vmbus.h

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#ifndef _IPXE_VMBUS_H
#define _IPXE_VMBUS_H

/** @file
 *
 * Hyper-V virtual machine bus
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <byteswap.h>
#include <ipxe/uuid.h>
#include <ipxe/device.h>
#include <ipxe/tables.h>
#include <ipxe/uaccess.h>
#include <ipxe/iobuf.h>
#include <ipxe/hyperv.h>

/** VMBus message connection ID */
#define VMBUS_MESSAGE_ID 1

/** VMBus event connection ID */
#define VMBUS_EVENT_ID 2

/** VMBus message type */
#define VMBUS_MESSAGE_TYPE 1

/** VMBus message synthetic interrupt */
#define VMBUS_MESSAGE_SINT 2

/** VMBus version number */
union vmbus_version {
        /** Raw version */
        uint32_t raw;
        /** Major/minor version */
        struct {
                /** Minor version */
                uint16_t minor;
                /** Major version */
                uint16_t major;
        };
} __attribute__ (( packed ));

/** Known VMBus protocol versions */
enum vmbus_raw_version {
        /** Windows Server 2008 */
        VMBUS_VERSION_WS2008 = ( ( 0 << 16 ) | ( 13 << 0 ) ),
        /** Windows 7 */
        VMBUS_VERSION_WIN7 = ( ( 1 << 16 ) | ( 1 << 0 ) ),
        /** Windows 8 */
        VMBUS_VERSION_WIN8 = ( ( 2 << 16 ) | ( 4 << 0 ) ),
        /** Windows 8.1 */
        VMBUS_VERSION_WIN8_1 = ( ( 3 << 16 ) | ( 0 << 0 ) ),
};

/** Guest physical address range descriptor */
struct vmbus_gpa_range {
        /** Byte count */
        uint32_t len;
        /** Starting byte offset */
        uint32_t offset;
        /** Page frame numbers
         *
         * The length of this array is implied by the byte count and
         * starting offset.
         */
        uint64_t pfn[0];
} __attribute__ (( packed ));

/** VMBus message header */
struct vmbus_message_header {
        /** Message type */
        uint32_t type;
        /** Reserved */
        uint32_t reserved;
} __attribute__ (( packed ));

/** VMBus message types */
enum vmbus_message_type {
        VMBUS_OFFER_CHANNEL = 1,
        VMBUS_REQUEST_OFFERS = 3,
        VMBUS_ALL_OFFERS_DELIVERED = 4,
        VMBUS_OPEN_CHANNEL = 5,
        VMBUS_OPEN_CHANNEL_RESULT = 6,
        VMBUS_CLOSE_CHANNEL = 7,
        VMBUS_GPADL_HEADER = 8,
        VMBUS_GPADL_CREATED = 10,
        VMBUS_GPADL_TEARDOWN = 11,
        VMBUS_GPADL_TORNDOWN = 12,
        VMBUS_INITIATE_CONTACT = 14,
        VMBUS_VERSION_RESPONSE = 15,
        VMBUS_UNLOAD = 16,
        VMBUS_UNLOAD_RESPONSE = 17,
};

/** VMBus "offer channel" message */
struct vmbus_offer_channel {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel type */
        union uuid type;
        /** Channel instance */
        union uuid instance;
        /** Reserved */
        uint8_t reserved_a[16];
        /** Flags */
        uint16_t flags;
        /** Reserved */
        uint8_t reserved_b[2];
        /** User data */
        uint8_t data[120];
        /** Reserved */
        uint8_t reserved_c[4];
        /** Channel ID */
        uint32_t channel;
        /** Monitor ID */
        uint8_t monitor;
        /** Monitor exists */
        uint8_t monitored;
        /** Reserved */
        uint8_t reserved[2];
        /** Connection ID */
        uint32_t connection;
} __attribute__ (( packed ));

/** VMBus "open channel" message */
struct vmbus_open_channel {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel ID */
        uint32_t channel;
        /** Open ID */
        uint32_t id;
        /** Ring buffer GPADL ID */
        uint32_t gpadl;
        /** Reserved */
        uint32_t reserved;
        /** Outbound ring buffer size (in pages) */
        uint32_t out_pages;
        /** User-specific data */
        uint8_t data[120];
} __attribute__ (( packed ));

/** VMBus "open channel result" message */
struct vmbus_open_channel_result {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel ID */
        uint32_t channel;
        /** Open ID */
        uint32_t id;
        /** Status */
        uint32_t status;
} __attribute__ (( packed ));

/** VMBus "close channel" message */
struct vmbus_close_channel {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel ID */
        uint32_t channel;
} __attribute__ (( packed ));

/** VMBus "GPADL header" message */
struct vmbus_gpadl_header {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel ID */
        uint32_t channel;
        /** GPADL ID */
        uint32_t gpadl;
        /** Length of range descriptors */
        uint16_t range_len;
        /** Number of range descriptors */
        uint16_t range_count;
        /** Range descriptors */
        struct vmbus_gpa_range range[0];
} __attribute__ (( packed ));

/** VMBus "GPADL created" message */
struct vmbus_gpadl_created {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel ID */
        uint32_t channel;
        /** GPADL ID */
        uint32_t gpadl;
        /** Creation status */
        uint32_t status;
} __attribute__ (( packed ));

/** VMBus "GPADL teardown" message */
struct vmbus_gpadl_teardown {
        /** Message header */
        struct vmbus_message_header header;
        /** Channel ID */
        uint32_t channel;
        /** GPADL ID */
        uint32_t gpadl;
} __attribute__ (( packed ));

/** VMBus "GPADL torndown" message */
struct vmbus_gpadl_torndown {
        /** Message header */
        struct vmbus_message_header header;
        /** GPADL ID */
        uint32_t gpadl;
} __attribute__ (( packed ));

/** VMBus "initiate contact" message */
struct vmbus_initiate_contact {
        /** Message header */
        struct vmbus_message_header header;
        /** Requested version */
        union vmbus_version version;
        /** Target virtual CPU */
        uint32_t vcpu;
        /** Interrupt page base address */
        uint64_t intr;
        /** Parent to child monitor page base address */
        uint64_t monitor_in;
        /** Child to parent monitor page base address */
        uint64_t monitor_out;
} __attribute__ (( packed ));

/** VMBus "version response" message */
struct vmbus_version_response {
        /** Message header */
        struct vmbus_message_header header;
        /** Version is supported */
        uint8_t supported;
        /** Reserved */
        uint8_t reserved[3];
        /** Version */
        union vmbus_version version;
} __attribute__ (( packed ));

/** VMBus message */
union vmbus_message {
        /** Common message header */
        struct vmbus_message_header header;
        /** "Offer channel" message */
        struct vmbus_offer_channel offer;
        /** "Open channel" message */
        struct vmbus_open_channel open;
        /** "Open channel result" message */
        struct vmbus_open_channel_result opened;
        /** "Close channel" message */
        struct vmbus_close_channel close;
        /** "GPADL header" message */
        struct vmbus_gpadl_header gpadlhdr;
        /** "GPADL created" message */
        struct vmbus_gpadl_created created;
        /** "GPADL teardown" message */
        struct vmbus_gpadl_teardown teardown;
        /** "GPADL torndown" message */
        struct vmbus_gpadl_torndown torndown;
        /** "Initiate contact" message */
        struct vmbus_initiate_contact initiate;
        /** "Version response" message */
        struct vmbus_version_response version;
};

/** VMBus packet header */
struct vmbus_packet_header {
        /** Type */
        uint16_t type;
        /** Length of packet header (in quadwords) */
        uint16_t hdr_qlen;
        /** Length of packet (in quadwords) */
        uint16_t qlen;
        /** Flags */
        uint16_t flags;
        /** Transaction ID
         *
         * This is an opaque token: we therefore treat it as
         * native-endian and don't worry about byte-swapping.
         */
        uint64_t xid;
} __attribute__ (( packed ));

/** VMBus packet types */
enum vmbus_packet_type {
        VMBUS_DATA_INBAND = 6,
        VMBUS_DATA_XFER_PAGES = 7,
        VMBUS_DATA_GPA_DIRECT = 9,
        VMBUS_CANCELLATION = 10,
        VMBUS_COMPLETION = 11,
};

/** VMBus packet flags */
enum vmbus_packet_flags {
        VMBUS_COMPLETION_REQUESTED = 0x0001,
};

/** VMBus GPA direct header */
struct vmbus_gpa_direct_header {
        /** Packet header */
        struct vmbus_packet_header header;
        /** Reserved */
        uint32_t reserved;
        /** Number of range descriptors */
        uint32_t range_count;
        /** Range descriptors */
        struct vmbus_gpa_range range[0];
} __attribute__ (( packed ));

/** VMBus transfer page range */
struct vmbus_xfer_page_range {
        /** Length */
        uint32_t len;
        /** Offset */
        uint32_t offset;
} __attribute__ (( packed ));

/** VMBus transfer page header */
struct vmbus_xfer_page_header {
        /** Packet header */
        struct vmbus_packet_header header;
        /** Page set ID */
        uint16_t pageset;
        /** Sender owns page set */
        uint8_t owner;
        /** Reserved */
        uint8_t reserved;
        /** Number of range descriptors */
        uint32_t range_count;
        /** Range descriptors */
        struct vmbus_xfer_page_range range[0];
} __attribute__ (( packed ));

/** Maximum expected size of VMBus packet header */
#define VMBUS_PACKET_MAX_HEADER_LEN 64

/** VMBus maximum-sized packet header */
union vmbus_packet_header_max {
        /** Common header */
        struct vmbus_packet_header header;
        /** GPA direct header */
        struct vmbus_gpa_direct_header gpa;
        /** Transfer page header */
        struct vmbus_xfer_page_header xfer;
        /** Padding to maximum supported size */
        uint8_t padding[VMBUS_PACKET_MAX_HEADER_LEN];
} __attribute__ (( packed ));

/** VMBus packet footer */
struct vmbus_packet_footer {
        /** Reserved */
        uint32_t reserved;
        /** Producer index of the first byte of the packet */
        uint32_t prod;
} __attribute__ (( packed ));

/** VMBus ring buffer
 *
 * This is the structure of the each of the ring buffers created when
 * a VMBus channel is opened.
 */
struct vmbus_ring {
        /** Producer index (modulo ring length) */
        uint32_t prod;
        /** Consumer index (modulo ring length) */
        uint32_t cons;
        /** Interrupt mask */
        uint32_t intr_mask;
        /** Reserved */
        uint8_t reserved[4084];
        /** Ring buffer contents */
        uint8_t data[0];
} __attribute__ (( packed ));

/** VMBus interrupt page */
struct vmbus_interrupt {
        /** Inbound interrupts */
        uint8_t in[ PAGE_SIZE / 2 ];
        /** Outbound interrupts */
        uint8_t out[ PAGE_SIZE / 2 ];
} __attribute__ (( packed ));

/** A virtual machine bus */
struct vmbus {
        /** Interrupt page */
        struct vmbus_interrupt *intr;
        /** Inbound notifications */
        struct hv_monitor *monitor_in;
        /** Outbound notifications */
        struct hv_monitor *monitor_out;
        /** Received message buffer */
        const union vmbus_message *message;
};

struct vmbus_device;

/** VMBus channel operations */
struct vmbus_channel_operations {
        /**
         * Handle received control packet
         *
         * @v vmdev             VMBus device
         * @v xid               Transaction ID
         * @v data              Data
         * @v len               Length of data
         * @ret rc              Return status code
         */
        int ( * recv_control ) ( struct vmbus_device *vmdev, uint64_t xid,
                                 const void *data, size_t len );
        /**
         * Handle received data packet
         *
         * @v vmdev             VMBus device
         * @v xid               Transaction ID
         * @v data              Data
         * @v len               Length of data
         * @v list              List of I/O buffers
         * @ret rc              Return status code
         *
         * This function takes ownership of the I/O buffer.  It should
         * eventually call vmbus_send_completion() to indicate to the
         * host that the buffer can be reused.
         */
        int ( * recv_data ) ( struct vmbus_device *vmdev, uint64_t xid,
                              const void *data, size_t len,
                              struct list_head *list );
        /**
         * Handle received completion packet
         *
         * @v vmdev             VMBus device
         * @v xid               Transaction ID
         * @v data              Data
         * @v len               Length of data
         * @ret rc              Return status code
         */
        int ( * recv_completion ) ( struct vmbus_device *vmdev, uint64_t xid,
                                    const void *data, size_t len );
        /**
         * Handle received cancellation packet
         *
         * @v vmdev             VMBus device
         * @v xid               Transaction ID
         * @ret rc              Return status code
         */
        int ( * recv_cancellation ) ( struct vmbus_device *vmdev,
                                      uint64_t xid );
};

struct vmbus_xfer_pages;

/** VMBus transfer page set operations */
struct vmbus_xfer_pages_operations {
        /**
         * Copy data from transfer page
         *
         * @v pages             Transfer page set
         * @v data              Data buffer
         * @v offset            Offset within page set
         * @v len               Length within page set
         * @ret rc              Return status code
         */
        int ( * copy ) ( struct vmbus_xfer_pages *pages, void *data,
                         size_t offset, size_t len );
};

/** VMBus transfer page set */
struct vmbus_xfer_pages {
        /** List of all transfer page sets */
        struct list_head list;
        /** Page set ID (in protocol byte order) */
        uint16_t pageset;
        /** Page set operations */
        struct vmbus_xfer_pages_operations *op;
};

/** A VMBus device */
struct vmbus_device {
        /** Generic iPXE device */
        struct device dev;
        /** Hyper-V hypervisor */
        struct hv_hypervisor *hv;

        /** Channel instance */
        union uuid instance;
        /** Channel ID */
        unsigned int channel;
        /** Monitor ID */
        unsigned int monitor;
        /** Signal channel
         *
         * @v vmdev             VMBus device
         */
        void ( * signal ) ( struct vmbus_device *vmdev );

        /** Outbound ring buffer length */
        uint32_t out_len;
        /** Inbound ring buffer length */
        uint32_t in_len;
        /** Outbound ring buffer */
        struct vmbus_ring *out;
        /** Inbound ring buffer */
        struct vmbus_ring *in;
        /** Ring buffer GPADL ID */
        unsigned int gpadl;

        /** Channel operations */
        struct vmbus_channel_operations *op;
        /** Maximum expected data packet length */
        size_t mtu;
        /** Packet buffer */
        void *packet;
        /** List of transfer page sets */
        struct list_head pages;

        /** Driver */
        struct vmbus_driver *driver;
        /** Driver-private data */
        void *priv;
};

/** A VMBus device driver */
struct vmbus_driver {
        /** Name */
        const char *name;
        /** Device type */
        union uuid type;
        /** Probe device
         *
         * @v vmdev             VMBus device
         * @ret rc              Return status code
         */
        int ( * probe ) ( struct vmbus_device *vmdev );
        /** Reset device
         *
         * @v vmdev             VMBus device
         * @ret rc              Return status code
         */
        int ( * reset ) ( struct vmbus_device *vmdev );
        /** Remove device
         *
         * @v vmdev             VMBus device
         */
        void ( * remove ) ( struct vmbus_device *vmdev );
};

/** VMBus device driver table */
#define VMBUS_DRIVERS __table ( struct vmbus_driver, "vmbus_drivers" )

/** Declare a VMBus device driver */
#define __vmbus_driver __table_entry ( VMBUS_DRIVERS, 01 )

/**
 * Set VMBus device driver-private data
 *
 * @v vmdev             VMBus device
 * @v priv              Private data
 */
static inline void vmbus_set_drvdata ( struct vmbus_device *vmdev, void *priv ){
        vmdev->priv = priv;
}

/**
 * Get VMBus device driver-private data
 *
 * @v vmdev             VMBus device
 * @ret priv            Private data
 */
static inline void * vmbus_get_drvdata ( struct vmbus_device *vmdev ) {
        return vmdev->priv;
}

/** Construct VMBus type */
#define VMBUS_TYPE( a, b, c, d, e0, e1, e2, e3, e4, e5 ) {              \
        .canonical = {                                                  \
                cpu_to_le32 ( a ), cpu_to_le16 ( b ),                   \
                cpu_to_le16 ( c ), cpu_to_be16 ( d ),                   \
                { e0, e1, e2, e3, e4, e5 }                              \
         } }

/**
 * Check if data is present in ring buffer
 *
 * @v vmdev             VMBus device
 * @v has_data          Data is present
 */
static inline __attribute__ (( always_inline )) int
vmbus_has_data ( struct vmbus_device *vmdev ) {

        return ( vmdev->in->prod != vmdev->in->cons );
}

/**
 * Register transfer page set
 *
 * @v vmdev             VMBus device
 * @v pages             Transfer page set
 * @ret rc              Return status code
 */
static inline __attribute__ (( always_inline )) int
vmbus_register_pages ( struct vmbus_device *vmdev,
                       struct vmbus_xfer_pages *pages ) {

        list_add ( &pages->list, &vmdev->pages );
        return 0;
}

/**
 * Unregister transfer page set
 *
 * @v vmdev             VMBus device
 * @v pages             Transfer page set
 */
static inline __attribute__ (( always_inline )) void
vmbus_unregister_pages ( struct vmbus_device *vmdev,
                         struct vmbus_xfer_pages *pages ) {

        list_check_contains_entry ( pages, &vmdev->pages, list );
        list_del ( &pages->list );
}

extern unsigned int vmbus_obsolete_gpadl;

/**
 * Check if GPADL is obsolete
 *
 * @v gpadl             GPADL ID
 * @v is_obsolete       GPADL ID is obsolete
 *
 * Check if GPADL is obsolete (i.e. was created before the most recent
 * Hyper-V reset).
 */
static inline __attribute__ (( always_inline )) int
vmbus_gpadl_is_obsolete ( unsigned int gpadl ) {

        return ( gpadl <= vmbus_obsolete_gpadl );
}

extern int vmbus_establish_gpadl ( struct vmbus_device *vmdev, userptr_t data,
                                   size_t len );
extern int vmbus_gpadl_teardown ( struct vmbus_device *vmdev,
                                  unsigned int gpadl );
extern int vmbus_open ( struct vmbus_device *vmdev,
                        struct vmbus_channel_operations *op,
                        size_t out_len, size_t in_len, size_t mtu );
extern void vmbus_close ( struct vmbus_device *vmdev );
extern int vmbus_send_control ( struct vmbus_device *vmdev, uint64_t xid,
                                const void *data, size_t len );
extern int vmbus_send_data ( struct vmbus_device *vmdev, uint64_t xid,
                             const void *data, size_t len,
                             struct io_buffer *iobuf );
extern int vmbus_send_completion ( struct vmbus_device *vmdev, uint64_t xid,
                                   const void *data, size_t len );
extern int vmbus_send_cancellation ( struct vmbus_device *vmdev, uint64_t xid );
extern int vmbus_poll ( struct vmbus_device *vmdev );
extern void vmbus_dump_channel ( struct vmbus_device *vmdev );

extern int vmbus_probe ( struct hv_hypervisor *hv, struct device *parent );
extern int vmbus_reset ( struct hv_hypervisor *hv, struct device *parent );
extern void vmbus_remove ( struct hv_hypervisor *hv, struct device *parent );

#endif /* _IPXE_VMBUS_H */