|
From: | Antonios Motakis |
Subject: | Re: [Qemu-devel] [PATCH v5 1/7] Convert -mem-path to QemuOpts and add prealloc, share and unlink properties |
Date: | Fri, 10 Jan 2014 12:05:57 +0100 |
On Thu, Jan 09, 2014 at 03:59:55PM +0100, Antonios Motakis wrote:typos
> 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
> - unlink=on|off - default on, inlink the file after openinng it
If we don't unlink, what will?
>
> Signed-off-by: Antonios Motakis <address@hidden>
> Signed-off-by: Nikolay Nikolaev <address@hidden>
> ---
> exec.c | 57 +++++++++++++++++++++++++++++++++++++++++---------
> include/exec/cpu-all.h | 3 ---
> qemu-options.hx | 10 +++++++--
> vl.c | 41 +++++++++++++++++++++++++++++++-----
> 4 files changed, 91 insertions(+), 20 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 7e49e8e..30f4019 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -957,6 +957,7 @@ void qemu_mutex_unlock_ramlist(void)
> #include <sys/vfs.h>
>
> #define HUGETLBFS_MAGIC 0x958458f6
> +#define MIN_HUGE_PAGE_SIZE (2*1024*1024)
>
> static long gethugepagesize(const char *path)
> {
> @@ -972,8 +973,9 @@ static long gethugepagesize(const char *path)
> return 0;
> }
>
> - if (fs.f_type != HUGETLBFS_MAGIC)
> - fprintf(stderr, "Warning: path not on HugeTLBFS: %s\n", path);
> + if (fs.f_type != HUGETLBFS_MAGIC) {
> + return 0;
> + }
>
> return fs.f_bsize;
> }
> @@ -994,11 +996,14 @@ 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, mem_unlink = 1;
>
> hpagesize = gethugepagesize(path);
> if (!hpagesize) {
> - return NULL;
> + hpagesize = MIN_HUGE_PAGE_SIZE;
> }
>
> if (memory < hpagesize) {
> @@ -1010,6 +1015,14 @@ 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);
> + mem_unlink = qemu_opt_get_bool(opts, "unlink", 1);
> + }
> +
> /* Make name safe to use with mkstemp by replacing '/' with '_'. */
> sanitized_name = g_strdup(block->mr->name);
> for (c = sanitized_name; *c != '\0'; c++) {
> @@ -1017,20 +1030,28 @@ static void *file_ram_alloc(RAMBlock *block,
> *c = '_';
> }
>
> - filename = g_strdup_printf("%s/qemu_back_mem.%s.XXXXXX", path,
> - sanitized_name);
> + filename = g_strdup_printf("%s/qemu_back_mem.%s%s", path, sanitized_name,
> + (mem_unlink) ? ".XXXXXX" : "");
> g_free(sanitized_name);
>
> - fd = mkstemp(filename);
> + if (mem_unlink) {
> + fd = mkstemp(filename);
> + } else {
> + fd = open(filename, O_CREAT | O_RDWR | O_EXCL,
> + S_IRWXU | S_IRWXG | S_IRWXO);
> + }
> if (fd < 0) {
> - perror("unable to create backing store for hugepages");
> + perror("unable to create guest RAM backing store");
> g_free(filename);
> return NULL;
> }
> - unlink(filename);
> +
> + if (mem_unlink) {
> + 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
> @@ -1041,7 +1062,8 @@ 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);
> @@ -1211,11 +1233,18 @@ 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;
>
> size = TARGET_PAGE_ALIGN(size);
> 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;
> @@ -1348,6 +1377,14 @@ 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 b6998f0..4f8e989 100644
> --- a/include/exec/cpu-all.h
> +++ b/include/exec/cpu-all.h
> @@ -467,9 +467,6 @@ 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 bcfe9ea..0d35c9c 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -221,9 +221,15 @@ 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][,unlink=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"
> + " unlink= enable unlinking the guest RAM files [default enabled]\n",
> + QEMU_ARCH_ALL)
> STEXI
> address@hidden -mem-path @var{path}
> address@hidden -mem-path address@hidden,prealloc=on|off][,share=on|off][,unlink=on|off]
> address@hidden -mem-path
> Allocate guest RAM from a temporarily created file in @var{path}.
> ETEXI
> diff --git a/vl.c b/vl.c
> index 7511e70..4a52e0d 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 +529,31 @@ 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,
> + },
> + {
> + .name = "unlink",
> + .type = QEMU_OPT_BOOL,
> + },
> + { /* end of list */ }
> + },
> +};
> +
> /**
> * Get machine options
> *
> @@ -2892,6 +2915,7 @@ 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();
>
> @@ -3209,11 +3233,18 @@ 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
>
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