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linux-sg2042/drivers/hv/channel.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2009, Microsoft Corporation.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/hyperv.h>
#include <linux/uio.h>
#include <linux/interrupt.h>
#include <asm/page.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
/*
* hv_gpadl_size - Return the real size of a gpadl, the size that Hyper-V uses
*
* For BUFFER gpadl, Hyper-V uses the exact same size as the guest does.
*
* For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the header
* (because of the alignment requirement), however, the hypervisor only
* uses the first HV_HYP_PAGE_SIZE as the header, therefore leaving a
* (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. And since there are two rings in a
* ringbuffer, the total size for a RING gpadl that Hyper-V uses is the
* total size that the guest uses minus twice of the gap size.
*/
static inline u32 hv_gpadl_size(enum hv_gpadl_type type, u32 size)
{
switch (type) {
case HV_GPADL_BUFFER:
return size;
case HV_GPADL_RING:
/* The size of a ringbuffer must be page-aligned */
BUG_ON(size % PAGE_SIZE);
/*
* Two things to notice here:
* 1) We're processing two ring buffers as a unit
* 2) We're skipping any space larger than HV_HYP_PAGE_SIZE in
* the first guest-size page of each of the two ring buffers.
* So we effectively subtract out two guest-size pages, and add
* back two Hyper-V size pages.
*/
return size - 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE);
}
BUG();
return 0;
}
/*
* hv_ring_gpadl_send_hvpgoffset - Calculate the send offset (in unit of
* HV_HYP_PAGE) in a ring gpadl based on the
* offset in the guest
*
* @offset: the offset (in bytes) where the send ringbuffer starts in the
* virtual address space of the guest
*/
static inline u32 hv_ring_gpadl_send_hvpgoffset(u32 offset)
{
/*
* For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the
* header (because of the alignment requirement), however, the
* hypervisor only uses the first HV_HYP_PAGE_SIZE as the header,
* therefore leaving a (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap.
*
* And to calculate the effective send offset in gpadl, we need to
* substract this gap.
*/
return (offset - (PAGE_SIZE - HV_HYP_PAGE_SIZE)) >> HV_HYP_PAGE_SHIFT;
}
/*
* hv_gpadl_hvpfn - Return the Hyper-V page PFN of the @i th Hyper-V page in
* the gpadl
*
* @type: the type of the gpadl
* @kbuffer: the pointer to the gpadl in the guest
* @size: the total size (in bytes) of the gpadl
* @send_offset: the offset (in bytes) where the send ringbuffer starts in the
* virtual address space of the guest
* @i: the index
*/
static inline u64 hv_gpadl_hvpfn(enum hv_gpadl_type type, void *kbuffer,
u32 size, u32 send_offset, int i)
{
int send_idx = hv_ring_gpadl_send_hvpgoffset(send_offset);
unsigned long delta = 0UL;
switch (type) {
case HV_GPADL_BUFFER:
break;
case HV_GPADL_RING:
if (i == 0)
delta = 0;
else if (i <= send_idx)
delta = PAGE_SIZE - HV_HYP_PAGE_SIZE;
else
delta = 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE);
break;
default:
BUG();
break;
}
return virt_to_hvpfn(kbuffer + delta + (HV_HYP_PAGE_SIZE * i));
}
/*
* vmbus_setevent- Trigger an event notification on the specified
* channel.
*/
void vmbus_setevent(struct vmbus_channel *channel)
{
struct hv_monitor_page *monitorpage;
trace_vmbus_setevent(channel);
/*
* For channels marked as in "low latency" mode
* bypass the monitor page mechanism.
*/
if (channel->offermsg.monitor_allocated && !channel->low_latency) {
vmbus_send_interrupt(channel->offermsg.child_relid);
/* Get the child to parent monitor page */
monitorpage = vmbus_connection.monitor_pages[1];
sync_set_bit(channel->monitor_bit,
(unsigned long *)&monitorpage->trigger_group
[channel->monitor_grp].pending);
} else {
vmbus_set_event(channel);
}
}
EXPORT_SYMBOL_GPL(vmbus_setevent);
/* vmbus_free_ring - drop mapping of ring buffer */
void vmbus_free_ring(struct vmbus_channel *channel)
{
hv_ringbuffer_cleanup(&channel->outbound);
hv_ringbuffer_cleanup(&channel->inbound);
if (channel->ringbuffer_page) {
__free_pages(channel->ringbuffer_page,
get_order(channel->ringbuffer_pagecount
<< PAGE_SHIFT));
channel->ringbuffer_page = NULL;
}
}
EXPORT_SYMBOL_GPL(vmbus_free_ring);
/* vmbus_alloc_ring - allocate and map pages for ring buffer */
int vmbus_alloc_ring(struct vmbus_channel *newchannel,
u32 send_size, u32 recv_size)
{
struct page *page;
int order;
if (send_size % PAGE_SIZE || recv_size % PAGE_SIZE)
return -EINVAL;
/* Allocate the ring buffer */
order = get_order(send_size + recv_size);
page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
GFP_KERNEL|__GFP_ZERO, order);
if (!page)
page = alloc_pages(GFP_KERNEL|__GFP_ZERO, order);
if (!page)
return -ENOMEM;
newchannel->ringbuffer_page = page;
newchannel->ringbuffer_pagecount = (send_size + recv_size) >> PAGE_SHIFT;
newchannel->ringbuffer_send_offset = send_size >> PAGE_SHIFT;
return 0;
}
EXPORT_SYMBOL_GPL(vmbus_alloc_ring);
/* Used for Hyper-V Socket: a guest client's connect() to the host */
int vmbus_send_tl_connect_request(const guid_t *shv_guest_servie_id,
const guid_t *shv_host_servie_id)
{
struct vmbus_channel_tl_connect_request conn_msg;
int ret;
memset(&conn_msg, 0, sizeof(conn_msg));
conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
conn_msg.guest_endpoint_id = *shv_guest_servie_id;
conn_msg.host_service_id = *shv_host_servie_id;
ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
trace_vmbus_send_tl_connect_request(&conn_msg, ret);
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
/*
* Set/change the vCPU (@target_vp) the channel (@child_relid) will interrupt.
*
* CHANNELMSG_MODIFYCHANNEL messages are aynchronous. Also, Hyper-V does not
* ACK such messages. IOW we can't know when the host will stop interrupting
* the "old" vCPU and start interrupting the "new" vCPU for the given channel.
*
* The CHANNELMSG_MODIFYCHANNEL message type is supported since VMBus version
* VERSION_WIN10_V4_1.
*/
int vmbus_send_modifychannel(u32 child_relid, u32 target_vp)
{
struct vmbus_channel_modifychannel conn_msg;
int ret;
memset(&conn_msg, 0, sizeof(conn_msg));
conn_msg.header.msgtype = CHANNELMSG_MODIFYCHANNEL;
conn_msg.child_relid = child_relid;
conn_msg.target_vp = target_vp;
ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
trace_vmbus_send_modifychannel(&conn_msg, ret);
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_send_modifychannel);
/*
* create_gpadl_header - Creates a gpadl for the specified buffer
*/
static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
u32 size, u32 send_offset,
struct vmbus_channel_msginfo **msginfo)
{
int i;
int pagecount;
struct vmbus_channel_gpadl_header *gpadl_header;
struct vmbus_channel_gpadl_body *gpadl_body;
struct vmbus_channel_msginfo *msgheader;
struct vmbus_channel_msginfo *msgbody = NULL;
u32 msgsize;
int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
pagecount = hv_gpadl_size(type, size) >> HV_HYP_PAGE_SHIFT;
/* do we need a gpadl body msg */
pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
sizeof(struct vmbus_channel_gpadl_header) -
sizeof(struct gpa_range);
pfncount = pfnsize / sizeof(u64);
if (pagecount > pfncount) {
/* we need a gpadl body */
/* fill in the header */
msgsize = sizeof(struct vmbus_channel_msginfo) +
sizeof(struct vmbus_channel_gpadl_header) +
sizeof(struct gpa_range) + pfncount * sizeof(u64);
msgheader = kzalloc(msgsize, GFP_KERNEL);
if (!msgheader)
goto nomem;
INIT_LIST_HEAD(&msgheader->submsglist);
msgheader->msgsize = msgsize;
gpadl_header = (struct vmbus_channel_gpadl_header *)
msgheader->msg;
gpadl_header->rangecount = 1;
gpadl_header->range_buflen = sizeof(struct gpa_range) +
pagecount * sizeof(u64);
gpadl_header->range[0].byte_offset = 0;
gpadl_header->range[0].byte_count = hv_gpadl_size(type, size);
for (i = 0; i < pfncount; i++)
gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn(
type, kbuffer, size, send_offset, i);
*msginfo = msgheader;
pfnsum = pfncount;
pfnleft = pagecount - pfncount;
/* how many pfns can we fit */
pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
sizeof(struct vmbus_channel_gpadl_body);
pfncount = pfnsize / sizeof(u64);
/* fill in the body */
while (pfnleft) {
if (pfnleft > pfncount)
pfncurr = pfncount;
else
pfncurr = pfnleft;
msgsize = sizeof(struct vmbus_channel_msginfo) +
sizeof(struct vmbus_channel_gpadl_body) +
pfncurr * sizeof(u64);
msgbody = kzalloc(msgsize, GFP_KERNEL);
if (!msgbody) {
struct vmbus_channel_msginfo *pos = NULL;
struct vmbus_channel_msginfo *tmp = NULL;
/*
* Free up all the allocated messages.
*/
list_for_each_entry_safe(pos, tmp,
&msgheader->submsglist,
msglistentry) {
list_del(&pos->msglistentry);
kfree(pos);
}
goto nomem;
}
msgbody->msgsize = msgsize;
gpadl_body =
(struct vmbus_channel_gpadl_body *)msgbody->msg;
/*
* Gpadl is u32 and we are using a pointer which could
* be 64-bit
* This is governed by the guest/host protocol and
* so the hypervisor guarantees that this is ok.
*/
for (i = 0; i < pfncurr; i++)
gpadl_body->pfn[i] = hv_gpadl_hvpfn(type,
kbuffer, size, send_offset, pfnsum + i);
/* add to msg header */
list_add_tail(&msgbody->msglistentry,
&msgheader->submsglist);
pfnsum += pfncurr;
pfnleft -= pfncurr;
}
} else {
/* everything fits in a header */
msgsize = sizeof(struct vmbus_channel_msginfo) +
sizeof(struct vmbus_channel_gpadl_header) +
sizeof(struct gpa_range) + pagecount * sizeof(u64);
msgheader = kzalloc(msgsize, GFP_KERNEL);
if (msgheader == NULL)
goto nomem;
INIT_LIST_HEAD(&msgheader->submsglist);
msgheader->msgsize = msgsize;
gpadl_header = (struct vmbus_channel_gpadl_header *)
msgheader->msg;
gpadl_header->rangecount = 1;
gpadl_header->range_buflen = sizeof(struct gpa_range) +
pagecount * sizeof(u64);
gpadl_header->range[0].byte_offset = 0;
gpadl_header->range[0].byte_count = hv_gpadl_size(type, size);
for (i = 0; i < pagecount; i++)
gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn(
type, kbuffer, size, send_offset, i);
*msginfo = msgheader;
}
return 0;
nomem:
kfree(msgheader);
kfree(msgbody);
return -ENOMEM;
}
/*
* __vmbus_establish_gpadl - Establish a GPADL for a buffer or ringbuffer
*
* @channel: a channel
* @type: the type of the corresponding GPADL, only meaningful for the guest.
* @kbuffer: from kmalloc or vmalloc
* @size: page-size multiple
* @send_offset: the offset (in bytes) where the send ring buffer starts,
* should be 0 for BUFFER type gpadl
* @gpadl_handle: some funky thing
*/
static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
enum hv_gpadl_type type, void *kbuffer,
u32 size, u32 send_offset,
u32 *gpadl_handle)
{
struct vmbus_channel_gpadl_header *gpadlmsg;
struct vmbus_channel_gpadl_body *gpadl_body;
struct vmbus_channel_msginfo *msginfo = NULL;
struct vmbus_channel_msginfo *submsginfo, *tmp;
struct list_head *curr;
u32 next_gpadl_handle;
unsigned long flags;
int ret = 0;
next_gpadl_handle =
(atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
ret = create_gpadl_header(type, kbuffer, size, send_offset, &msginfo);
if (ret)
return ret;
init_completion(&msginfo->waitevent);
msginfo->waiting_channel = channel;
gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
gpadlmsg->child_relid = channel->offermsg.child_relid;
gpadlmsg->gpadl = next_gpadl_handle;
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_add_tail(&msginfo->msglistentry,
&vmbus_connection.chn_msg_list);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
if (channel->rescind) {
ret = -ENODEV;
goto cleanup;
}
ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
sizeof(*msginfo), true);
trace_vmbus_establish_gpadl_header(gpadlmsg, ret);
if (ret != 0)
goto cleanup;
list_for_each(curr, &msginfo->submsglist) {
submsginfo = (struct vmbus_channel_msginfo *)curr;
gpadl_body =
(struct vmbus_channel_gpadl_body *)submsginfo->msg;
gpadl_body->header.msgtype =
CHANNELMSG_GPADL_BODY;
gpadl_body->gpadl = next_gpadl_handle;
ret = vmbus_post_msg(gpadl_body,
submsginfo->msgsize - sizeof(*submsginfo),
true);
trace_vmbus_establish_gpadl_body(gpadl_body, ret);
if (ret != 0)
goto cleanup;
}
wait_for_completion(&msginfo->waitevent);
if (msginfo->response.gpadl_created.creation_status != 0) {
pr_err("Failed to establish GPADL: err = 0x%x\n",
msginfo->response.gpadl_created.creation_status);
ret = -EDQUOT;
goto cleanup;
}
if (channel->rescind) {
ret = -ENODEV;
goto cleanup;
}
/* At this point, we received the gpadl created msg */
*gpadl_handle = gpadlmsg->gpadl;
cleanup:
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&msginfo->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
msglistentry) {
kfree(submsginfo);
}
kfree(msginfo);
return ret;
}
/*
* vmbus_establish_gpadl - Establish a GPADL for the specified buffer
*
* @channel: a channel
* @kbuffer: from kmalloc or vmalloc
* @size: page-size multiple
* @gpadl_handle: some funky thing
*/
int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
u32 size, u32 *gpadl_handle)
{
return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size,
0U, gpadl_handle);
}
EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
/**
* request_arr_init - Allocates memory for the requestor array. Each slot
* keeps track of the next available slot in the array. Initially, each
* slot points to the next one (as in a Linked List). The last slot
* does not point to anything, so its value is U64_MAX by default.
* @size The size of the array
*/
static u64 *request_arr_init(u32 size)
{
int i;
u64 *req_arr;
req_arr = kcalloc(size, sizeof(u64), GFP_KERNEL);
if (!req_arr)
return NULL;
for (i = 0; i < size - 1; i++)
req_arr[i] = i + 1;
/* Last slot (no more available slots) */
req_arr[i] = U64_MAX;
return req_arr;
}
/*
* vmbus_alloc_requestor - Initializes @rqstor's fields.
* Index 0 is the first free slot
* @size: Size of the requestor array
*/
static int vmbus_alloc_requestor(struct vmbus_requestor *rqstor, u32 size)
{
u64 *rqst_arr;
unsigned long *bitmap;
rqst_arr = request_arr_init(size);
if (!rqst_arr)
return -ENOMEM;
bitmap = bitmap_zalloc(size, GFP_KERNEL);
if (!bitmap) {
kfree(rqst_arr);
return -ENOMEM;
}
rqstor->req_arr = rqst_arr;
rqstor->req_bitmap = bitmap;
rqstor->size = size;
rqstor->next_request_id = 0;
spin_lock_init(&rqstor->req_lock);
return 0;
}
/*
* vmbus_free_requestor - Frees memory allocated for @rqstor
* @rqstor: Pointer to the requestor struct
*/
static void vmbus_free_requestor(struct vmbus_requestor *rqstor)
{
kfree(rqstor->req_arr);
bitmap_free(rqstor->req_bitmap);
}
static int __vmbus_open(struct vmbus_channel *newchannel,
void *userdata, u32 userdatalen,
void (*onchannelcallback)(void *context), void *context)
{
struct vmbus_channel_open_channel *open_msg;
struct vmbus_channel_msginfo *open_info = NULL;
struct page *page = newchannel->ringbuffer_page;
u32 send_pages, recv_pages;
unsigned long flags;
int err;
if (userdatalen > MAX_USER_DEFINED_BYTES)
return -EINVAL;
send_pages = newchannel->ringbuffer_send_offset;
recv_pages = newchannel->ringbuffer_pagecount - send_pages;
if (newchannel->state != CHANNEL_OPEN_STATE)
return -EINVAL;
/* Create and init requestor */
if (newchannel->rqstor_size) {
if (vmbus_alloc_requestor(&newchannel->requestor, newchannel->rqstor_size))
return -ENOMEM;
}
newchannel->state = CHANNEL_OPENING_STATE;
newchannel->onchannel_callback = onchannelcallback;
newchannel->channel_callback_context = context;
err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages);
if (err)
goto error_clean_ring;
err = hv_ringbuffer_init(&newchannel->inbound,
&page[send_pages], recv_pages);
if (err)
goto error_clean_ring;
/* Establish the gpadl for the ring buffer */
newchannel->ringbuffer_gpadlhandle = 0;
err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING,
page_address(newchannel->ringbuffer_page),
(send_pages + recv_pages) << PAGE_SHIFT,
newchannel->ringbuffer_send_offset << PAGE_SHIFT,
&newchannel->ringbuffer_gpadlhandle);
if (err)
goto error_clean_ring;
/* Create and init the channel open message */
open_info = kmalloc(sizeof(*open_info) +
sizeof(struct vmbus_channel_open_channel),
GFP_KERNEL);
if (!open_info) {
err = -ENOMEM;
goto error_free_gpadl;
}
init_completion(&open_info->waitevent);
open_info->waiting_channel = newchannel;
open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
open_msg->openid = newchannel->offermsg.child_relid;
open_msg->child_relid = newchannel->offermsg.child_relid;
open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
/*
* The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and
* the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so
* here we calculate it into HV_HYP_PAGE.
*/
open_msg->downstream_ringbuffer_pageoffset =
hv_ring_gpadl_send_hvpgoffset(send_pages << PAGE_SHIFT);
open_msg->target_vp = hv_cpu_number_to_vp_number(newchannel->target_cpu);
if (userdatalen)
memcpy(open_msg->userdata, userdata, userdatalen);
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_add_tail(&open_info->msglistentry,
&vmbus_connection.chn_msg_list);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
if (newchannel->rescind) {
err = -ENODEV;
goto error_free_info;
}
err = vmbus_post_msg(open_msg,
sizeof(struct vmbus_channel_open_channel), true);
trace_vmbus_open(open_msg, err);
if (err != 0)
goto error_clean_msglist;
wait_for_completion(&open_info->waitevent);
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&open_info->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
if (newchannel->rescind) {
err = -ENODEV;
goto error_free_info;
}
if (open_info->response.open_result.status) {
err = -EAGAIN;
goto error_free_info;
}
newchannel->state = CHANNEL_OPENED_STATE;
kfree(open_info);
return 0;
error_clean_msglist:
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&open_info->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
error_free_info:
kfree(open_info);
error_free_gpadl:
vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
newchannel->ringbuffer_gpadlhandle = 0;
error_clean_ring:
hv_ringbuffer_cleanup(&newchannel->outbound);
hv_ringbuffer_cleanup(&newchannel->inbound);
vmbus_free_requestor(&newchannel->requestor);
newchannel->state = CHANNEL_OPEN_STATE;
return err;
}
/*
* vmbus_connect_ring - Open the channel but reuse ring buffer
*/
int vmbus_connect_ring(struct vmbus_channel *newchannel,
void (*onchannelcallback)(void *context), void *context)
{
return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context);
}
EXPORT_SYMBOL_GPL(vmbus_connect_ring);
/*
* vmbus_open - Open the specified channel.
*/
int vmbus_open(struct vmbus_channel *newchannel,
u32 send_ringbuffer_size, u32 recv_ringbuffer_size,
void *userdata, u32 userdatalen,
void (*onchannelcallback)(void *context), void *context)
{
int err;
err = vmbus_alloc_ring(newchannel, send_ringbuffer_size,
recv_ringbuffer_size);
if (err)
return err;
err = __vmbus_open(newchannel, userdata, userdatalen,
onchannelcallback, context);
if (err)
vmbus_free_ring(newchannel);
return err;
}
EXPORT_SYMBOL_GPL(vmbus_open);
/*
* vmbus_teardown_gpadl -Teardown the specified GPADL handle
*/
int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
{
struct vmbus_channel_gpadl_teardown *msg;
struct vmbus_channel_msginfo *info;
unsigned long flags;
int ret;
info = kmalloc(sizeof(*info) +
sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
if (!info)
return -ENOMEM;
init_completion(&info->waitevent);
info->waiting_channel = channel;
msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
msg->child_relid = channel->offermsg.child_relid;
msg->gpadl = gpadl_handle;
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_add_tail(&info->msglistentry,
&vmbus_connection.chn_msg_list);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
if (channel->rescind)
goto post_msg_err;
ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
true);
trace_vmbus_teardown_gpadl(msg, ret);
if (ret)
goto post_msg_err;
wait_for_completion(&info->waitevent);
post_msg_err:
/*
* If the channel has been rescinded;
* we will be awakened by the rescind
* handler; set the error code to zero so we don't leak memory.
*/
if (channel->rescind)
ret = 0;
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&info->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
kfree(info);
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
void vmbus_reset_channel_cb(struct vmbus_channel *channel)
{
unsigned long flags;
/*
* vmbus_on_event(), running in the per-channel tasklet, can race
* with vmbus_close_internal() in the case of SMP guest, e.g., when
* the former is accessing channel->inbound.ring_buffer, the latter
* could be freeing the ring_buffer pages, so here we must stop it
* first.
*
* vmbus_chan_sched() might call the netvsc driver callback function
* that ends up scheduling NAPI work that accesses the ring buffer.
* At this point, we have to ensure that any such work is completed
* and that the channel ring buffer is no longer being accessed, cf.
* the calls to napi_disable() in netvsc_device_remove().
*/
tasklet_disable(&channel->callback_event);
/* See the inline comments in vmbus_chan_sched(). */
spin_lock_irqsave(&channel->sched_lock, flags);
channel->onchannel_callback = NULL;
spin_unlock_irqrestore(&channel->sched_lock, flags);
channel->sc_creation_callback = NULL;
/* Re-enable tasklet for use on re-open */
tasklet_enable(&channel->callback_event);
}
static int vmbus_close_internal(struct vmbus_channel *channel)
{
struct vmbus_channel_close_channel *msg;
int ret;
vmbus_reset_channel_cb(channel);
/*
* In case a device driver's probe() fails (e.g.,
* util_probe() -> vmbus_open() returns -ENOMEM) and the device is
* rescinded later (e.g., we dynamically disable an Integrated Service
* in Hyper-V Manager), the driver's remove() invokes vmbus_close():
* here we should skip most of the below cleanup work.
*/
if (channel->state != CHANNEL_OPENED_STATE)
return -EINVAL;
channel->state = CHANNEL_OPEN_STATE;
/* Send a closing message */
msg = &channel->close_msg.msg;
msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
msg->child_relid = channel->offermsg.child_relid;
ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel),
true);
trace_vmbus_close_internal(msg, ret);
if (ret) {
pr_err("Close failed: close post msg return is %d\n", ret);
/*
* If we failed to post the close msg,
* it is perhaps better to leak memory.
*/
}
/* Tear down the gpadl for the channel's ring buffer */
else if (channel->ringbuffer_gpadlhandle) {
ret = vmbus_teardown_gpadl(channel,
channel->ringbuffer_gpadlhandle);
if (ret) {
pr_err("Close failed: teardown gpadl return %d\n", ret);
/*
* If we failed to teardown gpadl,
* it is perhaps better to leak memory.
*/
}
channel->ringbuffer_gpadlhandle = 0;
}
if (!ret)
vmbus_free_requestor(&channel->requestor);
return ret;
}
/* disconnect ring - close all channels */
int vmbus_disconnect_ring(struct vmbus_channel *channel)
{
struct vmbus_channel *cur_channel, *tmp;
int ret;
if (channel->primary_channel != NULL)
return -EINVAL;
list_for_each_entry_safe(cur_channel, tmp, &channel->sc_list, sc_list) {
if (cur_channel->rescind)
wait_for_completion(&cur_channel->rescind_event);
mutex_lock(&vmbus_connection.channel_mutex);
if (vmbus_close_internal(cur_channel) == 0) {
vmbus_free_ring(cur_channel);
if (cur_channel->rescind)
hv_process_channel_removal(cur_channel);
}
mutex_unlock(&vmbus_connection.channel_mutex);
}
/*
* Now close the primary.
*/
mutex_lock(&vmbus_connection.channel_mutex);
ret = vmbus_close_internal(channel);
mutex_unlock(&vmbus_connection.channel_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_disconnect_ring);
/*
* vmbus_close - Close the specified channel
*/
void vmbus_close(struct vmbus_channel *channel)
{
if (vmbus_disconnect_ring(channel) == 0)
vmbus_free_ring(channel);
}
EXPORT_SYMBOL_GPL(vmbus_close);
/**
* vmbus_sendpacket() - Send the specified buffer on the given channel
* @channel: Pointer to vmbus_channel structure
* @buffer: Pointer to the buffer you want to send the data from.
* @bufferlen: Maximum size of what the buffer holds.
* @requestid: Identifier of the request
* @type: Type of packet that is being sent e.g. negotiate, time
* packet etc.
* @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
*
* Sends data in @buffer directly to Hyper-V via the vmbus.
* This will send the data unparsed to Hyper-V.
*
* Mainly used by Hyper-V drivers.
*/
int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
u32 bufferlen, u64 requestid,
enum vmbus_packet_type type, u32 flags)
{
struct vmpacket_descriptor desc;
u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
struct kvec bufferlist[3];
u64 aligned_data = 0;
int num_vecs = ((bufferlen != 0) ? 3 : 1);
/* Setup the descriptor */
desc.type = type; /* VmbusPacketTypeDataInBand; */
desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
/* in 8-bytes granularity */
desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
desc.len8 = (u16)(packetlen_aligned >> 3);
desc.trans_id = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */
bufferlist[0].iov_base = &desc;
bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
bufferlist[1].iov_base = buffer;
bufferlist[1].iov_len = bufferlen;
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid);
}
EXPORT_SYMBOL(vmbus_sendpacket);
/*
* vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
* packets using a GPADL Direct packet type. This interface allows you
* to control notifying the host. This will be useful for sending
* batched data. Also the sender can control the send flags
* explicitly.
*/
int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
struct hv_page_buffer pagebuffers[],
u32 pagecount, void *buffer, u32 bufferlen,
u64 requestid)
{
int i;
struct vmbus_channel_packet_page_buffer desc;
u32 descsize;
u32 packetlen;
u32 packetlen_aligned;
struct kvec bufferlist[3];
u64 aligned_data = 0;
if (pagecount > MAX_PAGE_BUFFER_COUNT)
return -EINVAL;
/*
* Adjust the size down since vmbus_channel_packet_page_buffer is the
* largest size we support
*/
descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
((MAX_PAGE_BUFFER_COUNT - pagecount) *
sizeof(struct hv_page_buffer));
packetlen = descsize + bufferlen;
packetlen_aligned = ALIGN(packetlen, sizeof(u64));
/* Setup the descriptor */
desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
desc.length8 = (u16)(packetlen_aligned >> 3);
desc.transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */
desc.reserved = 0;
desc.rangecount = pagecount;
for (i = 0; i < pagecount; i++) {
desc.range[i].len = pagebuffers[i].len;
desc.range[i].offset = pagebuffers[i].offset;
desc.range[i].pfn = pagebuffers[i].pfn;
}
bufferlist[0].iov_base = &desc;
bufferlist[0].iov_len = descsize;
bufferlist[1].iov_base = buffer;
bufferlist[1].iov_len = bufferlen;
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
}
EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
/*
* vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
* using a GPADL Direct packet type.
* The buffer includes the vmbus descriptor.
*/
int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
struct vmbus_packet_mpb_array *desc,
u32 desc_size,
void *buffer, u32 bufferlen, u64 requestid)
{
u32 packetlen;
u32 packetlen_aligned;
struct kvec bufferlist[3];
u64 aligned_data = 0;
packetlen = desc_size + bufferlen;
packetlen_aligned = ALIGN(packetlen, sizeof(u64));
/* Setup the descriptor */
desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */
desc->length8 = (u16)(packetlen_aligned >> 3);
desc->transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */
desc->reserved = 0;
desc->rangecount = 1;
bufferlist[0].iov_base = desc;
bufferlist[0].iov_len = desc_size;
bufferlist[1].iov_base = buffer;
bufferlist[1].iov_len = bufferlen;
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
}
EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
/**
* __vmbus_recvpacket() - Retrieve the user packet on the specified channel
* @channel: Pointer to vmbus_channel structure
* @buffer: Pointer to the buffer you want to receive the data into.
* @bufferlen: Maximum size of what the buffer can hold.
* @buffer_actual_len: The actual size of the data after it was received.
* @requestid: Identifier of the request
* @raw: true means keep the vmpacket_descriptor header in the received data.
*
* Receives directly from the hyper-v vmbus and puts the data it received
* into Buffer. This will receive the data unparsed from hyper-v.
*
* Mainly used by Hyper-V drivers.
*/
static inline int
__vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
bool raw)
{
return hv_ringbuffer_read(channel, buffer, bufferlen,
buffer_actual_len, requestid, raw);
}
int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
u32 bufferlen, u32 *buffer_actual_len,
u64 *requestid)
{
return __vmbus_recvpacket(channel, buffer, bufferlen,
buffer_actual_len, requestid, false);
}
EXPORT_SYMBOL(vmbus_recvpacket);
/*
* vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
*/
int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
u32 bufferlen, u32 *buffer_actual_len,
u64 *requestid)
{
return __vmbus_recvpacket(channel, buffer, bufferlen,
buffer_actual_len, requestid, true);
}
EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
/*
* vmbus_next_request_id - Returns a new request id. It is also
* the index at which the guest memory address is stored.
* Uses a spin lock to avoid race conditions.
* @rqstor: Pointer to the requestor struct
* @rqst_add: Guest memory address to be stored in the array
*/
u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr)
{
unsigned long flags;
u64 current_id;
const struct vmbus_channel *channel =
container_of(rqstor, const struct vmbus_channel, requestor);
/* Check rqstor has been initialized */
if (!channel->rqstor_size)
return VMBUS_NO_RQSTOR;
spin_lock_irqsave(&rqstor->req_lock, flags);
current_id = rqstor->next_request_id;
/* Requestor array is full */
if (current_id >= rqstor->size) {
spin_unlock_irqrestore(&rqstor->req_lock, flags);
return VMBUS_RQST_ERROR;
}
rqstor->next_request_id = rqstor->req_arr[current_id];
rqstor->req_arr[current_id] = rqst_addr;
/* The already held spin lock provides atomicity */
bitmap_set(rqstor->req_bitmap, current_id, 1);
spin_unlock_irqrestore(&rqstor->req_lock, flags);
/*
* Cannot return an ID of 0, which is reserved for an unsolicited
* message from Hyper-V.
*/
return current_id + 1;
}
EXPORT_SYMBOL_GPL(vmbus_next_request_id);
/*
* vmbus_request_addr - Returns the memory address stored at @trans_id
* in @rqstor. Uses a spin lock to avoid race conditions.
* @rqstor: Pointer to the requestor struct
* @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
* next request id.
*/
u64 vmbus_request_addr(struct vmbus_requestor *rqstor, u64 trans_id)
{
unsigned long flags;
u64 req_addr;
const struct vmbus_channel *channel =
container_of(rqstor, const struct vmbus_channel, requestor);
/* Check rqstor has been initialized */
if (!channel->rqstor_size)
return VMBUS_NO_RQSTOR;
/* Hyper-V can send an unsolicited message with ID of 0 */
if (!trans_id)
return trans_id;
spin_lock_irqsave(&rqstor->req_lock, flags);
/* Data corresponding to trans_id is stored at trans_id - 1 */
trans_id--;
/* Invalid trans_id */
if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap)) {
spin_unlock_irqrestore(&rqstor->req_lock, flags);
return VMBUS_RQST_ERROR;
}
req_addr = rqstor->req_arr[trans_id];
rqstor->req_arr[trans_id] = rqstor->next_request_id;
rqstor->next_request_id = trans_id;
/* The already held spin lock provides atomicity */
bitmap_clear(rqstor->req_bitmap, trans_id, 1);
spin_unlock_irqrestore(&rqstor->req_lock, flags);
return req_addr;
}
EXPORT_SYMBOL_GPL(vmbus_request_addr);
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