This commit adds a support to utilize exising UML drivers of block
devices for LKL. The goal is similar to networking drivers, add minimum
amount of code and use drivers code as-is.
This commit also adds a test code with several filesystems (ext4, vfat,
btrfs at the moment) to exercise the basic operations of disk.
Signed-off-by: Hajime Tazaki <thehajime@xxxxxxxxx>
---
arch/um/drivers/ubd_kern.c | 6 +++++-
arch/um/lkl/Kconfig | 3 +++
arch/um/lkl/include/uapi/asm/syscalls.h | 1 +
arch/um/lkl/kernel/setup.c | 5 +++++
tools/lkl/include/lkl.h | 15 +++++++++++++++
tools/lkl/lib/um/Build | 1 +
tools/lkl/lib/um/um_block.c | 17 +++++++++++++++++
tools/lkl/lib/um/um_glue.c | 24 +++++++++++++++++++++++-
tools/lkl/tests/disk.c | 14 ++++++++++++++
9 files changed, 84 insertions(+), 2 deletions(-)
create mode 100644 tools/lkl/lib/um/um_block.c
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index eae8c83364f7..248bac8e36b8 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -545,7 +545,7 @@ static irqreturn_t ubd_intr(int irq, void *dev)
/* Only changed by ubd_init, which is an initcall. */
static int io_pid = -1;
-static void kill_io_thread(void)
+void kill_io_thread(void)
{
if(io_pid != -1)
os_kill_process(io_pid, 1);
@@ -819,6 +819,7 @@ static int ubd_open_dev(struct ubd *ubd_dev)
}
ubd_dev->fd = fd;
+#ifdef CONFIG_UMMODE_KERN
if(ubd_dev->cow.file != NULL){
blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long));
@@ -843,6 +844,7 @@ static int ubd_open_dev(struct ubd *ubd_dev)
if(err < 0) goto error;
ubd_dev->cow.fd = err;
}
+#endif /* CONFIG_UMMODE_KERN */
if (ubd_dev->no_trim == 0) {
ubd_dev->queue->limits.discard_granularity = SECTOR_SIZE;
ubd_dev->queue->limits.discard_alignment = SECTOR_SIZE;
@@ -852,9 +854,11 @@ static int ubd_open_dev(struct ubd *ubd_dev)
}
blk_queue_flag_set(QUEUE_FLAG_NONROT, ubd_dev->queue);
return 0;
+#ifdef CONFIG_UMMODE_KERN
error:
os_close_file(ubd_dev->fd);
return err;
+#endif
}
static void ubd_device_release(struct device *dev)
diff --git a/arch/um/lkl/Kconfig b/arch/um/lkl/Kconfig
index 2b6b4063045c..8e4e0a465fc8 100644
--- a/arch/um/lkl/Kconfig
+++ b/arch/um/lkl/Kconfig
@@ -48,6 +48,9 @@ config OUTPUT_FORMAT
config ARCH_DMA_ADDR_T_64BIT
def_bool 64BIT
+config BLK_DEV_UBD
+ def_bool y if "$(OUTPUT_FORMAT)" = "elf32-i386" || "$(OUTPUT_FORMAT)" = "elf64-x86-64"
+
config X86_64
def_bool y if "$(OUTPUT_FORMAT)" = "elf64-x86-64"
diff --git a/arch/um/lkl/include/uapi/asm/syscalls.h b/arch/um/lkl/include/uapi/asm/syscalls.h
index a81534ffccb7..1384c34137d6 100644
--- a/arch/um/lkl/include/uapi/asm/syscalls.h
+++ b/arch/um/lkl/include/uapi/asm/syscalls.h
@@ -164,6 +164,7 @@ struct sockaddr {
#include <linux/virtio_ring.h>
#include <linux/pkt_sched.h>
#include <linux/io_uring.h>
+#include <linux/major.h>
struct user_msghdr {
void __user *msg_name;
diff --git a/arch/um/lkl/kernel/setup.c b/arch/um/lkl/kernel/setup.c
index 39b7b7c79581..daf55c216db9 100644
--- a/arch/um/lkl/kernel/setup.c
+++ b/arch/um/lkl/kernel/setup.c
@@ -126,6 +126,11 @@ long lkl_sys_halt(void)
LINUX_REBOOT_CMD_RESTART,
};
+#ifdef CONFIG_BLK_DEV_UBD
+void kill_io_thread(void);
+ kill_io_thread();
+#endif
+
err = lkl_syscall(__NR_reboot, params);
if (err < 0)
return err;
diff --git a/tools/lkl/include/lkl.h b/tools/lkl/include/lkl.h
index 952d11e30868..7d164e4dcad1 100644
--- a/tools/lkl/include/lkl.h
+++ b/tools/lkl/include/lkl.h
@@ -355,6 +355,10 @@ void lkl_perror(char *msg, int err);
*/
struct lkl_dev_blk_ops;
+enum {
+ BLK_BACKEND_UM,
+};
+
/**
* lkl_disk - host disk handle
*
@@ -368,6 +372,7 @@ struct lkl_disk {
int fd;
void *handle;
};
+ int backend;
struct lkl_dev_blk_ops *ops;
};
@@ -403,6 +408,16 @@ int lkl_disk_remove(struct lkl_disk disk);
*/
int lkl_encode_dev_from_sysfs(const char *sysfs_path, uint32_t *pdevid);
+
+#ifdef LKL_HOST_CONFIG_UML_DEV
+int lkl_disk_um_add(struct lkl_disk *disk, const char *blkparams);
+#else
+static inline int lkl_disk_um_add(struct lkl_disk *disk, const char *blkparams)
+{
+ return -LKL_ENOSYS;
+}
+#endif
+
/**
* lkl_mount_dev - mount a disk
*
diff --git a/tools/lkl/lib/um/Build b/tools/lkl/lib/um/Build
index 09a60975ecd6..52573c05a797 100644
--- a/tools/lkl/lib/um/Build
+++ b/tools/lkl/lib/um/Build
@@ -1,2 +1,3 @@
liblkl-y += um_glue.o
liblkl-y += um_net.o
+liblkl-y += um_block.o
diff --git a/tools/lkl/lib/um/um_block.c b/tools/lkl/lib/um/um_block.c
new file mode 100644
index 000000000000..70dc624ec43c
--- /dev/null
+++ b/tools/lkl/lib/um/um_block.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <lkl_host.h>
+
+
+static int registered_blk_dev_idx;
+
+int lkl_disk_um_add(struct lkl_disk *disk, const char *blkparams)
+{
+ /* concat strings */
+ snprintf(lkl_um_devs + strlen(lkl_um_devs), sizeof(lkl_um_devs),
+ " ubd%d=%s", registered_blk_dev_idx, blkparams);
+
+ return registered_blk_dev_idx++;
+}
diff --git a/tools/lkl/lib/um/um_glue.c b/tools/lkl/lib/um/um_glue.c
index f59e31a706de..fd5a338bcb9f 100644
--- a/tools/lkl/lib/um/um_glue.c
+++ b/tools/lkl/lib/um/um_glue.c
@@ -2,9 +2,10 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <signal.h>
#include <unistd.h>
#include <errno.h>
-
+#include <sys/wait.h>
char lkl_um_devs[4096];
@@ -37,3 +38,24 @@ void *um_os_signal(int signum, void *handler)
{
return signal(signum, handler);
}
+
+/* from util.c */
+/*
+ * UML helper threads must not handle SIGWINCH/INT/TERM
+ */
+void os_fix_helper_signals(void)
+{
+ signal(SIGWINCH, SIG_IGN);
+ signal(SIGINT, SIG_DFL);
+ signal(SIGTERM, SIG_DFL);
+}
+
+void os_kill_process(int pid, int reap_child)
+{
+ kill(pid, SIGKILL);
+ if (reap_child) {
+ while ((errno = 0, ((waitpid(pid, NULL, __WALL)) < 0))
+ && (errno == EINTR))
+ ;
+ }
+}
diff --git a/tools/lkl/tests/disk.c b/tools/lkl/tests/disk.c
index 0aa039876b54..f7801014d054 100644
--- a/tools/lkl/tests/disk.c
+++ b/tools/lkl/tests/disk.c
@@ -23,12 +23,17 @@ static struct {
const char *disk;
const char *fstype;
int partition;
+ int backend;
} cla;
+const char *backends[] = { "um", NULL };
+
struct cl_arg args[] = {
{"disk", 'd', "disk file to use", 1, CL_ARG_STR, &cla.disk},
{"partition", 'P', "partition to mount", 1, CL_ARG_INT, &cla.partition},
{"type", 't', "filesystem type", 1, CL_ARG_STR, &cla.fstype},
+ {"backend", 'b', "blockd evice backend type", 1, CL_ARG_STR_SET,
+ &cla.backend, backends},
{0},
};
@@ -50,6 +55,15 @@ int lkl_test_disk_add(void)
disk.ops = NULL;
+ disk.backend = cla.backend;
+
+ switch (disk.backend) {
+ case BLK_BACKEND_UM:
+ disk.dev = (char *)cla.disk;
+ default:
+ break;
+ }
+
disk_id = lkl_disk_add(&disk);
if (disk_id < 0)
goto out_close;
--
2.21.0 (Apple Git-122.2)
