Support multiple virtio block devices

.ci/boot-linux.sh

@@ -61,6 +61,20 @@ if [ "${ENABLE_VBLK}" -eq "1" ]; then
         expect "# " { send "\x01"; send "x" } timeout { exit 3 }
     ')
 
+    # multiple blocks, Read-only, one disk image, one loop device (/dev/loopx(Linux) or /dev/diskx(Darwin))
+    TEST_OPTIONS+=("${OPTS_BASE} -x vblk:${VBLK_IMG},readonly -x vblk:${BLK_DEV},readonly")
+    EXPECT_CMDS+=('
+        expect "buildroot login:" { send "root\n" } timeout { exit 1 }
+        expect "# " { send "uname -a\n" } timeout { exit 2 }
+        expect "riscv32 GNU/Linux" { send "mkdir mnt && mount /dev/vda mnt\n" } timeout { exit 3 }
+        expect "# " { send "echo rv32emu > mnt/emu.txt\n" } timeout { exit 3 }
+        expect -ex "-sh: can'\''t create mnt/emu.txt: Read-only file system" {} timeout { exit 3 }
+        expect "# " { send "mkdir mnt2 && mount /dev/vdb mnt2\n" } timeout { exit 3 }
+        expect "# " { send "echo rv32emu > mnt2/emu.txt\n" } timeout { exit 3 }
+        expect -ex "-sh: can'\''t create mnt2/emu.txt: Read-only file system" {} timeout { exit 3 }
+        expect "# " { send "\x01"; send "x" } timeout { exit 3 }
+    ')
+
     # Read-write using disk image
     TEST_OPTIONS+=("${OPTS_BASE} -x vblk:${VBLK_IMG}")
     VBLK_EXPECT_CMDS='
@@ -77,6 +91,23 @@ if [ "${ENABLE_VBLK}" -eq "1" ]; then
     # Read-write using /dev/loopx(Linux) or /dev/diskx(Darwin) block device
     TEST_OPTIONS+=("${OPTS_BASE} -x vblk:${BLK_DEV}")
     EXPECT_CMDS+=("${VBLK_EXPECT_CMDS}")
+
+    # multiple blocks, Read-write, one disk image and one loop device (/dev/loopx(Linux) or /dev/diskx(Darwin))
+    TEST_OPTIONS+=("${OPTS_BASE} -x vblk:${VBLK_IMG} -x vblk:${BLK_DEV}")
+    VBLK_EXPECT_CMDS='
+        expect "buildroot login:" { send "root\n" } timeout { exit 1 }
+        expect "# " { send "uname -a\n" } timeout { exit 2 }
+        expect "riscv32 GNU/Linux" { send "mkdir mnt && mount /dev/vda mnt\n" } timeout { exit 3 }
+        expect "# " { send "echo rv32emu > mnt/emu.txt\n" } timeout { exit 3 }
+        expect "# " { send "sync\n" } timeout { exit 3 }
+        expect "# " { send "umount mnt\n" } timeout { exit 3 }
+        expect "# " { send "mkdir mnt2 && mount /dev/vdb mnt2\n" } timeout { exit 3 }
+        expect "# " { send "echo rv32emu > mnt2/emu.txt\n" } timeout { exit 3 }
+        expect "# " { send "sync\n" } timeout { exit 3 }
+        expect "# " { send "umount mnt2\n" } timeout { exit 3 }
+        expect "# " { send "\x01"; send "x" } timeout { exit 3 }
+    '
+    EXPECT_CMDS+=("${VBLK_EXPECT_CMDS}")
 fi
 
 for i in "${!TEST_OPTIONS[@]}"; do

README.md

@@ -105,6 +105,12 @@ Mount the virtual block device and create a test file after booting, note that r
 ```
 Reboot and re-mount the virtual block device, the written file should remain existing.
 
+To specify multiple virtual block devices, pass multiple `-x vblk` options when launching the emulator. Each option can point to either a disk image or a hostOS block device, with optional read-only mode. For example:
+```shell
+$ build/rv32emu -k <kernel_img_path> -i <rootfs_img_path> -x vblk:disk.img -x vblk:/dev/loop22,readonly
+```
+Note that the /dev/vdx device order in guestOS is assigned in reverse: the first `-x vblk` argument corresponds to the device with the highest letter, while subsequent arguments receive lower-lettered device names.
+
 #### Customize bootargs
 Build and run with customized bootargs to boot the guestOS. Otherwise, the default bootargs defined in `src/devices/minimal.dts` will be used.
 ```shell

src/devices/minimal.dts

@@ -66,10 +66,14 @@
             clock-frequency = <5000000>; /* the baudrate divisor is ignored */
         };
 
-        blk0: virtio@4200000 {
+        /*
+         * Virtio block example subnode
+         * The actual subnode are generated dynamically depends on the CLI -x vblk option
+         */
+        /*blk0: virtio@4100000 {
             compatible = "virtio,mmio";
-            reg = <0x4200000 0x200>;
-            interrupts = <3>;
-        };
+            reg = <0x4100000 0x200>;
+            interrupts = <2>;
+        };*/
     };
 };

src/devices/virtio-blk.c

@@ -32,9 +32,6 @@
 
 #define DISK_BLK_SIZE 512
 
-/* TODO: Enable mutiple virtio-blk devices. */
-#define VBLK_DEV_CNT_MAX 1
-
 #define VBLK_FEATURES_0 0
 #define VBLK_FEATURES_1 1 /* VIRTIO_F_VERSION_1 */
 #define VBLK_QUEUE_NUM_MAX 1024
@@ -81,9 +78,6 @@ PACKED(struct vblk_req_header {
     uint8_t status;
 });
 
-static struct virtio_blk_config vblk_configs[VBLK_DEV_CNT_MAX];
-static int vblk_dev_cnt = 0;
-
 static void virtio_blk_set_fail(virtio_blk_state_t *vblk)
 {
     vblk->status |= VIRTIO_STATUS_DEVICE_NEEDS_RESET;
@@ -401,20 +395,16 @@ uint32_t *virtio_blk_init(virtio_blk_state_t *vblk,
                           char *disk_file,
                           bool readonly)
 {
-    if (vblk_dev_cnt >= VBLK_DEV_CNT_MAX) {
-        rv_log_error(
-            "Exceeded the number of virtio-blk devices that can be allocated");
-        exit(EXIT_FAILURE);
-    }
-
     /*
      * For mmap_fallback, if vblk is not specified, disk_fd should remain -1 and
      * no fsync should be performed on exit.
      */
+
     vblk->disk_fd = -1;
 
     /* Allocate memory for the private member */
-    vblk->priv = &vblk_configs[vblk_dev_cnt++];
+    vblk->priv = calloc(1, sizeof(struct virtio_blk_config));
+    assert(vblk->priv);
 
     /* No disk image is provided */
     if (!disk_file) {
@@ -549,5 +539,6 @@ void vblk_delete(virtio_blk_state_t *vblk)
     else
         munmap(vblk->disk, VBLK_PRIV(vblk)->disk_size);
 #endif
+    free(vblk->priv);
     free(vblk);
 }

src/devices/virtio.h

@@ -76,8 +76,7 @@ struct virtq_desc {
     uint16_t next;
 };
 
-#define IRQ_VBLK_SHIFT 3
-#define IRQ_VBLK_BIT (1 << IRQ_VBLK_SHIFT)
+#define IRQ_VBLK_BIT(base, i) (1 << (base + i))
 
 typedef struct {
     uint32_t queue_num;

src/main.c

@@ -60,7 +60,10 @@ static char *prof_out_file;
 static char *opt_kernel_img;
 static char *opt_rootfs_img;
 static char *opt_bootargs;
-static char *opt_virtio_blk_img;
+/* FIXME: handle overflow */
+#define VBLK_DEV_MAX 100
+static char *opt_virtio_blk_img[VBLK_DEV_MAX];
+static int opt_virtio_blk_idx = 0;
 #endif
 
 static void print_usage(const char *filename)
@@ -78,8 +81,10 @@ static void print_usage(const char *filename)
 #if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
         "  -k <image> : use <image> as kernel image\n"
         "  -i <image> : use <image> as rootfs\n"
-        "  -x vblk:<image>[,readonly] : use <image> as virtio-blk disk image "
-        "(default read and write)\n"
+        "  -x vblk:<image>[,readonly]: use "
+        "<image> as virtio-blk disk image "
+        "(default read and write). This option may be specified "
+        "multiple times for multiple block devices\n"
         "  -b <bootargs> : use customized <bootargs> for the kernel\n"
 #endif
         "  -d [filename]: dump registers as JSON to the "
@@ -127,7 +132,8 @@ static bool parse_args(int argc, char **args)
             break;
         case 'x':
             if (!strncmp("vblk:", optarg, 5))
-                opt_virtio_blk_img = optarg + 5; /* strlen("vblk:") */
+                opt_virtio_blk_img[opt_virtio_blk_idx++] =
+                    optarg + 5; /* strlen("vblk:") */
             else
                 return false;
             emu_argc++;
@@ -273,7 +279,12 @@ int main(int argc, char **args)
     attr.data.system.kernel = opt_kernel_img;
     attr.data.system.initrd = opt_rootfs_img;
     attr.data.system.bootargs = opt_bootargs;
-    attr.data.system.vblk_device = opt_virtio_blk_img;
+    if (opt_virtio_blk_idx) {
+        attr.data.system.vblk_device = opt_virtio_blk_img;
+        attr.data.system.vblk_device_cnt = opt_virtio_blk_idx;
+    } else {
+        attr.data.system.vblk_device = NULL;
+    }
 #else
     attr.data.user.elf_program = opt_prog_name;
 #endif