[PATCH AUTOSEL 4.14 101/371] vfio_pci: Enable memory accesses before calling pci_map_rom

[PATCH AUTOSEL 4.14 101/371] vfio_pci: Enable memory accesses before calling pci_map_rom

[Sasha Levin]

From: Eric Auger <eric.auger@redhat.com>

[ Upstream commit 0cfd027be1d6def4a462cdc180c055143af24069 ]

pci_map_rom/pci_get_rom_size() performs memory access in the ROM.
In case the Memory Space accesses were disabled, readw() is likely
to trigger a synchronous external abort on some platforms.

In case memory accesses were disabled, re-enable them before the
call and disable them back again just after.

Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vfio/pci/vfio_pci.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 9bd3e7911af2..550ab7707b57 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -717,6 +717,7 @@ static long vfio_pci_ioctl(void *device_data,
 		{
 			void __iomem *io;
 			size_t size;
+			u16 orig_cmd;
 
 			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 			info.flags = 0;
@@ -732,15 +733,23 @@ static long vfio_pci_ioctl(void *device_data,
 					break;
 			}
 
-			/* Is it really there? */
+			/*
+			 * Is it really there?  Enable memory decode for
+			 * implicit access in pci_map_rom().
+			 */
+			pci_read_config_word(pdev, PCI_COMMAND, &orig_cmd);
+			pci_write_config_word(pdev, PCI_COMMAND,
+					      orig_cmd | PCI_COMMAND_MEMORY);
+
 			io = pci_map_rom(pdev, &size);
-			if (!io || !size) {
+			if (io) {
+				info.flags = VFIO_REGION_INFO_FLAG_READ;
+				pci_unmap_rom(pdev, io);
+			} else {
 				info.size = 0;
-				break;
 			}
-			pci_unmap_rom(pdev, io);
 
-			info.flags = VFIO_REGION_INFO_FLAG_READ;
+			pci_write_config_word(pdev, PCI_COMMAND, orig_cmd);
 			break;
 		}
 		case VFIO_PCI_VGA_REGION_INDEX:
-- 
2.20.1

[PATCH AUTOSEL 4.14 190/371] vfio/mdev: Avoid release parent reference during error path

[Sasha Levin]

From: Parav Pandit <parav@mellanox.com>

[ Upstream commit 60e7f2c3fe9919cee9534b422865eed49f4efb15 ]

During mdev parent registration in mdev_register_device(),
if parent device is duplicate, it releases the reference of existing
parent device.
This is incorrect. Existing parent device should not be touched.

Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vfio/mdev/mdev_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 0212f0ee8aea..8cfa71230877 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -182,6 +182,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
 	/* Check for duplicate */
 	parent = __find_parent_device(dev);
 	if (parent) {
+		parent = NULL;
 		ret = -EEXIST;
 		goto add_dev_err;
 	}
-- 
2.20.1

[PATCH AUTOSEL 4.14 191/371] vfio/mdev: Fix aborting mdev child device removal if one fails

[Sasha Levin]

From: Parav Pandit <parav@mellanox.com>

[ Upstream commit 6093e348a5e2475c5bb2e571346460f939998670 ]

device_for_each_child() stops executing callback function for remaining
child devices, if callback hits an error.
Each child mdev device is independent of each other.
While unregistering parent device, mdev core must remove all child mdev
devices.
Therefore, mdev_device_remove_cb() always returns success so that
device_for_each_child doesn't abort if one child removal hits error.

While at it, improve remove and unregister functions for below simplicity.

There isn't need to pass forced flag pointer during mdev parent
removal which invokes mdev_device_remove(). So simplify the flow.

mdev_device_remove() is called from two paths.
1. mdev_unregister_driver()
     mdev_device_remove_cb()
       mdev_device_remove()
2. remove_store()
     mdev_device_remove()

Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vfio/mdev/mdev_core.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 8cfa71230877..e052f62fdea7 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -150,10 +150,10 @@ static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
 
 static int mdev_device_remove_cb(struct device *dev, void *data)
 {
-	if (!dev_is_mdev(dev))
-		return 0;
+	if (dev_is_mdev(dev))
+		mdev_device_remove(dev, true);
 
-	return mdev_device_remove(dev, data ? *(bool *)data : true);
+	return 0;
 }
 
 /*
@@ -241,7 +241,6 @@ EXPORT_SYMBOL(mdev_register_device);
 void mdev_unregister_device(struct device *dev)
 {
 	struct mdev_parent *parent;
-	bool force_remove = true;
 
 	mutex_lock(&parent_list_lock);
 	parent = __find_parent_device(dev);
@@ -255,8 +254,7 @@ void mdev_unregister_device(struct device *dev)
 	list_del(&parent->next);
 	class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
 
-	device_for_each_child(dev, (void *)&force_remove,
-			      mdev_device_remove_cb);
+	device_for_each_child(dev, NULL, mdev_device_remove_cb);
 
 	parent_remove_sysfs_files(parent);
 
-- 
2.20.1