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[Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize |
Date: |
Mon, 17 Nov 2014 22:08:53 +0200 |
Add API to manage on-device RAM.
This looks just like regular RAM from migration POV,
but has two special properties internally:
- it is never exposed to guest
- block is sized on migration, making it easier to extend
without breaking migration compatibility or wasting
virtual memory
- callers must specify an upper bound on size
Device is notified on resize, so it can adjust if necessary.
qemu_ram_alloc_device allocates this memory, qemu_ram_resize resizes it.
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
include/exec/cpu-all.h | 8 +++-
include/exec/ram_addr.h | 7 +++
exec.c | 113 +++++++++++++++++++++++++++++++++++++++++++-----
3 files changed, 115 insertions(+), 13 deletions(-)
diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 62f5581..26eb9b2 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -299,11 +299,15 @@ CPUArchState *cpu_copy(CPUArchState *env);
/* memory API */
-typedef struct RAMBlock {
+typedef struct RAMBlock RAMBlock;
+
+struct RAMBlock {
struct MemoryRegion *mr;
uint8_t *host;
ram_addr_t offset;
ram_addr_t length;
+ ram_addr_t max_length;
+ void (*resized)(const char*, uint64_t length, void *host);
uint32_t flags;
char idstr[256];
/* Reads can take either the iothread or the ramlist lock.
@@ -311,7 +315,7 @@ typedef struct RAMBlock {
*/
QTAILQ_ENTRY(RAMBlock) next;
int fd;
-} RAMBlock;
+};
static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
{
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index d7e5238..72ab12b 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -28,12 +28,19 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
MemoryRegion *mr, Error **errp);
ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp);
+ram_addr_t qemu_ram_alloc_device(ram_addr_t size, ram_addr_t max_size,
+ void (*resized)(const char*,
+ uint64_t length,
+ void *host),
+ MemoryRegion *mr, Error **errp);
int qemu_get_ram_fd(ram_addr_t addr);
void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
void *qemu_get_ram_ptr(ram_addr_t addr);
void qemu_ram_free(ram_addr_t addr);
void qemu_ram_free_from_ptr(ram_addr_t addr);
+int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp);
+
static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
ram_addr_t length,
unsigned client)
diff --git a/exec.c b/exec.c
index 9648669..a177816 100644
--- a/exec.c
+++ b/exec.c
@@ -75,6 +75,11 @@ static MemoryRegion io_mem_unassigned;
/* RAM is mmap-ed with MAP_SHARED */
#define RAM_SHARED (1 << 1)
+/* On-device RAM allocated with g_malloc: supports realloc,
+ * not accessible to vcpu on kvm.
+ */
+#define RAM_DEVICE (1 << 2)
+
#endif
struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus);
@@ -1186,7 +1191,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
ram_addr_t end, next = RAM_ADDR_MAX;
- end = block->offset + block->length;
+ end = block->offset + block->max_length;
QTAILQ_FOREACH(next_block, &ram_list.blocks, next) {
if (next_block->offset >= end) {
@@ -1214,7 +1219,7 @@ ram_addr_t last_ram_offset(void)
ram_addr_t last = 0;
QTAILQ_FOREACH(block, &ram_list.blocks, next)
- last = MAX(last, block->offset + block->length);
+ last = MAX(last, block->offset + block->max_length);
return last;
}
@@ -1296,6 +1301,50 @@ static int memory_try_enable_merging(void *addr, size_t
len)
return qemu_madvise(addr, len, QEMU_MADV_MERGEABLE);
}
+int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
+{
+ RAMBlock *block = find_ram_block(base);
+
+ assert(block);
+
+ if (block->length == newsize) {
+ return 0;
+ }
+
+ if (!(block->flags & RAM_DEVICE)) {
+ error_setg_errno(errp, EINVAL,
+ "Length mismatch: %s: 0x" RAM_ADDR_FMT
+ " in != 0x" RAM_ADDR_FMT, block->idstr,
+ newsize, block->length);
+ return -EINVAL;
+ }
+
+ if (block->max_length < newsize) {
+ error_setg_errno(errp, EINVAL,
+ "Length too large: %s: 0x" RAM_ADDR_FMT
+ " > 0x" RAM_ADDR_FMT, block->idstr,
+ newsize, block->max_length);
+ return -EINVAL;
+ }
+
+ block->host = g_realloc(block->host, newsize);
+ if (!block->host) {
+ error_setg_errno(errp, errno,
+ "cannot allocate guest memory '%s'",
+ memory_region_name(block->mr));
+ return -ENOMEM;
+ }
+
+ cpu_physical_memory_clear_dirty_range_nocode(block->offset, block->length);
+ block->length = newsize;
+ memset(block->host, 0, block->length);
+ cpu_physical_memory_set_dirty_range_nocode(block->offset, block->length);
+ if (block->resized) {
+ block->resized(block->idstr, newsize, block->host);
+ }
+ return 0;
+}
+
static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
{
RAMBlock *block;
@@ -1308,7 +1357,16 @@ static ram_addr_t ram_block_add(RAMBlock *new_block,
Error **errp)
new_block->offset = find_ram_offset(new_block->length);
if (!new_block->host) {
- if (xen_enabled()) {
+ if (new_block->flags & RAM_DEVICE) {
+ new_block->host = g_malloc0(new_block->length);
+ if (!new_block->host) {
+ error_setg_errno(errp, errno,
+ "cannot allocate guest memory '%s'",
+ memory_region_name(new_block->mr));
+ qemu_mutex_unlock_ramlist();
+ return -1;
+ }
+ } else if (xen_enabled()) {
xen_ram_alloc(new_block->offset, new_block->length, new_block->mr);
} else {
new_block->host = phys_mem_alloc(new_block->length,
@@ -1352,12 +1410,14 @@ static ram_addr_t ram_block_add(RAMBlock *new_block,
Error **errp)
}
cpu_physical_memory_set_dirty_range(new_block->offset, new_block->length);
- qemu_ram_setup_dump(new_block->host, new_block->length);
- qemu_madvise(new_block->host, new_block->length, QEMU_MADV_HUGEPAGE);
- qemu_madvise(new_block->host, new_block->length, QEMU_MADV_DONTFORK);
+ if (!(new_block->flags & RAM_DEVICE)) {
+ qemu_ram_setup_dump(new_block->host, new_block->length);
+ qemu_madvise(new_block->host, new_block->length, QEMU_MADV_HUGEPAGE);
+ qemu_madvise(new_block->host, new_block->length, QEMU_MADV_DONTFORK);
- if (kvm_enabled()) {
- kvm_setup_guest_memory(new_block->host, new_block->length);
+ if (kvm_enabled()) {
+ kvm_setup_guest_memory(new_block->host, new_block->length);
+ }
}
return new_block->offset;
@@ -1392,6 +1452,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
new_block->length = size;
+ new_block->max_length = size;
new_block->flags = share ? RAM_SHARED : 0;
new_block->host = file_ram_alloc(new_block, size,
mem_path, errp);
@@ -1410,7 +1471,12 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
}
#endif
-ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
+static
+ram_addr_t qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
+ void (*resized)(const char*,
+ uint64_t length,
+ void *host),
+ void *host, bool device,
MemoryRegion *mr, Error **errp)
{
RAMBlock *new_block;
@@ -1418,14 +1484,21 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size,
void *host,
Error *local_err = NULL;
size = TARGET_PAGE_ALIGN(size);
+ max_size = TARGET_PAGE_ALIGN(max_size);
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
+ new_block->resized = resized;
new_block->length = size;
+ new_block->max_length = max_size;
+ assert(max_size >= size);
new_block->fd = -1;
new_block->host = host;
if (host) {
new_block->flags |= RAM_PREALLOC;
}
+ if (device) {
+ new_block->flags |= RAM_DEVICE;
+ }
addr = ram_block_add(new_block, &local_err);
if (local_err) {
g_free(new_block);
@@ -1435,9 +1508,24 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void
*host,
return addr;
}
+ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
+ MemoryRegion *mr, Error **errp)
+{
+ return qemu_ram_alloc_internal(size, size, NULL, host, false, mr, errp);
+}
+
ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp)
{
- return qemu_ram_alloc_from_ptr(size, NULL, mr, errp);
+ return qemu_ram_alloc_internal(size, size, NULL, NULL, false, mr, errp);
+}
+
+ram_addr_t qemu_ram_alloc_device(ram_addr_t size, ram_addr_t maxsz,
+ void (*resized)(const char*,
+ uint64_t length,
+ void *host),
+ MemoryRegion *mr, Error **errp)
+{
+ return qemu_ram_alloc_internal(size, maxsz, resized, NULL, true, mr, errp);
}
void qemu_ram_free_from_ptr(ram_addr_t addr)
@@ -1471,6 +1559,8 @@ void qemu_ram_free(ram_addr_t addr)
ram_list.version++;
if (block->flags & RAM_PREALLOC) {
;
+ } else if (block->flags & RAM_DEVICE) {
+ g_free(block->host);
} else if (xen_enabled()) {
xen_invalidate_map_cache_entry(block->host);
#ifndef _WIN32
@@ -1501,7 +1591,8 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
offset = addr - block->offset;
if (offset < block->length) {
vaddr = ramblock_ptr(block, offset);
- if (block->flags & RAM_PREALLOC) {
+ if (block->flags & RAM_PREALLOC ||
+ block->flags & RAM_DEVICE) {
;
} else if (xen_enabled()) {
abort();
--
MST
- [Qemu-devel] [PATCH 0/5] pc: make ROMs resizeable, Michael S. Tsirkin, 2014/11/17
- [Qemu-devel] [PATCH 1/5] cpu: add cpu_physical_memory_clear_dirty_range_nocode, Michael S. Tsirkin, 2014/11/17
- [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize,
Michael S. Tsirkin <=
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Michael S. Tsirkin, 2014/11/17
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Paolo Bonzini, 2014/11/18
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Michael S. Tsirkin, 2014/11/18
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Juan Quintela, 2014/11/19
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Michael S. Tsirkin, 2014/11/19
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Juan Quintela, 2014/11/19
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Michael S. Tsirkin, 2014/11/19
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Juan Quintela, 2014/11/19
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Michael S. Tsirkin, 2014/11/19
- Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize, Paolo Bonzini, 2014/11/19