[PATCH v4 00/14] vdpa: add vdpa simulator for block device

[PATCH v4 00/14] vdpa: add vdpa simulator for block device

[Stefano Garzarella]

v4:
- added support for iproute2 vdpa management tool in vdpa_sim_blk
- removed get/set_config patches
  - 'vdpa: add return value to get_config/set_config callbacks'
  - 'vhost/vdpa: remove vhost_vdpa_config_validate()'
- added get_config_size() patches
  - 'vdpa: add get_config_size callback in vdpa_config_ops'
  - 'vhost/vdpa: use get_config_size callback in vhost_vdpa_config_validate()'

v3: https://lore.kernel.org/lkml/20210204172230.85853-1-sgarzare@redhat.com/
v2: https://lore.kernel.org/lkml/20210128144127.113245-1-sgarzare@redhat.com/
v1: https://lore.kernel.org/lkml/93f207c0-61e6-3696-f218-e7d7ea9a7c93@redhat.com/

This series is the second part of the v1 linked above. The first part with
refactoring of vdpa_sim has already been merged.

The patches are based on Max Gurtovoy's work and extend the block simulator to
have a ramdisk behaviour.

As mentioned in the v1 there was 2 issues and I fixed them in this series:
1. The identical mapping in the IOMMU used until now in vdpa_sim created issues
   when mapping different virtual pages with the same physical address.
   Fixed by patch "vdpa_sim: use iova module to allocate IOVA addresses"

2. There was a race accessing the IOMMU between the vdpasim_blk_work() and the
   device driver that map/unmap DMA regions. Fixed by patch "vringh: add
   'iotlb_lock' to synchronize iotlb accesses"

I used the Xie's patch coming from VDUSE series to allow vhost-vdpa to use
block devices, and I added get_config_size() callback to allow any device
in vhost-vdpa.

The series also includes small fixes for vringh, vdpa, and vdpa_sim that I
discovered while implementing and testing the block simulator.

Thanks for your feedback,
Stefano

Max Gurtovoy (1):
  vdpa: add vdpa simulator for block device

Stefano Garzarella (12):
  vdpa_sim: use iova module to allocate IOVA addresses
  vringh: add 'iotlb_lock' to synchronize iotlb accesses
  vringh: reset kiov 'consumed' field in __vringh_iov()
  vringh: explain more about cleaning riov and wiov
  vringh: implement vringh_kiov_advance()
  vringh: add vringh_kiov_length() helper
  vdpa_sim: cleanup kiovs in vdpasim_free()
  vdpa: add get_config_size callback in vdpa_config_ops
  vhost/vdpa: use get_config_size callback in
    vhost_vdpa_config_validate()
  vdpa_sim_blk: implement ramdisk behaviour
  vdpa_sim_blk: handle VIRTIO_BLK_T_GET_ID
  vdpa_sim_blk: add support for vdpa management tool

Xie Yongji (1):
  vhost/vdpa: Remove the restriction that only supports virtio-net
    devices

 drivers/vdpa/vdpa_sim/vdpa_sim.h     |   2 +
 include/linux/vdpa.h                 |   4 +
 include/linux/vringh.h               |  19 +-
 drivers/vdpa/ifcvf/ifcvf_main.c      |   6 +
 drivers/vdpa/mlx5/net/mlx5_vnet.c    |   6 +
 drivers/vdpa/vdpa_sim/vdpa_sim.c     | 127 ++++++----
 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 338 +++++++++++++++++++++++++++
 drivers/vdpa/virtio_pci/vp_vdpa.c    |   8 +
 drivers/vhost/vdpa.c                 |  15 +-
 drivers/vhost/vringh.c               |  69 ++++--
 drivers/vdpa/Kconfig                 |   8 +
 drivers/vdpa/vdpa_sim/Makefile       |   1 +
 12 files changed, 529 insertions(+), 74 deletions(-)
 create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c

-- 
2.30.2

[PATCH v4 01/14] vdpa_sim: use iova module to allocate IOVA addresses

[Stefano Garzarella]

The identical mapping used until now created issues when mapping
different virtual pages with the same physical address.
To solve this issue, we can use the iova module, to handle the IOVA
allocation.
For simplicity we use an IOVA allocator with byte granularity.

We add two new functions, vdpasim_map_range() and vdpasim_unmap_range(),
to handle the IOVA allocation and the registration into the IOMMU/IOTLB.
These functions are used by dma_map_ops callbacks.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v2:
- used ULONG_MAX instead of ~0UL [Jason]
- fixed typos in comment and patch description [Jason]
---
 drivers/vdpa/vdpa_sim/vdpa_sim.h |   2 +
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 108 +++++++++++++++++++------------
 drivers/vdpa/Kconfig             |   1 +
 3 files changed, 69 insertions(+), 42 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.h b/drivers/vdpa/vdpa_sim/vdpa_sim.h
index 6d75444f9948..cd58e888bcf3 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.h
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.h
@@ -6,6 +6,7 @@
 #ifndef _VDPA_SIM_H
 #define _VDPA_SIM_H
 
+#include <linux/iova.h>
 #include <linux/vringh.h>
 #include <linux/vdpa.h>
 #include <linux/virtio_byteorder.h>
@@ -57,6 +58,7 @@ struct vdpasim {
 	/* virtio config according to device type */
 	void *config;
 	struct vhost_iotlb *iommu;
+	struct iova_domain iova;
 	void *buffer;
 	u32 status;
 	u32 generation;
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 5b6b2f87d40c..fc2ec9599753 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -17,6 +17,7 @@
 #include <linux/vringh.h>
 #include <linux/vdpa.h>
 #include <linux/vhost_iotlb.h>
+#include <linux/iova.h>
 
 #include "vdpa_sim.h"
 
@@ -128,30 +129,57 @@ static int dir_to_perm(enum dma_data_direction dir)
 	return perm;
 }
 
+static dma_addr_t vdpasim_map_range(struct vdpasim *vdpasim, phys_addr_t paddr,
+				    size_t size, unsigned int perm)
+{
+	struct iova *iova;
+	dma_addr_t dma_addr;
+	int ret;
+
+	/* We set the limit_pfn to the maximum (ULONG_MAX - 1) */
+	iova = alloc_iova(&vdpasim->iova, size, ULONG_MAX - 1, true);
+	if (!iova)
+		return DMA_MAPPING_ERROR;
+
+	dma_addr = iova_dma_addr(&vdpasim->iova, iova);
+
+	spin_lock(&vdpasim->iommu_lock);
+	ret = vhost_iotlb_add_range(vdpasim->iommu, (u64)dma_addr,
+				    (u64)dma_addr + size - 1, (u64)paddr, perm);
+	spin_unlock(&vdpasim->iommu_lock);
+
+	if (ret) {
+		__free_iova(&vdpasim->iova, iova);
+		return DMA_MAPPING_ERROR;
+	}
+
+	return dma_addr;
+}
+
+static void vdpasim_unmap_range(struct vdpasim *vdpasim, dma_addr_t dma_addr,
+				size_t size)
+{
+	spin_lock(&vdpasim->iommu_lock);
+	vhost_iotlb_del_range(vdpasim->iommu, (u64)dma_addr,
+			      (u64)dma_addr + size - 1);
+	spin_unlock(&vdpasim->iommu_lock);
+
+	free_iova(&vdpasim->iova, iova_pfn(&vdpasim->iova, dma_addr));
+}
+
 static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
 				   unsigned long offset, size_t size,
 				   enum dma_data_direction dir,
 				   unsigned long attrs)
 {
 	struct vdpasim *vdpasim = dev_to_sim(dev);
-	struct vhost_iotlb *iommu = vdpasim->iommu;
-	u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset;
-	int ret, perm = dir_to_perm(dir);
+	phys_addr_t paddr = page_to_phys(page) + offset;
+	int perm = dir_to_perm(dir);
 
 	if (perm < 0)
 		return DMA_MAPPING_ERROR;
 
-	/* For simplicity, use identical mapping to avoid e.g iova
-	 * allocator.
-	 */
-	spin_lock(&vdpasim->iommu_lock);
-	ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
-				    pa, dir_to_perm(dir));
-	spin_unlock(&vdpasim->iommu_lock);
-	if (ret)
-		return DMA_MAPPING_ERROR;
-
-	return (dma_addr_t)(pa);
+	return vdpasim_map_range(vdpasim, paddr, size, perm);
 }
 
 static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
@@ -159,12 +187,8 @@ static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
 			       unsigned long attrs)
 {
 	struct vdpasim *vdpasim = dev_to_sim(dev);
-	struct vhost_iotlb *iommu = vdpasim->iommu;
 
-	spin_lock(&vdpasim->iommu_lock);
-	vhost_iotlb_del_range(iommu, (u64)dma_addr,
-			      (u64)dma_addr + size - 1);
-	spin_unlock(&vdpasim->iommu_lock);
+	vdpasim_unmap_range(vdpasim, dma_addr, size);
 }
 
 static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
@@ -172,27 +196,22 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
 				    unsigned long attrs)
 {
 	struct vdpasim *vdpasim = dev_to_sim(dev);
-	struct vhost_iotlb *iommu = vdpasim->iommu;
-	void *addr = kmalloc(size, flag);
-	int ret;
+	phys_addr_t paddr;
+	void *addr;
 
-	spin_lock(&vdpasim->iommu_lock);
+	addr = kmalloc(size, flag);
 	if (!addr) {
 		*dma_addr = DMA_MAPPING_ERROR;
-	} else {
-		u64 pa = virt_to_phys(addr);
-
-		ret = vhost_iotlb_add_range(iommu, (u64)pa,
-					    (u64)pa + size - 1,
-					    pa, VHOST_MAP_RW);
-		if (ret) {
-			*dma_addr = DMA_MAPPING_ERROR;
-			kfree(addr);
-			addr = NULL;
-		} else
-			*dma_addr = (dma_addr_t)pa;
+		return NULL;
+	}
+
+	paddr = virt_to_phys(addr);
+
+	*dma_addr = vdpasim_map_range(vdpasim, paddr, size, VHOST_MAP_RW);
+	if (*dma_addr == DMA_MAPPING_ERROR) {
+		kfree(addr);
+		return NULL;
 	}
-	spin_unlock(&vdpasim->iommu_lock);
 
 	return addr;
 }
@@ -202,14 +221,10 @@ static void vdpasim_free_coherent(struct device *dev, size_t size,
 				  unsigned long attrs)
 {
 	struct vdpasim *vdpasim = dev_to_sim(dev);
-	struct vhost_iotlb *iommu = vdpasim->iommu;
 
-	spin_lock(&vdpasim->iommu_lock);
-	vhost_iotlb_del_range(iommu, (u64)dma_addr,
-			      (u64)dma_addr + size - 1);
-	spin_unlock(&vdpasim->iommu_lock);
+	vdpasim_unmap_range(vdpasim, dma_addr, size);
 
-	kfree(phys_to_virt((uintptr_t)dma_addr));
+	kfree(vaddr);
 }
 
 static const struct dma_map_ops vdpasim_dma_ops = {
@@ -271,6 +286,13 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
 	for (i = 0; i < dev_attr->nvqs; i++)
 		vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu);
 
+	ret = iova_cache_get();
+	if (ret)
+		goto err_iommu;
+
+	/* For simplicity we use an IOVA allocator with byte granularity */
+	init_iova_domain(&vdpasim->iova, 1, 0);
+
 	vdpasim->vdpa.dma_dev = dev;
 
 	return vdpasim;
@@ -541,6 +563,8 @@ static void vdpasim_free(struct vdpa_device *vdpa)
 	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 
 	cancel_work_sync(&vdpasim->work);
+	put_iova_domain(&vdpasim->iova);
+	iova_cache_put();
 	kvfree(vdpasim->buffer);
 	if (vdpasim->iommu)
 		vhost_iotlb_free(vdpasim->iommu);
diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
index a245809c99d0..6e82a0e228c2 100644
--- a/drivers/vdpa/Kconfig
+++ b/drivers/vdpa/Kconfig
@@ -14,6 +14,7 @@ config VDPA_SIM
 	depends on RUNTIME_TESTING_MENU && HAS_DMA
 	select DMA_OPS
 	select VHOST_RING
+	select IOMMU_IOVA
 	help
 	  Enable this module to support vDPA device simulators. These devices
 	  are used for testing, prototyping and development of vDPA.
-- 
2.30.2

[PATCH v4 02/14] vringh: add 'iotlb_lock' to synchronize iotlb accesses

[Stefano Garzarella]

Usually iotlb accesses are synchronized with a spinlock.
Let's request it as a new parameter in vringh_set_iotlb() and
hold it when we navigate the iotlb in iotlb_translate() to avoid
race conditions with any new additions/deletions of ranges from
the ioltb.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/linux/vringh.h           | 6 +++++-
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 ++-
 drivers/vhost/vringh.c           | 9 ++++++++-
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 59bd50f99291..9c077863c8f6 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -46,6 +46,9 @@ struct vringh {
 	/* IOTLB for this vring */
 	struct vhost_iotlb *iotlb;
 
+	/* spinlock to synchronize IOTLB accesses */
+	spinlock_t *iotlb_lock;
+
 	/* The function to call to notify the guest about added buffers */
 	void (*notify)(struct vringh *);
 };
@@ -258,7 +261,8 @@ static inline __virtio64 cpu_to_vringh64(const struct vringh *vrh, u64 val)
 
 #if IS_REACHABLE(CONFIG_VHOST_IOTLB)
 
-void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb);
+void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb,
+		      spinlock_t *iotlb_lock);
 
 int vringh_init_iotlb(struct vringh *vrh, u64 features,
 		      unsigned int num, bool weak_barriers,
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index fc2ec9599753..a92c08880098 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -284,7 +284,8 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
 		goto err_iommu;
 
 	for (i = 0; i < dev_attr->nvqs; i++)
-		vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu);
+		vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu,
+				 &vdpasim->iommu_lock);
 
 	ret = iova_cache_get();
 	if (ret)
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 85d85faba058..f68122705719 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -1074,6 +1074,8 @@ static int iotlb_translate(const struct vringh *vrh,
 	int ret = 0;
 	u64 s = 0;
 
+	spin_lock(vrh->iotlb_lock);
+
 	while (len > s) {
 		u64 size, pa, pfn;
 
@@ -1103,6 +1105,8 @@ static int iotlb_translate(const struct vringh *vrh,
 		++ret;
 	}
 
+	spin_unlock(vrh->iotlb_lock);
+
 	return ret;
 }
 
@@ -1262,10 +1266,13 @@ EXPORT_SYMBOL(vringh_init_iotlb);
  * vringh_set_iotlb - initialize a vringh for a ring with IOTLB.
  * @vrh: the vring
  * @iotlb: iotlb associated with this vring
+ * @iotlb_lock: spinlock to synchronize the iotlb accesses
  */
-void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb)
+void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb,
+		      spinlock_t *iotlb_lock)
 {
 	vrh->iotlb = iotlb;
+	vrh->iotlb_lock = iotlb_lock;
 }
 EXPORT_SYMBOL(vringh_set_iotlb);
 
-- 
2.30.2

[PATCH v4 03/14] vringh: reset kiov 'consumed' field in __vringh_iov()

[Stefano Garzarella]

__vringh_iov() overwrites the contents of riov and wiov, in fact it
resets the 'i' and 'used' fields, but also the 'consumed' field should
be reset to avoid an inconsistent state.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vhost/vringh.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index f68122705719..bee63d68201a 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -290,9 +290,9 @@ __vringh_iov(struct vringh *vrh, u16 i,
 		return -EINVAL;
 
 	if (riov)
-		riov->i = riov->used = 0;
+		riov->i = riov->used = riov->consumed = 0;
 	if (wiov)
-		wiov->i = wiov->used = 0;
+		wiov->i = wiov->used = wiov->consumed = 0;
 
 	for (;;) {
 		void *addr;
-- 
2.30.2

[PATCH v4 04/14] vringh: explain more about cleaning riov and wiov

[Stefano Garzarella]

riov and wiov can be reused with subsequent calls of vringh_getdesc_*().

Let's add a paragraph in the documentation of these functions to better
explain when riov and wiov need to be cleaned up.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vhost/vringh.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index bee63d68201a..2a88e087afd8 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -662,7 +662,10 @@ EXPORT_SYMBOL(vringh_init_user);
  * *head will be vrh->vring.num.  You may be able to ignore an invalid
  * descriptor, but there's not much you can do with an invalid ring.
  *
- * Note that you may need to clean up riov and wiov, even on error!
+ * Note that you can reuse riov and wiov with subsequent calls. Content is
+ * overwritten and memory reallocated if more space is needed.
+ * When you don't have to use riov and wiov anymore, you should clean up them
+ * calling vringh_iov_cleanup() to release the memory, even on error!
  */
 int vringh_getdesc_user(struct vringh *vrh,
 			struct vringh_iov *riov,
@@ -932,7 +935,10 @@ EXPORT_SYMBOL(vringh_init_kern);
  * *head will be vrh->vring.num.  You may be able to ignore an invalid
  * descriptor, but there's not much you can do with an invalid ring.
  *
- * Note that you may need to clean up riov and wiov, even on error!
+ * Note that you can reuse riov and wiov with subsequent calls. Content is
+ * overwritten and memory reallocated if more space is needed.
+ * When you don't have to use riov and wiov anymore, you should clean up them
+ * calling vringh_kiov_cleanup() to release the memory, even on error!
  */
 int vringh_getdesc_kern(struct vringh *vrh,
 			struct vringh_kiov *riov,
@@ -1292,7 +1298,10 @@ EXPORT_SYMBOL(vringh_set_iotlb);
  * *head will be vrh->vring.num.  You may be able to ignore an invalid
  * descriptor, but there's not much you can do with an invalid ring.
  *
- * Note that you may need to clean up riov and wiov, even on error!
+ * Note that you can reuse riov and wiov with subsequent calls. Content is
+ * overwritten and memory reallocated if more space is needed.
+ * When you don't have to use riov and wiov anymore, you should clean up them
+ * calling vringh_kiov_cleanup() to release the memory, even on error!
  */
 int vringh_getdesc_iotlb(struct vringh *vrh,
 			 struct vringh_kiov *riov,
-- 
2.30.2

[PATCH v4 05/14] vringh: implement vringh_kiov_advance()

[Stefano Garzarella]

In some cases, it may be useful to provide a way to skip a number
of bytes in a vringh_kiov.

Let's implement vringh_kiov_advance() for this purpose, reusing the
code from vringh_iov_xfer().
We replace that code calling the new vringh_kiov_advance().

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/linux/vringh.h |  2 ++
 drivers/vhost/vringh.c | 41 +++++++++++++++++++++++++++++------------
 2 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 9c077863c8f6..755211ebd195 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -199,6 +199,8 @@ static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov)
 	kiov->iov = NULL;
 }
 
+void vringh_kiov_advance(struct vringh_kiov *kiov, size_t len);
+
 int vringh_getdesc_kern(struct vringh *vrh,
 			struct vringh_kiov *riov,
 			struct vringh_kiov *wiov,
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 2a88e087afd8..4af8fa259d65 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -75,6 +75,34 @@ static inline int __vringh_get_head(const struct vringh *vrh,
 	return head;
 }
 
+/**
+ * vringh_kiov_advance - skip bytes from vring_kiov
+ * @iov: an iov passed to vringh_getdesc_*() (updated as we consume)
+ * @len: the maximum length to advance
+ */
+void vringh_kiov_advance(struct vringh_kiov *iov, size_t len)
+{
+	while (len && iov->i < iov->used) {
+		size_t partlen = min(iov->iov[iov->i].iov_len, len);
+
+		iov->consumed += partlen;
+		iov->iov[iov->i].iov_len -= partlen;
+		iov->iov[iov->i].iov_base += partlen;
+
+		if (!iov->iov[iov->i].iov_len) {
+			/* Fix up old iov element then increment. */
+			iov->iov[iov->i].iov_len = iov->consumed;
+			iov->iov[iov->i].iov_base -= iov->consumed;
+
+			iov->consumed = 0;
+			iov->i++;
+		}
+
+		len -= partlen;
+	}
+}
+EXPORT_SYMBOL(vringh_kiov_advance);
+
 /* Copy some bytes to/from the iovec.  Returns num copied. */
 static inline ssize_t vringh_iov_xfer(struct vringh *vrh,
 				      struct vringh_kiov *iov,
@@ -95,19 +123,8 @@ static inline ssize_t vringh_iov_xfer(struct vringh *vrh,
 		done += partlen;
 		len -= partlen;
 		ptr += partlen;
-		iov->consumed += partlen;
-		iov->iov[iov->i].iov_len -= partlen;
-		iov->iov[iov->i].iov_base += partlen;
 
-		if (!iov->iov[iov->i].iov_len) {
-			/* Fix up old iov element then increment. */
-			iov->iov[iov->i].iov_len = iov->consumed;
-			iov->iov[iov->i].iov_base -= iov->consumed;
-
-			
-			iov->consumed = 0;
-			iov->i++;
-		}
+		vringh_kiov_advance(iov, partlen);
 	}
 	return done;
 }
-- 
2.30.2

[PATCH v4 06/14] vringh: add vringh_kiov_length() helper

[Stefano Garzarella]

This new helper returns the total number of bytes covered by
a vringh_kiov.

Suggested-by: Jason Wang <jasowang@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/linux/vringh.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 755211ebd195..84db7b8f912f 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -199,6 +199,17 @@ static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov)
 	kiov->iov = NULL;
 }
 
+static inline size_t vringh_kiov_length(struct vringh_kiov *kiov)
+{
+	size_t len = 0;
+	int i;
+
+	for (i = kiov->i; i < kiov->used; i++)
+		len += kiov->iov[i].iov_len;
+
+	return len;
+}
+
 void vringh_kiov_advance(struct vringh_kiov *kiov, size_t len);
 
 int vringh_getdesc_kern(struct vringh *vrh,
-- 
2.30.2

[PATCH v4 07/14] vdpa_sim: cleanup kiovs in vdpasim_free()

[Stefano Garzarella]

vringh_getdesc_iotlb() allocates memory to store the kvec, that
is freed with vringh_kiov_cleanup().

vringh_getdesc_iotlb() is able to reuse a kvec previously allocated,
so in order to avoid to allocate the kvec for each request, we are
not calling vringh_kiov_cleanup() when we finished to handle a
request, but we should call it when we free the entire device.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index a92c08880098..14dc2d3d983e 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -562,8 +562,15 @@ static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
 static void vdpasim_free(struct vdpa_device *vdpa)
 {
 	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+	int i;
 
 	cancel_work_sync(&vdpasim->work);
+
+	for (i = 0; i < vdpasim->dev_attr.nvqs; i++) {
+		vringh_kiov_cleanup(&vdpasim->vqs[i].out_iov);
+		vringh_kiov_cleanup(&vdpasim->vqs[i].in_iov);
+	}
+
 	put_iova_domain(&vdpasim->iova);
 	iova_cache_put();
 	kvfree(vdpasim->buffer);
-- 
2.30.2

[PATCH v4 08/14] vdpa: add get_config_size callback in vdpa_config_ops

[Stefano Garzarella]

This new callback is used to get the size of the configuration space
of vDPA devices.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 include/linux/vdpa.h              | 4 ++++
 drivers/vdpa/ifcvf/ifcvf_main.c   | 6 ++++++
 drivers/vdpa/mlx5/net/mlx5_vnet.c | 6 ++++++
 drivers/vdpa/vdpa_sim/vdpa_sim.c  | 9 +++++++++
 drivers/vdpa/virtio_pci/vp_vdpa.c | 8 ++++++++
 5 files changed, 33 insertions(+)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 15fa085fab05..1b094c1531f2 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -150,6 +150,9 @@ struct vdpa_iova_range {
  * @set_status:			Set the device status
  *				@vdev: vdpa device
  *				@status: virtio device status
+ * @get_config_size:		Get the size of the configuration space
+ *				@vdev: vdpa device
+ *				Returns size_t: configuration size
  * @get_config:			Read from device specific configuration space
  *				@vdev: vdpa device
  *				@offset: offset from the beginning of
@@ -231,6 +234,7 @@ struct vdpa_config_ops {
 	u32 (*get_vendor_id)(struct vdpa_device *vdev);
 	u8 (*get_status)(struct vdpa_device *vdev);
 	void (*set_status)(struct vdpa_device *vdev, u8 status);
+	size_t (*get_config_size)(struct vdpa_device *vdev);
 	void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
 			   void *buf, unsigned int len);
 	void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index d555a6a5d1ba..017ab07040c7 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -332,6 +332,11 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
 	return IFCVF_QUEUE_ALIGNMENT;
 }
 
+static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
+{
+	return sizeof(struct virtio_net_config);
+}
+
 static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,
 				  unsigned int offset,
 				  void *buf, unsigned int len)
@@ -392,6 +397,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops = {
 	.get_device_id	= ifcvf_vdpa_get_device_id,
 	.get_vendor_id	= ifcvf_vdpa_get_vendor_id,
 	.get_vq_align	= ifcvf_vdpa_get_vq_align,
+	.get_config_size	= ifcvf_vdpa_get_config_size,
 	.get_config	= ifcvf_vdpa_get_config,
 	.set_config	= ifcvf_vdpa_set_config,
 	.set_config_cb  = ifcvf_vdpa_set_config_cb,
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 71397fdafa6a..f6e03bf49e3e 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1814,6 +1814,11 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 	ndev->mvdev.status |= VIRTIO_CONFIG_S_FAILED;
 }
 
+static size_t mlx5_vdpa_get_config_size(struct vdpa_device *vdev)
+{
+	return sizeof(struct virtio_net_config);
+}
+
 static void mlx5_vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, void *buf,
 				 unsigned int len)
 {
@@ -1900,6 +1905,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
 	.get_vendor_id = mlx5_vdpa_get_vendor_id,
 	.get_status = mlx5_vdpa_get_status,
 	.set_status = mlx5_vdpa_set_status,
+	.get_config_size = mlx5_vdpa_get_config_size,
 	.get_config = mlx5_vdpa_get_config,
 	.set_config = mlx5_vdpa_set_config,
 	.get_generation = mlx5_vdpa_get_generation,
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 14dc2d3d983e..98f793bc9376 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -462,6 +462,13 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
 	spin_unlock(&vdpasim->lock);
 }
 
+static size_t vdpasim_get_config_size(struct vdpa_device *vdpa)
+{
+	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+	return vdpasim->dev_attr.config_size;
+}
+
 static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
 			     void *buf, unsigned int len)
 {
@@ -598,6 +605,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
 	.get_vendor_id          = vdpasim_get_vendor_id,
 	.get_status             = vdpasim_get_status,
 	.set_status             = vdpasim_set_status,
+	.get_config_size        = vdpasim_get_config_size,
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
 	.get_generation         = vdpasim_get_generation,
@@ -625,6 +633,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
 	.get_vendor_id          = vdpasim_get_vendor_id,
 	.get_status             = vdpasim_get_status,
 	.set_status             = vdpasim_set_status,
+	.get_config_size        = vdpasim_get_config_size,
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
 	.get_generation         = vdpasim_get_generation,
diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index 1321a2fcd088..dc27ec970884 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -295,6 +295,13 @@ static u32 vp_vdpa_get_vq_align(struct vdpa_device *vdpa)
 	return PAGE_SIZE;
 }
 
+static size_t vp_vdpa_get_config_size(struct vdpa_device *vdpa)
+{
+	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
+
+	return mdev->device_len;
+}
+
 static void vp_vdpa_get_config(struct vdpa_device *vdpa,
 			       unsigned int offset,
 			       void *buf, unsigned int len)
@@ -354,6 +361,7 @@ static const struct vdpa_config_ops vp_vdpa_ops = {
 	.get_device_id	= vp_vdpa_get_device_id,
 	.get_vendor_id	= vp_vdpa_get_vendor_id,
 	.get_vq_align	= vp_vdpa_get_vq_align,
+	.get_config_size = vp_vdpa_get_config_size,
 	.get_config	= vp_vdpa_get_config,
 	.set_config	= vp_vdpa_set_config,
 	.set_config_cb  = vp_vdpa_set_config_cb,
-- 
2.30.2

[PATCH v4 09/14] vhost/vdpa: use get_config_size callback in vhost_vdpa_config_validate()

[Stefano Garzarella]

Let's use the new 'get_config_size()' callback available instead of
using the 'virtio_id' to get the size of the device config space.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vhost/vdpa.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index e0a27e336293..7ae4080e57d8 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -188,13 +188,8 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
 				      struct vhost_vdpa_config *c)
 {
-	long size = 0;
-
-	switch (v->virtio_id) {
-	case VIRTIO_ID_NET:
-		size = sizeof(struct virtio_net_config);
-		break;
-	}
+	struct vdpa_device *vdpa = v->vdpa;
+	long size = vdpa->config->get_config_size(vdpa);
 
 	if (c->len == 0)
 		return -EINVAL;
-- 
2.30.2

[PATCH v4 10/14] vhost/vdpa: Remove the restriction that only supports virtio-net devices

[Stefano Garzarella]

From: Xie Yongji <xieyongji@bytedance.com>

Since the config checks are done by the vDPA drivers, we can remove the
virtio-net restriction and we should be able to support all kinds of
virtio devices.

<linux/virtio_net.h> is not needed anymore, but we need to include
<linux/slab.h> to avoid compilation failures.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vhost/vdpa.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 7ae4080e57d8..850ed4b62942 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -16,12 +16,12 @@
 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/mm.h>
+#include <linux/slab.h>
 #include <linux/iommu.h>
 #include <linux/uuid.h>
 #include <linux/vdpa.h>
 #include <linux/nospec.h>
 #include <linux/vhost.h>
-#include <linux/virtio_net.h>
 
 #include "vhost.h"
 
@@ -1018,10 +1018,6 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 	int minor;
 	int r;
 
-	/* Currently, we only accept the network devices. */
-	if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
-		return -ENOTSUPP;
-
 	v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 	if (!v)
 		return -ENOMEM;
-- 
2.30.2

[PATCH v4 11/14] vdpa: add vdpa simulator for block device

[Stefano Garzarella]

From: Max Gurtovoy <mgurtovoy@nvidia.com>

This will allow running vDPA for virtio block protocol.

It's a preliminary implementation with a simple request handling:
for each request, only the status (last byte) is set.
It's always set to VIRTIO_BLK_S_OK.

Also input validation is missing and will be added in the next commits.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
[sgarzare: various cleanups/fixes]
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v4:
- include linux/blkdev.h to fix a build issue
- fix vdpa_register_device() passing the new 'nvqs' params

v3:
- updated Mellanox copyright to NVIDIA [Max]
- explained in the commit message that inputs are validated in subsequent
  patches [Stefan]

v2:
- rebased on top of other changes (dev_attr, get_config(), notify(), etc.)
- memset to 0 the config structure in vdpasim_blk_get_config()
- used vdpasim pointer in vdpasim_blk_get_config()

v1:
- Removed unused headers
- Used cpu_to_vdpasim*() to store config fields
- Replaced 'select VDPA_SIM' with 'depends on VDPA_SIM' since selected
  option can not depend on other [Jason]
- Start with a single queue for now [Jason]
- Add comments to memory barriers
---
 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 145 +++++++++++++++++++++++++++
 drivers/vdpa/Kconfig                 |   7 ++
 drivers/vdpa/vdpa_sim/Makefile       |   1 +
 3 files changed, 153 insertions(+)
 create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
new file mode 100644
index 000000000000..64926a70af5e
--- /dev/null
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VDPA simulator for block device.
+ *
+ * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/blkdev.h>
+#include <linux/vringh.h>
+#include <linux/vdpa.h>
+#include <uapi/linux/virtio_blk.h>
+
+#include "vdpa_sim.h"
+
+#define DRV_VERSION  "0.1"
+#define DRV_AUTHOR   "Max Gurtovoy <mgurtovoy@nvidia.com>"
+#define DRV_DESC     "vDPA Device Simulator for block device"
+#define DRV_LICENSE  "GPL v2"
+
+#define VDPASIM_BLK_FEATURES	(VDPASIM_FEATURES | \
+				 (1ULL << VIRTIO_BLK_F_SIZE_MAX) | \
+				 (1ULL << VIRTIO_BLK_F_SEG_MAX)  | \
+				 (1ULL << VIRTIO_BLK_F_BLK_SIZE) | \
+				 (1ULL << VIRTIO_BLK_F_TOPOLOGY) | \
+				 (1ULL << VIRTIO_BLK_F_MQ))
+
+#define VDPASIM_BLK_CAPACITY	0x40000
+#define VDPASIM_BLK_SIZE_MAX	0x1000
+#define VDPASIM_BLK_SEG_MAX	32
+#define VDPASIM_BLK_VQ_NUM	1
+
+static struct vdpasim *vdpasim_blk_dev;
+
+static void vdpasim_blk_work(struct work_struct *work)
+{
+	struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
+	u8 status = VIRTIO_BLK_S_OK;
+	int i;
+
+	spin_lock(&vdpasim->lock);
+
+	if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
+		goto out;
+
+	for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) {
+		struct vdpasim_virtqueue *vq = &vdpasim->vqs[i];
+
+		if (!vq->ready)
+			continue;
+
+		while (vringh_getdesc_iotlb(&vq->vring, &vq->out_iov,
+					    &vq->in_iov, &vq->head,
+					    GFP_ATOMIC) > 0) {
+			int write;
+
+			vq->in_iov.i = vq->in_iov.used - 1;
+			write = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov,
+						      &status, 1);
+			if (write <= 0)
+				break;
+
+			/* Make sure data is wrote before advancing index */
+			smp_wmb();
+
+			vringh_complete_iotlb(&vq->vring, vq->head, write);
+
+			/* Make sure used is visible before rasing the interrupt. */
+			smp_wmb();
+
+			local_bh_disable();
+			if (vringh_need_notify_iotlb(&vq->vring) > 0)
+				vringh_notify(&vq->vring);
+			local_bh_enable();
+		}
+	}
+out:
+	spin_unlock(&vdpasim->lock);
+}
+
+static void vdpasim_blk_get_config(struct vdpasim *vdpasim, void *config)
+{
+	struct virtio_blk_config *blk_config = config;
+
+	memset(config, 0, sizeof(struct virtio_blk_config));
+
+	blk_config->capacity = cpu_to_vdpasim64(vdpasim, VDPASIM_BLK_CAPACITY);
+	blk_config->size_max = cpu_to_vdpasim32(vdpasim, VDPASIM_BLK_SIZE_MAX);
+	blk_config->seg_max = cpu_to_vdpasim32(vdpasim, VDPASIM_BLK_SEG_MAX);
+	blk_config->num_queues = cpu_to_vdpasim16(vdpasim, VDPASIM_BLK_VQ_NUM);
+	blk_config->min_io_size = cpu_to_vdpasim16(vdpasim, 1);
+	blk_config->opt_io_size = cpu_to_vdpasim32(vdpasim, 1);
+	blk_config->blk_size = cpu_to_vdpasim32(vdpasim, SECTOR_SIZE);
+}
+
+static int __init vdpasim_blk_init(void)
+{
+	struct vdpasim_dev_attr dev_attr = {};
+	int ret;
+
+	dev_attr.id = VIRTIO_ID_BLOCK;
+	dev_attr.supported_features = VDPASIM_BLK_FEATURES;
+	dev_attr.nvqs = VDPASIM_BLK_VQ_NUM;
+	dev_attr.config_size = sizeof(struct virtio_blk_config);
+	dev_attr.get_config = vdpasim_blk_get_config;
+	dev_attr.work_fn = vdpasim_blk_work;
+	dev_attr.buffer_size = PAGE_SIZE;
+
+	vdpasim_blk_dev = vdpasim_create(&dev_attr);
+	if (IS_ERR(vdpasim_blk_dev)) {
+		ret = PTR_ERR(vdpasim_blk_dev);
+		goto out;
+	}
+
+	ret = vdpa_register_device(&vdpasim_blk_dev->vdpa, VDPASIM_BLK_VQ_NUM);
+	if (ret)
+		goto put_dev;
+
+	return 0;
+
+put_dev:
+	put_device(&vdpasim_blk_dev->vdpa.dev);
+out:
+	return ret;
+}
+
+static void __exit vdpasim_blk_exit(void)
+{
+	struct vdpa_device *vdpa = &vdpasim_blk_dev->vdpa;
+
+	vdpa_unregister_device(vdpa);
+}
+
+module_init(vdpasim_blk_init)
+module_exit(vdpasim_blk_exit)
+
+MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE(DRV_LICENSE);
+MODULE_AUTHOR(DRV_AUTHOR);
+MODULE_DESCRIPTION(DRV_DESC);
diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
index 6e82a0e228c2..a503c1b2bfd9 100644
--- a/drivers/vdpa/Kconfig
+++ b/drivers/vdpa/Kconfig
@@ -26,6 +26,13 @@ config VDPA_SIM_NET
 	help
 	  vDPA networking device simulator which loops TX traffic back to RX.
 
+config VDPA_SIM_BLOCK
+	tristate "vDPA simulator for block device"
+	depends on VDPA_SIM
+	help
+	  vDPA block device simulator which terminates IO request in a
+	  memory buffer.
+
 config IFCVF
 	tristate "Intel IFC VF vDPA driver"
 	depends on PCI_MSI
diff --git a/drivers/vdpa/vdpa_sim/Makefile b/drivers/vdpa/vdpa_sim/Makefile
index 79d4536d347e..d458103302f2 100644
--- a/drivers/vdpa/vdpa_sim/Makefile
+++ b/drivers/vdpa/vdpa_sim/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_VDPA_SIM) += vdpa_sim.o
 obj-$(CONFIG_VDPA_SIM_NET) += vdpa_sim_net.o
+obj-$(CONFIG_VDPA_SIM_BLOCK) += vdpa_sim_blk.o
-- 
2.30.2

[PATCH v4 12/14] vdpa_sim_blk: implement ramdisk behaviour

[Stefano Garzarella]

The previous implementation wrote only the status of each request.
This patch implements a more accurate block device simulator,
providing a ramdisk-like behavior and adding input validation.

Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v2:
- used %zd %zx to print size_t and ssize_t variables in dev_err()
- removed unnecessary new line [Jason]
- moved VIRTIO_BLK_T_GET_ID in another patch [Jason]
- used push/pull instead of write/read terminology
- added vdpasim_blk_check_range() to avoid overflows [Stefan]
- use vdpasim*_to_cpu instead of le*_to_cpu
- used vringh_kiov_length() helper [Jason]
---
 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 164 ++++++++++++++++++++++++---
 1 file changed, 146 insertions(+), 18 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
index 64926a70af5e..a31964e3e5a4 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -3,6 +3,7 @@
  * VDPA simulator for block device.
  *
  * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2021, Red Hat Inc. All rights reserved.
  *
  */
 
@@ -14,6 +15,7 @@
 #include <linux/blkdev.h>
 #include <linux/vringh.h>
 #include <linux/vdpa.h>
+#include <linux/blkdev.h>
 #include <uapi/linux/virtio_blk.h>
 
 #include "vdpa_sim.h"
@@ -37,10 +39,151 @@
 
 static struct vdpasim *vdpasim_blk_dev;
 
+static bool vdpasim_blk_check_range(u64 start_sector, size_t range_size)
+{
+	u64 range_sectors = range_size >> SECTOR_SHIFT;
+
+	if (range_size > VDPASIM_BLK_SIZE_MAX * VDPASIM_BLK_SEG_MAX)
+		return false;
+
+	if (start_sector > VDPASIM_BLK_CAPACITY)
+		return false;
+
+	if (range_sectors > VDPASIM_BLK_CAPACITY - start_sector)
+		return false;
+
+	return true;
+}
+
+/* Returns 'true' if the request is handled (with or without an I/O error)
+ * and the status is correctly written in the last byte of the 'in iov',
+ * 'false' otherwise.
+ */
+static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim,
+				   struct vdpasim_virtqueue *vq)
+{
+	size_t pushed = 0, to_pull, to_push;
+	struct virtio_blk_outhdr hdr;
+	ssize_t bytes;
+	loff_t offset;
+	u64 sector;
+	u8 status;
+	u32 type;
+	int ret;
+
+	ret = vringh_getdesc_iotlb(&vq->vring, &vq->out_iov, &vq->in_iov,
+				   &vq->head, GFP_ATOMIC);
+	if (ret != 1)
+		return false;
+
+	if (vq->out_iov.used < 1 || vq->in_iov.used < 1) {
+		dev_err(&vdpasim->vdpa.dev, "missing headers - out_iov: %u in_iov %u\n",
+			vq->out_iov.used, vq->in_iov.used);
+		return false;
+	}
+
+	if (vq->in_iov.iov[vq->in_iov.used - 1].iov_len < 1) {
+		dev_err(&vdpasim->vdpa.dev, "request in header too short\n");
+		return false;
+	}
+
+	/* The last byte is the status and we checked if the last iov has
+	 * enough room for it.
+	 */
+	to_push = vringh_kiov_length(&vq->in_iov) - 1;
+
+	to_pull = vringh_kiov_length(&vq->out_iov);
+
+	bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->out_iov, &hdr,
+				      sizeof(hdr));
+	if (bytes != sizeof(hdr)) {
+		dev_err(&vdpasim->vdpa.dev, "request out header too short\n");
+		return false;
+	}
+
+	to_pull -= bytes;
+
+	type = vdpasim32_to_cpu(vdpasim, hdr.type);
+	sector = vdpasim64_to_cpu(vdpasim, hdr.sector);
+	offset = sector << SECTOR_SHIFT;
+	status = VIRTIO_BLK_S_OK;
+
+	switch (type) {
+	case VIRTIO_BLK_T_IN:
+		if (!vdpasim_blk_check_range(sector, to_push)) {
+			dev_err(&vdpasim->vdpa.dev,
+				"reading over the capacity - offset: 0x%llx len: 0x%zx\n",
+				offset, to_push);
+			status = VIRTIO_BLK_S_IOERR;
+			break;
+		}
+
+		bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov,
+					      vdpasim->buffer + offset,
+					      to_push);
+		if (bytes < 0) {
+			dev_err(&vdpasim->vdpa.dev,
+				"vringh_iov_push_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n",
+				bytes, offset, to_push);
+			status = VIRTIO_BLK_S_IOERR;
+			break;
+		}
+
+		pushed += bytes;
+		break;
+
+	case VIRTIO_BLK_T_OUT:
+		if (!vdpasim_blk_check_range(sector, to_pull)) {
+			dev_err(&vdpasim->vdpa.dev,
+				"writing over the capacity - offset: 0x%llx len: 0x%zx\n",
+				offset, to_pull);
+			status = VIRTIO_BLK_S_IOERR;
+			break;
+		}
+
+		bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->out_iov,
+					      vdpasim->buffer + offset,
+					      to_pull);
+		if (bytes < 0) {
+			dev_err(&vdpasim->vdpa.dev,
+				"vringh_iov_pull_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n",
+				bytes, offset, to_pull);
+			status = VIRTIO_BLK_S_IOERR;
+			break;
+		}
+		break;
+
+	default:
+		dev_warn(&vdpasim->vdpa.dev,
+			 "Unsupported request type %d\n", type);
+		status = VIRTIO_BLK_S_IOERR;
+		break;
+	}
+
+	/* If some operations fail, we need to skip the remaining bytes
+	 * to put the status in the last byte
+	 */
+	if (to_push - pushed > 0)
+		vringh_kiov_advance(&vq->in_iov, to_push - pushed);
+
+	/* Last byte is the status */
+	bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov, &status, 1);
+	if (bytes != 1)
+		return false;
+
+	pushed += bytes;
+
+	/* Make sure data is wrote before advancing index */
+	smp_wmb();
+
+	vringh_complete_iotlb(&vq->vring, vq->head, pushed);
+
+	return true;
+}
+
 static void vdpasim_blk_work(struct work_struct *work)
 {
 	struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
-	u8 status = VIRTIO_BLK_S_OK;
 	int i;
 
 	spin_lock(&vdpasim->lock);
@@ -54,22 +197,7 @@ static void vdpasim_blk_work(struct work_struct *work)
 		if (!vq->ready)
 			continue;
 
-		while (vringh_getdesc_iotlb(&vq->vring, &vq->out_iov,
-					    &vq->in_iov, &vq->head,
-					    GFP_ATOMIC) > 0) {
-			int write;
-
-			vq->in_iov.i = vq->in_iov.used - 1;
-			write = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov,
-						      &status, 1);
-			if (write <= 0)
-				break;
-
-			/* Make sure data is wrote before advancing index */
-			smp_wmb();
-
-			vringh_complete_iotlb(&vq->vring, vq->head, write);
-
+		while (vdpasim_blk_handle_req(vdpasim, vq)) {
 			/* Make sure used is visible before rasing the interrupt. */
 			smp_wmb();
 
@@ -109,7 +237,7 @@ static int __init vdpasim_blk_init(void)
 	dev_attr.config_size = sizeof(struct virtio_blk_config);
 	dev_attr.get_config = vdpasim_blk_get_config;
 	dev_attr.work_fn = vdpasim_blk_work;
-	dev_attr.buffer_size = PAGE_SIZE;
+	dev_attr.buffer_size = VDPASIM_BLK_CAPACITY << SECTOR_SHIFT;
 
 	vdpasim_blk_dev = vdpasim_create(&dev_attr);
 	if (IS_ERR(vdpasim_blk_dev)) {
-- 
2.30.2

[PATCH v4 13/14] vdpa_sim_blk: handle VIRTIO_BLK_T_GET_ID

[Stefano Garzarella]

Handle VIRTIO_BLK_T_GET_ID request, always answering the
"vdpa_blk_sim" string.

Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v2:
- made 'vdpasim_blk_id' static [Jason]
---
 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
index a31964e3e5a4..643ae3bc62c0 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -38,6 +38,7 @@
 #define VDPASIM_BLK_VQ_NUM	1
 
 static struct vdpasim *vdpasim_blk_dev;
+static char vdpasim_blk_id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim";
 
 static bool vdpasim_blk_check_range(u64 start_sector, size_t range_size)
 {
@@ -153,6 +154,20 @@ static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim,
 		}
 		break;
 
+	case VIRTIO_BLK_T_GET_ID:
+		bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov,
+					      vdpasim_blk_id,
+					      VIRTIO_BLK_ID_BYTES);
+		if (bytes < 0) {
+			dev_err(&vdpasim->vdpa.dev,
+				"vringh_iov_push_iotlb() error: %zd\n", bytes);
+			status = VIRTIO_BLK_S_IOERR;
+			break;
+		}
+
+		pushed += bytes;
+		break;
+
 	default:
 		dev_warn(&vdpasim->vdpa.dev,
 			 "Unsupported request type %d\n", type);
-- 
2.30.2

[PATCH v4 14/14] vdpa_sim_blk: add support for vdpa management tool

[Stefano Garzarella]

Enable the user to create vDPA block simulator devices using the
vdpa management tool:

    # Show vDPA supported devices
    $ vdpa mgmtdev show
    vdpasim_blk:
      supported_classes block

    # Create a vDPA block device named as 'blk0' from the management
    # device vdpasim:
    $ vdpa dev add mgmtdev vdpasim_blk name blk0

    # Show the info of the 'blk0' device just created
    $ vdpa dev show blk0 -jp
    {
        "dev": {
            "blk0": {
                "type": "block",
                "mgmtdev": "vdpasim_blk",
                "vendor_id": 0,
                "max_vqs": 1,
                "max_vq_size": 256
            }
        }
    }

    # Delete the vDPA device after its use
    $ vdpa dev del blk0

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 76 +++++++++++++++++++++++-----
 1 file changed, 63 insertions(+), 13 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
index 643ae3bc62c0..5bfe1c281645 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -37,7 +37,6 @@
 #define VDPASIM_BLK_SEG_MAX	32
 #define VDPASIM_BLK_VQ_NUM	1
 
-static struct vdpasim *vdpasim_blk_dev;
 static char vdpasim_blk_id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim";
 
 static bool vdpasim_blk_check_range(u64 start_sector, size_t range_size)
@@ -241,11 +240,23 @@ static void vdpasim_blk_get_config(struct vdpasim *vdpasim, void *config)
 	blk_config->blk_size = cpu_to_vdpasim32(vdpasim, SECTOR_SIZE);
 }
 
-static int __init vdpasim_blk_init(void)
+static void vdpasim_blk_mgmtdev_release(struct device *dev)
+{
+}
+
+static struct device vdpasim_blk_mgmtdev = {
+	.init_name = "vdpasim_blk",
+	.release = vdpasim_blk_mgmtdev_release,
+};
+
+static int vdpasim_blk_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
 {
 	struct vdpasim_dev_attr dev_attr = {};
+	struct vdpasim *simdev;
 	int ret;
 
+	dev_attr.mgmt_dev = mdev;
+	dev_attr.name = name;
 	dev_attr.id = VIRTIO_ID_BLOCK;
 	dev_attr.supported_features = VDPASIM_BLK_FEATURES;
 	dev_attr.nvqs = VDPASIM_BLK_VQ_NUM;
@@ -254,29 +265,68 @@ static int __init vdpasim_blk_init(void)
 	dev_attr.work_fn = vdpasim_blk_work;
 	dev_attr.buffer_size = VDPASIM_BLK_CAPACITY << SECTOR_SHIFT;
 
-	vdpasim_blk_dev = vdpasim_create(&dev_attr);
-	if (IS_ERR(vdpasim_blk_dev)) {
-		ret = PTR_ERR(vdpasim_blk_dev);
-		goto out;
-	}
+	simdev = vdpasim_create(&dev_attr);
+	if (IS_ERR(simdev))
+		return PTR_ERR(simdev);
 
-	ret = vdpa_register_device(&vdpasim_blk_dev->vdpa, VDPASIM_BLK_VQ_NUM);
+	ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_BLK_VQ_NUM);
 	if (ret)
 		goto put_dev;
 
 	return 0;
 
 put_dev:
-	put_device(&vdpasim_blk_dev->vdpa.dev);
-out:
+	put_device(&simdev->vdpa.dev);
 	return ret;
 }
 
-static void __exit vdpasim_blk_exit(void)
+static void vdpasim_blk_dev_del(struct vdpa_mgmt_dev *mdev,
+				struct vdpa_device *dev)
 {
-	struct vdpa_device *vdpa = &vdpasim_blk_dev->vdpa;
+	struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
+
+	_vdpa_unregister_device(&simdev->vdpa);
+}
+
+static const struct vdpa_mgmtdev_ops vdpasim_blk_mgmtdev_ops = {
+	.dev_add = vdpasim_blk_dev_add,
+	.dev_del = vdpasim_blk_dev_del
+};
 
-	vdpa_unregister_device(vdpa);
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct vdpa_mgmt_dev mgmt_dev = {
+	.device = &vdpasim_blk_mgmtdev,
+	.id_table = id_table,
+	.ops = &vdpasim_blk_mgmtdev_ops,
+};
+
+static int __init vdpasim_blk_init(void)
+{
+	int ret;
+
+	ret = device_register(&vdpasim_blk_mgmtdev);
+	if (ret)
+		return ret;
+
+	ret = vdpa_mgmtdev_register(&mgmt_dev);
+	if (ret)
+		goto parent_err;
+
+	return 0;
+
+parent_err:
+	device_unregister(&vdpasim_blk_mgmtdev);
+	return ret;
+}
+
+static void __exit vdpasim_blk_exit(void)
+{
+	vdpa_mgmtdev_unregister(&mgmt_dev);
+	device_unregister(&vdpasim_blk_mgmtdev);
 }
 
 module_init(vdpasim_blk_init)
-- 
2.30.2

Re: [PATCH v4 06/14] vringh: add vringh_kiov_length() helper

[Laurent Vivier]

On 15/03/2021 17:34, Stefano Garzarella wrote:
> This new helper returns the total number of bytes covered by
> a vringh_kiov.
> 
> Suggested-by: Jason Wang <jasowang@redhat.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
>  include/linux/vringh.h | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/include/linux/vringh.h b/include/linux/vringh.h
> index 755211ebd195..84db7b8f912f 100644
> --- a/include/linux/vringh.h
> +++ b/include/linux/vringh.h
> @@ -199,6 +199,17 @@ static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov)
>  	kiov->iov = NULL;
>  }
>  
> +static inline size_t vringh_kiov_length(struct vringh_kiov *kiov)
> +{
> +	size_t len = 0;
> +	int i;
> +
> +	for (i = kiov->i; i < kiov->used; i++)
> +		len += kiov->iov[i].iov_len;
> +
> +	return len;
> +}

Do we really need an helper?

For instance, we can use:

len = iov_length((struct iovec *)kiov->iov, kiov->used);

Or do we want to avoid the cast?

Thanks,
Laurent

Re: [PATCH v4 06/14] vringh: add vringh_kiov_length() helper

[Stefano Garzarella]

On Mon, Mar 15, 2021 at 05:51:30PM +0100, Laurent Vivier wrote:
>On 15/03/2021 17:34, Stefano Garzarella wrote:
>> This new helper returns the total number of bytes covered by
>> a vringh_kiov.
>>
>> Suggested-by: Jason Wang <jasowang@redhat.com>
>> Acked-by: Jason Wang <jasowang@redhat.com>
>> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
>> ---
>>  include/linux/vringh.h | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/include/linux/vringh.h b/include/linux/vringh.h
>> index 755211ebd195..84db7b8f912f 100644
>> --- a/include/linux/vringh.h
>> +++ b/include/linux/vringh.h
>> @@ -199,6 +199,17 @@ static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov)
>>  	kiov->iov = NULL;
>>  }
>>
>> +static inline size_t vringh_kiov_length(struct vringh_kiov *kiov)
>> +{
>> +	size_t len = 0;
>> +	int i;
>> +
>> +	for (i = kiov->i; i < kiov->used; i++)
>> +		len += kiov->iov[i].iov_len;
>> +
>> +	return len;
>> +}
>
>Do we really need an helper?
>
>For instance, we can use:
>
>len = iov_length((struct iovec *)kiov->iov, kiov->used);
>
>Or do we want to avoid the cast?

Yes, that should be fine. If we want, I can remove the helper and use 
iov_length() directly. I thought vringh wanted to hide iovec from users 
though.

Anyway talking to Jason, as a long term solution we should reconsider 
vringh and support iov_iter.

Thanks,
Stefano

Re: [PATCH v4 08/14] vdpa: add get_config_size callback in vdpa_config_ops

[Jason Wang]

在 2021/3/16 上午12:34, Stefano Garzarella 写道:
> This new callback is used to get the size of the configuration space
> of vDPA devices.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   include/linux/vdpa.h              | 4 ++++
>   drivers/vdpa/ifcvf/ifcvf_main.c   | 6 ++++++
>   drivers/vdpa/mlx5/net/mlx5_vnet.c | 6 ++++++
>   drivers/vdpa/vdpa_sim/vdpa_sim.c  | 9 +++++++++
>   drivers/vdpa/virtio_pci/vp_vdpa.c | 8 ++++++++
>   5 files changed, 33 insertions(+)
>
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 15fa085fab05..1b094c1531f2 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -150,6 +150,9 @@ struct vdpa_iova_range {
>    * @set_status:			Set the device status
>    *				@vdev: vdpa device
>    *				@status: virtio device status
> + * @get_config_size:		Get the size of the configuration space
> + *				@vdev: vdpa device
> + *				Returns size_t: configuration size
>    * @get_config:			Read from device specific configuration space
>    *				@vdev: vdpa device
>    *				@offset: offset from the beginning of
> @@ -231,6 +234,7 @@ struct vdpa_config_ops {
>   	u32 (*get_vendor_id)(struct vdpa_device *vdev);
>   	u8 (*get_status)(struct vdpa_device *vdev);
>   	void (*set_status)(struct vdpa_device *vdev, u8 status);
> +	size_t (*get_config_size)(struct vdpa_device *vdev);
>   	void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
>   			   void *buf, unsigned int len);
>   	void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index d555a6a5d1ba..017ab07040c7 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -332,6 +332,11 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
>   	return IFCVF_QUEUE_ALIGNMENT;
>   }
>   
> +static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
> +{
> +	return sizeof(struct virtio_net_config);
> +}
> +
>   static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,
>   				  unsigned int offset,
>   				  void *buf, unsigned int len)
> @@ -392,6 +397,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops = {
>   	.get_device_id	= ifcvf_vdpa_get_device_id,
>   	.get_vendor_id	= ifcvf_vdpa_get_vendor_id,
>   	.get_vq_align	= ifcvf_vdpa_get_vq_align,
> +	.get_config_size	= ifcvf_vdpa_get_config_size,
>   	.get_config	= ifcvf_vdpa_get_config,
>   	.set_config	= ifcvf_vdpa_set_config,
>   	.set_config_cb  = ifcvf_vdpa_set_config_cb,
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 71397fdafa6a..f6e03bf49e3e 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1814,6 +1814,11 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
>   	ndev->mvdev.status |= VIRTIO_CONFIG_S_FAILED;
>   }
>   
> +static size_t mlx5_vdpa_get_config_size(struct vdpa_device *vdev)
> +{
> +	return sizeof(struct virtio_net_config);
> +}
> +
>   static void mlx5_vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, void *buf,
>   				 unsigned int len)
>   {
> @@ -1900,6 +1905,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
>   	.get_vendor_id = mlx5_vdpa_get_vendor_id,
>   	.get_status = mlx5_vdpa_get_status,
>   	.set_status = mlx5_vdpa_set_status,
> +	.get_config_size = mlx5_vdpa_get_config_size,
>   	.get_config = mlx5_vdpa_get_config,
>   	.set_config = mlx5_vdpa_set_config,
>   	.get_generation = mlx5_vdpa_get_generation,
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 14dc2d3d983e..98f793bc9376 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -462,6 +462,13 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
>   	spin_unlock(&vdpasim->lock);
>   }
>   
> +static size_t vdpasim_get_config_size(struct vdpa_device *vdpa)
> +{
> +	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> +	return vdpasim->dev_attr.config_size;
> +}
> +
>   static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
>   			     void *buf, unsigned int len)
>   {
> @@ -598,6 +605,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
>   	.get_vendor_id          = vdpasim_get_vendor_id,
>   	.get_status             = vdpasim_get_status,
>   	.set_status             = vdpasim_set_status,
> +	.get_config_size        = vdpasim_get_config_size,
>   	.get_config             = vdpasim_get_config,
>   	.set_config             = vdpasim_set_config,
>   	.get_generation         = vdpasim_get_generation,
> @@ -625,6 +633,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
>   	.get_vendor_id          = vdpasim_get_vendor_id,
>   	.get_status             = vdpasim_get_status,
>   	.set_status             = vdpasim_set_status,
> +	.get_config_size        = vdpasim_get_config_size,
>   	.get_config             = vdpasim_get_config,
>   	.set_config             = vdpasim_set_config,
>   	.get_generation         = vdpasim_get_generation,
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index 1321a2fcd088..dc27ec970884 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -295,6 +295,13 @@ static u32 vp_vdpa_get_vq_align(struct vdpa_device *vdpa)
>   	return PAGE_SIZE;
>   }
>   
> +static size_t vp_vdpa_get_config_size(struct vdpa_device *vdpa)
> +{
> +	struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
> +
> +	return mdev->device_len;
> +}
> +
>   static void vp_vdpa_get_config(struct vdpa_device *vdpa,
>   			       unsigned int offset,
>   			       void *buf, unsigned int len)
> @@ -354,6 +361,7 @@ static const struct vdpa_config_ops vp_vdpa_ops = {
>   	.get_device_id	= vp_vdpa_get_device_id,
>   	.get_vendor_id	= vp_vdpa_get_vendor_id,
>   	.get_vq_align	= vp_vdpa_get_vq_align,
> +	.get_config_size = vp_vdpa_get_config_size,
>   	.get_config	= vp_vdpa_get_config,
>   	.set_config	= vp_vdpa_set_config,
>   	.set_config_cb  = vp_vdpa_set_config_cb,

Re: [PATCH v4 09/14] vhost/vdpa: use get_config_size callback in vhost_vdpa_config_validate()

[Jason Wang]

在 2021/3/16 上午12:34, Stefano Garzarella 写道:
> Let's use the new 'get_config_size()' callback available instead of
> using the 'virtio_id' to get the size of the device config space.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   drivers/vhost/vdpa.c | 9 ++-------
>   1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index e0a27e336293..7ae4080e57d8 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -188,13 +188,8 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
>   static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
>   				      struct vhost_vdpa_config *c)
>   {
> -	long size = 0;
> -
> -	switch (v->virtio_id) {
> -	case VIRTIO_ID_NET:
> -		size = sizeof(struct virtio_net_config);
> -		break;
> -	}
> +	struct vdpa_device *vdpa = v->vdpa;
> +	long size = vdpa->config->get_config_size(vdpa);
>   
>   	if (c->len == 0)
>   		return -EINVAL;

Re: [PATCH v4 10/14] vhost/vdpa: Remove the restriction that only supports virtio-net devices

[Jason Wang]

在 2021/3/16 上午12:34, Stefano Garzarella 写道:
> From: Xie Yongji <xieyongji@bytedance.com>
>
> Since the config checks are done by the vDPA drivers, we can remove the
> virtio-net restriction and we should be able to support all kinds of
> virtio devices.
>
> <linux/virtio_net.h> is not needed anymore, but we need to include
> <linux/slab.h> to avoid compilation failures.
>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   drivers/vhost/vdpa.c | 6 +-----
>   1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 7ae4080e57d8..850ed4b62942 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -16,12 +16,12 @@
>   #include <linux/cdev.h>
>   #include <linux/device.h>
>   #include <linux/mm.h>
> +#include <linux/slab.h>
>   #include <linux/iommu.h>
>   #include <linux/uuid.h>
>   #include <linux/vdpa.h>
>   #include <linux/nospec.h>
>   #include <linux/vhost.h>
> -#include <linux/virtio_net.h>
>   
>   #include "vhost.h"
>   
> @@ -1018,10 +1018,6 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>   	int minor;
>   	int r;
>   
> -	/* Currently, we only accept the network devices. */
> -	if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
> -		return -ENOTSUPP;
> -
>   	v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
>   	if (!v)
>   		return -ENOMEM;

Re: [PATCH v4 14/14] vdpa_sim_blk: add support for vdpa management tool

[Jason Wang]

在 2021/3/16 上午12:34, Stefano Garzarella 写道:
> Enable the user to create vDPA block simulator devices using the
> vdpa management tool:
>
>      # Show vDPA supported devices
>      $ vdpa mgmtdev show
>      vdpasim_blk:
>        supported_classes block
>
>      # Create a vDPA block device named as 'blk0' from the management
>      # device vdpasim:
>      $ vdpa dev add mgmtdev vdpasim_blk name blk0
>
>      # Show the info of the 'blk0' device just created
>      $ vdpa dev show blk0 -jp
>      {
>          "dev": {
>              "blk0": {
>                  "type": "block",
>                  "mgmtdev": "vdpasim_blk",
>                  "vendor_id": 0,
>                  "max_vqs": 1,
>                  "max_vq_size": 256
>              }
>          }
>      }
>
>      # Delete the vDPA device after its use
>      $ vdpa dev del blk0
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 76 +++++++++++++++++++++++-----
>   1 file changed, 63 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> index 643ae3bc62c0..5bfe1c281645 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> @@ -37,7 +37,6 @@
>   #define VDPASIM_BLK_SEG_MAX	32
>   #define VDPASIM_BLK_VQ_NUM	1
>   
> -static struct vdpasim *vdpasim_blk_dev;
>   static char vdpasim_blk_id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim";
>   
>   static bool vdpasim_blk_check_range(u64 start_sector, size_t range_size)
> @@ -241,11 +240,23 @@ static void vdpasim_blk_get_config(struct vdpasim *vdpasim, void *config)
>   	blk_config->blk_size = cpu_to_vdpasim32(vdpasim, SECTOR_SIZE);
>   }
>   
> -static int __init vdpasim_blk_init(void)
> +static void vdpasim_blk_mgmtdev_release(struct device *dev)
> +{
> +}
> +
> +static struct device vdpasim_blk_mgmtdev = {
> +	.init_name = "vdpasim_blk",
> +	.release = vdpasim_blk_mgmtdev_release,
> +};
> +
> +static int vdpasim_blk_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
>   {
>   	struct vdpasim_dev_attr dev_attr = {};
> +	struct vdpasim *simdev;
>   	int ret;
>   
> +	dev_attr.mgmt_dev = mdev;
> +	dev_attr.name = name;
>   	dev_attr.id = VIRTIO_ID_BLOCK;
>   	dev_attr.supported_features = VDPASIM_BLK_FEATURES;
>   	dev_attr.nvqs = VDPASIM_BLK_VQ_NUM;
> @@ -254,29 +265,68 @@ static int __init vdpasim_blk_init(void)
>   	dev_attr.work_fn = vdpasim_blk_work;
>   	dev_attr.buffer_size = VDPASIM_BLK_CAPACITY << SECTOR_SHIFT;
>   
> -	vdpasim_blk_dev = vdpasim_create(&dev_attr);
> -	if (IS_ERR(vdpasim_blk_dev)) {
> -		ret = PTR_ERR(vdpasim_blk_dev);
> -		goto out;
> -	}
> +	simdev = vdpasim_create(&dev_attr);
> +	if (IS_ERR(simdev))
> +		return PTR_ERR(simdev);
>   
> -	ret = vdpa_register_device(&vdpasim_blk_dev->vdpa, VDPASIM_BLK_VQ_NUM);
> +	ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_BLK_VQ_NUM);
>   	if (ret)
>   		goto put_dev;
>   
>   	return 0;
>   
>   put_dev:
> -	put_device(&vdpasim_blk_dev->vdpa.dev);
> -out:
> +	put_device(&simdev->vdpa.dev);
>   	return ret;
>   }
>   
> -static void __exit vdpasim_blk_exit(void)
> +static void vdpasim_blk_dev_del(struct vdpa_mgmt_dev *mdev,
> +				struct vdpa_device *dev)
>   {
> -	struct vdpa_device *vdpa = &vdpasim_blk_dev->vdpa;
> +	struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
> +
> +	_vdpa_unregister_device(&simdev->vdpa);
> +}
> +
> +static const struct vdpa_mgmtdev_ops vdpasim_blk_mgmtdev_ops = {
> +	.dev_add = vdpasim_blk_dev_add,
> +	.dev_del = vdpasim_blk_dev_del
> +};
>   
> -	vdpa_unregister_device(vdpa);
> +static struct virtio_device_id id_table[] = {
> +	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
> +	{ 0 },
> +};
> +
> +static struct vdpa_mgmt_dev mgmt_dev = {
> +	.device = &vdpasim_blk_mgmtdev,
> +	.id_table = id_table,
> +	.ops = &vdpasim_blk_mgmtdev_ops,
> +};
> +
> +static int __init vdpasim_blk_init(void)
> +{
> +	int ret;
> +
> +	ret = device_register(&vdpasim_blk_mgmtdev);
> +	if (ret)
> +		return ret;
> +
> +	ret = vdpa_mgmtdev_register(&mgmt_dev);
> +	if (ret)
> +		goto parent_err;
> +
> +	return 0;
> +
> +parent_err:
> +	device_unregister(&vdpasim_blk_mgmtdev);
> +	return ret;
> +}
> +
> +static void __exit vdpasim_blk_exit(void)
> +{
> +	vdpa_mgmtdev_unregister(&mgmt_dev);
> +	device_unregister(&vdpasim_blk_mgmtdev);
>   }
>   
>   module_init(vdpasim_blk_init)

Re: [PATCH v4 00/14] vdpa: add vdpa simulator for block device

[Stefano Garzarella]

Hi Michael,
do you think this series is in an acceptable state to be queued for the 
next merge window?

All patches should be already acked by Jason, let me know if I need to 
change anything.

Thanks,
Stefano

On Mon, Mar 15, 2021 at 05:34:36PM +0100, Stefano Garzarella wrote:
>v4:
>- added support for iproute2 vdpa management tool in vdpa_sim_blk
>- removed get/set_config patches
>  - 'vdpa: add return value to get_config/set_config callbacks'
>  - 'vhost/vdpa: remove vhost_vdpa_config_validate()'
>- added get_config_size() patches
>  - 'vdpa: add get_config_size callback in vdpa_config_ops'
>  - 'vhost/vdpa: use get_config_size callback in vhost_vdpa_config_validate()'
>
>v3: https://lore.kernel.org/lkml/20210204172230.85853-1-sgarzare@redhat.com/
>v2: https://lore.kernel.org/lkml/20210128144127.113245-1-sgarzare@redhat.com/
>v1: https://lore.kernel.org/lkml/93f207c0-61e6-3696-f218-e7d7ea9a7c93@redhat.com/
>
>This series is the second part of the v1 linked above. The first part with
>refactoring of vdpa_sim has already been merged.
>
>The patches are based on Max Gurtovoy's work and extend the block simulator to
>have a ramdisk behaviour.
>
>As mentioned in the v1 there was 2 issues and I fixed them in this series:
>1. The identical mapping in the IOMMU used until now in vdpa_sim created issues
>   when mapping different virtual pages with the same physical address.
>   Fixed by patch "vdpa_sim: use iova module to allocate IOVA addresses"
>
>2. There was a race accessing the IOMMU between the vdpasim_blk_work() and the
>   device driver that map/unmap DMA regions. Fixed by patch "vringh: add
>   'iotlb_lock' to synchronize iotlb accesses"
>
>I used the Xie's patch coming from VDUSE series to allow vhost-vdpa to use
>block devices, and I added get_config_size() callback to allow any device
>in vhost-vdpa.
>
>The series also includes small fixes for vringh, vdpa, and vdpa_sim that I
>discovered while implementing and testing the block simulator.
>
>Thanks for your feedback,
>Stefano
>
>Max Gurtovoy (1):
>  vdpa: add vdpa simulator for block device
>
>Stefano Garzarella (12):
>  vdpa_sim: use iova module to allocate IOVA addresses
>  vringh: add 'iotlb_lock' to synchronize iotlb accesses
>  vringh: reset kiov 'consumed' field in __vringh_iov()
>  vringh: explain more about cleaning riov and wiov
>  vringh: implement vringh_kiov_advance()
>  vringh: add vringh_kiov_length() helper
>  vdpa_sim: cleanup kiovs in vdpasim_free()
>  vdpa: add get_config_size callback in vdpa_config_ops
>  vhost/vdpa: use get_config_size callback in
>    vhost_vdpa_config_validate()
>  vdpa_sim_blk: implement ramdisk behaviour
>  vdpa_sim_blk: handle VIRTIO_BLK_T_GET_ID
>  vdpa_sim_blk: add support for vdpa management tool
>
>Xie Yongji (1):
>  vhost/vdpa: Remove the restriction that only supports virtio-net
>    devices
>
> drivers/vdpa/vdpa_sim/vdpa_sim.h     |   2 +
> include/linux/vdpa.h                 |   4 +
> include/linux/vringh.h               |  19 +-
> drivers/vdpa/ifcvf/ifcvf_main.c      |   6 +
> drivers/vdpa/mlx5/net/mlx5_vnet.c    |   6 +
> drivers/vdpa/vdpa_sim/vdpa_sim.c     | 127 ++++++----
> drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 338 +++++++++++++++++++++++++++
> drivers/vdpa/virtio_pci/vp_vdpa.c    |   8 +
> drivers/vhost/vdpa.c                 |  15 +-
> drivers/vhost/vringh.c               |  69 ++++--
> drivers/vdpa/Kconfig                 |   8 +
> drivers/vdpa/vdpa_sim/Makefile       |   1 +
> 12 files changed, 529 insertions(+), 74 deletions(-)
> create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
>
>-- 
>2.30.2
>
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>