diff options
Diffstat (limited to 'qemu/roms/ipxe/src/interface/hyperv')
| -rw-r--r-- | qemu/roms/ipxe/src/interface/hyperv/vmbus.c | 1333 |
1 files changed, 1333 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/interface/hyperv/vmbus.c b/qemu/roms/ipxe/src/interface/hyperv/vmbus.c new file mode 100644 index 000000000..795929eae --- /dev/null +++ b/qemu/roms/ipxe/src/interface/hyperv/vmbus.c @@ -0,0 +1,1333 @@ +/* + * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * You can also choose to distribute this program under the terms of + * the Unmodified Binary Distribution Licence (as given in the file + * COPYING.UBDL), provided that you have satisfied its requirements. + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +/** @file + * + * Hyper-V virtual machine bus + * + */ + +#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/hyperv.h> +#include <ipxe/vmbus.h> + +/** VMBus initial GPADL ID + * + * This is an opaque value with no meaning. The Linux kernel uses + * 0xe1e10. + */ +#define VMBUS_GPADL_MAGIC 0x18ae0000 + +/** + * Post message + * + * @v hv Hyper-V hypervisor + * @v header Message header + * @v len Length of message (including header) + * @ret rc Return status code + */ +static int vmbus_post_message ( struct hv_hypervisor *hv, + const struct vmbus_message_header *header, + size_t len ) { + 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; +} + +/** + * Post empty message + * + * @v hv Hyper-V hypervisor + * @v type Message type + * @ret rc Return status code + */ +static int vmbus_post_empty_message ( struct hv_hypervisor *hv, + unsigned int type ) { + struct vmbus_message_header header = { .type = cpu_to_le32 ( type ) }; + + return vmbus_post_message ( hv, &header, sizeof ( header ) ); +} + +/** + * Wait for received message + * + * @v hv Hyper-V hypervisor + * @ret rc Return status code + */ +static int vmbus_wait_for_message ( struct hv_hypervisor *hv ) { + 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; +} + +/** + * Initiate contact + * + * @v hv Hyper-V hypervisor + * @v raw VMBus protocol (raw) version + * @ret rc Return status code + */ +static int vmbus_initiate_contact ( struct hv_hypervisor *hv, + unsigned int raw ) { + 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 ) ) != 0 ) + return rc; + + /* Check response */ + if ( version->header.type != cpu_to_le32 ( VMBUS_VERSION_RESPONSE ) ) { + DBGC ( vmbus, "VMBUS %p unexpected version response type %d\n", + vmbus, le32_to_cpu ( version->header.type ) ); + return -EPROTO; + } + if ( ! version->supported ) { + DBGC ( vmbus, "VMBUS %p requested version not supported\n", + vmbus ); + return -ENOTSUP; + } + if ( version->version.raw != cpu_to_le32 ( raw ) ) { + DBGC ( vmbus, "VMBUS %p unexpected version %d.%d\n", + vmbus, le16_to_cpu ( version->version.major ), + le16_to_cpu ( version->version.minor ) ); + return -EPROTO; + } + + DBGC ( vmbus, "VMBUS %p initiated contact using version %d.%d\n", + vmbus, le16_to_cpu ( version->version.major ), + le16_to_cpu ( version->version.minor ) ); + return 0; +} + +/** + * Terminate contact + * + * @v hv Hyper-V hypervisor + * @ret rc Return status code + */ +static int vmbus_unload ( struct hv_hypervisor *hv ) { + struct vmbus *vmbus = hv->vmbus; + const struct vmbus_message_header *header = &vmbus->message->header; + 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 ) ) != 0 ) + return rc; + + /* Check response */ + if ( header->type != cpu_to_le32 ( VMBUS_UNLOAD_RESPONSE ) ) { + DBGC ( vmbus, "VMBUS %p unexpected unload response type %d\n", + vmbus, le32_to_cpu ( header->type ) ); + return -EPROTO; + } + + return 0; +} + +/** + * Negotiate protocol version + * + * @v hv Hyper-V hypervisor + * @ret rc Return status code + */ +static int vmbus_negotiate_version ( struct hv_hypervisor *hv ) { + 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; +} + +/** + * Establish GPA descriptor list + * + * @v vmdev VMBus device + * @v data Data buffer + * @v len Length of data buffer + * @ret gpadl GPADL ID, or negative error + */ +int vmbus_establish_gpadl ( struct vmbus_device *vmdev, userptr_t data, + size_t len ) { + 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; + static unsigned int gpadl = VMBUS_GPADL_MAGIC; + unsigned int i; + int rc; + + /* Allocate GPADL ID */ + 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 ) ) != 0 ) + return rc; + + /* Check response */ + if ( created->header.type != cpu_to_le32 ( VMBUS_GPADL_CREATED ) ) { + DBGC ( vmdev, "VMBUS %s unexpected GPADL response type %d\n", + vmdev->dev.name, le32_to_cpu ( created->header.type ) ); + return -EPROTO; + } + 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; +} + +/** + * Tear down GPA descriptor list + * + * @v vmdev VMBus device + * @v gpadl GPADL ID + * @ret rc Return status code + */ +int vmbus_gpadl_teardown ( struct vmbus_device *vmdev, unsigned int gpadl ) { + 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; + + /* 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 ) ) != 0 ) + return rc; + + /* Check response */ + if ( torndown->header.type != cpu_to_le32 ( VMBUS_GPADL_TORNDOWN ) ) { + DBGC ( vmdev, "VMBUS %s unexpected GPADL response type %d\n", + vmdev->dev.name, le32_to_cpu ( torndown->header.type ) ); + return -EPROTO; + } + 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; +} + +/** + * Open VMBus channel + * + * @v vmdev VMBus device + * @v op Channel operations + * @v out_len Outbound ring buffer length + * @v in_len Inbound ring buffer length + * @v mtu Maximum expected data packet length (including headers) + * @ret 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. + */ +int vmbus_open ( struct vmbus_device *vmdev, + struct vmbus_channel_operations *op, + size_t out_len, size_t in_len, size_t mtu ) { + 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_dma ( 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 ) + return rc; + + /* Wait for response */ + if ( ( rc = vmbus_wait_for_message ( hv ) ) != 0 ) + return rc; + + /* Check response */ + if ( opened->header.type != cpu_to_le32 ( VMBUS_OPEN_CHANNEL_RESULT ) ){ + DBGC ( vmdev, "VMBUS %s unexpected open response type %d\n", + vmdev->dev.name, le32_to_cpu ( opened->header.type ) ); + return -EPROTO; + } + 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 ) ); + return -EPROTO; + } + if ( opened->id != open_id /* Non-endian */ ) { + DBGC ( vmdev, "VMBUS %s unexpected open ID %#08x\n", + vmdev->dev.name, le32_to_cpu ( opened->id ) ); + return -EPROTO; + } + if ( opened->status != 0 ) { + DBGC ( vmdev, "VMBUS %s open failed: %#08x\n", + vmdev->dev.name, le32_to_cpu ( opened->status ) ); + return -EPROTO; + } + + /* 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; + + vmbus_gpadl_teardown ( vmdev, vmdev->gpadl ); + err_establish: + free_dma ( ring, len ); + err_alloc_ring: + free ( packet ); + err_alloc_packet: + return rc; +} + +/** + * Close VMBus channel + * + * @v vmdev VMBus device + */ +void vmbus_close ( struct vmbus_device *vmdev ) { + 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_dma ( 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 ); +} + +/** + * Signal channel via monitor page + * + * @v vmdev VMBus device + */ +static void vmbus_signal_monitor ( struct vmbus_device *vmdev ) { + 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]; + hv_set_bit ( trigger, bit ); +} + +/** + * Signal channel via hypervisor event + * + * @v vmdev VMBus device + */ +static void vmbus_signal_event ( struct vmbus_device *vmdev ) { + 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; + } +} + +/** + * Fill outbound ring buffer + * + * @v vmdev VMBus device + * @v prod Producer index + * @v data Data + * @v len Length + * @ret prod New producer index + * + * The caller must ensure that there is sufficient space in the ring + * buffer. + */ +static size_t vmbus_produce ( struct vmbus_device *vmdev, size_t prod, + const void *data, size_t len ) { + 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 ) ); +} + +/** + * Consume inbound ring buffer + * + * @v vmdev VMBus device + * @v cons Consumer index + * @v data Data buffer, or NULL + * @v len Length to consume + * @ret cons New consumer index + */ +static size_t vmbus_consume ( struct vmbus_device *vmdev, size_t cons, + void *data, size_t len ) { + 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 ) ); +} + +/** + * Send packet via ring buffer + * + * @v vmdev VMBus device + * @v header Packet header + * @v data Data + * @v len Length of data + * @ret 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. + */ +static int vmbus_send ( struct vmbus_device *vmdev, + struct vmbus_packet_header *header, + const void *data, size_t len ) { + 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 */ + hv_set_bit ( vmbus->intr->out, vmdev->channel ); + + /* Signal the host */ + vmdev->signal ( vmdev ); + + return 0; +} + +/** + * Send control packet via ring buffer + * + * @v vmdev VMBus device + * @v xid Transaction ID (or zero to not request completion) + * @v data Data + * @v len Length of data + * @ret rc Return status code + * + * Send data using a VMBUS_DATA_INBAND packet. + */ +int vmbus_send_control ( struct vmbus_device *vmdev, uint64_t xid, + const void *data, size_t len ) { + 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 ); +} + +/** + * Send data packet via ring buffer + * + * @v vmdev VMBus device + * @v xid Transaction ID + * @v data Data + * @v len Length of data + * @v iobuf I/O buffer + * @ret 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. + */ +int vmbus_send_data ( struct vmbus_device *vmdev, uint64_t xid, + const void *data, size_t len, struct io_buffer *iobuf ) { + 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 ); +} + +/** + * Send completion packet via ring buffer + * + * @v vmdev VMBus device + * @v xid Transaction ID + * @v data Data + * @v len Length of data + * @ret rc Return status code + * + * Send data using a VMBUS_COMPLETION packet. + */ +int vmbus_send_completion ( struct vmbus_device *vmdev, uint64_t xid, + const void *data, size_t len ) { + 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 ); +} + +/** + * Send cancellation packet via ring buffer + * + * @v vmdev VMBus device + * @v xid Transaction ID + * @ret rc Return status code + * + * Send data using a VMBUS_CANCELLATION packet. + */ +int vmbus_send_cancellation ( struct vmbus_device *vmdev, uint64_t xid ) { + 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 ); +} + +/** + * Get transfer page set from pageset ID + * + * @v vmdev VMBus device + * @v pageset Page set ID (in protocol byte order) + * @ret pages Page set, or NULL if not found + */ +static struct vmbus_xfer_pages * vmbus_xfer_pages ( struct vmbus_device *vmdev, + uint16_t pageset ) { + 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; +} + +/** + * Construct I/O buffer list from transfer pages + * + * @v vmdev VMBus device + * @v header Transfer page header + * @v list I/O buffer list to populate + * @ret rc Return status code + */ +static int vmbus_xfer_page_iobufs ( struct vmbus_device *vmdev, + struct vmbus_packet_header *header, + struct list_head *list ) { + 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; +} + +/** + * Poll ring buffer + * + * @v vmdev VMBus device + * @ret rc Return status code + */ +int vmbus_poll ( struct vmbus_device *vmdev ) { + 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; +} + +/** + * Dump channel status (for debugging) + * + * @v vmdev VMBus device + */ +void vmbus_dump_channel ( struct vmbus_device *vmdev ) { + 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 ); + } +} + +/** + * Find driver for VMBus device + * + * @v vmdev VMBus device + * @ret driver Driver, or NULL + */ +static struct vmbus_driver * vmbus_find_driver ( const union uuid *type ) { + struct vmbus_driver *vmdrv; + + for_each_table_entry ( vmdrv, VMBUS_DRIVERS ) { + if ( memcmp ( &vmdrv->type, type, sizeof ( *type ) ) == 0 ) + return vmdrv; + } + return NULL; +} + +/** + * Probe channels + * + * @v hv Hyper-V hypervisor + * @v parent Parent device + * @ret rc Return status code + */ +static int vmbus_probe_channels ( struct hv_hypervisor *hv, + struct device *parent ) { + 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_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_message ( hv ) ) != 0 ) + goto err_wait_for_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; + } + snprintf ( vmdev->dev.name, sizeof ( vmdev->dev.name ), + "vmbus:%02x", channel ); + 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; + 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 ) ) { + + 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_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; +} + +/** + * Remove channels + * + * @v hv Hyper-V hypervisor + * @v parent Parent device + */ +static void vmbus_remove_channels ( struct hv_hypervisor *hv __unused, + struct device *parent ) { + 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 ); + } +} + +/** + * Probe Hyper-V virtual machine bus + * + * @v hv Hyper-V hypervisor + * @v parent Parent device + * @ret rc Return status code + */ +int vmbus_probe ( struct hv_hypervisor *hv, struct device *parent ) { + 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; +} + +/** + * Remove Hyper-V virtual machine bus + * + * @v hv Hyper-V hypervisor + * @v parent Parent device + */ +void vmbus_remove ( struct hv_hypervisor *hv, struct device *parent ) { + 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 ); +} |