/*
* HAX memory mapping operations
*
* Copyright (c) 2015-16 Intel Corporation
* Copyright 2016 Google, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/address-spaces.h"
#include "exec/exec-all.h"
#include "qemu/error-report.h"
#include "target/i386/hax-i386.h"
#include "qemu/queue.h"
#define DEBUG_HAX_MEM 0
#define DPRINTF(fmt, ...) \
do { \
if (DEBUG_HAX_MEM) { \
fprintf(stdout, fmt, ## __VA_ARGS__); \
} \
} while (0)
/**
* HAXMapping: describes a pending guest physical memory mapping
*
* @start_pa: a guest physical address marking the start of the region; must be
* page-aligned
* @size: a guest physical address marking the end of the region; must be
* page-aligned
* @host_va: the host virtual address of the start of the mapping
* @flags: mapping parameters e.g. HAX_RAM_INFO_ROM or HAX_RAM_INFO_INVALID
* @entry: additional fields for linking #HAXMapping instances together
*/
typedef struct HAXMapping {
uint64_t start_pa;
uint32_t size;
uint64_t host_va;
int flags;
QTAILQ_ENTRY(HAXMapping) entry;
} HAXMapping;
/*
* A doubly-linked list (actually a tail queue) of the pending page mappings
* for the ongoing memory transaction.
*
* It is used to optimize the number of page mapping updates done through the
* kernel module. For example, it's effective when a driver is digging an MMIO
* hole inside an existing memory mapping. It will get a deletion of the whole
* region, then the addition of the 2 remaining RAM areas around the hole and
* finally the memory transaction commit. During the commit, it will effectively
* send to the kernel only the removal of the pages from the MMIO hole after
* having computed locally the result of the deletion and additions.
*/
static QTAILQ_HEAD(HAXMappingListHead, HAXMapping) mappings =
QTAILQ_HEAD_INITIALIZER(mappings);
/**
* hax_mapping_dump_list: dumps @mappings to stdout (for debugging)
*/
static void hax_mapping_dump_list(void)
{
HAXMapping *entry;
DPRINTF("%s updates:\n", __func__);
QTAILQ_FOREACH(entry, &mappings, entry) {
DPRINTF("\t%c 0x%016" PRIx64 "->0x%016" PRIx64 " VA 0x%016" PRIx64
"%s\n", entry->flags & HAX_RAM_INFO_INVALID ? '-' : '+',
entry->start_pa, entry->start_pa + entry->size, entry->host_va,
entry->flags & HAX_RAM_INFO_ROM ? " ROM" : "");
}
}
static void hax_insert_mapping_before(HAXMapping *next, uint64_t start_pa,
uint32_t size, uint64_t host_va,
uint8_t flags)
{
HAXMapping *entry;
entry = g_malloc0(sizeof(*entry));
entry->start_pa = start_pa;
entry->size = size;
entry->host_va = host_va;
entry->flags = flags;
if (!next) {
QTAILQ_INSERT_TAIL(&mappings, entry, entry);
} else {
QTAILQ_INSERT_BEFORE(next, entry, entry);
}
}
static bool hax_mapping_is_opposite(HAXMapping *entry, uint64_t host_va,
uint8_t flags)
{
/* removed then added without change for the read-only flag */
bool nop_flags = (entry->flags ^ flags) == HAX_RAM_INFO_INVALID;
return (entry->host_va == host_va) && nop_flags;
}
static void hax_update_mapping(uint64_t start_pa, uint32_t size,
uint64_t host_va, uint8_t flags)
{
uint64_t end_pa = start_pa + size;
HAXMapping *entry, *next;
QTAILQ_FOREACH_SAFE(entry, &mappings, entry, next) {
uint32_t chunk_sz;
if (start_pa >= entry->start_pa + entry->size) {
continue;
}
if (start_pa < entry->start_pa) {
chunk_sz = end_pa <= entry->start_pa ? size
: entry->start_pa - start_pa;
hax_insert_mapping_before(entry, start_pa, chunk_sz,
host_va, flags);
start_pa += chunk_sz;
host_va += chunk_sz;
size -= chunk_sz;
} else if (start_pa > entry->start_pa) {
/* split the existing chunk at start_pa */
chunk_sz = start_pa - entry->start_pa;
hax_insert_mapping_before(entry, entry->start_pa, chunk_sz,
entry->host_va, entry->flags);
entry->start_pa += chunk_sz;
entry->host_va += chunk_sz;
entry->size -= chunk_sz;
}
/* now start_pa == entry->start_pa */
chunk_sz = MIN(size, entry->size);
if (chunk_sz) {
bool nop = hax_mapping_is_opposite(entry, host_va, flags);
bool partial = chunk_sz < entry->size;
if (partial) {
/* remove the beginning of the existing chunk */
entry->start_pa += chunk_sz;
entry->host_va += chunk_sz;
entry->size -= chunk_sz;
if (!nop) {
hax_insert_mapping_before(entry, start_pa, chunk_sz,
host_va, flags);
}
} else { /* affects the full mapping entry */
if (nop) { /* no change to this mapping, remove it */
QTAILQ_REMOVE(&mappings, entry, entry);
g_free(entry);
} else { /* update mapping properties */
entry->host_va = host_va;
entry->flags = flags;
}
}
start_pa += chunk_sz;
host_va += chunk_sz;
size -= chunk_sz;
}
if (!size) { /* we are done */
break;
}
}
if (size) { /* add the leftover */
hax_insert_mapping_before(NULL, start_pa, size, host_va, flags);
}
}
static void hax_process_section(MemoryRegionSection *section, uint8_t flags)
{
MemoryRegion *mr = section->mr;
hwaddr start_pa = section->offset_within_address_space;
ram_addr_t size = int128_get64(section->size);
unsigned int delta;
uint64_t host_va;
/* We only care about RAM and ROM regions */
if (!memory_region_is_ram(mr)) {
if (memory_region_is_romd(mr)) {
/* HAXM kernel module does not support ROMD yet */
warn_report("Ignoring ROMD region 0x%016" PRIx64 "->0x%016" PRIx64,
start_pa, start_pa + size);
}
return;
}
/* Adjust start_pa and size so that they are page-aligned. (Cf
* kvm_set_phys_mem() in kvm-all.c).
*/
delta = qemu_real_host_page_size - (start_pa & ~qemu_real_host_page_mask);
delta &= ~qemu_real_host_page_mask;
if (delta > size) {
return;
}
start_pa += delta;
size -= delta;
size &= qemu_real_host_page_mask;
if (!size || (start_pa & ~qemu_real_host_page_mask)) {
return;
}
host_va = (uintptr_t)memory_region_get_ram_ptr(mr)
+ section->offset_within_region + delta;
if (memory_region_is_rom(section->mr)) {
flags |= HAX_RAM_INFO_ROM;
}
/* the kernel module interface uses 32-bit sizes (but we could split...) */
g_assert(size <= UINT32_MAX);
hax_update_mapping(start_pa, size, host_va, flags);
}
static void hax_region_add(MemoryListener *listener,
MemoryRegionSection *section)
{
memory_region_ref(section->mr);
hax_process_section(section, 0);
}
static void hax_region_del(MemoryListener *listener,
MemoryRegionSection *section)
{
hax_process_section(section, HAX_RAM_INFO_INVALID);
memory_region_unref(section->mr);
}
static void hax_transaction_begin(MemoryListener *listener)
{
g_assert(QTAILQ_EMPTY(&mappings));
}
static void hax_transaction_commit(MemoryListener *listener)
{
if (!QTAILQ_EMPTY(&mappings)) {
HAXMapping *entry, *next;
if (DEBUG_HAX_MEM) {
hax_mapping_dump_list();
}
QTAILQ_FOREACH_SAFE(entry, &mappings, entry, next) {
if (entry->flags & HAX_RAM_INFO_INVALID) {
/* for unmapping, put the values expected by the kernel */
entry->flags = HAX_RAM_INFO_INVALID;
entry->host_va = 0;
}
if (hax_set_ram(entry->start_pa, entry->size,
entry->host_va, entry->flags)) {
fprintf(stderr, "%s: Failed mapping @0x%016" PRIx64 "+0x%"
PRIx32 " flags %02x\n", __func__, entry->start_pa,
entry->size, entry->flags);
}
QTAILQ_REMOVE(&mappings, entry, entry);
g_free(entry);
}
}
}
/* currently we fake the dirty bitmap sync, always dirty */
static void hax_log_sync(MemoryListener *listener,
MemoryRegionSection *section)
{
MemoryRegion *mr = section->mr;
if (!memory_region_is_ram(mr)) {
/* Skip MMIO regions */
return;
}
memory_region_set_dirty(mr, 0, int128_get64(section->size));
}
static MemoryListener hax_memory_listener = {
.begin = hax_transaction_begin,
.commit = hax_transaction_commit,
.region_add = hax_region_add,
.region_del = hax_region_del,
.log_sync = hax_log_sync,
.priority = 10,
};
static void hax_ram_block_added(RAMBlockNotifier *n, void *host, size_t size)
{
/*
* In HAX, QEMU allocates the virtual address, and HAX kernel
* populates the memory with physical memory. Currently we have no
* paging, so user should make sure enough free memory in advance.
*/
if (hax_populate_ram((uint64_t)(uintptr_t)host, size) < 0) {
fprintf(stderr, "HAX failed to populate RAM");
abort();
}
}
static struct RAMBlockNotifier hax_ram_notifier = {
.ram_block_added = hax_ram_block_added,
};
void hax_memory_init(void)
{
ram_block_notifier_add(&hax_ram_notifier);
memory_listener_register(&hax_memory_listener, &address_space_memory);
}
