vhost,vdpa,virtio: cleanups, fixes

A very quiet cycle, no new features.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "vhost, vdpa, and virtio cleanups and fixes

  A very quiet cycle, no new features"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  MAINTAINERS: add URL for virtio-mem
  vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call
  vringh: fix __vringh_iov() when riov and wiov are different
  vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK
  s390: virtio: PV needs VIRTIO I/O device protection
  virtio: let arch advertise guest's memory access restrictions
  vhost_vdpa: Fix duplicate included kernel.h
  vhost: reduce stack usage in log_used
  virtio-mem: Constify mem_id_table
  virtio_input: Constify id_table
  virtio-balloon: Constify id_table
  vdpa/mlx5: Fix failure to bring link up
  vdpa/mlx5: Make use of a specific 16 bit endianness API

MAINTAINERS

@@ -18629,6 +18629,7 @@ VIRTIO MEM DRIVER
 M:	David Hildenbrand <david@redhat.com>
 L:	virtualization@lists.linux-foundation.org
 S:	Maintained
+W:	https://virtio-mem.gitlab.io/
 F:	drivers/virtio/virtio_mem.c
 F:	include/uapi/linux/virtio_mem.h
 

arch/s390/Kconfig

@@ -810,6 +810,7 @@ menu "Virtualization"
 config PROTECTED_VIRTUALIZATION_GUEST
 	def_bool n
 	prompt "Protected virtualization guest support"
+	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
 	help
 	  Select this option, if you want to be able to run this
 	  kernel as a protected virtualization KVM guest.

arch/s390/mm/init.c

@@ -46,6 +46,7 @@
 #include <asm/kasan.h>
 #include <asm/dma-mapping.h>
 #include <asm/uv.h>
+#include <linux/virtio_config.h>
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 
@@ -162,6 +163,16 @@ bool force_dma_unencrypted(struct device *dev)
 	return is_prot_virt_guest();
 }
 
+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+
+int arch_has_restricted_virtio_memory_access(void)
+{
+	return is_prot_virt_guest();
+}
+EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
+
+#endif
+
 /* protected virtualization */
 static void pv_init(void)
 {

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -1522,6 +1522,11 @@ static inline bool mlx5_vdpa_is_little_endian(struct mlx5_vdpa_dev *mvdev)
 		(mvdev->actual_features & (1ULL << VIRTIO_F_VERSION_1));
 }
 
+static __virtio16 cpu_to_mlx5vdpa16(struct mlx5_vdpa_dev *mvdev, u16 val)
+{
+	return __cpu_to_virtio16(mlx5_vdpa_is_little_endian(mvdev), val);
+}
+
 static int mlx5_vdpa_set_features(struct vdpa_device *vdev, u64 features)
 {
 	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
@@ -1535,8 +1540,8 @@ static int mlx5_vdpa_set_features(struct vdpa_device *vdev, u64 features)
 		return err;
 
 	ndev->mvdev.actual_features = features & ndev->mvdev.mlx_features;
-	ndev->config.mtu = __cpu_to_virtio16(mlx5_vdpa_is_little_endian(mvdev),
+	ndev->config.mtu = cpu_to_mlx5vdpa16(mvdev, ndev->mtu);
-					     ndev->mtu);
+	ndev->config.status |= cpu_to_mlx5vdpa16(mvdev, VIRTIO_NET_S_LINK_UP);
 	return err;
 }
 
@@ -1653,6 +1658,9 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_net *ndev, struct vhost_iotlb *
 	if (err)
 		goto err_mr;
 
+	if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
+		return 0;
+
 	restore_channels_info(ndev);
 	err = setup_driver(ndev);
 	if (err)

drivers/vhost/vdpa.c

@@ -22,7 +22,6 @@
 #include <linux/nospec.h>
 #include <linux/vhost.h>
 #include <linux/virtio_net.h>
-#include <linux/kernel.h>
 
 #include "vhost.h"
 
@@ -97,26 +96,20 @@ static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
 		return;
 
 	irq = ops->get_vq_irq(vdpa, qid);
-	spin_lock(&vq->call_ctx.ctx_lock);
 	irq_bypass_unregister_producer(&vq->call_ctx.producer);
-	if (!vq->call_ctx.ctx || irq < 0) {
+	if (!vq->call_ctx.ctx || irq < 0)
-		spin_unlock(&vq->call_ctx.ctx_lock);
 		return;
-	}
 
 	vq->call_ctx.producer.token = vq->call_ctx.ctx;
 	vq->call_ctx.producer.irq = irq;
 	ret = irq_bypass_register_producer(&vq->call_ctx.producer);
-	spin_unlock(&vq->call_ctx.ctx_lock);
 }
 
 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
 {
 	struct vhost_virtqueue *vq = &v->vqs[qid];
 
-	spin_lock(&vq->call_ctx.ctx_lock);
 	irq_bypass_unregister_producer(&vq->call_ctx.producer);
-	spin_unlock(&vq->call_ctx.ctx_lock);
 }
 
 static void vhost_vdpa_reset(struct vhost_vdpa *v)

drivers/vhost/vhost.c

@@ -302,7 +302,6 @@ static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx)
 {
 	call_ctx->ctx = NULL;
 	memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer));
-	spin_lock_init(&call_ctx->ctx_lock);
 }
 
 static void vhost_vq_reset(struct vhost_dev *dev,
@@ -1650,9 +1649,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
 			break;
 		}
 
-		spin_lock(&vq->call_ctx.ctx_lock);
 		swap(ctx, vq->call_ctx.ctx);
-		spin_unlock(&vq->call_ctx.ctx_lock);
 		break;
 	case VHOST_SET_VRING_ERR:
 		if (copy_from_user(&f, argp, sizeof f)) {
@@ -1897,7 +1894,7 @@ static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len)
 
 static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len)
 {
-	struct iovec iov[64];
+	struct iovec *iov = vq->log_iov;
 	int i, ret;
 
 	if (!vq->iotlb)

drivers/vhost/vhost.h

@@ -64,7 +64,6 @@ enum vhost_uaddr_type {
 struct vhost_vring_call {
 	struct eventfd_ctx *ctx;
 	struct irq_bypass_producer producer;
-	spinlock_t ctx_lock;
 };
 
 /* The virtqueue structure describes a queue attached to a device. */
@@ -123,6 +122,7 @@ struct vhost_virtqueue {
 	/* Log write descriptors */
 	void __user *log_base;
 	struct vhost_log *log;
+	struct iovec log_iov[64];
 
 	/* Ring endianness. Defaults to legacy native endianness.
 	 * Set to true when starting a modern virtio device. */

drivers/vhost/vringh.c

@@ -284,13 +284,14 @@ __vringh_iov(struct vringh *vrh, u16 i,
 	desc_max = vrh->vring.num;
 	up_next = -1;
 
+	/* You must want something! */
+	if (WARN_ON(!riov && !wiov))
+		return -EINVAL;
+
 	if (riov)
 		riov->i = riov->used = 0;
-	else if (wiov)
+	if (wiov)
 		wiov->i = wiov->used = 0;
-	else
-		/* You must want something! */
-		BUG();
 
 	for (;;) {
 		void *addr;

drivers/virtio/Kconfig

@@ -6,6 +6,12 @@ config VIRTIO
 	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
 	  or CONFIG_S390_GUEST.
 
+config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+	bool
+	help
+	  This option is selected if the architecture may need to enforce
+	  VIRTIO_F_ACCESS_PLATFORM
+
 menuconfig VIRTIO_MENU
 	bool "Virtio drivers"
 	default y

drivers/virtio/virtio.c

@@ -176,6 +176,21 @@ int virtio_finalize_features(struct virtio_device *dev)
 	if (ret)
 		return ret;
 
+	ret = arch_has_restricted_virtio_memory_access();
+	if (ret) {
+		if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
+			dev_warn(&dev->dev,
+				 "device must provide VIRTIO_F_VERSION_1\n");
+			return -ENODEV;
+		}
+
+		if (!virtio_has_feature(dev, VIRTIO_F_ACCESS_PLATFORM)) {
+			dev_warn(&dev->dev,
+				 "device must provide VIRTIO_F_ACCESS_PLATFORM\n");
+			return -ENODEV;
+		}
+	}
+
 	if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
 		return 0;
 

drivers/virtio/virtio_balloon.c

@@ -128,7 +128,7 @@ struct virtio_balloon {
 	struct page_reporting_dev_info pr_dev_info;
 };
 
-static struct virtio_device_id id_table[] = {
+static const struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_BALLOON, VIRTIO_DEV_ANY_ID },
 	{ 0 },
 };

drivers/virtio/virtio_input.c

@@ -363,7 +363,7 @@ static int virtinput_restore(struct virtio_device *vdev)
 static unsigned int features[] = {
 	/* none */
 };
-static struct virtio_device_id id_table[] = {
+static const struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
 	{ 0 },
 };

drivers/virtio/virtio_mem.c

@@ -1927,7 +1927,7 @@ static unsigned int virtio_mem_features[] = {
 #endif
 };
 
-static struct virtio_device_id virtio_mem_id_table[] = {
+static const struct virtio_device_id virtio_mem_id_table[] = {
 	{ VIRTIO_ID_MEM, VIRTIO_DEV_ANY_ID },
 	{ 0 },
 };

include/linux/virtio_config.h

@@ -557,4 +557,14 @@ static inline void virtio_cwrite64(struct virtio_device *vdev,
 			virtio_cread_le((vdev), structname, member, ptr); \
 		_r;							\
 	})
+
+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+int arch_has_restricted_virtio_memory_access(void);
+#else
+static inline int arch_has_restricted_virtio_memory_access(void)
+{
+	return 0;
+}
+#endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */
+
 #endif /* _LINUX_VIRTIO_CONFIG_H */