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dataplane: replace hostmem with memory_region_find 

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Paolo Bonzini 2013-12-10 13:27:01 +01:00 committed by Stefan Hajnoczi
parent 8c1b566fd1
commit 87b7f2f8c8
5 changed files with 72 additions and 252 deletions
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2
hw/virtio/dataplane/Makefile.objs
View File

@ -1 +1 @@
common-obj-y += hostmem.o vring.o
common-obj-y += vring.o

183
hw/virtio/dataplane/hostmem.c
View File

@ -1,183 +0,0 @@
/*
* Thread-safe guest to host memory mapping
*
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "exec/address-spaces.h"
#include "hw/virtio/dataplane/hostmem.h"
static int hostmem_lookup_cmp(const void *phys_, const void *region_)
{
hwaddr phys = *(const hwaddr *)phys_;
const HostMemRegion *region = region_;
if (phys < region->guest_addr) {
return -1;
} else if (phys >= region->guest_addr + region->size) {
return 1;
} else {
return 0;
}
}
/**
* Map guest physical address to host pointer
*/
void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write)
{
HostMemRegion *region;
void *host_addr = NULL;
hwaddr offset_within_region;
qemu_mutex_lock(&hostmem->current_regions_lock);
region = bsearch(&phys, hostmem->current_regions,
hostmem->num_current_regions,
sizeof(hostmem->current_regions[0]),
hostmem_lookup_cmp);
if (!region) {
goto out;
}
if (is_write && region->readonly) {
goto out;
}
offset_within_region = phys - region->guest_addr;
if (len <= region->size - offset_within_region) {
host_addr = region->host_addr + offset_within_region;
}
out:
qemu_mutex_unlock(&hostmem->current_regions_lock);
return host_addr;
}
/**
* Install new regions list
*/
static void hostmem_listener_commit(MemoryListener *listener)
{
HostMem *hostmem = container_of(listener, HostMem, listener);
int i;
qemu_mutex_lock(&hostmem->current_regions_lock);
for (i = 0; i < hostmem->num_current_regions; i++) {
memory_region_unref(hostmem->current_regions[i].mr);
}
g_free(hostmem->current_regions);
hostmem->current_regions = hostmem->new_regions;
hostmem->num_current_regions = hostmem->num_new_regions;
qemu_mutex_unlock(&hostmem->current_regions_lock);
/* Reset new regions list */
hostmem->new_regions = NULL;
hostmem->num_new_regions = 0;
}
/**
* Add a MemoryRegionSection to the new regions list
*/
static void hostmem_append_new_region(HostMem *hostmem,
MemoryRegionSection *section)
{
void *ram_ptr = memory_region_get_ram_ptr(section->mr);
size_t num = hostmem->num_new_regions;
size_t new_size = (num + 1) * sizeof(hostmem->new_regions[0]);
hostmem->new_regions = g_realloc(hostmem->new_regions, new_size);
hostmem->new_regions[num] = (HostMemRegion){
.host_addr = ram_ptr + section->offset_within_region,
.guest_addr = section->offset_within_address_space,
.size = int128_get64(section->size),
.readonly = section->readonly,
.mr = section->mr,
};
hostmem->num_new_regions++;
memory_region_ref(section->mr);
}
static void hostmem_listener_append_region(MemoryListener *listener,
MemoryRegionSection *section)
{
HostMem *hostmem = container_of(listener, HostMem, listener);
/* Ignore non-RAM regions, we may not be able to map them */
if (!memory_region_is_ram(section->mr)) {
return;
}
/* Ignore regions with dirty logging, we cannot mark them dirty */
if (memory_region_is_logging(section->mr)) {
return;
}
hostmem_append_new_region(hostmem, section);
}
/* We don't implement most MemoryListener callbacks, use these nop stubs */
static void hostmem_listener_dummy(MemoryListener *listener)
{
}
static void hostmem_listener_section_dummy(MemoryListener *listener,
MemoryRegionSection *section)
{
}
static void hostmem_listener_eventfd_dummy(MemoryListener *listener,
MemoryRegionSection *section,
bool match_data, uint64_t data,
EventNotifier *e)
{
}
static void hostmem_listener_coalesced_mmio_dummy(MemoryListener *listener,
MemoryRegionSection *section,
hwaddr addr, hwaddr len)
{
}
void hostmem_init(HostMem *hostmem)
{
memset(hostmem, 0, sizeof(*hostmem));
qemu_mutex_init(&hostmem->current_regions_lock);
hostmem->listener = (MemoryListener){
.begin = hostmem_listener_dummy,
.commit = hostmem_listener_commit,
.region_add = hostmem_listener_append_region,
.region_del = hostmem_listener_section_dummy,
.region_nop = hostmem_listener_append_region,
.log_start = hostmem_listener_section_dummy,
.log_stop = hostmem_listener_section_dummy,
.log_sync = hostmem_listener_section_dummy,
.log_global_start = hostmem_listener_dummy,
.log_global_stop = hostmem_listener_dummy,
.eventfd_add = hostmem_listener_eventfd_dummy,
.eventfd_del = hostmem_listener_eventfd_dummy,
.coalesced_mmio_add = hostmem_listener_coalesced_mmio_dummy,
.coalesced_mmio_del = hostmem_listener_coalesced_mmio_dummy,
.priority = 10,
};
memory_listener_register(&hostmem->listener, &address_space_memory);
if (hostmem->num_new_regions > 0) {
hostmem_listener_commit(&hostmem->listener);
}
}
void hostmem_finalize(HostMem *hostmem)
{
memory_listener_unregister(&hostmem->listener);
g_free(hostmem->new_regions);
g_free(hostmem->current_regions);
qemu_mutex_destroy(&hostmem->current_regions_lock);
}

78
hw/virtio/dataplane/vring.c
View File

@ -15,9 +15,53 @@
*/
#include "trace.h"
#include "hw/hw.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "hw/virtio/dataplane/vring.h"
#include "qemu/error-report.h"
/* vring_map can be coupled with vring_unmap or (if you still have the
* value returned in *mr) memory_region_unref.
*/
static void *vring_map(MemoryRegion **mr, hwaddr phys, hwaddr len,
bool is_write)
{
MemoryRegionSection section = memory_region_find(get_system_memory(), phys, len);
if (!section.mr || int128_get64(section.size) < len) {
goto out;
}
if (is_write && section.readonly) {
goto out;
}
if (!memory_region_is_ram(section.mr)) {
goto out;
}
/* Ignore regions with dirty logging, we cannot mark them dirty */
if (memory_region_is_logging(section.mr)) {
goto out;
}
*mr = section.mr;
return memory_region_get_ram_ptr(section.mr) + section.offset_within_region;
out:
memory_region_unref(section.mr);
*mr = NULL;
return NULL;
}
static void vring_unmap(void *buffer, bool is_write)
{
ram_addr_t addr;
MemoryRegion *mr;
mr = qemu_ram_addr_from_host(buffer, &addr);
memory_region_unref(mr);
}
/* Map the guest's vring to host memory */
bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
{
@ -27,8 +71,7 @@ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
vring->broken = false;
hostmem_init(&vring->hostmem);
vring_ptr = hostmem_lookup(&vring->hostmem, vring_addr, vring_size, true);
vring_ptr = vring_map(&vring->mr, vring_addr, vring_size, true);
if (!vring_ptr) {
error_report("Failed to map vring "
"addr %#" HWADDR_PRIx " size %" HWADDR_PRIu,
@ -54,7 +97,7 @@ void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
virtio_queue_set_last_avail_idx(vdev, n, vring->last_avail_idx);
virtio_queue_invalidate_signalled_used(vdev, n);
hostmem_finalize(&vring->hostmem);
memory_region_unref(vring->mr);
}
/* Disable guest->host notifies */
@ -117,6 +160,7 @@ static int get_desc(Vring *vring, VirtQueueElement *elem,
unsigned *num;
struct iovec *iov;
hwaddr *addr;
MemoryRegion *mr;
if (desc->flags & VRING_DESC_F_WRITE) {
num = &elem->in_num;
@ -141,14 +185,16 @@ static int get_desc(Vring *vring, VirtQueueElement *elem,
}
/* TODO handle non-contiguous memory across region boundaries */
iov->iov_base = hostmem_lookup(&vring->hostmem, desc->addr, desc->len,
desc->flags & VRING_DESC_F_WRITE);
iov->iov_base = vring_map(&mr, desc->addr, desc->len,
desc->flags & VRING_DESC_F_WRITE);
if (!iov->iov_base) {
error_report("Failed to map descriptor addr %#" PRIx64 " len %u",
(uint64_t)desc->addr, desc->len);
return -EFAULT;
}
/* The MemoryRegion is looked up again and unref'ed later, leave the
* ref in place. */
iov->iov_len = desc->len;
*addr = desc->addr;
*num += 1;
@ -183,11 +229,12 @@ static int get_indirect(Vring *vring, VirtQueueElement *elem,
do {
struct vring_desc *desc_ptr;
MemoryRegion *mr;
/* Translate indirect descriptor */
desc_ptr = hostmem_lookup(&vring->hostmem,
indirect->addr + found * sizeof(desc),
sizeof(desc), false);
desc_ptr = vring_map(&mr,
indirect->addr + found * sizeof(desc),
sizeof(desc), false);
if (!desc_ptr) {
error_report("Failed to map indirect descriptor "
"addr %#" PRIx64 " len %zu",
@ -197,6 +244,7 @@ static int get_indirect(Vring *vring, VirtQueueElement *elem,
return -EFAULT;
}
desc = *desc_ptr;
memory_region_unref(mr);
/* Ensure descriptor has been loaded before accessing fields */
barrier(); /* read_barrier_depends(); */
@ -226,6 +274,20 @@ static int get_indirect(Vring *vring, VirtQueueElement *elem,
void vring_free_element(VirtQueueElement *elem)
{
int i;
/* This assumes that the iovecs, if changed, are never moved past
* the end of the valid area. This is true if iovec manipulations
* are done with iov_discard_front and iov_discard_back.
*/
for (i = 0; i < elem->out_num; i++) {
vring_unmap(elem->out_sg[i].iov_base, false);
}
for (i = 0; i < elem->in_num; i++) {
vring_unmap(elem->in_sg[i].iov_base, true);
}
g_slice_free(VirtQueueElement, elem);
}

58
include/hw/virtio/dataplane/hostmem.h
View File

@ -1,58 +0,0 @@
/*
* Thread-safe guest to host memory mapping
*
* Copyright 2012 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Stefan Hajnoczi <stefanha@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef HOSTMEM_H
#define HOSTMEM_H
#include "exec/memory.h"
#include "qemu/thread.h"
typedef struct {
MemoryRegion *mr;
void *host_addr;
hwaddr guest_addr;
uint64_t size;
bool readonly;
} HostMemRegion;
typedef struct {
/* The listener is invoked when regions change and a new list of regions is
* built up completely before they are installed.
*/
MemoryListener listener;
HostMemRegion *new_regions;
size_t num_new_regions;
/* Current regions are accessed from multiple threads either to lookup
* addresses or to install a new list of regions. The lock protects the
* pointer and the regions.
*/
QemuMutex current_regions_lock;
HostMemRegion *current_regions;
size_t num_current_regions;
} HostMem;
void hostmem_init(HostMem *hostmem);
void hostmem_finalize(HostMem *hostmem);
/**
* Map a guest physical address to a pointer
*
* Note that there is map/unmap mechanism here. The caller must ensure that
* mapped memory is no longer used across events like hot memory unplug. This
* can be done with other mechanisms like bdrv_drain_all() that quiesce
* in-flight I/O.
*/
void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write);
#endif /* HOSTMEM_H */

3
include/hw/virtio/dataplane/vring.h
View File

@ -19,11 +19,10 @@
#include <linux/virtio_ring.h>
#include "qemu-common.h"
#include "hostmem.h"
#include "hw/virtio/virtio.h"
typedef struct {
HostMem hostmem; /* guest memory mapper */
MemoryRegion *mr; /* memory region containing the vring */
struct vring vr; /* virtqueue vring mapped to host memory */
uint16_t last_avail_idx; /* last processed avail ring index */
uint16_t last_used_idx; /* last processed used ring index */