[PATCH V2 0/3] vDPA: API for reporting IOVA range

[PATCH V2 0/3] vDPA: API for reporting IOVA range

[Jason Wang]

Hi All:

This series introduces API for reporing IOVA range. This is a must for
userspace to work correclty:

- for the process that uses vhost-vDPA directly to properly allocate
  IOVA
- for VM(qemu), when vIOMMU is not enabled, fail early if GPA is out
  of range
- for VM(qemu), when vIOMMU is enabled, determine a valid guest
  address width

Please review.

Changes from V1:

- do not mandate get_iova_range() for device with its own DMA
  translation logic and assume a [0, ULLONG_MAX] range
- mandate IOVA range only for IOMMU that forcing aperture
- forbid the map which is out of the IOVA range in vhost-vDPA

Thanks

Jason Wang (3):
  vdpa: introduce config op to get valid iova range
  vhost: vdpa: report iova range
  vdpa_sim: implement get_iova_range()

 drivers/vdpa/vdpa_sim/vdpa_sim.c | 12 ++++++++++
 drivers/vhost/vdpa.c             | 41 ++++++++++++++++++++++++++++++++
 include/linux/vdpa.h             | 15 ++++++++++++
 include/uapi/linux/vhost.h       |  4 ++++
 include/uapi/linux/vhost_types.h |  9 +++++++
 5 files changed, 81 insertions(+)

-- 
2.18.1

[PATCH V2 1/3] vdpa: introduce config op to get valid iova range

[Jason Wang]

This patch introduce a config op to get valid iova range from the vDPA
device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 include/linux/vdpa.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index eae0bfd87d91..30bc7a7223bb 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -52,6 +52,16 @@ struct vdpa_device {
 	int nvqs;
 };
 
+/**
+ * vDPA IOVA range - the IOVA range support by the device
+ * @first: start of the IOVA range
+ * @last: end of the IOVA range
+ */
+struct vdpa_iova_range {
+	u64 first;
+	u64 last;
+};
+
 /**
  * vDPA_config_ops - operations for configuring a vDPA device.
  * Note: vDPA device drivers are required to implement all of the
@@ -151,6 +161,10 @@ struct vdpa_device {
  * @get_generation:		Get device config generation (optional)
  *				@vdev: vdpa device
  *				Returns u32: device generation
+ * @get_iova_range:		Get supported iova range (optional)
+ *				@vdev: vdpa device
+ *				Returns the iova range supported by
+ *				the device.
  * @set_map:			Set device memory mapping (optional)
  *				Needed for device that using device
  *				specific DMA translation (on-chip IOMMU)
@@ -216,6 +230,7 @@ struct vdpa_config_ops {
 	void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
 			   const void *buf, unsigned int len);
 	u32 (*get_generation)(struct vdpa_device *vdev);
+	struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
 
 	/* DMA ops */
 	int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
-- 
2.18.1

[PATCH V2 2/3] vhost: vdpa: report iova range

[Jason Wang]

This patch introduces a new ioctl for vhost-vdpa device that can
report the iova range by the device.

For device that implements get_iova_range() method, we fetch it from
the vDPA device. If device doesn't implement get_iova_range() but
depends on platform IOMMU, we will query via DOMAIN_ATTR_GEOMETRY,
otherwise [0, ULLONG_MAX] is assumed.

For safety, this patch also rules out the map request which is not in
the valid range.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/vdpa.c             | 41 ++++++++++++++++++++++++++++++++
 include/uapi/linux/vhost.h       |  4 ++++
 include/uapi/linux/vhost_types.h |  9 +++++++
 3 files changed, 54 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 3fab94f88894..1adb4adb0345 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -48,6 +48,7 @@ struct vhost_vdpa {
 	int minor;
 	struct eventfd_ctx *config_ctx;
 	int in_batch;
+	struct vdpa_iova_range range;
 };
 
 static DEFINE_IDA(vhost_vdpa_ida);
@@ -344,6 +345,16 @@ static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
 	return 0;
 }
 
+static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
+{
+	struct vhost_vdpa_iova_range range = {
+		.first = v->range.first,
+		.last = v->range.last,
+	};
+
+	return copy_to_user(argp, &range, sizeof(range));
+}
+
 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 				   void __user *argp)
 {
@@ -476,6 +487,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
 	case VHOST_VDPA_SET_CONFIG_CALL:
 		r = vhost_vdpa_set_config_call(v, argp);
 		break;
+	case VHOST_VDPA_GET_IOVA_RANGE:
+		r = vhost_vdpa_get_iova_range(v, argp);
+		break;
 	default:
 		r = vhost_dev_ioctl(&v->vdev, cmd, argp);
 		if (r == -ENOIOCTLCMD)
@@ -597,6 +611,10 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
 	u64 iova = msg->iova;
 	int ret = 0;
 
+	if (msg->iova < v->range.first ||
+	    msg->iova + msg->size - 1 > v->range.last)
+		return -EINVAL;
+
 	if (vhost_iotlb_itree_first(iotlb, msg->iova,
 				    msg->iova + msg->size - 1))
 		return -EEXIST;
@@ -762,6 +780,27 @@ static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
 	v->domain = NULL;
 }
 
+static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
+{
+	struct vdpa_iova_range *range = &v->range;
+	struct iommu_domain_geometry geo;
+	struct vdpa_device *vdpa = v->vdpa;
+	const struct vdpa_config_ops *ops = vdpa->config;
+
+	if (ops->get_iova_range) {
+		*range = ops->get_iova_range(vdpa);
+	} else if (v->domain &&
+		   !iommu_domain_get_attr(v->domain,
+		   DOMAIN_ATTR_GEOMETRY, &geo) &&
+		   geo.force_aperture) {
+		range->first = geo.aperture_start;
+		range->last = geo.aperture_end;
+	} else {
+		range->first = 0;
+		range->last = ULLONG_MAX;
+	}
+}
+
 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 {
 	struct vhost_vdpa *v;
@@ -802,6 +841,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 	if (r)
 		goto err_init_iotlb;
 
+	vhost_vdpa_set_iova_range(v);
+
 	filep->private_data = v;
 
 	return 0;
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index 75232185324a..c998860d7bbc 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -146,4 +146,8 @@
 
 /* Set event fd for config interrupt*/
 #define VHOST_VDPA_SET_CONFIG_CALL	_IOW(VHOST_VIRTIO, 0x77, int)
+
+/* Get the valid iova range */
+#define VHOST_VDPA_GET_IOVA_RANGE	_IOR(VHOST_VIRTIO, 0x78, \
+					     struct vhost_vdpa_iova_range)
 #endif
diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
index 9a269a88a6ff..f7f6a3a28977 100644
--- a/include/uapi/linux/vhost_types.h
+++ b/include/uapi/linux/vhost_types.h
@@ -138,6 +138,15 @@ struct vhost_vdpa_config {
 	__u8 buf[0];
 };
 
+/* vhost vdpa IOVA range
+ * @first: First address that can be mapped by vhost-vDPA
+ * @last: Last address that can be mapped by vhost-vDPA
+ */
+struct vhost_vdpa_iova_range {
+	__u64 first;
+	__u64 last;
+};
+
 /* Feature bits */
 /* Log all write descriptors. Can be changed while device is active. */
 #define VHOST_F_LOG_ALL 26
-- 
2.18.1

[PATCH V2 3/3] vdpa_sim: implement get_iova_range()

[Jason Wang]

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 62d640327145..89854e17c3c2 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -574,6 +574,16 @@ static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
 	return vdpasim->generation;
 }
 
+struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
+{
+	struct vdpa_iova_range range = {
+		.first = 0ULL,
+		.last = ULLONG_MAX,
+	};
+
+	return range;
+}
+
 static int vdpasim_set_map(struct vdpa_device *vdpa,
 			   struct vhost_iotlb *iotlb)
 {
@@ -657,6 +667,7 @@ static const struct vdpa_config_ops vdpasim_net_config_ops = {
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
 	.get_generation         = vdpasim_get_generation,
+	.get_iova_range         = vdpasim_get_iova_range,
 	.dma_map                = vdpasim_dma_map,
 	.dma_unmap              = vdpasim_dma_unmap,
 	.free                   = vdpasim_free,
@@ -683,6 +694,7 @@ static const struct vdpa_config_ops vdpasim_net_batch_config_ops = {
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
 	.get_generation         = vdpasim_get_generation,
+	.get_iova_range         = vdpasim_get_iova_range,
 	.set_map                = vdpasim_set_map,
 	.free                   = vdpasim_free,
 };
-- 
2.18.1

Re: [PATCH V2 3/3] vdpa_sim: implement get_iova_range()

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2119 bytes --]

Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on linus/master v5.9-rc1 next-20200821]
[cannot apply to linux/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: ia64-allmodconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/vdpa/vdpa_sim/vdpa_sim.c:577:24: warning: no previous prototype for 'vdpasim_get_iova_range' [-Wmissing-prototypes]
     577 | struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
         |                        ^~~~~~~~~~~~~~~~~~~~~~

# https://github.com/0day-ci/linux/commit/fba5ff6281e9d46144860bcc558068b5516e5e62
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
git checkout fba5ff6281e9d46144860bcc558068b5516e5e62
vim +/vdpasim_get_iova_range +577 drivers/vdpa/vdpa_sim/vdpa_sim.c

   576	
 > 577	struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
   578	{
   579		struct vdpa_iova_range range = {
   580			.first = 0ULL,
   581			.last = ULLONG_MAX,
   582		};
   583	
   584		return range;
   585	}
   586	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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Re: [PATCH V2 3/3] vdpa_sim: implement get_iova_range()

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 1364 bytes --]

Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on linus/master v5.9-rc1 next-20200821]
[cannot apply to linux/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: i386-randconfig-s001-20200820 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-191-g10164920-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)

>> drivers/vdpa/vdpa_sim/vdpa_sim.c:577:24: sparse: sparse: symbol 'vdpasim_get_iova_range' was not declared. Should it be static?

Please review and possibly fold the followup patch.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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[RFC PATCH] vdpa_sim: vdpasim_get_iova_range() can be static

[kernel test robot]

Signed-off-by: kernel test robot <lkp@intel.com>
---
 vdpa_sim.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 89854e17c3c27b..ff6c9fd8d879bd 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -574,7 +574,7 @@ static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
 	return vdpasim->generation;
 }
 
-struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
+static struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
 {
 	struct vdpa_iova_range range = {
 		.first = 0ULL,

Re: [PATCH V2 3/3] vdpa_sim: implement get_iova_range()

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2750 bytes --]

Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on linus/master v5.9-rc1 next-20200821]
[cannot apply to linux/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: arm-randconfig-r026-20200820 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b587ca93be114d07ec3bf654add97d7872325281)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/vdpa/vdpa_sim/vdpa_sim.c:577:24: warning: no previous prototype for function 'vdpasim_get_iova_range' [-Wmissing-prototypes]
   struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
                          ^
   drivers/vdpa/vdpa_sim/vdpa_sim.c:577:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
   ^
   static 
   drivers/vdpa/vdpa_sim/vdpa_sim.c:89:19: warning: unused function 'vdpasim16_to_cpu' [-Wunused-function]
   static inline u16 vdpasim16_to_cpu(struct vdpasim *vdpasim, __virtio16 val)
                     ^
   2 warnings generated.

# https://github.com/0day-ci/linux/commit/fba5ff6281e9d46144860bcc558068b5516e5e62
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
git checkout fba5ff6281e9d46144860bcc558068b5516e5e62
vim +/vdpasim_get_iova_range +577 drivers/vdpa/vdpa_sim/vdpa_sim.c

   576	
 > 577	struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
   578	{
   579		struct vdpa_iova_range range = {
   580			.first = 0ULL,
   581			.last = ULLONG_MAX,
   582		};
   583	
   584		return range;
   585	}
   586	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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Re: [PATCH V2 3/3] vdpa_sim: implement get_iova_range()

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2758 bytes --]

Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on linus/master v5.9-rc1 next-20200821]
[cannot apply to linux/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: x86_64-randconfig-a002-20200820 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b587ca93be114d07ec3bf654add97d7872325281)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/vdpa/vdpa_sim/vdpa_sim.c:577:24: warning: no previous prototype for function 'vdpasim_get_iova_range' [-Wmissing-prototypes]
   struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
                          ^
   drivers/vdpa/vdpa_sim/vdpa_sim.c:577:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
   ^
   static 
   drivers/vdpa/vdpa_sim/vdpa_sim.c:89:19: warning: unused function 'vdpasim16_to_cpu' [-Wunused-function]
   static inline u16 vdpasim16_to_cpu(struct vdpasim *vdpasim, __virtio16 val)
                     ^
   2 warnings generated.

# https://github.com/0day-ci/linux/commit/fba5ff6281e9d46144860bcc558068b5516e5e62
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jason-Wang/vDPA-API-for-reporting-IOVA-range/20200821-173030
git checkout fba5ff6281e9d46144860bcc558068b5516e5e62
vim +/vdpasim_get_iova_range +577 drivers/vdpa/vdpa_sim/vdpa_sim.c

   576	
 > 577	struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
   578	{
   579		struct vdpa_iova_range range = {
   580			.first = 0ULL,
   581			.last = ULLONG_MAX,
   582		};
   583	
   584		return range;
   585	}
   586	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 41815 bytes --]

Re: [PATCH V2 2/3] vhost: vdpa: report iova range

[Eli Cohen]

On Fri, Aug 21, 2020 at 05:28:12AM -0400, Jason Wang wrote:
> This patch introduces a new ioctl for vhost-vdpa device that can
> report the iova range by the device.
> 
> For device that implements get_iova_range() method, we fetch it from
> the vDPA device. If device doesn't implement get_iova_range() but
> depends on platform IOMMU, we will query via DOMAIN_ATTR_GEOMETRY,
> otherwise [0, ULLONG_MAX] is assumed.
> 
> For safety, this patch also rules out the map request which is not in
> the valid range.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/vhost/vdpa.c             | 41 ++++++++++++++++++++++++++++++++
>  include/uapi/linux/vhost.h       |  4 ++++
>  include/uapi/linux/vhost_types.h |  9 +++++++
>  3 files changed, 54 insertions(+)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 3fab94f88894..1adb4adb0345 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -48,6 +48,7 @@ struct vhost_vdpa {
>  	int minor;
>  	struct eventfd_ctx *config_ctx;
>  	int in_batch;
> +	struct vdpa_iova_range range;
>  };
>  
>  static DEFINE_IDA(vhost_vdpa_ida);
> @@ -344,6 +345,16 @@ static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
>  	return 0;
>  }
>  
> +static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
> +{
> +	struct vhost_vdpa_iova_range range = {
> +		.first = v->range.first,
> +		.last = v->range.last,
> +	};
> +
> +	return copy_to_user(argp, &range, sizeof(range));
> +}
> +
>  static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
>  				   void __user *argp)
>  {
> @@ -476,6 +487,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
>  	case VHOST_VDPA_SET_CONFIG_CALL:
>  		r = vhost_vdpa_set_config_call(v, argp);
>  		break;
> +	case VHOST_VDPA_GET_IOVA_RANGE:
> +		r = vhost_vdpa_get_iova_range(v, argp);
> +		break;
>  	default:
>  		r = vhost_dev_ioctl(&v->vdev, cmd, argp);
>  		if (r == -ENOIOCTLCMD)
> @@ -597,6 +611,10 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>  	u64 iova = msg->iova;
>  	int ret = 0;
>  
> +	if (msg->iova < v->range.first ||
> +	    msg->iova + msg->size - 1 > v->range.last)
> +		return -EINVAL;
> +
>  	if (vhost_iotlb_itree_first(iotlb, msg->iova,
>  				    msg->iova + msg->size - 1))
>  		return -EEXIST;
> @@ -762,6 +780,27 @@ static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
>  	v->domain = NULL;
>  }
>  
> +static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
> +{
> +	struct vdpa_iova_range *range = &v->range;
> +	struct iommu_domain_geometry geo;
> +	struct vdpa_device *vdpa = v->vdpa;
> +	const struct vdpa_config_ops *ops = vdpa->config;
> +
> +	if (ops->get_iova_range) {
> +		*range = ops->get_iova_range(vdpa);
> +	} else if (v->domain &&
> +		   !iommu_domain_get_attr(v->domain,
> +		   DOMAIN_ATTR_GEOMETRY, &geo) &&
> +		   geo.force_aperture) {
> +		range->first = geo.aperture_start;
> +		range->last = geo.aperture_end;
> +	} else {
> +		range->first = 0;
> +		range->last = ULLONG_MAX;
> +	}

Shouldn't we require drivers that publish VIRTIO_F_ACCESS_PLATFORM to
implement get_iova_range?

> +}
> +
>  static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  {
>  	struct vhost_vdpa *v;
> @@ -802,6 +841,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
>  	if (r)
>  		goto err_init_iotlb;
>  
> +	vhost_vdpa_set_iova_range(v);
> +
>  	filep->private_data = v;
>  
>  	return 0;
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index 75232185324a..c998860d7bbc 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -146,4 +146,8 @@
>  
>  /* Set event fd for config interrupt*/
>  #define VHOST_VDPA_SET_CONFIG_CALL	_IOW(VHOST_VIRTIO, 0x77, int)
> +
> +/* Get the valid iova range */
> +#define VHOST_VDPA_GET_IOVA_RANGE	_IOR(VHOST_VIRTIO, 0x78, \
> +					     struct vhost_vdpa_iova_range)
>  #endif
> diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h
> index 9a269a88a6ff..f7f6a3a28977 100644
> --- a/include/uapi/linux/vhost_types.h
> +++ b/include/uapi/linux/vhost_types.h
> @@ -138,6 +138,15 @@ struct vhost_vdpa_config {
>  	__u8 buf[0];
>  };
>  
> +/* vhost vdpa IOVA range
> + * @first: First address that can be mapped by vhost-vDPA
> + * @last: Last address that can be mapped by vhost-vDPA
> + */
> +struct vhost_vdpa_iova_range {
> +	__u64 first;
> +	__u64 last;
> +};
> +
>  /* Feature bits */
>  /* Log all write descriptors. Can be changed while device is active. */
>  #define VHOST_F_LOG_ALL 26
> -- 
> 2.18.1
> 

Re: [PATCH V2 2/3] vhost: vdpa: report iova range

[Jason Wang]

On 2020/8/23 下午2:40, Eli Cohen wrote:
>> +static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
>> +{
>> +	struct vdpa_iova_range *range = &v->range;
>> +	struct iommu_domain_geometry geo;
>> +	struct vdpa_device *vdpa = v->vdpa;
>> +	const struct vdpa_config_ops *ops = vdpa->config;
>> +
>> +	if (ops->get_iova_range) {
>> +		*range = ops->get_iova_range(vdpa);
>> +	} else if (v->domain &&
>> +		   !iommu_domain_get_attr(v->domain,
>> +		   DOMAIN_ATTR_GEOMETRY, &geo) &&
>> +		   geo.force_aperture) {
>> +		range->first = geo.aperture_start;
>> +		range->last = geo.aperture_end;
>> +	} else {
>> +		range->first = 0;
>> +		range->last = ULLONG_MAX;
>> +	}
> Shouldn't we require drivers that publish VIRTIO_F_ACCESS_PLATFORM to
> implement get_iova_range?


Probably not, since ACCESS_PLATFORM does not exclude the device that 
depends on the chipset IOMMU to work. So in that case, we should query 
IOMMU driver instead of vDPA device driver.

Thanks


>
>> +}