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06ddecff24
qemu/include/exec/ram_addr.h
David Hildenbrand 5c52a219bb softmmu/physmem: Distinguish between file access mode and mmap protection 
There is a difference between how we open a file and how we mmap it,
and we want to support writable private mappings of readonly files. Let's
define RAM_READONLY and RAM_READONLY_FD flags, to replace the single
"readonly" parameter for file-related functions.

In memory_region_init_ram_from_fd() and memory_region_init_ram_from_file(),
initialize mr->readonly based on the new RAM_READONLY flag.

While at it, add some RAM_* flags we missed to add to the list of accepted
flags in the documentation of some functions.

No change in functionality intended. We'll make use of both flags next
and start setting them independently for memory-backend-file.

Message-ID: <20230906120503.359863-3-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
2023-09-19 10:23:21 +02:00

540 lines
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/*
* Declarations for cpu physical memory functions
*
* Copyright 2011 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Avi Kivity <avi@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.
*
*/
/*
* This header is for use by exec.c and memory.c ONLY. Do not include it.
* The functions declared here will be removed soon.
*/
#ifndef RAM_ADDR_H
#define RAM_ADDR_H
#ifndef CONFIG_USER_ONLY
#include "cpu.h"
#include "sysemu/xen.h"
#include "sysemu/tcg.h"
#include "exec/ramlist.h"
#include "exec/ramblock.h"
extern uint64_t total_dirty_pages;
/**
* clear_bmap_size: calculate clear bitmap size
*
* @pages: number of guest pages
* @shift: guest page number shift
*
* Returns: number of bits for the clear bitmap
*/
static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
{
return DIV_ROUND_UP(pages, 1UL << shift);
}
/**
* clear_bmap_set: set clear bitmap for the page range. Must be with
* bitmap_mutex held.
*
* @rb: the ramblock to operate on
* @start: the start page number
* @size: number of pages to set in the bitmap
*
* Returns: None
*/
static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
uint64_t npages)
{
uint8_t shift = rb->clear_bmap_shift;
bitmap_set(rb->clear_bmap, start >> shift, clear_bmap_size(npages, shift));
}
/**
* clear_bmap_test_and_clear: test clear bitmap for the page, clear if set.
* Must be with bitmap_mutex held.
*
* @rb: the ramblock to operate on
* @page: the page number to check
*
* Returns: true if the bit was set, false otherwise
*/
static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
{
uint8_t shift = rb->clear_bmap_shift;
return bitmap_test_and_clear(rb->clear_bmap, page >> shift, 1);
}
static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
{
return (b && b->host && offset < b->used_length) ? true : false;
}
static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
{
assert(offset_in_ramblock(block, offset));
return (char *)block->host + offset;
}
static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
RAMBlock *rb)
{
uint64_t host_addr_offset =
(uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
return host_addr_offset >> TARGET_PAGE_BITS;
}
bool ramblock_is_pmem(RAMBlock *rb);
long qemu_minrampagesize(void);
long qemu_maxrampagesize(void);
/**
* qemu_ram_alloc_from_file,
* qemu_ram_alloc_from_fd: Allocate a ram block from the specified backing
* file or device
*
* Parameters:
* @size: the size in bytes of the ram block
* @mr: the memory region where the ram block is
* @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
* RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
* RAM_READONLY_FD
* @mem_path or @fd: specify the backing file or device
* @offset: Offset into target file
* @errp: pointer to Error*, to store an error if it happens
*
* Return:
* On success, return a pointer to the ram block.
* On failure, return NULL.
*/
RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, const char *mem_path,
off_t offset, Error **errp);
RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, int fd, off_t offset,
Error **errp);
RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
MemoryRegion *mr, Error **errp);
RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
Error **errp);
RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
void (*resized)(const char*,
uint64_t length,
void *host),
MemoryRegion *mr, Error **errp);
void qemu_ram_free(RAMBlock *block);
int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
/* Clear whole block of mem */
static inline void qemu_ram_block_writeback(RAMBlock *block)
{
qemu_ram_msync(block, 0, block->used_length);
}
#define DIRTY_CLIENTS_ALL ((1 << DIRTY_MEMORY_NUM) - 1)
#define DIRTY_CLIENTS_NOCODE (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
ram_addr_t length,
unsigned client)
{
DirtyMemoryBlocks *blocks;
unsigned long end, page;
unsigned long idx, offset, base;
bool dirty = false;
assert(client < DIRTY_MEMORY_NUM);
end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
page = start >> TARGET_PAGE_BITS;
WITH_RCU_READ_LOCK_GUARD() {
blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
idx = page / DIRTY_MEMORY_BLOCK_SIZE;
offset = page % DIRTY_MEMORY_BLOCK_SIZE;
base = page - offset;
while (page < end) {
unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
unsigned long num = next - base;
unsigned long found = find_next_bit(blocks->blocks[idx],
num, offset);
if (found < num) {
dirty = true;
break;
}
page = next;
idx++;
offset = 0;
base += DIRTY_MEMORY_BLOCK_SIZE;
}
}
return dirty;
}
static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
ram_addr_t length,
unsigned client)
{
DirtyMemoryBlocks *blocks;
unsigned long end, page;
unsigned long idx, offset, base;
bool dirty = true;
assert(client < DIRTY_MEMORY_NUM);
end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
page = start >> TARGET_PAGE_BITS;
RCU_READ_LOCK_GUARD();
blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
idx = page / DIRTY_MEMORY_BLOCK_SIZE;
offset = page % DIRTY_MEMORY_BLOCK_SIZE;
base = page - offset;
while (page < end) {
unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
unsigned long num = next - base;
unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
if (found < num) {
dirty = false;
break;
}
page = next;
idx++;
offset = 0;
base += DIRTY_MEMORY_BLOCK_SIZE;
}
return dirty;
}
static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
unsigned client)
{
return cpu_physical_memory_get_dirty(addr, 1, client);
}
static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
{
bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
bool migration =
cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
return !(vga && code && migration);
}
static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
ram_addr_t length,
uint8_t mask)
{
uint8_t ret = 0;
if (mask & (1 << DIRTY_MEMORY_VGA) &&
!cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
ret |= (1 << DIRTY_MEMORY_VGA);
}
if (mask & (1 << DIRTY_MEMORY_CODE) &&
!cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
ret |= (1 << DIRTY_MEMORY_CODE);
}
if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
!cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
ret |= (1 << DIRTY_MEMORY_MIGRATION);
}
return ret;
}
static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
unsigned client)
{
unsigned long page, idx, offset;
DirtyMemoryBlocks *blocks;
assert(client < DIRTY_MEMORY_NUM);
page = addr >> TARGET_PAGE_BITS;
idx = page / DIRTY_MEMORY_BLOCK_SIZE;
offset = page % DIRTY_MEMORY_BLOCK_SIZE;
RCU_READ_LOCK_GUARD();
blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
set_bit_atomic(offset, blocks->blocks[idx]);
}
static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
ram_addr_t length,
uint8_t mask)
{
DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
unsigned long end, page;
unsigned long idx, offset, base;
int i;
if (!mask && !xen_enabled()) {
return;
}
end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
page = start >> TARGET_PAGE_BITS;
WITH_RCU_READ_LOCK_GUARD() {
for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
}
idx = page / DIRTY_MEMORY_BLOCK_SIZE;
offset = page % DIRTY_MEMORY_BLOCK_SIZE;
base = page - offset;
while (page < end) {
unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
offset, next - page);
}
if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
offset, next - page);
}
if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
offset, next - page);
}
page = next;
idx++;
offset = 0;
base += DIRTY_MEMORY_BLOCK_SIZE;
}
}
xen_hvm_modified_memory(start, length);
}
#if !defined(_WIN32)
/*
* Contrary to cpu_physical_memory_sync_dirty_bitmap() this function returns
* the number of dirty pages in @bitmap passed as argument. On the other hand,
* cpu_physical_memory_sync_dirty_bitmap() returns newly dirtied pages that
* weren't set in the global migration bitmap.
*/
static inline
uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
ram_addr_t start,
ram_addr_t pages)
{
unsigned long i, j;
unsigned long page_number, c, nbits;
hwaddr addr;
ram_addr_t ram_addr;
uint64_t num_dirty = 0;
unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
/* start address is aligned at the start of a word? */
if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
(hpratio == 1)) {
unsigned long **blocks[DIRTY_MEMORY_NUM];
unsigned long idx;
unsigned long offset;
long k;
long nr = BITS_TO_LONGS(pages);
idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
DIRTY_MEMORY_BLOCK_SIZE);
WITH_RCU_READ_LOCK_GUARD() {
for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
blocks[i] =
qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
}
for (k = 0; k < nr; k++) {
if (bitmap[k]) {
unsigned long temp = leul_to_cpu(bitmap[k]);
nbits = ctpopl(temp);
qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
if (global_dirty_tracking) {
qatomic_or(
&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
temp);
if (unlikely(
global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
total_dirty_pages += nbits;
}
}
num_dirty += nbits;
if (tcg_enabled()) {
qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
temp);
}
}
if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
offset = 0;
idx++;
}
}
}
xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
} else {
uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
if (!global_dirty_tracking) {
clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
}
/*
* bitmap-traveling is faster than memory-traveling (for addr...)
* especially when most of the memory is not dirty.
*/
for (i = 0; i < len; i++) {
if (bitmap[i] != 0) {
c = leul_to_cpu(bitmap[i]);
nbits = ctpopl(c);
if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
total_dirty_pages += nbits;
}
num_dirty += nbits;
do {
j = ctzl(c);
c &= ~(1ul << j);
page_number = (i * HOST_LONG_BITS + j) * hpratio;
addr = page_number * TARGET_PAGE_SIZE;
ram_addr = start + addr;
cpu_physical_memory_set_dirty_range(ram_addr,
TARGET_PAGE_SIZE * hpratio, clients);
} while (c != 0);
}
}
}
return num_dirty;
}
#endif /* not _WIN32 */
bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
ram_addr_t length,
unsigned client);
DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
(MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
ram_addr_t start,
ram_addr_t length);
static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
ram_addr_t length)
{
cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
}
/* Called with RCU critical section */
static inline
uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
ram_addr_t start,
ram_addr_t length)
{
ram_addr_t addr;
unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
uint64_t num_dirty = 0;
unsigned long *dest = rb->bmap;
/* start address and length is aligned at the start of a word? */
if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
(start + rb->offset) &&
!(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
int k;
int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
unsigned long * const *src;
unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
DIRTY_MEMORY_BLOCK_SIZE);
unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
src = qatomic_rcu_read(
&ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
for (k = page; k < page + nr; k++) {
if (src[idx][offset]) {
unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
unsigned long new_dirty;
new_dirty = ~dest[k];
dest[k] |= bits;
new_dirty &= bits;
num_dirty += ctpopl(new_dirty);
}
if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
offset = 0;
idx++;
}
}
if (rb->clear_bmap) {
/*
* Postpone the dirty bitmap clear to the point before we
* really send the pages, also we will split the clear
* dirty procedure into smaller chunks.
*/
clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
length >> TARGET_PAGE_BITS);
} else {
/* Slow path - still do that in a huge chunk */
memory_region_clear_dirty_bitmap(rb->mr, start, length);
}
} else {
ram_addr_t offset = rb->offset;
for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
if (cpu_physical_memory_test_and_clear_dirty(
start + addr + offset,
TARGET_PAGE_SIZE,
DIRTY_MEMORY_MIGRATION)) {
long k = (start + addr) >> TARGET_PAGE_BITS;
if (!test_and_set_bit(k, dest)) {
num_dirty++;
}
}
}
}
return num_dirty;
}
#endif
#endif
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