kvm tools: Add cmdline options for loading multiple images

Introduced new syntax for loading disk images.
Example:

./kvm run --image image1.img,ro --image image2.img

Will load image1.img with read only, and image2.img as
read/write.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/include/kvm/parse-options.h b/tools/kvm/include/kvm/parse-options.h
index 5d8c618c28cdac4230698737941892679dd9d5e4..2d5c99e73a4e8e6dca5d4736cda4ba4c5eabe464 100644 (file)
--- a/tools/kvm/include/kvm/parse-options.h
+++ b/tools/kvm/include/kvm/parse-options.h
@@ -138,6 +138,41 @@ intptr_t defval;
        .help = (h)                         \
 }
 
+#define OPT_CALLBACK(s, l, v, a, h, f)      \
+{                                          \
+       .type = OPTION_CALLBACK,            \
+       .short_name = (s),                  \
+       .long_name = (l),                   \
+       .value = (v),                       \
+       (a),                                \
+       .help = (h),                        \
+       .callback = (f)                     \
+}
+
+#define OPT_CALLBACK_NOOPT(s, l, v, a, h, f) \
+{                                          \
+       .type = OPTION_CALLBACK,            \
+       .short_name = (s),                  \
+       .long_name = (l),                   \
+       .value = (v),                       \
+       (a),                                \
+       .help = (h),                        \
+       .callback = (f),                    \
+       .flags = PARSE_OPT_NOARG            \
+}
+
+#define OPT_CALLBACK_DEFAULT(s, l, v, a, h, f, d) \
+{                                          \
+       .type = OPTION_CALLBACK,            \
+       .short_name = (s),                  \
+       .long_name = (l),                   \
+       .value = (v), (a),                  \
+       .help = (h),                        \
+       .callback = (f),                    \
+       .defval = (intptr_t)d,              \
+       .flags = PARSE_OPT_LASTARG_DEFAULT  \
+}
+
 #define OPT_END() { .type = OPTION_END }
 
 enum {

diff --git a/tools/kvm/kvm-run.c b/tools/kvm/kvm-run.c
index b92232d8795609838978c9479fee5baf6d017330..2182dc5e0612923cf27680a5df6323c6c76f51cc 100644 (file)
--- a/tools/kvm/kvm-run.c
+++ b/tools/kvm/kvm-run.c
@@ -42,16 +42,18 @@
 #define MB_SHIFT               (20)
 #define MIN_RAM_SIZE_MB                (64ULL)
 #define MIN_RAM_SIZE_BYTE      (MIN_RAM_SIZE_MB << MB_SHIFT)
+#define MAX_DISK_IMAGES                4
 
 static struct kvm *kvm;
 static struct kvm_cpu *kvm_cpus[KVM_NR_CPUS];
 static __thread struct kvm_cpu *current_kvm_cpu;
 
 static u64 ram_size = MIN_RAM_SIZE_MB;
+static u8  image_count;
 static const char *kernel_cmdline;
 static const char *kernel_filename;
 static const char *initrd_filename;
-static const char *image_filename;
+static const char *image_filename[MAX_DISK_IMAGES];
 static const char *console;
 static const char *kvm_dev;
 static const char *network;
@@ -59,7 +61,7 @@ static const char *host_ip_addr;
 static const char *guest_mac;
 static const char *script;
 static bool single_step;
-static bool readonly_image;
+static bool readonly_image[MAX_DISK_IMAGES];
 static bool virtio_rng;
 extern bool ioport_debug;
 extern int  active_console;
@@ -71,13 +73,31 @@ static const char * const run_usage[] = {
        NULL
 };
 
+static int img_name_parser(const struct option *opt, const char *arg, int unset)
+{
+       char *sep;
+
+       if (image_count >= MAX_DISK_IMAGES)
+               die("Currently only 4 images are supported");
+
+       image_filename[image_count] = arg;
+       sep = strstr(arg, ",");
+       if (sep) {
+               if (strcmp(sep + 1, "ro") == 0)
+                       readonly_image[image_count] = 1;
+               *sep = 0;
+       }
+
+       image_count++;
+
+       return 0;
+}
+
 static const struct option options[] = {
        OPT_GROUP("Basic options:"),
        OPT_INTEGER('\0', "cpus", &nrcpus, "Number of CPUs"),
        OPT_U64('m', "mem", &ram_size, "Virtual machine memory size in MiB."),
-       OPT_STRING('i', "image", &image_filename, "image", "Disk image"),
-       OPT_BOOLEAN('\0', "readonly", &readonly_image,
-                       "Don't write changes back to disk image"),
+       OPT_CALLBACK('i', "image", NULL, "image", "Disk image", img_name_parser),
        OPT_STRING('c', "console", &console, "serial or virtio",
                        "Console to use"),
        OPT_BOOLEAN('\0', "virtio-rng", &virtio_rng,
@@ -397,23 +417,25 @@ int kvm_cmd_run(int argc, const char **argv, const char *prefix)
                strlcat(real_cmdline, kernel_cmdline, sizeof(real_cmdline));
 
        hi = NULL;
-       if (!image_filename) {
+       if (!image_filename[0]) {
                hi = host_image(real_cmdline, sizeof(real_cmdline));
                if (hi) {
-                       image_filename = hi;
-                       readonly_image = true;
+                       image_filename[0] = hi;
+                       readonly_image[0] = true;
                }
        }
 
        if (!strstr(real_cmdline, "root="))
                strlcat(real_cmdline, " root=/dev/vda rw ", sizeof(real_cmdline));
 
-       if (image_filename) {
-               struct disk_image *disk = disk_image__open(image_filename, readonly_image);
-               if (!disk)
-                       die("unable to load disk image %s", image_filename);
+       for (i = 0; i < image_count; i++) {
+               if (image_filename[i]) {
+                       struct disk_image *disk = disk_image__open(image_filename[i], readonly_image[i]);
+                       if (!disk)
+                               die("unable to load disk image %s", image_filename[i]);
 
-               virtio_blk__init(kvm, disk);
+                       virtio_blk__init(kvm, disk);
+               }
        }
        free(hi);