Extend -mem-path with additional properties:
- prealloc=on|off - default off, same as -mem-prealloc
- share=on|off - default off, memory is mmapped with MAP_SHARED flag
Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
---
exec.c | 30 ++++++++++++++++++++++++++++--
include/exec/cpu-all.h | 3 ---
qemu-options.hx | 9 +++++++--
vl.c | 37 ++++++++++++++++++++++++++++++++-----
4 files changed, 67 insertions(+), 12 deletions(-)
diff --git a/exec.c b/exec.c
index 2435d9e..324f3d8 100644
--- a/exec.c
+++ b/exec.c
@@ -990,7 +990,10 @@ static void *file_ram_alloc(RAMBlock *block,
char *c;
void *area;
int fd;
+ int flags;
unsigned long hpagesize;
+ QemuOpts *opts;
+ unsigned int mem_prealloc = 0, mem_share = 0;
hpagesize = gethugepagesize(path);
if (!hpagesize) {
@@ -1006,6 +1009,13 @@ static void *file_ram_alloc(RAMBlock *block,
return NULL;
}
+ /* Fill config options */
+ opts = qemu_opts_find(qemu_find_opts("mem-path"), NULL);
+ if (opts) {
+ mem_prealloc = qemu_opt_get_bool(opts, "prealloc", 0);
+ mem_share = qemu_opt_get_bool(opts, "share", 0);
+ }
+
/* Make name safe to use with mkstemp by replacing '/' with '_'. */
sanitized_name = g_strdup(block->mr->name);
for (c = sanitized_name; *c != '\0'; c++) {
@@ -1026,7 +1036,7 @@ static void *file_ram_alloc(RAMBlock *block,
unlink(filename);
g_free(filename);
- memory = (memory+hpagesize-1) & ~(hpagesize-1);
+ memory = (memory + hpagesize - 1) & ~(hpagesize - 1);
/*
* ftruncate is not supported by hugetlbfs in older
@@ -1037,7 +1047,8 @@ static void *file_ram_alloc(RAMBlock *block,
if (ftruncate(fd, memory))
perror("ftruncate");
- area = mmap(0, memory, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ flags = mem_share ? MAP_SHARED : MAP_PRIVATE;
+ area = mmap(0, memory, PROT_READ | PROT_WRITE, flags, fd, 0);
if (area == MAP_FAILED) {
perror("file_ram_alloc: can't mmap RAM pages");
close(fd);
@@ -1207,6 +1218,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void
*host,
MemoryRegion *mr)
{
RAMBlock *block, *new_block;
+ QemuOpts *opts;
+ const char *mem_path = 0;
ram_addr_t old_ram_size, new_ram_size;
old_ram_size = last_ram_offset() >> TARGET_PAGE_BITS;
@@ -1215,6 +1228,11 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void
*host,
new_block = g_malloc0(sizeof(*new_block));
new_block->fd = -1;
+ opts = qemu_opts_find(qemu_find_opts("mem-path"), NULL);
+ if (opts) {
+ mem_path = qemu_opt_get(opts, "path");
+ }
+
/* This assumes the iothread lock is taken here too. */
qemu_mutex_lock_ramlist();
new_block->mr = mr;
@@ -1353,6 +1371,14 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
ram_addr_t offset;
int flags;
void *area, *vaddr;
+ QemuOpts *opts;
+ unsigned int mem_prealloc = 0;
+
+ /* Fill config options */
+ opts = qemu_opts_find(qemu_find_opts("mem-path"), NULL);
+ if (opts) {
+ mem_prealloc = qemu_opt_get_bool(opts, "prealloc", 0);
+ }
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
offset = addr - block->offset;
diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 4cb4b4a..b46055d 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -468,9 +468,6 @@ typedef struct RAMList {
} RAMList;
extern RAMList ram_list;
-extern const char *mem_path;
-extern int mem_prealloc;
-
/* Flags stored in the low bits of the TLB virtual address. These are
defined so that fast path ram access is all zeros. */
/* Zero if TLB entry is valid. */
diff --git a/qemu-options.hx b/qemu-options.hx
index 56e5fdf..60ecc95 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -221,9 +221,14 @@ gigabytes respectively.
ETEXI
DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
- "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
+ "-mem-path [path=]path[,prealloc=on|off][,share=on|off]\n"
+ " provide backing storage for guest RAM\n"
+ " path= a directory path for the backing store\n"
+ " prealloc= preallocate guest memory [default disabled]\n"
+ " share= enable mmap share flag [default disabled]\n",
+ QEMU_ARCH_ALL)
STEXI
-@item -mem-path @var{path}
+@item -mem-path [path=]@var{path}[,prealloc=on|off][,share=on|off]
@findex -mem-path
Allocate guest RAM from a temporarily created file in @var{path}.
ETEXI
diff --git a/vl.c b/vl.c
index 2b47866..7e67cdd 100644
--- a/vl.c
+++ b/vl.c
@@ -187,8 +187,6 @@ DisplayType display_type = DT_DEFAULT;
static int display_remote;
const char* keyboard_layout = NULL;
ram_addr_t ram_size;
-const char *mem_path = NULL;
-int mem_prealloc = 0; /* force preallocation of physical target memory */
int nb_nics;
NICInfo nd_table[MAX_NICS];
int autostart;
@@ -531,6 +529,27 @@ static QemuOptsList qemu_msg_opts = {
},
};
+static QemuOptsList qemu_mem_path_opts = {
+ .name = "mem-path",
+ .implied_opt_name = "path",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_mem_path_opts.head),
+ .desc = {
+ {
+ .name = "path",
+ .type = QEMU_OPT_STRING,
+ },
+ {
+ .name = "prealloc",
+ .type = QEMU_OPT_BOOL,
+ },
+ {
+ .name = "share",
+ .type = QEMU_OPT_BOOL,
+ },
+ { /* end of list */ }
+ },
+};
+
/**
* Get machine options
*
@@ -2895,6 +2914,7 @@ int main(int argc, char **argv, char **envp)
qemu_add_opts(&qemu_tpmdev_opts);
qemu_add_opts(&qemu_realtime_opts);
qemu_add_opts(&qemu_msg_opts);
+ qemu_add_opts(&qemu_mem_path_opts);
runstate_init();
@@ -3212,11 +3232,18 @@ int main(int argc, char **argv, char **envp)
break;
#endif
case QEMU_OPTION_mempath:
- mem_path = optarg;
+ if (!qemu_opts_parse(qemu_find_opts("mem-path"), optarg, 1)) {
+ exit(1);
+ }
break;
- case QEMU_OPTION_mem_prealloc:
- mem_prealloc = 1;
+ case QEMU_OPTION_mem_prealloc: {
+ QemuOpts *mem_opts = qemu_opts_find(qemu_find_opts("mem-path"),
+ NULL);
+ if (mem_opts) {
+ qemu_opt_set(mem_opts, "prealloc", "on");
+ }
break;
+ }
case QEMU_OPTION_d:
log_mask = optarg;
break;
--
1.8.3.2
