[Libguestfs] [PATCH] lib: direct: Remove support for virtio-blk as the default.
Richard W.M. Jones
rjones at redhat.com
Wed Apr 19 10:00:17 UTC 2017
virtio-scsi has been supported in qemu since 2012, and it is superior
in every respect to virtio-blk. There's no reason to still be using
virtio-blk.
virtio-scsi support was initially added in 2012
(commit 0c0a7d0d868d153adf0600189f771459e1068b0a).
You can still use virtio-blk using the (deprecated) iface parameter,
but don't do that in new code.
---
lib/guestfs-internal.h | 1 -
lib/launch-direct.c | 87 ++++++++++++++------------------------------------
lib/qemu.c | 47 ---------------------------
3 files changed, 24 insertions(+), 111 deletions(-)
diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
index 5e9d97c07..a04ccff09 100644
--- a/lib/guestfs-internal.h
+++ b/lib/guestfs-internal.h
@@ -983,7 +983,6 @@ struct qemu_data;
extern struct qemu_data *guestfs_int_test_qemu (guestfs_h *g, struct version *qemu_version);
extern int guestfs_int_qemu_supports (guestfs_h *g, const struct qemu_data *, const char *option);
extern int guestfs_int_qemu_supports_device (guestfs_h *g, const struct qemu_data *, const char *device_name);
-extern int guestfs_int_qemu_supports_virtio_scsi (guestfs_h *g, struct qemu_data *, const struct version *qemu_version);
extern char *guestfs_int_drive_source_qemu_param (guestfs_h *g, const struct drive_source *src);
extern bool guestfs_int_discard_possible (guestfs_h *g, struct drive *drv, const struct version *qemu_version);
extern char *guestfs_int_qemu_escape_param (guestfs_h *g, const char *param);
diff --git a/lib/launch-direct.c b/lib/launch-direct.c
index db9b9f3ef..b0038c6a9 100644
--- a/lib/launch-direct.c
+++ b/lib/launch-direct.c
@@ -60,7 +60,7 @@ struct backend_direct_data {
};
static int is_openable (guestfs_h *g, const char *path, int flags);
-static char *make_appliance_dev (guestfs_h *g, int virtio_scsi);
+static char *make_appliance_dev (guestfs_h *g);
static void print_qemu_command_line (guestfs_h *g, char **argv);
static char *
@@ -234,7 +234,6 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
CLEANUP_FREE void *buf = NULL;
struct drive *drv;
size_t i;
- int virtio_scsi;
struct hv_param *hp;
bool has_kvm;
int force_tcg;
@@ -336,14 +335,10 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
ADD_CMDLINE (g->hv);
/* CVE-2011-4127 mitigation: Disable SCSI ioctls on virtio-blk
- * devices. The -global option must exist, but you can pass any
- * strings to it so we don't need to check for the specific virtio
- * feature.
+ * devices.
*/
- if (guestfs_int_qemu_supports (g, data->qemu_data, "-global")) {
- ADD_CMDLINE ("-global");
- ADD_CMDLINE (VIRTIO_BLK ".scsi=off");
- }
+ ADD_CMDLINE ("-global");
+ ADD_CMDLINE (VIRTIO_BLK ".scsi=off");
if (guestfs_int_qemu_supports (g, data->qemu_data, "-nodefconfig"))
ADD_CMDLINE ("-nodefconfig");
@@ -461,16 +456,11 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
ADD_CMDLINE ("virtio-rng-pci,rng=rng0");
}
- /* Add drives */
- virtio_scsi = guestfs_int_qemu_supports_virtio_scsi (g, data->qemu_data,
- &data->qemu_version);
-
- if (virtio_scsi) {
- /* Create the virtio-scsi bus. */
- ADD_CMDLINE ("-device");
- ADD_CMDLINE (VIRTIO_SCSI ",id=scsi");
- }
+ /* Create the virtio-scsi bus. */
+ ADD_CMDLINE ("-device");
+ ADD_CMDLINE (VIRTIO_SCSI ",id=scsi");
+ /* Add drives */
ITER_DRIVES (g, i, drv) {
CLEANUP_FREE char *file = NULL, *escaped_file = NULL, *param = NULL;
@@ -529,10 +519,14 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
}
/* If there's an explicit 'iface', use it. Otherwise default to
- * virtio-scsi if available. Otherwise default to virtio-blk.
+ * virtio-scsi.
*/
- if (drv->iface && STREQ (drv->iface, "virtio")) /* virtio-blk */
- goto virtio_blk;
+ if (drv->iface && STREQ (drv->iface, "virtio")) { /* virtio-blk */
+ ADD_CMDLINE ("-drive");
+ ADD_CMDLINE_PRINTF ("%s,if=none" /* sic */, param);
+ ADD_CMDLINE ("-device");
+ ADD_CMDLINE_PRINTF (VIRTIO_BLK ",drive=hd%zu", i);
+ }
#if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__)
else if (drv->iface && STREQ (drv->iface, "ide")) {
error (g, "'ide' interface does not work on ARM or PowerPC");
@@ -543,19 +537,12 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
ADD_CMDLINE ("-drive");
ADD_CMDLINE_PRINTF ("%s,if=%s", param, drv->iface);
}
- else if (virtio_scsi) {
+ else /* virtio-scsi */ {
ADD_CMDLINE ("-drive");
ADD_CMDLINE_PRINTF ("%s,if=none" /* sic */, param);
ADD_CMDLINE ("-device");
ADD_CMDLINE_PRINTF ("scsi-hd,drive=hd%zu", i);
}
- else {
- virtio_blk:
- ADD_CMDLINE ("-drive");
- ADD_CMDLINE_PRINTF ("%s,if=none" /* sic */, param);
- ADD_CMDLINE ("-device");
- ADD_CMDLINE_PRINTF (VIRTIO_BLK ",drive=hd%zu", i);
- }
}
/* Add the ext2 appliance drive (after all the drives). */
@@ -565,16 +552,10 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
"cache=unsafe,if=none,format=raw",
appliance);
- if (virtio_scsi) {
- ADD_CMDLINE ("-device");
- ADD_CMDLINE ("scsi-hd,drive=appliance");
- }
- else {
- ADD_CMDLINE ("-device");
- ADD_CMDLINE (VIRTIO_BLK ",drive=appliance");
- }
+ ADD_CMDLINE ("-device");
+ ADD_CMDLINE ("scsi-hd,drive=appliance");
- appliance_dev = make_appliance_dev (g, virtio_scsi);
+ appliance_dev = make_appliance_dev (g);
}
/* Create the virtio serial bus. */
@@ -881,25 +862,18 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
* NULL, "ide" or "virtio" (which means virtio-blk). See RHBZ#975797.
*/
static char *
-make_appliance_dev (guestfs_h *g, int virtio_scsi)
+make_appliance_dev (guestfs_h *g)
{
size_t i, index = 0;
struct drive *drv;
- char dev[64] = "/dev/Xd";
+ char dev[64] = "/dev/sd";
/* Calculate the index of the drive. */
ITER_DRIVES (g, i, drv) {
- if (virtio_scsi) {
- if (drv->iface == NULL || STREQ (drv->iface, "ide"))
- index++;
- }
- else /* virtio-blk */ {
- if (drv->iface == NULL || STRNEQ (drv->iface, "virtio"))
- index++;
- }
+ if (drv->iface == NULL || STREQ (drv->iface, "ide"))
+ index++;
}
- dev[5] = virtio_scsi ? 's' : 'v';
guestfs_int_drive_name (index, &dev[7]);
return safe_strdup (g, dev); /* Caller frees. */
@@ -1012,20 +986,7 @@ get_pid_direct (guestfs_h *g, void *datav)
static int
max_disks_direct (guestfs_h *g, void *datav)
{
- struct backend_direct_data *data = datav;
-
- /* Get qemu help text and version. */
- if (data->qemu_data == NULL) {
- data->qemu_data = guestfs_int_test_qemu (g, &data->qemu_version);
- if (data->qemu_data == NULL)
- return -1;
- }
-
- if (guestfs_int_qemu_supports_virtio_scsi (g, data->qemu_data,
- &data->qemu_version))
- return 255;
- else
- return 27; /* conservative estimate */
+ return 255;
}
static struct backend_ops backend_direct_ops = {
diff --git a/lib/qemu.c b/lib/qemu.c
index 6d8fe3594..8bec6bab0 100644
--- a/lib/qemu.c
+++ b/lib/qemu.c
@@ -46,9 +46,6 @@
struct qemu_data {
char *qemu_help; /* Output of qemu -help. */
char *qemu_devices; /* Output of qemu -device ? */
-
- int virtio_scsi; /* See function
- guestfs_int_qemu_supports_virtio_scsi */
};
static int test_qemu (guestfs_h *g, struct qemu_data *data, struct version *qemu_version);
@@ -303,50 +300,6 @@ guestfs_int_qemu_supports_device (guestfs_h *g,
return strstr (data->qemu_devices, device_name) != NULL;
}
-static int
-old_or_broken_virtio_scsi (const struct version *qemu_version)
-{
- /* qemu 1.1 claims to support virtio-scsi but in reality it's broken. */
- if (!guestfs_int_version_ge (qemu_version, 1, 2, 0))
- return 1;
-
- return 0;
-}
-
-/**
- * Test if qemu supports virtio-scsi.
- *
- * Returns C<1> = use virtio-scsi, or C<0> = use virtio-blk.
- */
-int
-guestfs_int_qemu_supports_virtio_scsi (guestfs_h *g, struct qemu_data *data,
- const struct version *qemu_version)
-{
- int r;
-
- /* data->virtio_scsi has these values:
- * 0 = untested (after handle creation)
- * 1 = supported
- * 2 = not supported (use virtio-blk)
- * 3 = test failed (use virtio-blk)
- */
- if (data->virtio_scsi == 0) {
- if (old_or_broken_virtio_scsi (qemu_version))
- data->virtio_scsi = 2;
- else {
- r = guestfs_int_qemu_supports_device (g, data, VIRTIO_SCSI);
- if (r > 0)
- data->virtio_scsi = 1;
- else if (r == 0)
- data->virtio_scsi = 2;
- else
- data->virtio_scsi = 3;
- }
- }
-
- return data->virtio_scsi == 1;
-}
-
/**
* Escape a qemu parameter.
*
--
2.12.0
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