vmbus.c File Reference

Hyper-V virtual machine bus. More...

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <byteswap.h>
#include <ipxe/nap.h>
#include <ipxe/malloc.h>
#include <ipxe/iobuf.h>
#include <ipxe/bitops.h>
#include <ipxe/hyperv.h>
#include <ipxe/vmbus.h>

Go to the source code of this file.

Macros
#define	VMBUS_GPADL_MAGIC   0x18ae0000
	VMBus initial GPADL ID. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static int	vmbus_post_message (struct hv_hypervisor *hv, const struct vmbus_message_header *header, size_t len)
	Post message. More...
static int	vmbus_post_empty_message (struct hv_hypervisor *hv, unsigned int type)
	Post empty message. More...
static int	vmbus_wait_for_any_message (struct hv_hypervisor *hv)
	Wait for received message of any type. More...
static int	vmbus_wait_for_message (struct hv_hypervisor *hv, unsigned int type)
	Wait for received message of a specified type, ignoring any others. More...
static int	vmbus_initiate_contact (struct hv_hypervisor *hv, unsigned int raw)
	Initiate contact. More...
static int	vmbus_unload (struct hv_hypervisor *hv)
	Terminate contact. More...
static int	vmbus_negotiate_version (struct hv_hypervisor *hv)
	Negotiate protocol version. More...
int	vmbus_establish_gpadl (struct vmbus_device *vmdev, userptr_t data, size_t len)
	Establish GPA descriptor list. More...
int	vmbus_gpadl_teardown (struct vmbus_device *vmdev, unsigned int gpadl)
	Tear down GPA descriptor list. More...
int	vmbus_open (struct vmbus_device *vmdev, struct vmbus_channel_operations *op, size_t out_len, size_t in_len, size_t mtu)
	Open VMBus channel. More...
void	vmbus_close (struct vmbus_device *vmdev)
	Close VMBus channel. More...
static void	vmbus_signal_monitor (struct vmbus_device *vmdev)
	Signal channel via monitor page. More...
static void	vmbus_signal_event (struct vmbus_device *vmdev)
	Signal channel via hypervisor event. More...
static size_t	vmbus_produce (struct vmbus_device *vmdev, size_t prod, const void *data, size_t len)
	Fill outbound ring buffer. More...
static size_t	vmbus_consume (struct vmbus_device *vmdev, size_t cons, void *data, size_t len)
	Consume inbound ring buffer. More...
static int	vmbus_send (struct vmbus_device *vmdev, struct vmbus_packet_header *header, const void *data, size_t len)
	Send packet via ring buffer. More...
int	vmbus_send_control (struct vmbus_device *vmdev, uint64_t xid, const void *data, size_t len)
	Send control packet via ring buffer. More...
int	vmbus_send_data (struct vmbus_device *vmdev, uint64_t xid, const void *data, size_t len, struct io_buffer *iobuf)
	Send data packet via ring buffer. More...
int	vmbus_send_completion (struct vmbus_device *vmdev, uint64_t xid, const void *data, size_t len)
	Send completion packet via ring buffer. More...
int	vmbus_send_cancellation (struct vmbus_device *vmdev, uint64_t xid)
	Send cancellation packet via ring buffer. More...
static struct vmbus_xfer_pages *	vmbus_xfer_pages (struct vmbus_device *vmdev, uint16_t pageset)
	Get transfer page set from pageset ID. More...
static int	vmbus_xfer_page_iobufs (struct vmbus_device *vmdev, struct vmbus_packet_header *header, struct list_head *list)
	Construct I/O buffer list from transfer pages. More...
int	vmbus_poll (struct vmbus_device *vmdev)
	Poll ring buffer. More...
void	vmbus_dump_channel (struct vmbus_device *vmdev)
	Dump channel status (for debugging) More...
static struct vmbus_driver *	vmbus_find_driver (const union uuid *type)
	Find driver for VMBus device. More...
static int	vmbus_probe_channels (struct hv_hypervisor *hv, struct device *parent)
	Probe channels. More...
static int	vmbus_reset_channels (struct hv_hypervisor *hv, struct device *parent)
	Reset channels. More...
static void	vmbus_remove_channels (struct hv_hypervisor *hv __unused, struct device *parent)
	Remove channels. More...
int	vmbus_probe (struct hv_hypervisor *hv, struct device *parent)
	Probe Hyper-V virtual machine bus. More...
int	vmbus_reset (struct hv_hypervisor *hv, struct device *parent)
	Reset Hyper-V virtual machine bus. More...
void	vmbus_remove (struct hv_hypervisor *hv, struct device *parent)
	Remove Hyper-V virtual machine bus. More...

Variables
static unsigned int	vmbus_gpadl = VMBUS_GPADL_MAGIC
	Current (i.e. More...
unsigned int	vmbus_obsolete_gpadl
	Obsolete GPADL ID threshold. More...

Detailed Description

Hyper-V virtual machine bus.

Definition in file vmbus.c.

Macro Definition Documentation

VMBUS_GPADL_MAGIC

#define VMBUS_GPADL_MAGIC   0x18ae0000

VMBus initial GPADL ID.

This is an opaque value with no meaning. The Linux kernel uses 0xe1e10.

Definition at line 51 of file vmbus.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

vmbus_post_message()

static int vmbus_post_message ( struct hv_hypervisor *  hv, const struct vmbus_message_header *  header, size_t  len  )

static

Post message.

Parameters

hv	Hyper-V hypervisor
header	Message header
len	Length of message (including header)

Return values

rc	Return status code

Definition at line 71 of file vmbus.c.

                                             {
        struct vmbus *vmbus = hv->vmbus;
        int rc;

        /* Post message */
        if ( ( rc = hv_post_message ( hv, VMBUS_MESSAGE_ID, VMBUS_MESSAGE_TYPE,
                                      header, len ) ) != 0 ) {
                DBGC ( vmbus, "VMBUS %p could not post message: %s\n",
                       vmbus, strerror ( rc ) );
                return rc;
        }

        return 0;
}

References DBGC, header, len, rc, strerror(), hv_hypervisor::vmbus, VMBUS_MESSAGE_ID, and VMBUS_MESSAGE_TYPE.

Referenced by vmbus_close(), vmbus_establish_gpadl(), vmbus_gpadl_teardown(), vmbus_initiate_contact(), vmbus_open(), and vmbus_post_empty_message().

vmbus_post_empty_message()

static int vmbus_post_empty_message ( struct hv_hypervisor *  hv, unsigned int  type  )

static

Post empty message.

Parameters

hv	Hyper-V hypervisor
type	Message type

Return values

rc	Return status code

Definition at line 95 of file vmbus.c.

                                                          {
        struct vmbus_message_header header = { .type = cpu_to_le32 ( type ) };

        return vmbus_post_message ( hv, &header, sizeof ( header ) );
}

References cpu_to_le32, header, type, and vmbus_post_message().

Referenced by vmbus_probe_channels(), vmbus_reset_channels(), and vmbus_unload().

vmbus_wait_for_any_message()

static int vmbus_wait_for_any_message ( struct hv_hypervisor *  hv )

static

Wait for received message of any type.

Parameters

hv	Hyper-V hypervisor

Return values

rc	Return status code

Definition at line 108 of file vmbus.c.

                                                                   {
        struct vmbus *vmbus = hv->vmbus;
        int rc;

        /* Wait for message */
        if ( ( rc = hv_wait_for_message ( hv, VMBUS_MESSAGE_SINT ) ) != 0 ) {
                DBGC ( vmbus, "VMBUS %p failed waiting for message: %s\n",
                       vmbus, strerror ( rc ) );
                return rc;
        }

        /* Sanity check */
        if ( hv->message->received.type != cpu_to_le32 ( VMBUS_MESSAGE_TYPE ) ){
                DBGC ( vmbus, "VMBUS %p invalid message type %d\n",
                       vmbus, le32_to_cpu ( hv->message->received.type ) );
                return -EINVAL;
        }

        return 0;
}

References cpu_to_le32, DBGC, EINVAL, hv_wait_for_message(), le32_to_cpu, hv_hypervisor::message, rc, hv_message_buffer::received, strerror(), hv_message::type, hv_hypervisor::vmbus, VMBUS_MESSAGE_SINT, and VMBUS_MESSAGE_TYPE.

Referenced by vmbus_probe_channels(), vmbus_reset_channels(), and vmbus_wait_for_message().

vmbus_wait_for_message()

static int vmbus_wait_for_message ( struct hv_hypervisor *  hv, unsigned int  type  )

static

Wait for received message of a specified type, ignoring any others.

Parameters

hv	Hyper-V hypervisor
type	Message type

Return values

rc	Return status code

Definition at line 136 of file vmbus.c.

                                                        {
        struct vmbus *vmbus = hv->vmbus;
        const struct vmbus_message_header *header = &vmbus->message->header;
        int rc;

        /* Loop until specified message arrives, or until an error occurs */
        while ( 1 ) {

                /* Wait for message */
                if ( ( rc = vmbus_wait_for_any_message ( hv ) ) != 0 )
                        return rc;

                /* Check for requested message type */
                if ( header->type == cpu_to_le32 ( type ) )
                        return 0;

                /* Ignore any other messages (e.g. due to additional
                 * channels being offered at runtime).
                 */
                DBGC ( vmbus, "VMBUS %p ignoring message type %d (expecting "
                       "%d)\n", vmbus, le32_to_cpu ( header->type ), type );
        }
}

References cpu_to_le32, DBGC, vmbus_message::header, header, le32_to_cpu, vmbus::message, rc, type, hv_hypervisor::vmbus, and vmbus_wait_for_any_message().

Referenced by vmbus_establish_gpadl(), vmbus_gpadl_teardown(), vmbus_initiate_contact(), vmbus_open(), and vmbus_unload().

vmbus_initiate_contact()

static int vmbus_initiate_contact ( struct hv_hypervisor *  hv, unsigned int  raw  )

static

Initiate contact.

Parameters

hv	Hyper-V hypervisor
raw	VMBus protocol (raw) version

Return values

rc	Return status code

Definition at line 168 of file vmbus.c.

                                                       {
        struct vmbus *vmbus = hv->vmbus;
        const struct vmbus_version_response *version = &vmbus->message->version;
        struct vmbus_initiate_contact initiate;
        int rc;

        /* Construct message */
        memset ( &initiate, 0, sizeof ( initiate ) );
        initiate.header.type = cpu_to_le32 ( VMBUS_INITIATE_CONTACT );
        initiate.version.raw = cpu_to_le32 ( raw );
        initiate.intr = virt_to_phys ( vmbus->intr );
        initiate.monitor_in = virt_to_phys ( vmbus->monitor_in );
        initiate.monitor_out = virt_to_phys ( vmbus->monitor_out );

        /* Post message */
        if ( ( rc = vmbus_post_message ( hv, &initiate.header,
                                         sizeof ( initiate ) ) ) != 0 )
                return rc;

        /* Wait for response */
        if ( ( rc = vmbus_wait_for_message ( hv, VMBUS_VERSION_RESPONSE ) ) !=0)
                return rc;

        /* Check response */
        if ( ! version->supported ) {
                DBGC ( vmbus, "VMBUS %p requested version not supported\n",
                       vmbus );
                return -ENOTSUP;
        }

        DBGC ( vmbus, "VMBUS %p initiated contact using version %d.%d\n",
               vmbus, le16_to_cpu ( initiate.version.major ),
               le16_to_cpu ( initiate.version.minor ) );
        return 0;
}

References cpu_to_le32, DBGC, ENOTSUP, vmbus_initiate_contact::header, vmbus_initiate_contact::intr, vmbus::intr, le16_to_cpu, vmbus_version::major, memset(), vmbus::message, vmbus_version::minor, vmbus_initiate_contact::monitor_in, vmbus::monitor_in, vmbus_initiate_contact::monitor_out, vmbus::monitor_out, raw, vmbus_version::raw, rc, vmbus_message_header::type, vmbus_initiate_contact::version, vmbus_message::version, version, virt_to_phys(), hv_hypervisor::vmbus, VMBUS_INITIATE_CONTACT, vmbus_post_message(), VMBUS_VERSION_RESPONSE, and vmbus_wait_for_message().

vmbus_unload()

static int vmbus_unload ( struct hv_hypervisor *  hv )

static

Terminate contact.

Parameters

hv	Hyper-V hypervisor

Return values

rc	Return status code

Definition at line 211 of file vmbus.c.

                                                     {
        int rc;

        /* Post message */
        if ( ( rc = vmbus_post_empty_message ( hv, VMBUS_UNLOAD ) ) != 0 )
                return rc;

        /* Wait for response */
        if ( ( rc = vmbus_wait_for_message ( hv, VMBUS_UNLOAD_RESPONSE ) ) != 0)
                return rc;

        return 0;
}

References rc, vmbus_post_empty_message(), VMBUS_UNLOAD, VMBUS_UNLOAD_RESPONSE, and vmbus_wait_for_message().

Referenced by vmbus_negotiate_version(), vmbus_probe(), and vmbus_remove().

vmbus_negotiate_version()

static int vmbus_negotiate_version ( struct hv_hypervisor *  hv )

static

Negotiate protocol version.

Parameters

hv	Hyper-V hypervisor

Return values

rc	Return status code

Definition at line 231 of file vmbus.c.

                                                                {
        int rc;

        /* We require the ability to disconnect from and reconnect to
         * VMBus; if we don't have this then there is no (viable) way
         * for a loaded operating system to continue to use any VMBus
         * devices.  (There is also a small but non-zero risk that the
         * host will continue to write to our interrupt and monitor
         * pages, since the VMBUS_UNLOAD message in earlier versions
         * is essentially a no-op.)
         *
         * This requires us to ensure that the host supports protocol
         * version 3.0 (VMBUS_VERSION_WIN8_1).  However, we can't
         * actually _use_ protocol version 3.0, since doing so causes
         * an iSCSI-booted Windows Server 2012 R2 VM to crash due to a
         * NULL pointer dereference in vmbus.sys.
         *
         * To work around this problem, we first ensure that we can
         * connect using protocol v3.0, then disconnect and reconnect
         * using the oldest known protocol.
         */

        /* Initiate contact to check for required protocol support */
        if ( ( rc = vmbus_initiate_contact ( hv, VMBUS_VERSION_WIN8_1 ) ) != 0 )
                return rc;

        /* Terminate contact */
        if ( ( rc = vmbus_unload ( hv ) ) != 0 )
                return rc;

        /* Reinitiate contact using the oldest known protocol version */
        if ( ( rc = vmbus_initiate_contact ( hv, VMBUS_VERSION_WS2008 ) ) != 0 )
                return rc;

        return 0;
}

References rc, vmbus_unload(), VMBUS_VERSION_WIN8_1, and VMBUS_VERSION_WS2008.

Referenced by vmbus_probe(), and vmbus_reset().

vmbus_establish_gpadl()

int vmbus_establish_gpadl	(	struct vmbus_device *	vmdev,
		userptr_t	data,
		size_t	len
	)

Establish GPA descriptor list.

Parameters

vmdev	VMBus device
data	Data buffer
len	Length of data buffer

Return values

gpadl

GPADL ID, or negative error

Definition at line 276 of file vmbus.c.

                                         {
        struct hv_hypervisor *hv = vmdev->hv;
        struct vmbus *vmbus = hv->vmbus;
        physaddr_t addr = user_to_phys ( data, 0 );
        unsigned int pfn_count = hv_pfn_count ( addr, len );
        struct {
                struct vmbus_gpadl_header gpadlhdr;
                struct vmbus_gpa_range range;
                uint64_t pfn[pfn_count];
        } __attribute__ (( packed )) gpadlhdr;
        const struct vmbus_gpadl_created *created = &vmbus->message->created;
        unsigned int gpadl;
        unsigned int i;
        int rc;

        /* Allocate GPADL ID */
        gpadl = ++vmbus_gpadl;

        /* Construct message */
        memset ( &gpadlhdr, 0, sizeof ( gpadlhdr ) );
        gpadlhdr.gpadlhdr.header.type = cpu_to_le32 ( VMBUS_GPADL_HEADER );
        gpadlhdr.gpadlhdr.channel = cpu_to_le32 ( vmdev->channel );
        gpadlhdr.gpadlhdr.gpadl = cpu_to_le32 ( gpadl );
        gpadlhdr.gpadlhdr.range_len =
                cpu_to_le16 ( ( sizeof ( gpadlhdr.range ) +
                                sizeof ( gpadlhdr.pfn ) ) );
        gpadlhdr.gpadlhdr.range_count = cpu_to_le16 ( 1 );
        gpadlhdr.range.len = cpu_to_le32 ( len );
        gpadlhdr.range.offset = cpu_to_le32 ( addr & ( PAGE_SIZE - 1 ) );
        for ( i = 0 ; i < pfn_count ; i++ )
                gpadlhdr.pfn[i] = ( ( addr / PAGE_SIZE ) + i );

        /* Post message */
        if ( ( rc = vmbus_post_message ( hv, &gpadlhdr.gpadlhdr.header,
                                         sizeof ( gpadlhdr ) ) ) != 0 )
                return rc;

        /* Wait for response */
        if ( ( rc = vmbus_wait_for_message ( hv, VMBUS_GPADL_CREATED ) ) != 0 )
                return rc;

        /* Check response */
        if ( created->channel != cpu_to_le32 ( vmdev->channel ) ) {
                DBGC ( vmdev, "VMBUS %s unexpected GPADL channel %d\n",
                       vmdev->dev.name, le32_to_cpu ( created->channel ) );
                return -EPROTO;
        }
        if ( created->gpadl != cpu_to_le32 ( gpadl ) ) {
                DBGC ( vmdev, "VMBUS %s unexpected GPADL ID %#08x\n",
                       vmdev->dev.name, le32_to_cpu ( created->gpadl ) );
                return -EPROTO;
        }
        if ( created->status != 0 ) {
                DBGC ( vmdev, "VMBUS %s GPADL creation failed: %#08x\n",
                       vmdev->dev.name, le32_to_cpu ( created->status ) );
                return -EPROTO;
        }

        DBGC ( vmdev, "VMBUS %s GPADL %#08x is [%08lx,%08lx)\n",
               vmdev->dev.name, gpadl, addr, ( addr + len ) );
        return gpadl;
}

References __attribute__, addr, vmbus_gpadl_created::channel, vmbus_device::channel, cpu_to_le16, cpu_to_le32, vmbus_message::created, data, DBGC, vmbus_device::dev, EPROTO, gpadl, vmbus_gpadl_created::gpadl, vmbus_device::hv, hv_pfn_count(), le32_to_cpu, len, memset(), vmbus::message, device::name, PAGE_SIZE, vmbus_gpa_range::pfn, range, rc, vmbus_gpadl_created::status, user_to_phys(), hv_hypervisor::vmbus, vmbus_gpadl, VMBUS_GPADL_CREATED, VMBUS_GPADL_HEADER, vmbus_post_message(), and vmbus_wait_for_message().

Referenced by netvsc_create_buffer(), and vmbus_open().

vmbus_gpadl_teardown()

int vmbus_gpadl_teardown	(	struct vmbus_device *	vmdev,
		unsigned int	gpadl
	)

Tear down GPA descriptor list.

Parameters

vmdev	VMBus device
gpadl	GPADL ID

Return values

rc	Return status code

Definition at line 347 of file vmbus.c.

                                                                            {
        struct hv_hypervisor *hv = vmdev->hv;
        struct vmbus *vmbus = hv->vmbus;
        struct vmbus_gpadl_teardown teardown;
        const struct vmbus_gpadl_torndown *torndown = &vmbus->message->torndown;
        int rc;

        /* If GPADL is obsolete (i.e. was created before the most
         * recent Hyper-V reset), then we will never receive a
         * response to the teardown message.  Since the GPADL is
         * already destroyed as far as the hypervisor is concerned, no
         * further action is required.
         */
        if ( vmbus_gpadl_is_obsolete ( gpadl ) )
                return 0;

        /* Construct message */
        memset ( &teardown, 0, sizeof ( teardown ) );
        teardown.header.type = cpu_to_le32 ( VMBUS_GPADL_TEARDOWN );
        teardown.channel = cpu_to_le32 ( vmdev->channel );
        teardown.gpadl = cpu_to_le32 ( gpadl );

        /* Post message */
        if ( ( rc = vmbus_post_message ( hv, &teardown.header,
                                         sizeof ( teardown ) ) ) != 0 )
                return rc;

        /* Wait for response */
        if ( ( rc = vmbus_wait_for_message ( hv, VMBUS_GPADL_TORNDOWN ) ) != 0 )
                return rc;

        /* Check response */
        if ( torndown->gpadl != cpu_to_le32 ( gpadl ) ) {
                DBGC ( vmdev, "VMBUS %s unexpected GPADL ID %#08x\n",
                       vmdev->dev.name, le32_to_cpu ( torndown->gpadl ) );
                return -EPROTO;
        }

        return 0;
}

References vmbus_gpadl_teardown::channel, vmbus_device::channel, cpu_to_le32, DBGC, vmbus_device::dev, EPROTO, gpadl, vmbus_gpadl_teardown::gpadl, vmbus_gpadl_torndown::gpadl, vmbus_gpadl_teardown::header, vmbus_device::hv, le32_to_cpu, memset(), vmbus::message, device::name, rc, vmbus_message::torndown, vmbus_message_header::type, hv_hypervisor::vmbus, vmbus_gpadl_is_obsolete(), VMBUS_GPADL_TEARDOWN, VMBUS_GPADL_TORNDOWN, vmbus_post_message(), and vmbus_wait_for_message().

Referenced by netvsc_create_buffer(), and vmbus_open().

vmbus_open()

int vmbus_open	(	struct vmbus_device *	vmdev,
		struct vmbus_channel_operations *	op,
		size_t	out_len,
		size_t	in_len,
		size_t	mtu
	)

Open VMBus channel.

Parameters

vmdev	VMBus device
op	Channel operations
out_len	Outbound ring buffer length
in_len	Inbound ring buffer length
mtu	Maximum expected data packet length (including headers)

Return values

rc	Return status code

Both outbound and inbound ring buffer lengths must be a power of two and a multiple of PAGE_SIZE. The requirement to be a power of two is a policy decision taken to simplify the ring buffer indexing logic.

Definition at line 403 of file vmbus.c.

                                                             {
        struct hv_hypervisor *hv = vmdev->hv;
        struct vmbus *vmbus = hv->vmbus;
        struct vmbus_open_channel open;
        const struct vmbus_open_channel_result *opened =
                &vmbus->message->opened;
        size_t len;
        void *ring;
        void *packet;
        int gpadl;
        uint32_t open_id;
        int rc;

        /* Sanity checks */
        assert ( ( out_len % PAGE_SIZE ) == 0 );
        assert ( ( out_len & ( out_len - 1 ) ) == 0 );
        assert ( ( in_len % PAGE_SIZE ) == 0 );
        assert ( ( in_len & ( in_len - 1 ) ) == 0 );
        assert ( mtu >= ( sizeof ( struct vmbus_packet_header ) +
                          sizeof ( struct vmbus_packet_footer ) ) );

        /* Allocate packet buffer */
        packet = malloc ( mtu );
        if ( ! packet ) {
                rc = -ENOMEM;
                goto err_alloc_packet;
        }

        /* Allocate ring buffer */
        len = ( sizeof ( *vmdev->out ) + out_len +
                sizeof ( *vmdev->in ) + in_len );
        assert ( ( len % PAGE_SIZE ) == 0 );
        ring = malloc_phys ( len, PAGE_SIZE );
        if ( ! ring ) {
                rc = -ENOMEM;
                goto err_alloc_ring;
        }
        memset ( ring, 0, len );

        /* Establish GPADL for ring buffer */
        gpadl = vmbus_establish_gpadl ( vmdev, virt_to_user ( ring ), len );
        if ( gpadl < 0 ) {
                rc = gpadl;
                goto err_establish;
        }

        /* Construct message */
        memset ( &open, 0, sizeof ( open ) );
        open.header.type = cpu_to_le32 ( VMBUS_OPEN_CHANNEL );
        open.channel = cpu_to_le32 ( vmdev->channel );
        open_id = random();
        open.id = open_id; /* Opaque random value: endianness irrelevant */
        open.gpadl = cpu_to_le32 ( gpadl );
        open.out_pages = ( ( sizeof ( *vmdev->out ) / PAGE_SIZE ) +
                           ( out_len / PAGE_SIZE ) );

        /* Post message */
        if ( ( rc = vmbus_post_message ( hv, &open.header,
                                         sizeof ( open ) ) ) != 0 )
                goto err_post_message;

        /* Wait for response */
        if ( ( rc = vmbus_wait_for_message ( hv,
                                             VMBUS_OPEN_CHANNEL_RESULT ) ) != 0)
                goto err_wait_for_message;

        /* Check response */
        if ( opened->channel != cpu_to_le32 ( vmdev->channel ) ) {
                DBGC ( vmdev, "VMBUS %s unexpected opened channel %#08x\n",
                       vmdev->dev.name, le32_to_cpu ( opened->channel ) );
                rc = -EPROTO;
                goto err_check_response;
        }
        if ( opened->id != open_id /* Non-endian */ ) {
                DBGC ( vmdev, "VMBUS %s unexpected open ID %#08x\n",
                       vmdev->dev.name, le32_to_cpu ( opened->id ) );
                rc = -EPROTO;
                goto err_check_response;
        }
        if ( opened->status != 0 ) {
                DBGC ( vmdev, "VMBUS %s open failed: %#08x\n",
                       vmdev->dev.name, le32_to_cpu ( opened->status ) );
                rc = -EPROTO;
                goto err_check_response;
        }

        /* Store channel parameters */
        vmdev->out_len = out_len;
        vmdev->in_len = in_len;
        vmdev->out = ring;
        vmdev->in = ( ring + sizeof ( *vmdev->out ) + out_len );
        vmdev->gpadl = gpadl;
        vmdev->op = op;
        vmdev->mtu = mtu;
        vmdev->packet = packet;

        DBGC ( vmdev, "VMBUS %s channel GPADL %#08x ring "
                "[%#08lx,%#08lx,%#08lx)\n", vmdev->dev.name, vmdev->gpadl,
                virt_to_phys ( vmdev->out ), virt_to_phys ( vmdev->in ),
                ( virt_to_phys ( vmdev->out ) + len ) );
        return 0;

 err_check_response:
 err_wait_for_message:
 err_post_message:
        vmbus_gpadl_teardown ( vmdev, vmdev->gpadl );
 err_establish:
        free_phys ( ring, len );
 err_alloc_ring:
        free ( packet );
 err_alloc_packet:
        return rc;
}

References assert(), vmbus_open_channel_result::channel, vmbus_device::channel, cpu_to_le32, DBGC, vmbus_device::dev, ENOMEM, EPROTO, free, free_phys(), gpadl, vmbus_device::gpadl, vmbus_device::hv, vmbus_open_channel_result::id, vmbus_device::in, vmbus_device::in_len, le32_to_cpu, len, malloc(), malloc_phys(), memset(), vmbus::message, mtu, vmbus_device::mtu, device::name, op, vmbus_device::op, open(), vmbus_message::opened, vmbus_device::out, vmbus_device::out_len, vmbus_device::packet, PAGE_SIZE, random(), rc, vmbus_open_channel_result::status, virt_to_phys(), virt_to_user(), hv_hypervisor::vmbus, vmbus_establish_gpadl(), vmbus_gpadl_teardown(), VMBUS_OPEN_CHANNEL, VMBUS_OPEN_CHANNEL_RESULT, vmbus_post_message(), and vmbus_wait_for_message().

Referenced by netvsc_open().

vmbus_close()

void vmbus_close

(

struct vmbus_device *

vmdev

)

Close VMBus channel.

Parameters

vmdev

VMBus device

Definition at line 524 of file vmbus.c.

                                                {
        struct hv_hypervisor *hv = vmdev->hv;
        struct vmbus_close_channel close;
        size_t len;
        int rc;

        /* Construct message */
        memset ( &close, 0, sizeof ( close ) );
        close.header.type = cpu_to_le32 ( VMBUS_CLOSE_CHANNEL );
        close.channel = cpu_to_le32 ( vmdev->channel );

        /* Post message */
        if ( ( rc = vmbus_post_message ( hv, &close.header,
                                         sizeof ( close ) ) ) != 0 ) {
                DBGC ( vmdev, "VMBUS %s failed to close: %s\n",
                       vmdev->dev.name, strerror ( rc ) );
                /* Continue to attempt to tear down GPADL, so that our
                 * memory is no longer accessible by the remote VM.
                 */
        }

        /* Tear down GPADL */
        if ( ( rc = vmbus_gpadl_teardown ( vmdev, vmdev->gpadl ) ) != 0 ) {
                DBGC ( vmdev, "VMBUS %s failed to tear down channel GPADL: "
                       "%s\n", vmdev->dev.name, strerror ( rc ) );
                /* We can't prevent the remote VM from continuing to
                 * access this memory, so leak it.
                 */
                return;
        }

        /* Free ring buffer */
        len = ( sizeof ( *vmdev->out ) + vmdev->out_len +
                sizeof ( *vmdev->in ) + vmdev->in_len );
        free_phys ( vmdev->out, len );
        vmdev->out = NULL;
        vmdev->in = NULL;

        /* Free packet buffer */
        free ( vmdev->packet );
        vmdev->packet = NULL;

        DBGC ( vmdev, "VMBUS %s closed\n", vmdev->dev.name );
}

References vmbus_device::channel, close, cpu_to_le32, DBGC, vmbus_device::dev, free, free_phys(), vmbus_device::gpadl, vmbus_device::hv, vmbus_device::in, vmbus_device::in_len, len, memset(), device::name, NULL, vmbus_device::out, vmbus_device::out_len, vmbus_device::packet, rc, strerror(), VMBUS_CLOSE_CHANNEL, and vmbus_post_message().

Referenced by netvsc_close(), and netvsc_open().

vmbus_signal_monitor()

static void vmbus_signal_monitor ( struct vmbus_device *  vmdev )

static

Signal channel via monitor page.

Parameters

vmdev

VMBus device

Definition at line 574 of file vmbus.c.

                                                                {
        struct hv_hypervisor *hv = vmdev->hv;
        struct vmbus *vmbus = hv->vmbus;
        struct hv_monitor_trigger *trigger;
        unsigned int group;
        unsigned int bit;

        /* Set bit in monitor trigger group */
        group = ( vmdev->monitor / ( 8 * sizeof ( trigger->pending ) ));
        bit = ( vmdev->monitor % ( 8 * sizeof ( trigger->pending ) ) );
        trigger = &vmbus->monitor_out->trigger[group];
        set_bit ( bit, trigger );
}

References bit, group, vmbus_device::hv, vmbus_device::monitor, vmbus::monitor_out, hv_monitor_trigger::pending, set_bit(), trigger, hv_monitor::trigger, and hv_hypervisor::vmbus.

Referenced by vmbus_probe_channels().

vmbus_signal_event()

static void vmbus_signal_event ( struct vmbus_device *  vmdev )

static

Signal channel via hypervisor event.

Parameters

vmdev

VMBus device

Definition at line 593 of file vmbus.c.

                                                              {
        struct hv_hypervisor *hv = vmdev->hv;
        int rc;

        /* Signal hypervisor event */
        if ( ( rc = hv_signal_event ( hv, VMBUS_EVENT_ID, 0 ) ) != 0 ) {
                DBGC ( vmdev, "VMBUS %s could not signal event: %s\n",
                       vmdev->dev.name, strerror ( rc ) );
                return;
        }
}

References DBGC, vmbus_device::dev, vmbus_device::hv, device::name, rc, strerror(), and VMBUS_EVENT_ID.

Referenced by vmbus_probe_channels().

vmbus_produce()

static size_t vmbus_produce ( struct vmbus_device *  vmdev, size_t  prod, const void *  data, size_t  len  )

static

Fill outbound ring buffer.

Parameters

vmdev	VMBus device
prod	Producer index
data	Data
len	Length

Return values

prod	New producer index

The caller must ensure that there is sufficient space in the ring buffer.

Definition at line 617 of file vmbus.c.

                                                             {
        size_t first;
        size_t second;

        /* Determine fragment lengths */
        first = ( vmdev->out_len - prod );
        if ( first > len )
                first = len;
        second = ( len - first );

        /* Copy fragment(s) */
        memcpy ( &vmdev->out->data[prod], data, first );
        if ( second )
                memcpy ( &vmdev->out->data[0], ( data + first ), second );

        return ( ( prod + len ) & ( vmdev->out_len - 1 ) );
}

References data, vmbus_ring::data, first, len, memcpy(), vmbus_device::out, vmbus_device::out_len, and second.

Referenced by vmbus_send().

vmbus_consume()

static size_t vmbus_consume ( struct vmbus_device *  vmdev, size_t  cons, void *  data, size_t  len  )

static

Consume inbound ring buffer.

Parameters

vmdev	VMBus device
cons	Consumer index
data	Data buffer, or NULL
len	Length to consume

Return values

cons	New consumer index

Definition at line 645 of file vmbus.c.

                                                       {
        size_t first;
        size_t second;

        /* Determine fragment lengths */
        first = ( vmdev->in_len - cons );
        if ( first > len )
                first = len;
        second = ( len - first );

        /* Copy fragment(s) */
        memcpy ( data, &vmdev->in->data[cons], first );
        if ( second )
                memcpy ( ( data + first ), &vmdev->in->data[0], second );

        return ( ( cons + len ) & ( vmdev->in_len - 1 ) );
}

References cons, data, vmbus_ring::data, first, vmbus_device::in, vmbus_device::in_len, len, memcpy(), and second.

Referenced by vmbus_poll().

vmbus_send()

static int vmbus_send ( struct vmbus_device *  vmdev, struct vmbus_packet_header *  header, const void *  data, size_t  len  )

static

Send packet via ring buffer.

Parameters

vmdev	VMBus device
header	Packet header
data	Data
len	Length of data

Return values

rc	Return status code

Send a packet via the outbound ring buffer. All fields in the packet header must be filled in, with the exception of the total packet length.

Definition at line 677 of file vmbus.c.

                                                       {
        struct hv_hypervisor *hv = vmdev->hv;
        struct vmbus *vmbus = hv->vmbus;
        static uint8_t padding[ 8 - 1 ];
        struct vmbus_packet_footer footer;
        size_t header_len;
        size_t pad_len;
        size_t footer_len;
        size_t ring_len;
        size_t cons;
        size_t prod;
        size_t old_prod;
        size_t fill;

        /* Sanity check */
        assert ( vmdev->out != NULL );

        /* Calculate lengths */
        header_len = ( le16_to_cpu ( header->hdr_qlen ) * 8 );
        pad_len = ( ( -len ) & ( 8 - 1 ) );
        footer_len = sizeof ( footer );
        ring_len = ( header_len + len + pad_len + footer_len );

        /* Check that we have enough room in the outbound ring buffer */
        cons = le32_to_cpu ( vmdev->out->cons );
        prod = le32_to_cpu ( vmdev->out->prod );
        old_prod = prod;
        fill = ( ( prod - cons ) & ( vmdev->out_len - 1 ) );
        if ( ( fill + ring_len ) >= vmdev->out_len ) {
                DBGC ( vmdev, "VMBUS %s ring buffer full\n", vmdev->dev.name );
                return -ENOBUFS;
        }

        /* Complete header */
        header->qlen = cpu_to_le16 ( ( ring_len - footer_len ) / 8 );

        /* Construct footer */
        footer.reserved = 0;
        footer.prod = vmdev->out->prod;

        /* Copy packet to buffer */
        DBGC2 ( vmdev, "VMBUS %s sending:\n", vmdev->dev.name );
        DBGC2_HDA ( vmdev, prod, header, header_len );
        prod = vmbus_produce ( vmdev, prod, header, header_len );
        DBGC2_HDA ( vmdev, prod, data, len );
        prod = vmbus_produce ( vmdev, prod, data, len );
        prod = vmbus_produce ( vmdev, prod, padding, pad_len );
        DBGC2_HDA ( vmdev, prod, &footer, sizeof ( footer ) );
        prod = vmbus_produce ( vmdev, prod, &footer, sizeof ( footer ) );
        assert ( ( ( prod - old_prod ) & ( vmdev->out_len - 1 ) ) == ring_len );

        /* Update producer index */
        wmb();
        vmdev->out->prod = cpu_to_le32 ( prod );

        /* Return if we do not need to signal the host.  This follows
         * the logic of hv_need_to_signal() in the Linux driver.
         */
        mb();
        if ( vmdev->out->intr_mask )
                return 0;
        rmb();
        cons = le32_to_cpu ( vmdev->out->cons );
        if ( cons != old_prod )
                return 0;

        /* Set channel bit in interrupt page */
        set_bit ( vmdev->channel, vmbus->intr->out );

        /* Signal the host */
        vmdev->signal ( vmdev );

        return 0;
}

References assert(), vmbus_device::channel, cons, vmbus_ring::cons, cpu_to_le16, cpu_to_le32, data, DBGC, DBGC2, DBGC2_HDA, vmbus_device::dev, ENOBUFS, fill, header, vmbus_device::hv, vmbus::intr, vmbus_ring::intr_mask, le16_to_cpu, le32_to_cpu, len, mb(), device::name, NULL, vmbus_interrupt::out, vmbus_device::out, vmbus_device::out_len, pad_len, vmbus_packet_footer::prod, vmbus_ring::prod, vmbus_packet_footer::reserved, rmb, set_bit(), vmbus_device::signal, hv_hypervisor::vmbus, vmbus_produce(), and wmb().

Referenced by vmbus_send_cancellation(), vmbus_send_completion(), vmbus_send_control(), and vmbus_send_data().

vmbus_send_control()

int vmbus_send_control	(	struct vmbus_device *	vmdev,
		uint64_t	xid,
		const void *	data,
		size_t	len
	)

Send control packet via ring buffer.

Parameters

vmdev	VMBus device
xid	Transaction ID (or zero to not request completion)
data	Data
len	Length of data

Return values

rc	Return status code

Send data using a VMBUS_DATA_INBAND packet.

Definition at line 765 of file vmbus.c.

                                                        {
        struct vmbus_packet_header *header = vmdev->packet;

        /* Construct header in packet buffer */
        assert ( header != NULL );
        header->type = cpu_to_le16 ( VMBUS_DATA_INBAND );
        header->hdr_qlen = cpu_to_le16 ( sizeof ( *header ) / 8 );
        header->flags = ( xid ?
                          cpu_to_le16 ( VMBUS_COMPLETION_REQUESTED ) : 0 );
        header->xid = xid; /* Non-endian */

        return vmbus_send ( vmdev, header, data, len );
}

References assert(), cpu_to_le16, data, ena_aq_header::flags, header, len, NULL, vmbus_device::packet, VMBUS_COMPLETION_REQUESTED, VMBUS_DATA_INBAND, vmbus_send(), and vmbus_packet_header::xid.

Referenced by netvsc_control().

vmbus_send_data()

int vmbus_send_data	(	struct vmbus_device *	vmdev,
		uint64_t	xid,
		const void *	data,
		size_t	len,
		struct io_buffer *	iobuf
	)

Send data packet via ring buffer.

Parameters

vmdev	VMBus device
xid	Transaction ID
data	Data
len	Length of data
iobuf	I/O buffer

Return values

rc	Return status code

Send data using a VMBUS_DATA_GPA_DIRECT packet. The caller is responsible for ensuring that the I/O buffer remains untouched until the corresponding completion has been received.

Definition at line 794 of file vmbus.c.

                                                                              {
        physaddr_t addr = virt_to_phys ( iobuf->data );
        unsigned int pfn_count = hv_pfn_count ( addr, iob_len ( iobuf ) );
        struct {
                struct vmbus_gpa_direct_header gpa;
                struct vmbus_gpa_range range;
                uint64_t pfn[pfn_count];
        } __attribute__ (( packed )) *header = vmdev->packet;
        unsigned int i;

        /* Sanity check */
        assert ( header != NULL );
        assert ( sizeof ( *header ) <= vmdev->mtu );

        /* Construct header in packet buffer */
        header->gpa.header.type = cpu_to_le16 ( VMBUS_DATA_GPA_DIRECT );
        header->gpa.header.hdr_qlen = cpu_to_le16 ( sizeof ( *header ) / 8 );
        header->gpa.header.flags = cpu_to_le16 ( VMBUS_COMPLETION_REQUESTED );
        header->gpa.header.xid = xid; /* Non-endian */
        header->gpa.range_count = 1;
        header->range.len = cpu_to_le32 ( iob_len ( iobuf ) );
        header->range.offset = cpu_to_le32 ( addr & ( PAGE_SIZE - 1 ) );
        for ( i = 0 ; i < pfn_count ; i++ )
                header->pfn[i] = ( ( addr / PAGE_SIZE ) + i );

        return vmbus_send ( vmdev, &header->gpa.header, data, len );
}

References __attribute__, addr, assert(), cpu_to_le16, cpu_to_le32, data, io_buffer::data, ena_aq_header::flags, header, hv_pfn_count(), iob_len(), len, vmbus_device::mtu, NULL, vmbus_device::packet, PAGE_SIZE, vmbus_gpa_range::pfn, range, virt_to_phys(), VMBUS_COMPLETION_REQUESTED, VMBUS_DATA_GPA_DIRECT, and vmbus_send().

Referenced by netvsc_transmit().

vmbus_send_completion()

int vmbus_send_completion	(	struct vmbus_device *	vmdev,
		uint64_t	xid,
		const void *	data,
		size_t	len
	)

Send completion packet via ring buffer.

Parameters

vmdev	VMBus device
xid	Transaction ID
data	Data
len	Length of data

Return values

rc	Return status code

Send data using a VMBUS_COMPLETION packet.

Definition at line 834 of file vmbus.c.

                                                           {
        struct vmbus_packet_header *header = vmdev->packet;

        /* Construct header in packet buffer */
        assert ( header != NULL );
        header->type = cpu_to_le16 ( VMBUS_COMPLETION );
        header->hdr_qlen = cpu_to_le16 ( sizeof ( *header ) / 8 );
        header->flags = 0;
        header->xid = xid; /* Non-endian */

        return vmbus_send ( vmdev, header, data, len );
}

References assert(), cpu_to_le16, data, ena_aq_header::flags, header, len, NULL, vmbus_device::packet, VMBUS_COMPLETION, vmbus_send(), and vmbus_packet_header::xid.

Referenced by netvsc_recv_data().

vmbus_send_cancellation()

int vmbus_send_cancellation	(	struct vmbus_device *	vmdev,
		uint64_t	xid
	)

Send cancellation packet via ring buffer.

Parameters

vmdev	VMBus device
xid	Transaction ID

Return values

rc	Return status code

Send data using a VMBUS_CANCELLATION packet.

Definition at line 857 of file vmbus.c.

                                                                         {
        struct vmbus_packet_header *header = vmdev->packet;

        /* Construct header in packet buffer */
        assert ( header != NULL );
        header->type = cpu_to_le16 ( VMBUS_CANCELLATION );
        header->hdr_qlen = cpu_to_le16 ( sizeof ( *header ) / 8 );
        header->flags = 0;
        header->xid = xid; /* Non-endian */

        return vmbus_send ( vmdev, header, NULL, 0 );
}

References assert(), cpu_to_le16, ena_aq_header::flags, header, NULL, vmbus_device::packet, VMBUS_CANCELLATION, vmbus_send(), and vmbus_packet_header::xid.

Referenced by netvsc_cancel_transmit().

vmbus_xfer_pages()

static struct vmbus_xfer_pages* vmbus_xfer_pages ( struct vmbus_device *  vmdev, uint16_t  pageset  )

static

Get transfer page set from pageset ID.

Parameters

vmdev	VMBus device
pageset	Page set ID (in protocol byte order)

Return values

pages

Page set, or NULL if not found

Definition at line 877 of file vmbus.c.

                                                                       {
        struct vmbus_xfer_pages *pages;

        /* Locate page set */
        list_for_each_entry ( pages, &vmdev->pages, list ) {
                if ( pages->pageset == pageset )
                        return pages;
        }

        DBGC ( vmdev, "VMBUS %s unrecognised page set ID %#04x\n",
               vmdev->dev.name, le16_to_cpu ( pageset ) );
        return NULL;
}

References DBGC, vmbus_device::dev, le16_to_cpu, vmbus_xfer_pages::list, list_for_each_entry, device::name, NULL, vmbus_device::pages, pageset, and vmbus_xfer_pages::pageset.

Referenced by vmbus_xfer_page_iobufs().

vmbus_xfer_page_iobufs()

static int vmbus_xfer_page_iobufs ( struct vmbus_device *  vmdev, struct vmbus_packet_header *  header, struct list_head *  list  )

static

Construct I/O buffer list from transfer pages.

Parameters

vmdev	VMBus device
header	Transfer page header
list	I/O buffer list to populate

Return values

rc	Return status code

Definition at line 900 of file vmbus.c.

                                                             {
        struct vmbus_xfer_page_header *page_header =
                container_of ( header, struct vmbus_xfer_page_header, header );
        struct vmbus_xfer_pages *pages;
        struct io_buffer *iobuf;
        struct io_buffer *tmp;
        size_t len;
        size_t offset;
        unsigned int range_count;
        unsigned int i;
        int rc;

        /* Sanity check */
        assert ( header->type == cpu_to_le16 ( VMBUS_DATA_XFER_PAGES ) );

        /* Locate page set */
        pages = vmbus_xfer_pages ( vmdev, page_header->pageset );
        if ( ! pages ) {
                rc = -ENOENT;
                goto err_pages;
        }

        /* Allocate and populate I/O buffers */
        range_count = le32_to_cpu ( page_header->range_count );
        for ( i = 0 ; i < range_count ; i++ ) {

                /* Parse header */
                len = le32_to_cpu ( page_header->range[i].len );
                offset = le32_to_cpu ( page_header->range[i].offset );

                /* Allocate I/O buffer */
                iobuf = alloc_iob ( len );
                if ( ! iobuf ) {
                        DBGC ( vmdev, "VMBUS %s could not allocate %zd-byte "
                               "I/O buffer\n", vmdev->dev.name, len );
                        rc = -ENOMEM;
                        goto err_alloc;
                }

                /* Add I/O buffer to list */
                list_add ( &iobuf->list, list );

                /* Populate I/O buffer */
                if ( ( rc = pages->op->copy ( pages, iob_put ( iobuf, len ),
                                              offset, len ) ) != 0 ) {
                        DBGC ( vmdev, "VMBUS %s could not populate I/O buffer "
                               "range [%zd,%zd): %s\n",
                               vmdev->dev.name, offset, len, strerror ( rc ) );
                        goto err_copy;
                }
        }

        return 0;

 err_copy:
 err_alloc:
        list_for_each_entry_safe ( iobuf, tmp, list, list ) {
                list_del ( &iobuf->list );
                free_iob ( iobuf );
        }
 err_pages:
        return rc;
}

References alloc_iob(), assert(), container_of, vmbus_xfer_pages_operations::copy, cpu_to_le16, DBGC, vmbus_device::dev, ENOENT, ENOMEM, free_iob(), header, iob_put, le32_to_cpu, len, vmbus_xfer_page_range::len, io_buffer::list, list_add, list_del, list_for_each_entry_safe, device::name, offset, vmbus_xfer_page_range::offset, vmbus_xfer_pages::op, vmbus_xfer_page_header::pageset, vmbus_xfer_page_header::range, vmbus_xfer_page_header::range_count, rc, strerror(), tmp, VMBUS_DATA_XFER_PAGES, and vmbus_xfer_pages().

Referenced by vmbus_poll().

vmbus_poll()

int vmbus_poll

(

struct vmbus_device *

vmdev

)

Poll ring buffer.

Parameters

vmdev

VMBus device

Return values

rc	Return status code

Definition at line 972 of file vmbus.c.

                                              {
        struct vmbus_packet_header *header = vmdev->packet;
        struct list_head list;
        void *data;
        size_t header_len;
        size_t len;
        size_t footer_len;
        size_t ring_len;
        size_t cons;
        size_t old_cons;
        uint64_t xid;
        int rc;

        /* Sanity checks */
        assert ( vmdev->packet != NULL );
        assert ( vmdev->in != NULL );

        /* Return immediately if buffer is empty */
        if ( ! vmbus_has_data ( vmdev ) )
                return 0;
        cons = le32_to_cpu ( vmdev->in->cons );
        old_cons = cons;

        /* Consume (start of) header */
        cons = vmbus_consume ( vmdev, cons, header, sizeof ( *header ) );

        /* Parse and sanity check header */
        header_len = ( le16_to_cpu ( header->hdr_qlen ) * 8 );
        if ( header_len < sizeof ( *header ) ) {
                DBGC ( vmdev, "VMBUS %s received underlength header (%zd "
                       "bytes)\n", vmdev->dev.name, header_len );
                return -EINVAL;
        }
        len = ( ( le16_to_cpu ( header->qlen ) * 8 ) - header_len );
        footer_len = sizeof ( struct vmbus_packet_footer );
        ring_len = ( header_len + len + footer_len );
        if ( ring_len > vmdev->mtu ) {
                DBGC ( vmdev, "VMBUS %s received overlength packet (%zd "
                       "bytes)\n", vmdev->dev.name, ring_len );
                return -ERANGE;
        }
        xid = le64_to_cpu ( header->xid );

        /* Consume remainder of packet */
        cons = vmbus_consume ( vmdev, cons,
                               ( ( ( void * ) header ) + sizeof ( *header ) ),
                               ( ring_len - sizeof ( *header ) ) );
        DBGC2 ( vmdev, "VMBUS %s received:\n", vmdev->dev.name );
        DBGC2_HDA ( vmdev, old_cons, header, ring_len );
        assert ( ( ( cons - old_cons ) & ( vmdev->in_len - 1 ) ) == ring_len );

        /* Allocate I/O buffers, if applicable */
        INIT_LIST_HEAD ( &list );
        if ( header->type == cpu_to_le16 ( VMBUS_DATA_XFER_PAGES ) ) {
                if ( ( rc = vmbus_xfer_page_iobufs ( vmdev, header,
                                                     &list ) ) != 0 )
                        return rc;
        }

        /* Update producer index */
        rmb();
        vmdev->in->cons = cpu_to_le32 ( cons );

        /* Handle packet */
        data = ( ( ( void * ) header ) + header_len );
        switch ( header->type ) {

        case cpu_to_le16 ( VMBUS_DATA_INBAND ) :
                if ( ( rc = vmdev->op->recv_control ( vmdev, xid, data,
                                                      len ) ) != 0 ) {
                        DBGC ( vmdev, "VMBUS %s could not handle control "
                               "packet: %s\n",
                               vmdev->dev.name, strerror ( rc ) );
                        return rc;
                }
                break;

        case cpu_to_le16 ( VMBUS_DATA_XFER_PAGES ) :
                if ( ( rc = vmdev->op->recv_data ( vmdev, xid, data, len,
                                                   &list ) ) != 0 ) {
                        DBGC ( vmdev, "VMBUS %s could not handle data packet: "
                               "%s\n", vmdev->dev.name, strerror ( rc ) );
                        return rc;
                }
                break;

        case cpu_to_le16 ( VMBUS_COMPLETION ) :
                if ( ( rc = vmdev->op->recv_completion ( vmdev, xid, data,
                                                         len ) ) != 0 ) {
                        DBGC ( vmdev, "VMBUS %s could not handle completion: "
                               "%s\n", vmdev->dev.name, strerror ( rc ) );
                        return rc;
                }
                break;

        case cpu_to_le16 ( VMBUS_CANCELLATION ) :
                if ( ( rc = vmdev->op->recv_cancellation ( vmdev, xid ) ) != 0){
                        DBGC ( vmdev, "VMBUS %s could not handle cancellation: "
                               "%s\n", vmdev->dev.name, strerror ( rc ) );
                        return rc;
                }
                break;

        default:
                DBGC ( vmdev, "VMBUS %s unknown packet type %d\n",
                       vmdev->dev.name, le16_to_cpu ( header->type ) );
                return -ENOTSUP;
        }

        return 0;
}

References assert(), cons, vmbus_ring::cons, cpu_to_le16, cpu_to_le32, data, DBGC, DBGC2, DBGC2_HDA, vmbus_device::dev, EINVAL, ENOTSUP, ERANGE, header, vmbus_device::in, vmbus_device::in_len, INIT_LIST_HEAD, le16_to_cpu, le32_to_cpu, le64_to_cpu, len, vmbus_device::mtu, device::name, NULL, vmbus_device::op, vmbus_device::packet, rc, vmbus_channel_operations::recv_cancellation, vmbus_channel_operations::recv_completion, vmbus_channel_operations::recv_control, vmbus_channel_operations::recv_data, rmb, strerror(), VMBUS_CANCELLATION, VMBUS_COMPLETION, vmbus_consume(), VMBUS_DATA_INBAND, VMBUS_DATA_XFER_PAGES, vmbus_has_data(), and vmbus_xfer_page_iobufs().

Referenced by netvsc_control(), and netvsc_poll().

vmbus_dump_channel()

void vmbus_dump_channel

(

struct vmbus_device *

vmdev

)

Dump channel status (for debugging)

Parameters

vmdev

VMBus device

Definition at line 1089 of file vmbus.c.

                                                       {
        size_t out_prod = le32_to_cpu ( vmdev->out->prod );
        size_t out_cons = le32_to_cpu ( vmdev->out->cons );
        size_t in_prod = le32_to_cpu ( vmdev->in->prod );
        size_t in_cons = le32_to_cpu ( vmdev->in->cons );
        size_t in_len;
        size_t first;
        size_t second;

        /* Dump ring status */
        DBGC ( vmdev, "VMBUS %s out %03zx:%03zx%s in %03zx:%03zx%s\n",
               vmdev->dev.name, out_prod, out_cons,
               ( vmdev->out->intr_mask ? "(m)" : "" ), in_prod, in_cons,
               ( vmdev->in->intr_mask ? "(m)" : "" ) );

        /* Dump inbound ring contents, if any */
        if ( in_prod != in_cons ) {
                in_len = ( ( in_prod - in_cons ) &
                           ( vmdev->in_len - 1 ) );
                first = ( vmdev->in_len - in_cons );
                if ( first > in_len )
                        first = in_len;
                second = ( in_len - first );
                DBGC_HDA ( vmdev, in_cons, &vmdev->in->data[in_cons], first );
                DBGC_HDA ( vmdev, 0, &vmdev->in->data[0], second );
        }
}

References vmbus_ring::cons, vmbus_ring::data, DBGC, DBGC_HDA, vmbus_device::dev, first, vmbus_device::in, vmbus_device::in_len, vmbus_ring::intr_mask, le32_to_cpu, device::name, vmbus_device::out, vmbus_ring::prod, and second.

Referenced by netvsc_control().

vmbus_find_driver()

static struct vmbus_driver* vmbus_find_driver ( const union uuid *  type )

static

Find driver for VMBus device.

Parameters

vmdev

VMBus device

Return values

driver

Driver, or NULL

Definition at line 1123 of file vmbus.c.

                                                                          {
        struct vmbus_driver *vmdrv;

        for_each_table_entry ( vmdrv, VMBUS_DRIVERS ) {
                if ( memcmp ( &vmdrv->type, type, sizeof ( *type ) ) == 0 )
                        return vmdrv;
        }
        return NULL;
}

References for_each_table_entry, memcmp(), NULL, type, vmbus_driver::type, and VMBUS_DRIVERS.

Referenced by vmbus_probe_channels().

vmbus_probe_channels()

static int vmbus_probe_channels ( struct hv_hypervisor *  hv, struct device *  parent  )

static

Probe channels.

Parameters

hv	Hyper-V hypervisor
parent	Parent device

Return values

rc	Return status code

Definition at line 1140 of file vmbus.c.

                                                          {
        struct vmbus *vmbus = hv->vmbus;
        const struct vmbus_message_header *header = &vmbus->message->header;
        const struct vmbus_offer_channel *offer = &vmbus->message->offer;
        const union uuid *type;
        union uuid instance;
        struct vmbus_driver *driver;
        struct vmbus_device *vmdev;
        struct vmbus_device *tmp;
        unsigned int channel;
        int rc;

        /* Post message */
        if ( ( rc = vmbus_post_empty_message ( hv, VMBUS_REQUEST_OFFERS ) ) !=0)
                goto err_post_message;

        /* Collect responses */
        while ( 1 ) {

                /* Wait for response */
                if ( ( rc = vmbus_wait_for_any_message ( hv ) ) != 0 )
                        goto err_wait_for_any_message;

                /* Handle response */
                if ( header->type == cpu_to_le32 ( VMBUS_OFFER_CHANNEL ) ) {

                        /* Parse offer */
                        type = &offer->type;
                        channel = le32_to_cpu ( offer->channel );
                        DBGC2 ( vmbus, "VMBUS %p offer %d type %s",
                                vmbus, channel, uuid_ntoa ( type ) );
                        if ( offer->monitored )
                                DBGC2 ( vmbus, " monitor %d", offer->monitor );
                        DBGC2 ( vmbus, "\n" );

                        /* Look for a driver */
                        driver = vmbus_find_driver ( type );
                        if ( ! driver ) {
                                DBGC2 ( vmbus, "VMBUS %p has no driver for "
                                        "type %s\n", vmbus, uuid_ntoa ( type ));
                                /* Not a fatal error */
                                continue;
                        }

                        /* Allocate and initialise device */
                        vmdev = zalloc ( sizeof ( *vmdev ) );
                        if ( ! vmdev ) {
                                rc = -ENOMEM;
                                goto err_alloc_vmdev;
                        }
                        memcpy ( &instance, &offer->instance,
                                 sizeof ( instance ) );
                        uuid_mangle ( &instance );
                        snprintf ( vmdev->dev.name, sizeof ( vmdev->dev.name ),
                                   "{%s}", uuid_ntoa ( &instance ) );
                        vmdev->dev.desc.bus_type = BUS_TYPE_HV;
                        INIT_LIST_HEAD ( &vmdev->dev.children );
                        list_add_tail ( &vmdev->dev.siblings,
                                        &parent->children );
                        vmdev->dev.parent = parent;
                        vmdev->hv = hv;
                        memcpy ( &vmdev->instance, &offer->instance,
                                 sizeof ( vmdev->instance ) );
                        vmdev->channel = channel;
                        vmdev->monitor = offer->monitor;
                        vmdev->signal = ( offer->monitored ?
                                          vmbus_signal_monitor :
                                          vmbus_signal_event );
                        INIT_LIST_HEAD ( &vmdev->pages );
                        vmdev->driver = driver;
                        vmdev->dev.driver_name = driver->name;
                        DBGC ( vmdev, "VMBUS %s has driver \"%s\"\n",
                               vmdev->dev.name, vmdev->driver->name );

                } else if ( header->type ==
                            cpu_to_le32 ( VMBUS_ALL_OFFERS_DELIVERED ) ) {

                        /* End of offer list */
                        break;

                } else {
                        DBGC ( vmbus, "VMBUS %p unexpected offer response type "
                               "%d\n", vmbus, le32_to_cpu ( header->type ) );
                        rc = -EPROTO;
                        goto err_unexpected_offer;
                }
        }

        /* Probe all devices.  We do this only after completing
         * enumeration since devices will need to send and receive
         * VMBus messages.
         */
        list_for_each_entry ( vmdev, &parent->children, dev.siblings ) {
                if ( ( rc = vmdev->driver->probe ( vmdev ) ) != 0 ) {
                        DBGC ( vmdev, "VMBUS %s could not probe: %s\n",
                               vmdev->dev.name, strerror ( rc ) );
                        goto err_probe;
                }
        }

        return 0;

 err_probe:
        /* Remove driver from each device that was already probed */
        list_for_each_entry_continue_reverse ( vmdev, &parent->children,
                                               dev.siblings ) {
                vmdev->driver->remove ( vmdev );
        }
 err_unexpected_offer:
 err_alloc_vmdev:
 err_wait_for_any_message:
        /* Free any devices allocated (but potentially not yet probed) */
        list_for_each_entry_safe ( vmdev, tmp, &parent->children,
                                   dev.siblings ) {
                list_del ( &vmdev->dev.siblings );
                free ( vmdev );
        }
 err_post_message:
        return rc;
}

References device_description::bus_type, BUS_TYPE_HV, channel, vmbus_offer_channel::channel, vmbus_device::channel, device::children, cpu_to_le32, DBGC, DBGC2, device::desc, vmbus_device::dev, vmbus_device::driver, device::driver_name, ENOMEM, EPROTO, free, vmbus_message::header, header, vmbus_device::hv, INIT_LIST_HEAD, vmbus_offer_channel::instance, vmbus_device::instance, le32_to_cpu, list_add_tail, list_del, list_for_each_entry, list_for_each_entry_continue_reverse, list_for_each_entry_safe, memcpy(), vmbus::message, vmbus_offer_channel::monitor, vmbus_device::monitor, vmbus_offer_channel::monitored, device::name, vmbus_driver::name, vmbus_message::offer, vmbus_device::pages, device::parent, vmbus_driver::probe, rc, vmbus_driver::remove, device::siblings, vmbus_device::signal, snprintf(), strerror(), tmp, type, vmbus_offer_channel::type, uuid_mangle(), uuid_ntoa(), hv_hypervisor::vmbus, VMBUS_ALL_OFFERS_DELIVERED, vmbus_find_driver(), VMBUS_OFFER_CHANNEL, vmbus_post_empty_message(), VMBUS_REQUEST_OFFERS, vmbus_signal_event(), vmbus_signal_monitor(), vmbus_wait_for_any_message(), and zalloc().

Referenced by vmbus_probe().

vmbus_reset_channels()

static int vmbus_reset_channels ( struct hv_hypervisor *  hv, struct device *  parent  )

static

Reset channels.

Parameters

hv	Hyper-V hypervisor
parent	Parent device

Return values

rc	Return status code

Definition at line 1270 of file vmbus.c.

                                                          {
        struct vmbus *vmbus = hv->vmbus;
        const struct vmbus_message_header *header = &vmbus->message->header;
        const struct vmbus_offer_channel *offer = &vmbus->message->offer;
        const union uuid *type;
        struct vmbus_device *vmdev;
        unsigned int channel;
        int rc;

        /* Post message */
        if ( ( rc = vmbus_post_empty_message ( hv, VMBUS_REQUEST_OFFERS ) ) !=0)
                return rc;

        /* Collect responses */
        while ( 1 ) {

                /* Wait for response */
                if ( ( rc = vmbus_wait_for_any_message ( hv ) ) != 0 )
                        return rc;

                /* Handle response */
                if ( header->type == cpu_to_le32 ( VMBUS_OFFER_CHANNEL ) ) {

                        /* Parse offer */
                        type = &offer->type;
                        channel = le32_to_cpu ( offer->channel );
                        DBGC2 ( vmbus, "VMBUS %p offer %d type %s",
                                vmbus, channel, uuid_ntoa ( type ) );
                        if ( offer->monitored )
                                DBGC2 ( vmbus, " monitor %d", offer->monitor );
                        DBGC2 ( vmbus, "\n" );

                        /* Do nothing with the offer; we already have all
                         * of the relevant state from the initial probe.
                         */

                } else if ( header->type ==
                            cpu_to_le32 ( VMBUS_ALL_OFFERS_DELIVERED ) ) {

                        /* End of offer list */
                        break;

                } else {
                        DBGC ( vmbus, "VMBUS %p unexpected offer response type "
                               "%d\n", vmbus, le32_to_cpu ( header->type ) );
                        return -EPROTO;
                }
        }

        /* Reset all devices */
        list_for_each_entry ( vmdev, &parent->children, dev.siblings ) {
                if ( ( rc = vmdev->driver->reset ( vmdev ) ) != 0 ) {
                        DBGC ( vmdev, "VMBUS %s could not reset: %s\n",
                               vmdev->dev.name, strerror ( rc ) );
                        /* Continue attempting to reset other devices */
                        continue;
                }
        }

        return 0;
}

References channel, vmbus_offer_channel::channel, device::children, cpu_to_le32, DBGC, DBGC2, vmbus_device::dev, vmbus_device::driver, EPROTO, vmbus_message::header, header, vmbus_device::hv, le32_to_cpu, list_for_each_entry, vmbus::message, vmbus_offer_channel::monitor, vmbus_offer_channel::monitored, device::name, vmbus_message::offer, rc, vmbus_driver::reset, device::siblings, strerror(), type, vmbus_offer_channel::type, uuid_ntoa(), hv_hypervisor::vmbus, VMBUS_ALL_OFFERS_DELIVERED, VMBUS_OFFER_CHANNEL, vmbus_post_empty_message(), VMBUS_REQUEST_OFFERS, and vmbus_wait_for_any_message().

Referenced by vmbus_reset().

vmbus_remove_channels()

static void vmbus_remove_channels ( struct hv_hypervisor *hv  __unused, struct device *  parent  )

static

Remove channels.

Parameters

hv	Hyper-V hypervisor
parent	Parent device

Definition at line 1339 of file vmbus.c.

                                                            {
        struct vmbus_device *vmdev;
        struct vmbus_device *tmp;

        /* Remove devices */
        list_for_each_entry_safe ( vmdev, tmp, &parent->children,
                                   dev.siblings ) {
                vmdev->driver->remove ( vmdev );
                assert ( list_empty ( &vmdev->dev.children ) );
                assert ( vmdev->out == NULL );
                assert ( vmdev->in == NULL );
                assert ( vmdev->packet == NULL );
                assert ( list_empty ( &vmdev->pages ) );
                list_del ( &vmdev->dev.siblings );
                free ( vmdev );
        }
}

References assert(), device::children, vmbus_device::dev, vmbus_device::driver, free, vmbus_device::in, list_del, list_empty, list_for_each_entry_safe, NULL, vmbus_device::out, vmbus_device::packet, vmbus_device::pages, vmbus_driver::remove, device::siblings, and tmp.

Referenced by vmbus_probe(), and vmbus_remove().

vmbus_probe()

int vmbus_probe	(	struct hv_hypervisor *	hv,
		struct device *	parent
	)

Probe Hyper-V virtual machine bus.

Parameters

hv	Hyper-V hypervisor
parent	Parent device

Return values

rc	Return status code

Definition at line 1365 of file vmbus.c.

                                                                    {
        struct vmbus *vmbus;
        int rc;

        /* Allocate and initialise structure */
        vmbus = zalloc ( sizeof ( *vmbus ) );
        if ( ! vmbus ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        hv->vmbus = vmbus;

        /* Initialise message buffer pointer
         *
         * We use a pointer to the fixed-size Hyper-V received message
         * buffer.  This allows us to access fields within received
         * messages without first checking the message size: any
         * fields beyond the end of the message will read as zero.
         */
        vmbus->message = ( ( void * ) hv->message->received.data );
        assert ( sizeof ( *vmbus->message ) <=
                 sizeof ( hv->message->received.data ) );

        /* Allocate interrupt and monitor pages */
        if ( ( rc = hv_alloc_pages ( hv, &vmbus->intr, &vmbus->monitor_in,
                                     &vmbus->monitor_out, NULL ) ) != 0 )
                goto err_alloc_pages;

        /* Enable message interrupt */
        hv_enable_sint ( hv, VMBUS_MESSAGE_SINT );

        /* Negotiate protocol version */
        if ( ( rc = vmbus_negotiate_version ( hv ) ) != 0 )
                goto err_negotiate_version;

        /* Enumerate channels */
        if ( ( rc = vmbus_probe_channels ( hv, parent ) ) != 0 )
                goto err_probe_channels;

        return 0;

        vmbus_remove_channels ( hv, parent );
 err_probe_channels:
        vmbus_unload ( hv );
 err_negotiate_version:
        hv_disable_sint ( hv, VMBUS_MESSAGE_SINT );
        hv_free_pages ( hv, vmbus->intr, vmbus->monitor_in, vmbus->monitor_out,
                        NULL );
 err_alloc_pages:
        free ( vmbus );
 err_alloc:
        return rc;
}

References assert(), hv_message::data, ENOMEM, free, hv_alloc_pages(), hv_disable_sint(), hv_enable_sint(), hv_free_pages(), vmbus::intr, hv_hypervisor::message, vmbus::message, vmbus::monitor_in, vmbus::monitor_out, NULL, rc, hv_message_buffer::received, hv_hypervisor::vmbus, VMBUS_MESSAGE_SINT, vmbus_negotiate_version(), vmbus_probe_channels(), vmbus_remove_channels(), vmbus_unload(), and zalloc().

Referenced by hv_probe().

vmbus_reset()

int vmbus_reset	(	struct hv_hypervisor *	hv,
		struct device *	parent
	)

Reset Hyper-V virtual machine bus.

Parameters

hv	Hyper-V hypervisor
parent	Parent device

Return values

rc	Return status code

Definition at line 1426 of file vmbus.c.

                                                                    {
        struct vmbus *vmbus = hv->vmbus;
        int rc;

        /* Mark all existent GPADLs as obsolete */
        vmbus_obsolete_gpadl = vmbus_gpadl;

        /* Clear interrupt and monitor pages */
        memset ( vmbus->intr, 0, PAGE_SIZE );
        memset ( vmbus->monitor_in, 0, PAGE_SIZE );
        memset ( vmbus->monitor_out, 0, PAGE_SIZE );

        /* Enable message interrupt */
        hv_enable_sint ( hv, VMBUS_MESSAGE_SINT );

        /* Renegotiate protocol version */
        if ( ( rc = vmbus_negotiate_version ( hv ) ) != 0 )
                return rc;

        /* Reenumerate channels */
        if ( ( rc = vmbus_reset_channels ( hv, parent ) ) != 0 )
                return rc;

        return 0;
}

References hv_enable_sint(), vmbus::intr, memset(), vmbus::monitor_in, vmbus::monitor_out, PAGE_SIZE, rc, hv_hypervisor::vmbus, vmbus_gpadl, VMBUS_MESSAGE_SINT, vmbus_negotiate_version(), vmbus_obsolete_gpadl, and vmbus_reset_channels().

Referenced by hv_unquiesce().

vmbus_remove()

void vmbus_remove	(	struct hv_hypervisor *	hv,
		struct device *	parent
	)

Remove Hyper-V virtual machine bus.

Parameters

hv	Hyper-V hypervisor
parent	Parent device

Definition at line 1458 of file vmbus.c.

                                                                      {
        struct vmbus *vmbus = hv->vmbus;

        vmbus_remove_channels ( hv, parent );
        vmbus_unload ( hv );
        hv_disable_sint ( hv, VMBUS_MESSAGE_SINT );
        hv_free_pages ( hv, vmbus->intr, vmbus->monitor_in, vmbus->monitor_out,
                        NULL );
        free ( vmbus );
}

References free, hv_disable_sint(), hv_free_pages(), vmbus::intr, vmbus::monitor_in, vmbus::monitor_out, NULL, hv_hypervisor::vmbus, VMBUS_MESSAGE_SINT, vmbus_remove_channels(), and vmbus_unload().

Referenced by hv_probe(), and hv_remove().

Variable Documentation

vmbus_gpadl

unsigned int vmbus_gpadl = VMBUS_GPADL_MAGIC

static

Current (i.e.

most recently issued) GPADL ID

Definition at line 54 of file vmbus.c.

Referenced by vmbus_establish_gpadl(), and vmbus_reset().

vmbus_obsolete_gpadl

unsigned int vmbus_obsolete_gpadl

Obsolete GPADL ID threshold.

When the Hyper-V connection is reset, any previous GPADLs are automatically rendered obsolete.

Definition at line 61 of file vmbus.c.

Referenced by vmbus_gpadl_is_obsolete(), and vmbus_reset().