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Subject: [PATCH V2 3/5] Introduce the commands set of the transport vq
This commit introduces the commands set of the
transport virtqueue, including:
The command to query available resources of the management device
The commands to create / destroy the managed devices.
The commands to config the managed devices.
The commands to config virtqueues of the managed devices.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
content.tex | 656 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 656 insertions(+)
diff --git a/content.tex b/content.tex
index 143949e..e625faf 100644
--- a/content.tex
+++ b/content.tex
@@ -2980,6 +2980,662 @@ \subsection{Transport Virtqueue Features}\label{sec:Virtio Transport Options /Vi
The management device MUST not accept VIRTIO_F_TRANSPT_VQ_MDEV if VIRTIO_F_TRANSPT_VQ is not negotiated.
+\subsection{Available Resource of the Management Device}\label{sec:Virtio Transport Options / Virtio Over Transport Virtqueue / Available Resource of the Management Device}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+statistical information of available resources of the management device could be fetched
+by the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_AVAIL_RES 1 (class)
+ #define VIRTIO_TRANSPTQ_CTRL_AVAIL_RES_GET 0 (command)
+\end{lstlisting}
+
+VIRTIO_TRANSPTQ_CTRL_AVAIL_RES_GET command is used to get the statistical information of the available
+resource of a management device. There is no command-out-data for VIRTIO_TRANSPTQ_CTRL_AVAIL_RES_GET
+command. The management device fills command-in-data in the following format:
+
+\begin{lstlisting}
+struct mgmt_dev_avail_res{
+ /* The number of total remaining virtqueues for the managed devices */
+ u16 num_avail_vqs;
+ /* The minimal number of virtqueues for a managed device */
+ u16 min_mdev_vqs;
+ /* The maximum number of virtqueues for a managed device */
+ u16 max_mdev_vqs;
+ /* The number of managed devices that can be created with min_mdev_vqs virtqueues.
+ * This number may not equal to num_avail_vqs divided by min_mdev_vqs due to
+ * the limitations of other resources
+ */
+ u16 num_avail_mdev;
+};
+\end{lstlisting}
+
+If \field{min_mdev_vqs} equals to \field{min_mdev_vqs}, that means the management device
+can only create managed devices with a fixed number of virtqueues, then the managed devices
+can be pre-allocated.
+
+\devicenormative{\subsubsection}{Available resource of the management device}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Available resource of the management device}
+
+The management device MUST fail VIRTIO_TRANSPTQ_CTRL_AVAIL_RES_GET command if \field{device_id} is not 0
+
+\drivernormative{\subsubsection}{Available resource of the management device}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Available resource of the management device}
+
+The management driver MUST use 0 as \field{device_id} for
+VIRTIO_TRANSPTQ_CTRL_AVAIL_RES_GET command.
+
+\subsection{Create and Destroy Managed Devices}\label{sec:Virtio Transport Options / Virtio Over Transport Virtqueue / Create and Destroy Managed Devices}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+managed devices must be created and destroyed through the transport virtqueue.
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPORTQ_CTRL_MDEV 2
+ #define VIRTIO_TRANSPORTQ_CTRL_MDEV_CREATE 0
+ #define VIRTIO_TRANSPORTQ_CTRL_MDEV_DESTROY 1
+
+struct transportq_ctrl_mdev_attribute {
+ u32 virtio_device_id;
+ u64 device_features;
+ u8 dev_config[];
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPORTQ_CTRL_MDEV_CREATE command is used to create a managed device.
+The command-out-data for VIRTIO_TRANSPTQ_CTRL_MDEV_CREATE is the virtio device id (\field{virtio_device_id}),
+feature bits and device type specific configuration (\field{dev_config}) for creating the managed device.
+(as described in struct transportq_ctrl_mdev_attribute)
+
+The field \field{dev_config} is device type specific configurations. E.g., for a virtio-net device,
+it is struct virtio_net_config in section \ref{sec:Device Types / Network Device / Device configuration layout};
+for a virtio-block device, it is struct virtio_blk_config in section \ref{sec:Device Types / Block Device / Device configuration layout}
+
+The field \field{device_features} is the device feature bits for the managed device.
+
+When succeed, the device returns a 64 bits UUID as an unique identifier of the created managed device in command-in-data.
+
+The VIRTIO_TRANSPORTQ_CTRL_MDEV_DESTROY command is used to destroy a
+managed device which is identified by its 64 bits UUID
+\field{device_id}. There's no command-in-data nor command-out-data for
+VIRTIO_TRANSPTQ_CTRL_MDEV_DESTROY command.
+
+\devicenormative{\subsubsection}{Create and Destroy Managed Devices}{Virtio Transport Options / Virtio Over Transport Virtqueue / Create and Destroy Managed Devices}
+
+The management device MUST fail VIRTIO_TRANSPORTQ_CTRL_MDEV_CREATE command
+if \field{device_id} is not 0.
+
+The management device MUST fail VIRTIO_TRANSPORTQ_CTRL_MDEV CREATE command
+if \field{device_features} exceeds the feature bits of the management device.
+
+The management device MUST fail VIRTO_TRANSPORTQ_CTRL_MDEV_DESTROY command
+if \field{device_id} is 0.
+
+\drivernormative{\subsubsection}{Create and Destroy Managed Devices}{Virtio Transport Options / Virtio Over Transport Virtqueue / Create and Destroy Managed Devices}
+
+The management driver MUST use 0 as \field{device_id} for
+TRANSPORTQ_CTRL_MDEV_CREATE command.
+
+\subsection{Features Negotiation}\label{sec:Virtio Transport Options / Virtio
+Over Transport Virtqueue / Features Negotiation}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the features negotiation of managed devices is done by the
+following commands:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_FEAT 3
+ #define VIRTIO_TRANSPTQ_CTRL_FEAT_DEVICE_GET 0
+ #define VIRTIO_TRANSPTQ_CTRL_FEAT_DRIVER_SET 1
+ #define VIRTIO_TRANSPTQ_CTRL_FEAT_DRIVER_GET 2
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_FEAT_DEVICE_GET command is used to get the features offered
+by a managed device.
+
+The VIRTIO_TRANSPTQ_CTRL_FEAT_DRIVER_SET command is for the driver to accept feature
+bits offered by the managed device.
+
+The VIRTIO_TRANSPTQ_CTRL_FEAT_DRIVER_GET command is used to get the features accepted
+by both the virtual driver and the device.
+
+The features is a 64 bits mask of the virtio features bit.
+For VIRTIO_TRANSPTQ_CTRL_DRIVER_SET, the feature bits are passed to the device
+through command-out-data. For VIRTIO_TRANSPTQ_CTRL_FEAT_DEVICE_GET and
+VIRTIO_TRANSPTQ_CTRL_DRIVER_GET the feature is returned for the device
+through command-in-data.
+
+\devicenormative{\subsubsection}{Features Negotiation}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Features Negotiation}
+
+The management device MUST fail VIRTIO_TRANSPTQ_F_CTRL_FEAT class commands if
+\field{device_id} is 0.
+
+\drivernormative{\subsubsection}{Features Negotiation}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Features Negotiation}
+
+The management driver MAY mediate between the feature negotiation
+request of the managed devices and the transport virtqueue. E.g when
+offering features to the managed device, the management driver MAY
+exclude some features in order to limit the behaviors of the managed
+device.
+
+\subsection{Device Status}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / Device Status}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the device status of a managed device can be accessed by the following
+commands:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_STATUS 4
+ #define VIRTIO_TRANSPTQ_CTRL_STATUS_SET 0
+ #define VIRTIO_TRANSPTQ_CTRL_STATUS_GET 1
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_STATUS_SET command is used to set the device status of
+a managed device. The command-out-data is the one byte status
+to set to the device. There's no command-in-data for this command.
+
+The VIRTIO_TRANSPTQ_CTRL_STATUS_GET command is used to get the device status of
+a managed device. The command-in-data is the one byte status
+returned from the device. There's no command-out-data for this
+command.
+
+\devicenormative{\subsubsection}{Device Status}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / Device Status}
+
+The management device MUST reset the managed device when 0
+is set via VIRTIO_TRANSPTQ_CTRL_STATUS_SET, the success of this
+command demonstrates the success of the reset.
+
+The management device MUST present 0 through
+VIRTIO_TRANSPTQ_CTRL_STATUS_GET once the reset is successfully done.
+
+The management device MUST fail the device status access if
+\field{device_id} is 0.
+
+\drivernormative{\subsubsection}{Device Status}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / Device Status}
+
+After writing 0 via VIRTIO_TRANSPTQ_CTRL_STATUS_SET, the driver MUST wait
+for the success of the command before re-initializing the device.
+
+\subsection{Device Generation}\label{sec:Virtio Transport Options / Virtio Over Transport Virtqueue / Device Generation}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the device generation count can be read from the following commands:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_GENERATION 5
+ #define VIRTIO_TRANSPTQ_CTRL_GENERATION_GET 0
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_GENERATION_GET command is used to get the device configuration generation count
+of the managed device. The command-in-data is the one byte device
+generation returned from the device. There's no command-out-data for
+this command.
+
+\devicenormative{\subsubsection}{Device Generation}{Virtio Transport Options / Virtio Over Transport Virtqueue / Device Generation}
+
+The management device MUST present a changed generation count after the driver
+has read a device-specific configuration value which has changed since
+any part of the device-specific configuration was last read.
+
+The management device MUST fail the device generation access if \field{device_id} is 0.
+
+\subsection{Device Specific Configuration}\label{sec:Virtio Transport Options /
+Virtio Over Transport Virtqueue / Device Specific Configuration}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the device config space contents of a managed device can be accessed through
+the following commands:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_CONFIG 6
+ #define VIRTIO_TRANSPTQ_CTRL_CONFIG_GET 0
+ #define VIRTIO_TRANSPTQ_CTRL_CONFIG_SET 1
+
+struct transportq_ctrl_mdev_config_get {
+ u32 offset;
+ u32 size;
+};
+
+struct transportq_ctrl_mdev_config_set {
+ u32 offset;
+ u32 size;
+ u8 data[];
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_CONFIG_GET command is used to read data from the
+device configuration space. The command-out-data is the \field{offset}
+from the start of the config space and the \field{size}
+of the data (as described in struct transportq_ctrl_mdev_config_get).
+The command-in-data is an array of the data that read from the config space.
+
+The VIRTIO_TRANSPTQ_CTRL_CONFIG_SET command is used to write data to the device
+configuration space. The command-out-data contains the
+\field{offset} from the start of the config space, the \field{size} of the data and
+the \field{data} to be written (as described in struct transportq_ctrl_mdev_config_set).
+There's no command-in-data for this command.
+
+\devicenormative{\subsubsection}{Device Specific Configuration}{Virtio Transport
+Options / Virtio Over Transport Virtqueue / Device Specific Configuration}
+
+The management device MUST fail the device configuration space access
+if the driver wants to access the range which is outside the config space.
+
+The management device MUST fail the device configuration space access
+if \field{device_id} is 0.
+
+\subsection{MSI Configuration}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / MSI Configuration}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the MSI entries of a managed device are set through the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_MSI 7
+ #define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_SET 0
+ #define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_ENABLE 1
+ #define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_MASK 2
+ #define VIRTIO_TRANSPTQ_CTRL_MSI_CONFIG_SET 3
+ #define VIRTIO_TRANSPTQ_CTRL_MSI_CONFIG_ENABLE 4
+ #define VIRTIO_TRANSPTQ_CTRL_MSI_CONFIG_MASK 5
+
+struct transportq_ctrl_mdev_msi_vq_config {
+ u16 queue_index;
+ u64 address;
+ u32 data;
+};
+
+struct transportq_ctrl_mdev_msi_vq_enable {
+ u16 queue_index;
+ u8 enable;
+};
+
+struct transportq_ctrl_mdev_msi_vq_mask {
+ u16 queue_index;
+ u8 mask;
+};
+
+struct transportq_ctrl_mdev_msi_config {
+ u64 address;
+ u32 data;
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_MSI_VQ_SET command is used to set the MSI entry for a
+specific virtqueue. The command-out-data is the \field{queue_index} and
+the MSI \field{address} and \field{data} (as described in struct transportq_ctrl_mdev_msi_vq_config).
+
+The VIRTIO_TRANSPTQ_CTRL_MSI_VQ_ENABLE command is used to enable or disable
+the MSI interrupt for a specific virtqueue. The command-out-data is the
+\field{queue_index} and an \field{enable} which representing ENABLE or DISABLE the MSI.
+(as described in struct transportq_ctrl_mdev_msi_vq_enable).
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_ENABLE 1
+#define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_DISABLE 0
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_MSI_VQ_MASK command is used to mask or unmask the
+MSI interrupt for a specific virtqueue. The command-out-data is the
+\field{queue_index} and the \field{mask} status
+(as described in struct transportq_ctrl_mdev_msi_vq_mask).
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_MASK 0
+#define VIRTIO_TRANSPTQ_CTRL_MSI_VQ_UNMASK 1
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_MSI_CONFIG_SET command is used to set the MSI entry
+for the config interrupt. The command-out-data is the MSI \field{address} and
+\field{data} (as described in struct transportq_ctrl_mdev_msi_config).
+
+The VIRTIO_TRANSPTQ_CTRL_MSI_CONFIG_ENABLE command is used to enable and disable
+MSI for config space. The command-out-data is an u8 byte which representing
+ENABLE or DISABLE the config MSI.
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_MSI_CFG_ENABLE 1
+#define VIRTIO_TRANSPTQ_CTRL_MSI_CFG_DISABLE 0
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_MSI_CONFIG_MASK command is used to mask and unmask the
+MSI interrupt for config space. The command-out-data is an u8 byte which representing
+the mask status.
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_MSI_CFG_MASK 0
+#define VIRTIO_TRANSPTQ_CTRL_MSI_CFG_UNMASK 1
+\end{lstlisting}
+
+There's no command-in-data for all the above MSI commands.
+
+\devicenormative{\subsubsection}{MSI Configuration}{Virtio Transport Options / Virtio
+ver Transport Virtqueue / MSI Configuration}
+
+The managed device MUST record the pending MSI interrupts when masking, and
+re-generate the pending MSI interrupts when unmasking.
+
+The managed device MUST disable the MSI for both virtqueues and config space
+upon reset.
+
+\drivernormative{\subsubsection}{MSI Configuration}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / MSI Configuration}
+
+The driver MUST allocate transport or platform specific MSI entries
+for both virtqueues and config space if it wants to use interrupts.
+
+The driver MAY choose to disable the MSI if polling mode is used.
+
+\subsection{Virtqueue Address}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / Virtqueue Address}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the addresses of a specific virtqueue are accessed through the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_ADDR 8
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_ADDR_SET 0
+
+struct transportq_ctrl_mdev_vq_addr {
+ u16 queue_index;
+ u64 descriptor_area;
+ u64 device_area;
+ u64 driver_area;
+};
+\end{lstlisting}
+
+The command-out-data is the \field{queue_index}, the addresses of \field{device_area},
+\field{descriptor_area} and \field{driver_area} (as described in struct
+transportq_ctrl_mdev_vq_addr. There's no command-in-data.
+
+\devicenormative{\subsubsection}{Virtqueue Address}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueeu Address}
+
+The management device MUST fail the commands of class
+VIRTIO_TRANSPTQ_CTRL_VQ_ADDR if \field{device_id} is 0.
+
+The management device MUST fail the commands of class
+VIRTIO_TRANSPTQ_CTRL_VQ_ADDR if \field{queue_index} is invalid.
+
+\subsection{Virtqueue Status}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / Virtqueue Status}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+virtqueue status is accessed through the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE 9
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE_SET 0
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE_GET 1
+
+struct transportq_ctrl_mdev_vq_status_set {
+ u16 queue_index;
+ u8 status;
+
+#define VIRTIO_TRANSPTQ_VQ_ENABLE 1
+#define VIRTIO_TRANSPTQ_VQ_DISABLE 0
+
+};
+
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE_SET command is used to set the status of a
+specific virtqueue. The command-out-data is the \field{queue_index} and the
+\field{status} representing ENABLE or DISABLE that is set to the virtqueue
+(as described in struct virtio_transportq_ctrl_vq_status_set).
+There's no command-in-data.
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE_GET is used to get the status of a
+specific virtqueue. The command-out-data is the queue
+index. The command-in-data is the virtqueue status.
+
+\devicenormative{\subsubsection}{Virtqueue Status}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue Status}
+
+When disabled, the managed device MUST stop processing requests from
+this virtqueue.
+
+The management device MUST present a 0 via
+VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE_GET upon a reset of the managed device.
+
+The management device MUST fail the virtqueue status access if
+\field{device_id} is 0.
+
+The management device MUST fail the virtqueue status access if
+the queue_index is invalid.
+
+\drivernormative{\subsubsection}{Virtqueue Status}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue Status}
+
+The driver MUST configure other virtqueue fields before enabling
+the virtqueue with VIRTIO_TRANSPTQ_CTRL_VQ_ENABLE_SET.
+
+\subsection{Virtqueue Size}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / Virtqueue Size}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+virtqueue size is accessed through the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_SIZE 10
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_SIZE_SET 0
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_SIZE_GET 1
+
+struct transportq_ctrl_mdev_vq_size_set {
+ u16 queue_index;
+ u16 size;
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_SIZE_SET command is used to set the virtqueue
+size. The command-out-data is the \field{queue_index} and the \field{size}
+of the virtqueue (as described in struct transportq_ctrl_mdev_vq_size_set).
+There's no command-in-data.
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_SIZE_GET command is used to get the virtqueue
+size. On reset, the maximum queue size supported by the device is
+returned. The command-out-data is an u16 of the queue index. The
+command-in-data is an u16 of the queue size of the virtqueue.
+
+\devicenormative{\subsubsection}{Virtqueue Status}{Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue Size}
+
+The management device MUST fail the virtqueue size access if
+\field{device_id} is 0.
+
+The management device MUST fail the virtqueue size access if
+the queue index is invalid.
+
+\subsection{Virtqueue Notification}\label{sec:Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue Notification}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the virtqueue notification area information can be get through the following commands:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_NOTIFY 11
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_NOTIFY_GET 1
+
+struct transportq_ctrl_mdev_vq_notification_area {
+ u64 address;
+ u64 size;
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_NOTIFY_GET is used to get the transport
+specific address area that can be used to notify a virtqueue. The
+command-out-data is an u16 of the queue index. The command-in-data
+contains the \field{address} and the \field{size}
+of the notification area (as described in struct transportq_ctrl_mdev_vq_notification_area).
+
+\devicenormative{\subsubsection}{Virtqueue Notification}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Virtqueue Notification}
+
+The management device MUST fail the virtqueue notification area information
+access if \field{device_id} is 0.
+
+The management device MUST fail the virtqueue notification area information
+access if the queue index is invalid.
+
+\drivernormative{\subsubsection}{Virtqueue Notification}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Virtqueue Notification}
+
+The driver MAY choose to notify the virtqueue by writing the queue
+index at address \field{address} which is fetched from the
+VIRTIO_TRANSPTQ_CTRL_VQ_NOTIFY_GET command.
+
+\subsection{Virtqueue State}\label{sec:Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue State}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated,
+the virtqueue state is accessed through the following commands:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_STATE 12
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_STATE_SET 0
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_STATE_GET 1
+\end{lstlisting}
+
+\subsubsection{Split Virtqueue State}\label{sec:Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue State / Split Virtqueue State}
+
+\begin{lstlisting}
+struct transportq_ctrl_mdev_split_vq_state_set {
+ u16 queue_index;
+ u16 avail_index;
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_STATE_SET command can be used to set the state of a
+split virtqueue. The command-out-data contains the \field{queue_index} and the
+available index for the virtqueue (as described in struct transportq_ctrl_mdev_split_vq_state_set).
+There is no command-in-data.
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_STATE_GET command can be used to get the state of a
+split virtqueue. The command-out-data is the queue index, the command-in-data is the available index of the virtqueue.
+
+\subsubsection{Packed Virtqueue State}\label{sec:Virtio Transport Options / Virtio
+Over Transport Virtqueue / Virtqueue State / Packed Virtqueue State}
+
+\begin{lstlisting}
+struct transportq_ctrl_mdev_packed_vq_state_set {
+ u16 queue_index;
+ u16 avail_counter;
+ u16 avail_index;
+ u16 used_counter;
+ u16 used_index;
+};
+
+struct transportq_ctrl_mdev_packed_vq_state_get {
+ u16 avail_counter;
+ u16 avail_index;
+ u16 used_counter;
+ u16 used_index;
+};
+\end{lstlisting}
+
+The state of a packed virtqueue includes :\\
+\field{avail_counter}: last driver ring wrap counter observed by device.\\
+\field{avail_index}: virtqueue available index.\\
+\field{used_counter}: device ring wrap counter.\\
+\field{used_index}: virtqueue used index.
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_STATE_SET command can be used to set the state of a packed virtqueue.
+The command-out-data contains the \field{queue_index}, \field{avail_counter}, \field{avail_index},
+\field{used_counter} and \field{used_index} for the virtqueue
+(as described in transportq_ctrl_mdev_packed_vq_state_set).
+There is no command-in-data.
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_STATE_GET command can be used to get the state of a packed virtqueue.
+The command-out-data is the queue index, the command-in-data contains \field{avail_counter}, \field{avail_index},
+\field{used_counter} and \field{used_index} of the virtqueue
+(as described in transportq_ctrl_mdev_packed_vq_state_set).
+
+\devicenormative{\subsubsection}{Virtqueue State}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Virtqueue State}
+
+The management device MUST fail the virtqueue index access if \field{device_id} is 0.
+
+The management device MUST fail the virtqueue index access if \field{queue_index} is invalid.
+
+\subsection{Virtqueue ASID}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / Virtqueue ASID}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV is negotiated, the address space id of a virtqueue
+could be set through the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_ASID 13
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_ASID_SET 1
+
+struct transportq_ctrl_mdev_vq_asid_set {
+ u16 queue_index;
+ u32 asid;
+};
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_ASID_SET command is used to set the address space id(\field{asid})
+of a virtqueue.
+
+The address space id is an identifier of a memory space which is used to convey the address space targeted by the
+memory accesses, and to distinguish memory accesses performed by different virtqueues
+
+One example of the address space id is PASID (Process Address Space Identifier) which is
+defined in \hyperref[intro:PCIe]{[PCIe]} specification.
+
+The command-out-data of VIRTIO_TRANSPTQ_CTRL_VQ_ASID_SET command is the \field{queue_index}
+and the address space id \field{asid}
+(as described in struct transportq_ctrl_mdev_vq_asid_set).
+
+\devicenormative{\subsubsection}{Virtqueue ASID}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Virtqueue ASID}
+
+Once a virtqueue has been set an asid, it MUST perform any memory accesses with the asid.
+
+The management device MUST fail the virtqueue index access if \field{device_id} is 0.
+
+The management device MUST fail the virtqueue index access if \field{queue_index} is invalid.
+
+\subsection{Virtqueue Reset}\label{sec:Virtio Transport Options / Virtio Over
+Transport Virtqueue / Virtqueue Reset}
+
+When VIRTIO_F_TRANSPT_VQ_MDEV and VIRTIO_F_RING_RESET are negotiated,
+a virtqueue can be reset through the following command:
+
+\begin{lstlisting}
+#define VIRTIO_TRANSPTQ_CTRL_VQ_RESET 14
+ #define VIRTIO_TRANSPTQ_CTRL_VQ_DO_RESET 1
+\end{lstlisting}
+
+The VIRTIO_TRANSPTQ_CTRL_VQ_DO_RESET command is used to reset a virtqueue.
+The command-out-data is the virtqueue index, there is no command-in-data.
+
+\devicenormative{\subsubsection}{Virtqueue Reset}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Virtqueue Reset}
+
+The management device MUST fail VIRTIO_TRANSPTQ_CTRL_VQ_RESET if
+\field{device_id} is 0.
+
+The management device MUST fail VIRTIO_TRANSPTQ_CTRL_VQ_RESET if
+the virtqueue index is invalid.
+
+The managed device MUST stop consuming the descriptors in the virtqueue once reset it.
+
+The managed device MUST present default states of a virtqueue after reset it.
+
+\drivernormative{\subsubsection}{Virtqueue Reset}{Virtio Transport Options /
+Virtio Over Transport Virtqueue / Virtqueue Reset}
+
+After reseting a virtqueue, the driver MUST wait until the reset is successfully
+done (by verifying the virtqueue state has been reset to default)
+before re-enabling it.
+
\chapter{Device Types}\label{sec:Device Types}
On top of the queues, config space and feature negotiation facilities
--
2.35.3
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