than
+ *			  VFIO_PIN_PAGES_MAX_ENTRIES.
+ * Return error or number of pages unpinned.
+ */
+int vfio_group_unpin_pages(struct vfio_group *group,
+			   unsigned long *user_iova_pfn, int npage)
+{
+	struct vfio_container *container;
+	struct vfio_iommu_driver *driver;
+	int ret;
+
+	if (!group || !user_iova_pfn || !npage)
+		return -EINVAL;
+
+	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
+		return -E2BIG;
+
+	container = group->container;
+	driver = container->iommu_driver;
+	if (likely(driver && driver->ops->unpin_pages))
+		ret = driver->ops->unpin_pages(container->iommu_data,
+					       user_iova_pfn, npage);
+	else
+		ret = -ENOTTY;
+
+	return ret;
+}
+EXPORT_SYMBOL(vfio_group_unpin_pages);
+
+
+/*
+ * This interface allows the CPUs to perform some sort of virtual DMA on
+ * behalf of the device.
+ *
+ * CPUs read/write from/into a range of IOVAs pointing to user space memory
+ * into/from a kernel buffer.
+ *
+ * As the read/write of user space memory is conducted via the CPUs and is
+ * not a real device DMA, it is not necessary to pin the user space memory.
+ *
+ * The caller needs to call vfio_group_get_external_user() or
+ * vfio_group_get_external_user_from_dev() prior to calling this interface,
+ * so as to prevent the VFIO group from disposal in the middle of the call.
+ * But it can keep the reference to the VFIO group for several calls into
+ * this interface.
+ * After finishing using of the VFIO group, the caller needs to release the
+ * VFIO group by calling vfio_group_put_external_user().
+ *
+ * @group [in]		: VFIO group
+ * @user_iova [in]	: base IOVA of a user space buffer
+ * @data [in]		: pointer to kernel buffer
+ * @len [in]		: kernel buffer length
+ * @write		: indicate read or write
+ * Return error code on failure or 0 on success.
+ */
+int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova,
+		void *data, size_t len, bool write)
+{
+	struct vfio_container *container;
+	struct vfio_iommu_driver *driver;
+	int ret = 0;
+
+	if (!group || !data || len <= 0)
+		return -EINVAL;
+
+	container = group->container;
+	driver = container->iommu_driver;
+
+	if (likely(driver && driver->ops->dma_rw))
+		ret = driver->ops->dma_rw(container->iommu_data,
+					  user_iova, data, len, write);
+	else
+		ret = -ENOTTY;
+
+	return ret;
+}
+EXPORT_SYMBOL(vfio_dma_rw);
+
 static int vfio_register_iommu_notifier(struct vfio_group *group,
 					unsigned long *events,
 					struct notifier_block *nb)

drivers/vfio/vfio.c

@@ -27,6 +27,7 @@
 #include <linux/iommu.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/mmu_context.h>
 #include <linux/rbtree.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/mm.h>
@@ -1786,7 +1787,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 
 	if (resv_msi) {
 		ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
-		if (ret)
+		if (ret && ret != -ENODEV)
 			goto out_detach;
 	}
 
@@ -2305,6 +2306,80 @@ static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
 	return blocking_notifier_chain_unregister(&iommu->notifier, nb);
 }
 
+static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
+					 dma_addr_t user_iova, void *data,
+					 size_t count, bool write,
+					 size_t *copied)
+{
+	struct mm_struct *mm;
+	unsigned long vaddr;
+	struct vfio_dma *dma;
+	bool kthread = current->mm == NULL;
+	size_t offset;
+
+	*copied = 0;
+
+	dma = vfio_find_dma(iommu, user_iova, 1);
+	if (!dma)
+		return -EINVAL;
+
+	if ((write && !(dma->prot & IOMMU_WRITE)) ||
+			!(dma->prot & IOMMU_READ))
+		return -EPERM;
+
+	mm = get_task_mm(dma->task);
+
+	if (!mm)
+		return -EPERM;
+
+	if (kthread)
+		use_mm(mm);
+	else if (current->mm != mm)
+		goto out;
+
+	offset = user_iova - dma->iova;
+
+	if (count > dma->size - offset)
+		count = dma->size - offset;
+
+	vaddr = dma->vaddr + offset;
+
+	if (write)
+		*copied = __copy_to_user((void __user *)vaddr, data,
+					 count) ? 0 : count;
+	else
+		*copied = __copy_from_user(data, (void __user *)vaddr,
+					   count) ? 0 : count;
+	if (kthread)
+		unuse_mm(mm);
+out:
+	mmput(mm);
+	return *copied ? 0 : -EFAULT;
+}
+
+static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova,
+				   void *data, size_t count, bool write)
+{
+	struct vfio_iommu *iommu = iommu_data;
+	int ret = 0;
+	size_t done;
+
+	mutex_lock(&iommu->lock);
+	while (count > 0) {
+		ret = vfio_iommu_type1_dma_rw_chunk(iommu, user_iova, data,
+						    count, write, &done);
+		if (ret)
+			break;
+
+		count -= done;
+		data += done;
+		user_iova += done;
+	}
+
+	mutex_unlock(&iommu->lock);
+	return ret;
+}
+
 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
 	.name			= "vfio-iommu-type1",
 	.owner			= THIS_MODULE,
@@ -2317,6 +2392,7 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
 	.unpin_pages		= vfio_iommu_type1_unpin_pages,
 	.register_notifier	= vfio_iommu_type1_register_notifier,
 	.unregister_notifier	= vfio_iommu_type1_unregister_notifier,
+	.dma_rw			= vfio_iommu_type1_dma_rw,
 };
 
 static int __init vfio_iommu_type1_init(void)