PCI passthru on Hyper-V (Part I)

[PATCH v0 05/15] mshv: Declarations and definitions for VFIO-MSHV bridge device

Posted by Mukesh R 2 weeks, 4 days ago

From: Mukesh Rathor <mrathor@linux.microsoft.com>

Add data structs needed by the subsequent patch that introduces a new
module to implement VFIO-MSHV pseudo device.

Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
---
 drivers/hv/mshv_root.h    | 23 +++++++++++++++++++++++
 include/uapi/linux/mshv.h | 31 +++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h
index c3753b009fd8..42e1da1d545b 100644
--- a/drivers/hv/mshv_root.h
+++ b/drivers/hv/mshv_root.h
@@ -220,6 +220,29 @@ struct port_table_info {
 	};
 };
 
+struct mshv_device {
+	const struct mshv_device_ops *device_ops;
+	struct mshv_partition *device_pt;
+	void *device_private;
+	struct hlist_node device_ptnode;
+};
+
+struct mshv_device_ops {
+	const char *device_name;
+	long (*device_create)(struct mshv_device *dev, u32 type);
+	void (*device_release)(struct mshv_device *dev);
+	long (*device_set_attr)(struct mshv_device *dev,
+				struct mshv_device_attr *attr);
+	long (*device_has_attr)(struct mshv_device *dev,
+				struct mshv_device_attr *attr);
+};
+
+extern struct mshv_device_ops mshv_vfio_device_ops;
+int mshv_vfio_ops_init(void);
+void mshv_vfio_ops_exit(void);
+long mshv_partition_ioctl_create_device(struct mshv_partition *partition,
+					void __user *user_args);
+
 int mshv_update_routing_table(struct mshv_partition *partition,
 			      const struct mshv_user_irq_entry *entries,
 			      unsigned int numents);
diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h
index dee3ece28ce5..b7b10f9e2896 100644
--- a/include/uapi/linux/mshv.h
+++ b/include/uapi/linux/mshv.h
@@ -252,6 +252,7 @@ struct mshv_root_hvcall {
 #define MSHV_GET_GPAP_ACCESS_BITMAP	_IOWR(MSHV_IOCTL, 0x06, struct mshv_gpap_access_bitmap)
 /* Generic hypercall */
 #define MSHV_ROOT_HVCALL		_IOWR(MSHV_IOCTL, 0x07, struct mshv_root_hvcall)
+#define MSHV_CREATE_DEVICE		_IOWR(MSHV_IOCTL, 0x08, struct mshv_create_device)
 
 /*
  ********************************
@@ -402,4 +403,34 @@ struct mshv_sint_mask {
 /* hv_hvcall device */
 #define MSHV_HVCALL_SETUP        _IOW(MSHV_IOCTL, 0x1E, struct mshv_vtl_hvcall_setup)
 #define MSHV_HVCALL              _IOWR(MSHV_IOCTL, 0x1F, struct mshv_vtl_hvcall)
+
+/* device passhthru */
+#define MSHV_CREATE_DEVICE_TEST		1
+
+enum {
+	MSHV_DEV_TYPE_VFIO,
+	MSHV_DEV_TYPE_MAX,
+};
+
+struct mshv_create_device {
+	__u32	type;	     /* in: MSHV_DEV_TYPE_xxx */
+	__u32	fd;	     /* out: device handle */
+	__u32	flags;	     /* in: MSHV_CREATE_DEVICE_xxx */
+};
+
+#define MSHV_DEV_VFIO_FILE      1
+#define MSHV_DEV_VFIO_FILE_ADD	1
+#define MSHV_DEV_VFIO_FILE_DEL	2
+
+struct mshv_device_attr {
+	__u32	flags;		/* no flags currently defined */
+	__u32	group;		/* device-defined */
+	__u64	attr;		/* group-defined */
+	__u64	addr;		/* userspace address of attr data */
+};
+
+/* Device fds created with MSHV_CREATE_DEVICE */
+#define MSHV_SET_DEVICE_ATTR	_IOW(MSHV_IOCTL, 0x00, struct mshv_device_attr)
+#define MSHV_HAS_DEVICE_ATTR	_IOW(MSHV_IOCTL, 0x01, struct mshv_device_attr)
+
 #endif
-- 
2.51.2.vfs.0.1

Re: [PATCH v0 05/15] mshv: Declarations and definitions for VFIO-MSHV bridge device

Posted by Nuno Das Neves 2 weeks, 1 day ago

On 1/19/2026 10:42 PM, Mukesh R wrote:
> From: Mukesh Rathor <mrathor@linux.microsoft.com>
> 
> Add data structs needed by the subsequent patch that introduces a new
> module to implement VFIO-MSHV pseudo device.
> 
> Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
> ---
>  drivers/hv/mshv_root.h    | 23 +++++++++++++++++++++++
>  include/uapi/linux/mshv.h | 31 +++++++++++++++++++++++++++++++
>  2 files changed, 54 insertions(+)
> 
> diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h
> index c3753b009fd8..42e1da1d545b 100644
> --- a/drivers/hv/mshv_root.h
> +++ b/drivers/hv/mshv_root.h
> @@ -220,6 +220,29 @@ struct port_table_info {
>  	};
>  };
>  
> +struct mshv_device {
> +	const struct mshv_device_ops *device_ops;
> +	struct mshv_partition *device_pt;
> +	void *device_private;
> +	struct hlist_node device_ptnode;
> +};
> +
> +struct mshv_device_ops {
> +	const char *device_name;
> +	long (*device_create)(struct mshv_device *dev, u32 type);
> +	void (*device_release)(struct mshv_device *dev);
> +	long (*device_set_attr)(struct mshv_device *dev,
> +				struct mshv_device_attr *attr);
> +	long (*device_has_attr)(struct mshv_device *dev,
> +				struct mshv_device_attr *attr);
> +};
> +
> +extern struct mshv_device_ops mshv_vfio_device_ops;
> +int mshv_vfio_ops_init(void);
> +void mshv_vfio_ops_exit(void);
> +long mshv_partition_ioctl_create_device(struct mshv_partition *partition,
> +					void __user *user_args);
> +
>  int mshv_update_routing_table(struct mshv_partition *partition,
>  			      const struct mshv_user_irq_entry *entries,
>  			      unsigned int numents);
> diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h
> index dee3ece28ce5..b7b10f9e2896 100644
> --- a/include/uapi/linux/mshv.h
> +++ b/include/uapi/linux/mshv.h
> @@ -252,6 +252,7 @@ struct mshv_root_hvcall {
>  #define MSHV_GET_GPAP_ACCESS_BITMAP	_IOWR(MSHV_IOCTL, 0x06, struct mshv_gpap_access_bitmap)
>  /* Generic hypercall */
>  #define MSHV_ROOT_HVCALL		_IOWR(MSHV_IOCTL, 0x07, struct mshv_root_hvcall)
> +#define MSHV_CREATE_DEVICE		_IOWR(MSHV_IOCTL, 0x08, struct mshv_create_device)
>  

With this commit, the IOCTL number is exposed to userspace but it doesn't work.
Ideally the IOCTL number should be added in the commit where it becomes usable.

>  /*
>   ********************************
> @@ -402,4 +403,34 @@ struct mshv_sint_mask {
>  /* hv_hvcall device */
>  #define MSHV_HVCALL_SETUP        _IOW(MSHV_IOCTL, 0x1E, struct mshv_vtl_hvcall_setup)
>  #define MSHV_HVCALL              _IOWR(MSHV_IOCTL, 0x1F, struct mshv_vtl_hvcall)
> +
> +/* device passhthru */
> +#define MSHV_CREATE_DEVICE_TEST		1
> +
> +enum {
> +	MSHV_DEV_TYPE_VFIO,
> +	MSHV_DEV_TYPE_MAX,
> +};
> +
> +struct mshv_create_device {
> +	__u32	type;	     /* in: MSHV_DEV_TYPE_xxx */
> +	__u32	fd;	     /* out: device handle */
> +	__u32	flags;	     /* in: MSHV_CREATE_DEVICE_xxx */
> +};
> +
> +#define MSHV_DEV_VFIO_FILE      1
> +#define MSHV_DEV_VFIO_FILE_ADD	1
> +#define MSHV_DEV_VFIO_FILE_DEL	2
> +
> +struct mshv_device_attr {
> +	__u32	flags;		/* no flags currently defined */
> +	__u32	group;		/* device-defined */
> +	__u64	attr;		/* group-defined */
> +	__u64	addr;		/* userspace address of attr data */
> +};
> +
> +/* Device fds created with MSHV_CREATE_DEVICE */
> +#define MSHV_SET_DEVICE_ATTR	_IOW(MSHV_IOCTL, 0x00, struct mshv_device_attr)
> +#define MSHV_HAS_DEVICE_ATTR	_IOW(MSHV_IOCTL, 0x01, struct mshv_device_attr)
> +
>  #endif

Re: [PATCH v0 05/15] mshv: Declarations and definitions for VFIO-MSHV bridge device

Posted by Mukesh R 2 weeks, 1 day ago

On 1/23/26 10:25, Nuno Das Neves wrote:
> On 1/19/2026 10:42 PM, Mukesh R wrote:
>> From: Mukesh Rathor <mrathor@linux.microsoft.com>
>>
>> Add data structs needed by the subsequent patch that introduces a new
>> module to implement VFIO-MSHV pseudo device.
>>
>> Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
>> ---
>>   drivers/hv/mshv_root.h    | 23 +++++++++++++++++++++++
>>   include/uapi/linux/mshv.h | 31 +++++++++++++++++++++++++++++++
>>   2 files changed, 54 insertions(+)
>>
>> diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h
>> index c3753b009fd8..42e1da1d545b 100644
>> --- a/drivers/hv/mshv_root.h
>> +++ b/drivers/hv/mshv_root.h
>> @@ -220,6 +220,29 @@ struct port_table_info {
>>   	};
>>   };
>>   
>> +struct mshv_device {
>> +	const struct mshv_device_ops *device_ops;
>> +	struct mshv_partition *device_pt;
>> +	void *device_private;
>> +	struct hlist_node device_ptnode;
>> +};
>> +
>> +struct mshv_device_ops {
>> +	const char *device_name;
>> +	long (*device_create)(struct mshv_device *dev, u32 type);
>> +	void (*device_release)(struct mshv_device *dev);
>> +	long (*device_set_attr)(struct mshv_device *dev,
>> +				struct mshv_device_attr *attr);
>> +	long (*device_has_attr)(struct mshv_device *dev,
>> +				struct mshv_device_attr *attr);
>> +};
>> +
>> +extern struct mshv_device_ops mshv_vfio_device_ops;
>> +int mshv_vfio_ops_init(void);
>> +void mshv_vfio_ops_exit(void);
>> +long mshv_partition_ioctl_create_device(struct mshv_partition *partition,
>> +					void __user *user_args);
>> +
>>   int mshv_update_routing_table(struct mshv_partition *partition,
>>   			      const struct mshv_user_irq_entry *entries,
>>   			      unsigned int numents);
>> diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h
>> index dee3ece28ce5..b7b10f9e2896 100644
>> --- a/include/uapi/linux/mshv.h
>> +++ b/include/uapi/linux/mshv.h
>> @@ -252,6 +252,7 @@ struct mshv_root_hvcall {
>>   #define MSHV_GET_GPAP_ACCESS_BITMAP	_IOWR(MSHV_IOCTL, 0x06, struct mshv_gpap_access_bitmap)
>>   /* Generic hypercall */
>>   #define MSHV_ROOT_HVCALL		_IOWR(MSHV_IOCTL, 0x07, struct mshv_root_hvcall)
>> +#define MSHV_CREATE_DEVICE		_IOWR(MSHV_IOCTL, 0x08, struct mshv_create_device)
>>   
> 
> With this commit, the IOCTL number is exposed to userspace but it doesn't work.
> Ideally the IOCTL number should be added in the commit where it becomes usable.
> 


Correct, I switched it because the next patch won't compile without it as
it needs the declarations here. It could be combined into one big patch,
but I think normally one would not expect full functionality until the
release is certified to be that feature compliant anyways. Hope that
makes sense.

Thanks,
-Mukesh




>>   /*
>>    ********************************
>> @@ -402,4 +403,34 @@ struct mshv_sint_mask {
>>   /* hv_hvcall device */
>>   #define MSHV_HVCALL_SETUP        _IOW(MSHV_IOCTL, 0x1E, struct mshv_vtl_hvcall_setup)
>>   #define MSHV_HVCALL              _IOWR(MSHV_IOCTL, 0x1F, struct mshv_vtl_hvcall)
>> +
>> +/* device passhthru */
>> +#define MSHV_CREATE_DEVICE_TEST		1
>> +
>> +enum {
>> +	MSHV_DEV_TYPE_VFIO,
>> +	MSHV_DEV_TYPE_MAX,
>> +};
>> +
>> +struct mshv_create_device {
>> +	__u32	type;	     /* in: MSHV_DEV_TYPE_xxx */
>> +	__u32	fd;	     /* out: device handle */
>> +	__u32	flags;	     /* in: MSHV_CREATE_DEVICE_xxx */
>> +};
>> +
>> +#define MSHV_DEV_VFIO_FILE      1
>> +#define MSHV_DEV_VFIO_FILE_ADD	1
>> +#define MSHV_DEV_VFIO_FILE_DEL	2
>> +
>> +struct mshv_device_attr {
>> +	__u32	flags;		/* no flags currently defined */
>> +	__u32	group;		/* device-defined */
>> +	__u64	attr;		/* group-defined */
>> +	__u64	addr;		/* userspace address of attr data */
>> +};
>> +
>> +/* Device fds created with MSHV_CREATE_DEVICE */
>> +#define MSHV_SET_DEVICE_ATTR	_IOW(MSHV_IOCTL, 0x00, struct mshv_device_attr)
>> +#define MSHV_HAS_DEVICE_ATTR	_IOW(MSHV_IOCTL, 0x01, struct mshv_device_attr)
>> +
>>   #endif