Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost cross endian support from Michael Tsirkin:
 "I have just queued some more bugfix patches today but none fix
  regressions and none are related to these ones, so it looks like a
  good time for a merge for -rc1.

  The motivation for this is support for legacy BE guests on the new LE
  hosts.  There are two redeeming properties that made me merge this:

   - It's a trivial amount of code: since we wrap host/guest accesses
     anyway, almost all of it is well hidden from drivers.

   - Sane platforms would never set flags like VHOST_CROSS_ENDIAN_LEGACY,
     and when it's clear, there's zero overhead (as some point it was
     tested by compiling with and without the patches, got the same
     stripped binary).

  Maybe we could create a Kconfig symbol to enforce the second point:
  prevent people from enabling it eg on x86.  I will look into this"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio-pci: alloc only resources actually used.
  macvtap/tun: cross-endian support for little-endian hosts
  vhost: cross-endian support for legacy devices
  virtio: add explicit big-endian support to memory accessors
  vhost: introduce vhost_is_little_endian() helper
  vringh: introduce vringh_is_little_endian() helper
  macvtap: introduce macvtap_is_little_endian() helper
  tun: add tun_is_little_endian() helper
  virtio: introduce virtio_is_little_endian() helper

4 files changed, 32 insertions, 14 deletions

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 5447b8186332..78f804af6c20 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -507,10 +507,6 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
 	if (rc)
 		goto err_enable_device;
 
-	rc = pci_request_regions(pci_dev, "virtio-pci");
-	if (rc)
-		goto err_request_regions;
-
 	if (force_legacy) {
 		rc = virtio_pci_legacy_probe(vp_dev);
 		/* Also try modern mode if we can't map BAR0 (no IO space). */
@@ -540,8 +536,6 @@ err_register:
 	else
 	     virtio_pci_modern_remove(vp_dev);
 err_probe:
-	pci_release_regions(pci_dev);
-err_request_regions:
 	pci_disable_device(pci_dev);
 err_enable_device:
 	kfree(vp_dev);
@@ -559,7 +553,6 @@ static void virtio_pci_remove(struct pci_dev *pci_dev)
 	else
 		virtio_pci_modern_remove(vp_dev);
 
-	pci_release_regions(pci_dev);
 	pci_disable_device(pci_dev);
 }
 
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index 28ee4e56badf..b976d968e793 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -75,6 +75,8 @@ struct virtio_pci_device {
 	/* Multiply queue_notify_off by this value. (non-legacy mode). */
 	u32 notify_offset_multiplier;
 
+	int modern_bars;
+
 	/* Legacy only field */
 	/* the IO mapping for the PCI config space */
 	void __iomem *ioaddr;
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index 256a5278a515..48bc9797e530 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -215,6 +215,7 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
 int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 {
 	struct pci_dev *pci_dev = vp_dev->pci_dev;
+	int rc;
 
 	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
 	if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
@@ -226,9 +227,14 @@ int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 		return -ENODEV;
 	}
 
+	rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
+	if (rc)
+		return rc;
+
+	rc = -ENOMEM;
 	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
 	if (!vp_dev->ioaddr)
-		return -ENOMEM;
+		goto err_iomap;
 
 	vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
 
@@ -246,6 +252,10 @@ int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 	vp_dev->del_vq = del_vq;
 
 	return 0;
+
+err_iomap:
+	pci_release_region(pci_dev, 0);
+	return rc;
 }
 
 void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
@@ -253,4 +263,5 @@ void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 	struct pci_dev *pci_dev = vp_dev->pci_dev;
 
 	pci_iounmap(pci_dev, vp_dev->ioaddr);
+	pci_release_region(pci_dev, 0);
 }
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index e88e0997a889..8e5cf194cc0b 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -499,7 +499,7 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
  * Returns offset of the capability, or 0.
  */
 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
-					     u32 ioresource_types)
+					     u32 ioresource_types, int *bars)
 {
 	int pos;
 
@@ -520,8 +520,10 @@ static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
 
 		if (type == cfg_type) {
 			if (pci_resource_len(dev, bar) &&
-			    pci_resource_flags(dev, bar) & ioresource_types)
+			    pci_resource_flags(dev, bar) & ioresource_types) {
+				*bars |= (1 << bar);
 				return pos;
+			}
 		}
 	}
 	return 0;
@@ -617,7 +619,8 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
 
 	/* check for a common config: if not, use legacy mode (bar 0). */
 	common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
-					    IORESOURCE_IO | IORESOURCE_MEM);
+					    IORESOURCE_IO | IORESOURCE_MEM,
+					    &vp_dev->modern_bars);
 	if (!common) {
 		dev_info(&pci_dev->dev,
 			 "virtio_pci: leaving for legacy driver\n");
@@ -626,9 +629,11 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
 
 	/* If common is there, these should be too... */
 	isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
-					 IORESOURCE_IO | IORESOURCE_MEM);
+					 IORESOURCE_IO | IORESOURCE_MEM,
+					 &vp_dev->modern_bars);
 	notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
-					    IORESOURCE_IO | IORESOURCE_MEM);
+					    IORESOURCE_IO | IORESOURCE_MEM,
+					    &vp_dev->modern_bars);
 	if (!isr || !notify) {
 		dev_err(&pci_dev->dev,
 			"virtio_pci: missing capabilities %i/%i/%i\n",
@@ -640,7 +645,13 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
 	 * device-specific configuration.
 	 */
 	device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
-					    IORESOURCE_IO | IORESOURCE_MEM);
+					    IORESOURCE_IO | IORESOURCE_MEM,
+					    &vp_dev->modern_bars);
+
+	err = pci_request_selected_regions(pci_dev, vp_dev->modern_bars,
+					   "virtio-pci-modern");
+	if (err)
+		return err;
 
 	err = -EINVAL;
 	vp_dev->common = map_capability(pci_dev, common,
@@ -727,4 +738,5 @@ void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
 		pci_iounmap(pci_dev, vp_dev->notify_base);
 	pci_iounmap(pci_dev, vp_dev->isr);
 	pci_iounmap(pci_dev, vp_dev->common);
+	pci_release_selected_regions(pci_dev, vp_dev->modern_bars);
 }