Virt-df[1] has now gained the ability to fully parse LVM2 partitions,
thus:
# virt-df -c qemu:///system -h
Filesystem Size Used Available Type
rhel51x32kvm:hda1 96.8 MiB 14.6 MiB 82.2 MiB Linux ext2/3
rhel51x32kvm:VolGroup00/LogVol00 6.4 GiB 3.6 GiB 2.8 GiB Linux ext2/3
rhel51x32kvm:VolGroup00/LogVol01 992.0 MiB Linux swap
However it still has to do it by opening the local partitions / files,
which means it isn't using a "proper" part of libvirt and more
importantly it cannot run remotely.
I'd like to find out whether the time has come for us to look again at
a virDomainBlockPeek call for libvirt. Here is the original thread
plus patch from 7 months ago:
http://www.redhat.com/archives/libvir-list/2007-October/thread.html#00089
(I've attached an updated patch against current CVS).
I appreciate that some cases might not be simple (iSCSI?), but the
same argument applies to block device statistics too, and we make
those available where possible. I think a best-effort call allowing
callers to peek into the block devices of guests would be very useful.
Rich.
[1] http://hg.et.redhat.com/applications/virt/applications/virt-df--devel
--
Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
Index: configure.in
===================================================================
RCS file: /data/cvs/libvirt/configure.in,v
retrieving revision 1.139
diff -u -r1.139 configure.in
--- configure.in 8 Apr 2008 16:45:57 -0000 1.139
+++ configure.in 16 Apr 2008 15:18:07 -0000
@@ -60,6 +60,10 @@
LIBVIRT_COMPILE_WARNINGS(maximum)
+dnl Support large files / 64 bit seek offsets.
+dnl Use --disable-largefile if you don't want this.
+AC_SYS_LARGEFILE
+
dnl Availability of various common functions (non-fatal if missing).
AC_CHECK_FUNCS([cfmakeraw regexec uname])
Index: include/libvirt/libvirt.h
===================================================================
RCS file: /data/cvs/libvirt/include/libvirt/libvirt.h,v
retrieving revision 1.72
diff -u -r1.72 libvirt.h
--- include/libvirt/libvirt.h 10 Apr 2008 16:54:54 -0000 1.72
+++ include/libvirt/libvirt.h 16 Apr 2008 15:18:08 -0000
@@ -522,7 +522,11 @@
const char *path,
virDomainInterfaceStatsPtr stats,
size_t size);
-
+int virDomainBlockPeek (virDomainPtr dom,
+ const char *path,
+ long long offset,
+ size_t size,
+ void *buffer);
/*
* defined but not running domains
Index: include/libvirt/libvirt.h.in
===================================================================
RCS file: /data/cvs/libvirt/include/libvirt/libvirt.h.in,v
retrieving revision 1.47
diff -u -r1.47 libvirt.h.in
--- include/libvirt/libvirt.h.in 10 Apr 2008 16:54:54 -0000 1.47
+++ include/libvirt/libvirt.h.in 16 Apr 2008 15:18:09 -0000
@@ -522,7 +522,11 @@
const char *path,
virDomainInterfaceStatsPtr stats,
size_t size);
-
+int virDomainBlockPeek (virDomainPtr dom,
+ const char *path,
+ long long offset,
+ size_t size,
+ void *buffer);
/*
* defined but not running domains
Index: src/driver.h
===================================================================
RCS file: /data/cvs/libvirt/src/driver.h,v
retrieving revision 1.46
diff -u -r1.46 driver.h
--- src/driver.h 10 Apr 2008 16:54:54 -0000 1.46
+++ src/driver.h 16 Apr 2008 15:18:10 -0000
@@ -224,6 +224,13 @@
struct _virDomainInterfaceStats *stats);
typedef int
+ (*virDrvDomainBlockPeek)
+ (virDomainPtr domain,
+ const char *path,
+ long long offset, size_t size,
+ void *buffer);
+
+typedef int
(*virDrvDomainMigratePrepare)
(virConnectPtr dconn,
char **cookie,
@@ -335,6 +342,7 @@
virDrvDomainMigrateFinish domainMigrateFinish;
virDrvDomainBlockStats domainBlockStats;
virDrvDomainInterfaceStats domainInterfaceStats;
+ virDrvDomainBlockPeek domainBlockPeek;
virDrvNodeGetCellsFreeMemory nodeGetCellsFreeMemory;
virDrvNodeGetFreeMemory getFreeMemory;
};
Index: src/libvirt.c
===================================================================
RCS file: /data/cvs/libvirt/src/libvirt.c,v
retrieving revision 1.137
diff -u -r1.137 libvirt.c
--- src/libvirt.c 10 Apr 2008 16:54:54 -0000 1.137
+++ src/libvirt.c 16 Apr 2008 15:18:14 -0000
@@ -2573,7 +2573,78 @@
return -1;
}
+/**
+ * virDomainBlockPeek:
+ * @dom: pointer to the domain object
+ * @path: path to the block device
+ * @offset: offset within block device
+ * @size: size to read
+ * @buffer: return buffer (must be at least size bytes)
+ *
+ * This function allows you to read the contents of a domain's
+ * disk device.
+ *
+ * Typical uses for this are to determine if the domain has
+ * written a Master Boot Record (indicating that the domain
+ * has completed installation), or to try to work out the state
+ * of the domain's filesystems.
+ *
+ * (Note that in the local case you might try to open the
+ * block device or file directly, but that won't work in the
+ * remote case, nor if you don't have sufficient permission.
+ * Hence the need for this call).
+ *
+ * 'path' must be a device or file corresponding to the domain.
+ * In other words it must be the precise string returned in
+ * a <disk><source dev='...'/></disk> from
+ * virDomainGetXMLDesc.
+ *
+ * 'offset' and 'size' represent an area which must lie entirely
+ * within the device or file. 'size' may be 0 to test if the
+ * call would succeed.
+ *
+ * 'buffer' is the return buffer and must be at least 'size' bytes.
+ *
+ * Returns: 0 in case of success or -1 in case of failure.
+ */
+int
+virDomainBlockPeek (virDomainPtr dom,
+ const char *path,
+ long long offset /* really 64 bits */,
+ size_t size,
+ void *buffer)
+{
+ virConnectPtr conn;
+ DEBUG("domain=%p, path=%s, offset=%lld, size=%zi, buffer=%p",
+ dom, path, offset, size, buffer);
+
+ if (!VIR_IS_CONNECTED_DOMAIN (dom)) {
+ virLibDomainError (NULL, VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+ return -1;
+ }
+ conn = dom->conn;
+
+ if (!path) {
+ virLibDomainError (dom, VIR_ERR_INVALID_ARG, "path == NULL");
+ return -1;
+ }
+ /* Allow size == 0 as an access test. */
+ if (offset < 0) {
+ virLibDomainError (dom, VIR_ERR_INVALID_ARG,
+ "offset is negative");
+ return -1;
+ }
+ if (size > 0 && !buffer) {
+ virLibDomainError (dom, VIR_ERR_INVALID_ARG, "buffer == NULL");
+ return -1;
+ }
+
+ if (conn->driver->domainBlockPeek)
+ return conn->driver->domainBlockPeek (dom, path, offset, size, buffer);
+ virLibDomainError (dom, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+ return -1;
+}
/************************************************************************
Index: src/libvirt_sym.version
===================================================================
RCS file: /data/cvs/libvirt/src/libvirt_sym.version,v
retrieving revision 1.38
diff -u -r1.38 libvirt_sym.version
--- src/libvirt_sym.version 28 Feb 2008 17:06:32 -0000 1.38
+++ src/libvirt_sym.version 16 Apr 2008 15:18:14 -0000
@@ -73,6 +73,7 @@
virDomainSetSchedulerParameters;
virDomainBlockStats;
virDomainInterfaceStats;
+ virDomainBlockPeek;
virDomainAttachDevice;
virDomainDetachDevice;
Index: src/qemu_driver.c
===================================================================
RCS file: /data/cvs/libvirt/src/qemu_driver.c,v
retrieving revision 1.67
diff -u -r1.67 qemu_driver.c
--- src/qemu_driver.c 10 Apr 2008 16:54:54 -0000 1.67
+++ src/qemu_driver.c 16 Apr 2008 15:18:16 -0000
@@ -3064,6 +3064,7 @@
NULL, /* domainMigrateFinish */
qemudDomainBlockStats, /* domainBlockStats */
qemudDomainInterfaceStats, /* domainInterfaceStats */
+ NULL, /* domainBlockPeek */
NULL, /* nodeGetCellsFreeMemory */
NULL, /* getFreeMemory */
};
Index: src/test.c
===================================================================
RCS file: /data/cvs/libvirt/src/test.c,v
retrieving revision 1.72
diff -u -r1.72 test.c
--- src/test.c 10 Apr 2008 16:53:29 -0000 1.72
+++ src/test.c 16 Apr 2008 15:18:18 -0000
@@ -2066,6 +2066,7 @@
NULL, /* domainMigrateFinish */
NULL, /* domainBlockStats */
NULL, /* domainInterfaceStats */
+ NULL, /* domainBlockPeek */
testNodeGetCellsFreeMemory, /* nodeGetCellsFreeMemory */
NULL, /* getFreeMemory */
};
Index: src/virsh.c
===================================================================
RCS file: /data/cvs/libvirt/src/virsh.c,v
retrieving revision 1.145
diff -u -r1.145 virsh.c
--- src/virsh.c 10 Apr 2008 17:37:23 -0000 1.145
+++ src/virsh.c 16 Apr 2008 15:18:22 -0000
@@ -237,6 +237,7 @@
static vshCmdOpt *vshCommandOpt(vshCmd * cmd, const char *name);
static int vshCommandOptInt(vshCmd * cmd, const char *name, int *found);
+static long long vshCommandOptInt64(vshCmd * cmd, const char *name, int *found);
static char *vshCommandOptString(vshCmd * cmd, const char *name,
int *found);
#if 0
@@ -820,6 +821,77 @@
return TRUE;
}
+/* "domblkpeek" command
+ */
+static vshCmdInfo info_domblkpeek[] = {
+ {"syntax", "domblkpeek <domain> <path> <offset> <size>"},
+ {"help", gettext_noop("peek at a domain block device")},
+ {"desc", gettext_noop("Peek into a domain block device.")},
+ {NULL,NULL}
+};
+
+static vshCmdOptDef opts_domblkpeek[] = {
+ {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, gettext_noop("domain name, id or uuid")},
+ {"path", VSH_OT_DATA, VSH_OFLAG_REQ, gettext_noop("block device path")},
+ {"offset", VSH_OT_DATA, VSH_OFLAG_REQ, gettext_noop("start offset")},
+ {"size", VSH_OT_DATA, VSH_OFLAG_REQ, gettext_noop("size in bytes")},
+ {NULL, 0, 0, NULL}
+};
+
+static int
+cmdDomblkpeek (vshControl *ctl, vshCmd *cmd)
+{
+ virDomainPtr dom;
+ char *name, *path;
+ long long offset;
+ size_t size;
+ char *buffer = 0;
+ int found, ret = FALSE;
+
+ if (!vshConnectionUsability (ctl, ctl->conn, TRUE))
+ return FALSE;
+
+ if (!(dom = vshCommandOptDomain (ctl, cmd, "domain", &name)))
+ goto done;
+
+ if (!(path = vshCommandOptString (cmd, "path", NULL)))
+ goto done;
+
+ offset = vshCommandOptInt64 (cmd, "offset", &found);
+ if (!found) goto done;
+
+ size = vshCommandOptInt (cmd, "size", &found);
+ if (!found) goto done;
+
+ buffer = malloc (size);
+ if (!buffer) {
+ vshError (ctl, FALSE, _("Memory allocation failed for buffer"));
+ goto done;
+ }
+
+ if (virDomainBlockPeek (dom, path, offset, size, buffer) == -1) {
+ vshError (ctl, FALSE, _("Failed to peek block device %s %s"),
+ name, path);
+ goto done;
+ }
+
+ /* Dump out the memory - user can pipe into od/hexdump if they
+ * desire.
+ */
+ if (size > 0) {
+ if (fwrite (buffer, size, 1, stdout) != 1) {
+ vshError (ctl, FALSE, "write: %s", strerror (errno));
+ goto done;
+ }
+ }
+
+ ret = TRUE;
+ done:
+ if (buffer) free (buffer);
+ if (dom) virDomainFree(dom);
+ return ret;
+}
+
/*
* "suspend" command
*/
@@ -5105,6 +5177,7 @@
{"domstate", cmdDomstate, opts_domstate, info_domstate},
{"domblkstat", cmdDomblkstat, opts_domblkstat, info_domblkstat},
{"domifstat", cmdDomIfstat, opts_domifstat, info_domifstat},
+ {"domblkpeek", cmdDomblkpeek, opts_domblkpeek, info_domblkpeek},
{"dumpxml", cmdDumpXML, opts_dumpxml, info_dumpxml},
{"freecell", cmdFreecell, opts_freecell, info_freecell},
{"hostname", cmdHostname, NULL, info_hostname},
@@ -5384,6 +5457,37 @@
return res;
}
+static int
+xstrtoint64 (char const *s, int base, long long *result)
+{
+ char *p;
+
+ errno = 0;
+ *result = strtoll (s, &p, base);
+ if (errno || !(*p == 0 || *p == '\n') || p == s)
+ return -1;
+ return 0;
+}
+
+/*
+ * Returns option as 64 bit integer.
+ */
+static long long
+vshCommandOptInt64(vshCmd * cmd, const char *name, int *found)
+{
+ vshCmdOpt *arg = vshCommandOpt(cmd, name);
+ long long res;
+
+ if (arg && arg->data) {
+ if (xstrtoint64 (arg->data, 10, &res) == 0) {
+ *found = TRUE;
+ return res;
+ }
+ }
+ *found = FALSE;
+ return -1;
+}
+
/*
* Returns option as STRING
*/
Index: src/xen_unified.c
===================================================================
RCS file: /data/cvs/libvirt/src/xen_unified.c,v
retrieving revision 1.42
diff -u -r1.42 xen_unified.c
--- src/xen_unified.c 10 Apr 2008 16:54:54 -0000 1.42
+++ src/xen_unified.c 16 Apr 2008 15:18:23 -0000
@@ -1207,6 +1207,29 @@
}
static int
+xenUnifiedDomainBlockPeek (virDomainPtr dom, const char *path,
+ long long offset, size_t size,
+ void *buffer)
+{
+ int r;
+ GET_PRIVATE (dom->conn);
+
+ if (priv->opened[XEN_UNIFIED_XEND_OFFSET]) {
+ r = xenDaemonDomainBlockPeek (dom, path, offset, size, buffer);
+ if (r != -2) return r;
+ /* r == -2 means declined, so fall through to XM driver ... */
+ }
+
+ if (priv->opened[XEN_UNIFIED_XM_OFFSET]) {
+ if (xenXMDomainBlockPeek (dom, path, offset, size, buffer) == 0)
+ return 0;
+ }
+
+ xenUnifiedError (dom->conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+ return -1;
+}
+
+static int
xenUnifiedNodeGetCellsFreeMemory (virConnectPtr conn, unsigned long long *freeMems,
int startCell, int maxCells)
{
@@ -1299,6 +1322,7 @@
.domainMigrateFinish = xenUnifiedDomainMigrateFinish,
.domainBlockStats = xenUnifiedDomainBlockStats,
.domainInterfaceStats = xenUnifiedDomainInterfaceStats,
+ .domainBlockPeek = xenUnifiedDomainBlockPeek,
.nodeGetCellsFreeMemory = xenUnifiedNodeGetCellsFreeMemory,
.getFreeMemory = xenUnifiedNodeGetFreeMemory,
};
Index: src/xend_internal.c
===================================================================
RCS file: /data/cvs/libvirt/src/xend_internal.c,v
retrieving revision 1.180
diff -u -r1.180 xend_internal.c
--- src/xend_internal.c 10 Apr 2008 16:54:54 -0000 1.180
+++ src/xend_internal.c 16 Apr 2008 15:18:26 -0000
@@ -18,6 +18,8 @@
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
@@ -1376,6 +1378,213 @@
return(0);
}
+typedef int
+ (*sexp_blockdevs_cb)
+ (virConnectPtr conn, void *data,
+ int isBlock, int cdrom, int isNoSrcCdrom,
+ const char *drvName, const char *drvType,
+ const char *src, const char *dst,
+ const char *mode);
+
+/**
+ * xend_parse_sexp_blockdevs:
+ * @conn: connection
+ * @root: root sexpr
+ * @xendConfigVersion: version of xend
+ * @fn: callback function
+ * @data: optional data for callback function
+ *
+ * This parses out block devices from the domain sexpr and calls
+ * fn (conn, data, ...) for each block device found.
+ *
+ * Returns 0 if successful or -1 if failed.
+ */
+static int
+xend_parse_sexp_blockdevs (virConnectPtr conn, struct sexpr *root,
+ int xendConfigVersion,
+ sexp_blockdevs_cb fn, void *data)
+{
+ struct sexpr *cur, *node;
+ int hvm;
+
+ hvm = sexpr_lookup(root, "domain/image/hvm") ? 1 : 0;
+
+ for (cur = root; cur->kind == SEXPR_CONS; cur = cur->u.s.cdr) {
+ node = cur->u.s.car;
+ /* Normally disks are in a (device (vbd ...)) block
+ but blktap disks ended up in a differently named
+ (device (tap ....)) block.... */
+ if (sexpr_lookup(node, "device/vbd") ||
+ sexpr_lookup(node, "device/tap")) {
+ char *offset;
+ int ret = -1;
+ int isBlock = 0;
+ int cdrom = 0;
+ int isNoSrcCdrom = 0;
+ char *drvName = NULL;
+ char *drvType = NULL;
+ const char *src;
+ const char *dst;
+ const char *mode;
+
+ /* Again dealing with (vbd...) vs (tap ...) differences */
+ if (sexpr_lookup(node, "device/vbd")) {
+ src = sexpr_node(node, "device/vbd/uname");
+ dst = sexpr_node(node, "device/vbd/dev");
+ mode = sexpr_node(node, "device/vbd/mode");
+ } else {
+ src = sexpr_node(node, "device/tap/uname");
+ dst = sexpr_node(node, "device/tap/dev");
+ mode = sexpr_node(node, "device/tap/mode");
+ }
+
+ if (dst == NULL) {
+ virXendError(conn, VIR_ERR_INTERNAL_ERROR,
+ _("domain information incomplete, vbd has no dev"));
+ goto bad_parse;
+ }
+
+ if (src == NULL) {
+ /* There is a case without the uname to the CD-ROM device */
+ offset = strchr(dst, ':');
+ if (offset) {
+ if (hvm && STREQ(offset , ":cdrom")) {
+ isNoSrcCdrom = 1;
+ }
+ offset[0] = '\0';
+ }
+ if (!isNoSrcCdrom) {
+ virXendError(conn, VIR_ERR_INTERNAL_ERROR,
+ _("domain information incomplete, vbd has no src"));
+ goto bad_parse;
+ }
+ }
+
+ if (!isNoSrcCdrom) {
+ offset = strchr(src, ':');
+ if (!offset) {
+ virXendError(conn, VIR_ERR_INTERNAL_ERROR,
+ _("cannot parse vbd filename, missing driver name"));
+ goto bad_parse;
+ }
+
+ drvName = malloc((offset-src)+1);
+ if (!drvName) {
+ virXendError(conn, VIR_ERR_NO_MEMORY,
+ _("allocate new buffer"));
+ goto bad_parse;
+ }
+ strncpy(drvName, src, (offset-src));
+ drvName[offset-src] = '\0';
+
+ src = offset + 1;
+
+ if (STREQ (drvName, "tap")) {
+ offset = strchr(src, ':');
+ if (!offset) {
+ virXendError(conn, VIR_ERR_INTERNAL_ERROR,
+ _("cannot parse vbd filename, missing driver type"));
+ goto bad_parse;
+ }
+
+ drvType = malloc((offset-src)+1);
+ if (!drvType) {
+ virXendError(conn, VIR_ERR_NO_MEMORY,
+ _("allocate new buffer"));
+ goto bad_parse;
+ }
+ strncpy(drvType, src, (offset-src));
+ drvType[offset-src] = '\0';
+ src = offset + 1;
+ /* Its possible to use blktap driver for block devs
+ too, but kinda pointless because blkback is better,
+ so we assume common case here. If blktap becomes
+ omnipotent, we can revisit this, perhaps stat()'ing
+ the src file in question */
+ isBlock = 0;
+ } else if (STREQ(drvName, "phy")) {
+ isBlock = 1;
+ } else if (STREQ(drvName, "file")) {
+ isBlock = 0;
+ }
+ }
+
+ if (STREQLEN (dst, "ioemu:", 6))
+ dst += 6;
+
+ /* New style disk config from Xen >= 3.0.3 */
+ if (xendConfigVersion > 1) {
+ offset = strrchr(dst, ':');
+ if (offset) {
+ if (STREQ (offset, ":cdrom")) {
+ cdrom = 1;
+ } else if (STREQ (offset, ":disk")) {
+ /* The default anyway */
+ } else {
+ /* Unknown, lets pretend its a disk too */
+ }
+ offset[0] = '\0';
+ }
+ }
+
+ /* Call the callback function. */
+ ret = fn (conn, data, isBlock, cdrom, isNoSrcCdrom,
+ drvName, drvType, src, dst, mode);
+
+ bad_parse:
+ if (drvName)
+ free(drvName);
+ if (drvType)
+ free(drvType);
+
+ if (ret == -1) return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int
+xend_parse_sexp_desc_blockdev (virConnectPtr conn ATTRIBUTE_UNUSED,
+ void *data,
+ int isBlock, int cdrom, int isNoSrcCdrom,
+ const char *drvName, const char *drvType,
+ const char *src, const char *dst,
+ const char *mode)
+{
+ virBuffer *buf = (virBuffer *) data;
+
+ if (!isNoSrcCdrom) {
+ virBufferVSprintf(buf, " <disk type='%s' device='%s'>\n",
+ isBlock ? "block" : "file",
+ cdrom ? "cdrom" : "disk");
+ if (drvType) {
+ virBufferVSprintf(buf, " <driver name='%s' type='%s'/>\n", drvName, drvType);
+ } else {
+ virBufferVSprintf(buf, " <driver name='%s'/>\n", drvName);
+ }
+ if (isBlock) {
+ virBufferVSprintf(buf, " <source dev='%s'/>\n", src);
+ } else {
+ virBufferVSprintf(buf, " <source file='%s'/>\n", src);
+ }
+ } else {
+ /* This case is the cdrom device only */
+ virBufferAddLit(buf, " <disk device='cdrom'>\n");
+ }
+ virBufferVSprintf(buf, " <target dev='%s'/>\n", dst);
+
+ /* XXX should we force mode == r, if cdrom==1, or assume
+ xend has already done this ? */
+ if ((mode != NULL) && (STREQ (mode, "r")))
+ virBufferAddLit(buf, " <readonly/>\n");
+ else if ((mode != NULL) && (STREQ (mode, "w!")))
+ virBufferAddLit(buf, " <shareable/>\n");
+ virBufferAddLit(buf, " </disk>\n");
+
+ return 0;
+}
+
/**
* xend_parse_sexp_desc:
* @conn: the connection associated with the XML
@@ -1525,156 +1734,16 @@
if ((tmp != NULL) && (tmp[0] != 0))
virBufferVSprintf(&buf, " <emulator>%s</emulator>\n", tmp);
+ /* append block devices */
+ if (xend_parse_sexp_blockdevs (conn, root, xendConfigVersion,
+ xend_parse_sexp_desc_blockdev, &buf) == -1)
+ goto error;
+
+ /* append network devices and framebuffer */
for (cur = root; cur->kind == SEXPR_CONS; cur = cur->u.s.cdr) {
node = cur->u.s.car;
- /* Normally disks are in a (device (vbd ...)) block
- but blktap disks ended up in a differently named
- (device (tap ....)) block.... */
- if (sexpr_lookup(node, "device/vbd") ||
- sexpr_lookup(node, "device/tap")) {
- char *offset;
- int isBlock = 0;
- int cdrom = 0;
- int isNoSrcCdrom = 0;
- char *drvName = NULL;
- char *drvType = NULL;
- const char *src = NULL;
- const char *dst = NULL;
- const char *mode = NULL;
- /* Again dealing with (vbd...) vs (tap ...) differences */
- if (sexpr_lookup(node, "device/vbd")) {
- src = sexpr_node(node, "device/vbd/uname");
- dst = sexpr_node(node, "device/vbd/dev");
- mode = sexpr_node(node, "device/vbd/mode");
- } else {
- src = sexpr_node(node, "device/tap/uname");
- dst = sexpr_node(node, "device/tap/dev");
- mode = sexpr_node(node, "device/tap/mode");
- }
-
- if (dst == NULL) {
- virXendError(conn, VIR_ERR_INTERNAL_ERROR,
- _("domain information incomplete, vbd has no dev"));
- goto bad_parse;
- }
-
- if (src == NULL) {
- /* There is a case without the uname to the CD-ROM device */
- offset = strchr(dst, ':');
- if (offset) {
- if (hvm && !strcmp( offset , ":cdrom")) {
- isNoSrcCdrom = 1;
- }
- offset[0] = '\0';
- }
- if (!isNoSrcCdrom) {
- virXendError(conn, VIR_ERR_INTERNAL_ERROR,
- _("domain information incomplete, vbd has no src"));
- goto bad_parse;
- }
- }
-
- if (!isNoSrcCdrom) {
- offset = strchr(src, ':');
- if (!offset) {
- virXendError(conn, VIR_ERR_INTERNAL_ERROR,
- _("cannot parse vbd filename, missing driver name"));
- goto bad_parse;
- }
-
- drvName = malloc((offset-src)+1);
- if (!drvName) {
- virXendError(conn, VIR_ERR_NO_MEMORY,
- _("allocate new buffer"));
- goto bad_parse;
- }
- strncpy(drvName, src, (offset-src));
- drvName[offset-src] = '\0';
-
- src = offset + 1;
-
- if (!strcmp(drvName, "tap")) {
- offset = strchr(src, ':');
- if (!offset) {
- virXendError(conn, VIR_ERR_INTERNAL_ERROR,
- _("cannot parse vbd filename, missing driver type"));
- goto bad_parse;
- }
-
- drvType = malloc((offset-src)+1);
- if (!drvType) {
- virXendError(conn, VIR_ERR_NO_MEMORY,
- _("allocate new buffer"));
- goto bad_parse;
- }
- strncpy(drvType, src, (offset-src));
- drvType[offset-src] = '\0';
- src = offset + 1;
- /* Its possible to use blktap driver for block devs
- too, but kinda pointless because blkback is better,
- so we assume common case here. If blktap becomes
- omnipotent, we can revisit this, perhaps stat()'ing
- the src file in question */
- isBlock = 0;
- } else if (!strcmp(drvName, "phy")) {
- isBlock = 1;
- } else if (!strcmp(drvName, "file")) {
- isBlock = 0;
- }
- }
-
- if (!strncmp(dst, "ioemu:", 6))
- dst += 6;
-
- /* New style disk config from Xen >= 3.0.3 */
- if (xendConfigVersion > 1) {
- offset = strrchr(dst, ':');
- if (offset) {
- if (!strcmp(offset, ":cdrom")) {
- cdrom = 1;
- } else if (!strcmp(offset, ":disk")) {
- /* The default anyway */
- } else {
- /* Unknown, lets pretend its a disk too */
- }
- offset[0] = '\0';
- }
- }
-
- if (!isNoSrcCdrom) {
- virBufferVSprintf(&buf, " <disk type='%s' device='%s'>\n",
- isBlock ? "block" : "file",
- cdrom ? "cdrom" : "disk");
- if (drvType) {
- virBufferVSprintf(&buf, " <driver name='%s' type='%s'/>\n", drvName, drvType);
- } else {
- virBufferVSprintf(&buf, " <driver name='%s'/>\n", drvName);
- }
- if (isBlock) {
- virBufferVSprintf(&buf, " <source dev='%s'/>\n", src);
- } else {
- virBufferVSprintf(&buf, " <source file='%s'/>\n", src);
- }
- } else {
- /* This case is the cdrom device only */
- virBufferAddLit(&buf, " <disk device='cdrom'>\n");
- }
- virBufferVSprintf(&buf, " <target dev='%s'/>\n", dst);
-
-
- /* XXX should we force mode == r, if cdrom==1, or assume
- xend has already done this ? */
- if ((mode != NULL) && (!strcmp(mode, "r")))
- virBufferAddLit(&buf, " <readonly/>\n");
- else if ((mode != NULL) && (!strcmp(mode, "w!")))
- virBufferAddLit(&buf, " <shareable/>\n");
- virBufferAddLit(&buf, " </disk>\n");
-
- bad_parse:
- free(drvName);
- free(drvType);
- } else if (sexpr_lookup(node, "device/vif")) {
+ if (sexpr_lookup(node, "device/vif")) {
const char *tmp2;
tmp2 = sexpr_node(node, "device/vif/script");
tmp = sexpr_node(node, "device/vif/bridge");
@@ -3944,5 +4013,124 @@
return (ret);
}
+struct check_path_data {
+ const char *path;
+ int ok;
+};
+
+static int
+check_path (virConnectPtr conn ATTRIBUTE_UNUSED, void *vp,
+ int isBlock ATTRIBUTE_UNUSED,
+ int cdrom, int isNoSrcCdrom,
+ const char *drvName ATTRIBUTE_UNUSED,
+ const char *drvType ATTRIBUTE_UNUSED,
+ const char *src, const char *dst ATTRIBUTE_UNUSED,
+ const char *mode ATTRIBUTE_UNUSED)
+{
+ struct check_path_data *data = (struct check_path_data *) vp;
+
+ if (!isNoSrcCdrom && !cdrom && src && STREQ (src, data->path))
+ data->ok = 1;
+
+ return 0;
+}
+
+/**
+ * xenDaemonDomainBlockPeek:
+ * @dom: domain object
+ * @path: path to the file or device
+ * @offset: offset
+ * @size: size
+ * @buffer: return buffer
+ *
+ * Returns 0 if successful, -1 if error, -2 if declined.
+ */
+int
+xenDaemonDomainBlockPeek (virDomainPtr domain, const char *path,
+ long long offset, size_t size,
+ void *buffer)
+{
+ xenUnifiedPrivatePtr priv;
+ struct sexpr *root;
+ struct check_path_data data;
+ int fd, ret = -1;
+ struct stat statbuf;
+
+ priv = (xenUnifiedPrivatePtr) domain->conn->privateData;
+
+ if (domain->id < 0 && priv->xendConfigVersion < 3)
+ return -2; /* Decline, allow XM to handle it. */
+
+ /* Security check: The path must correspond to a block device. */
+ if (domain->id > 0)
+ root = sexpr_get (domain->conn, "/xend/domain/%d?detail=1",
+ domain->id);
+ else if (domain->id < 0)
+ root = sexpr_get (domain->conn, "/xend/domain/%s?detail=1",
+ domain->name);
+ else {
+ /* This call always fails for dom0. */
+ virXendError (domain->conn, VIR_ERR_NO_SUPPORT,
+ "domainBlockPeek is not supported for dom0");
+ return -1;
+ }
+
+ if (!root) {
+ virXendError (domain->conn, VIR_ERR_XEN_CALL, __FUNCTION__);
+ return -1;
+ }
+
+ data.path = path;
+ data.ok = 0;
+
+ if (xend_parse_sexp_blockdevs (domain->conn, root,
+ priv->xendConfigVersion,
+ check_path, &data) == -1)
+ return -1;
+
+ if (!data.ok) {
+ virXendError (domain->conn, VIR_ERR_INVALID_ARG, "path");
+ return -1;
+ }
+
+ /* The path is correct, now try to open it and get its size. */
+ fd = open (path, O_RDONLY);
+ if (fd == -1 || fstat (fd, &statbuf) == -1) {
+ virXendError (domain->conn, VIR_ERR_SYSTEM_ERROR, strerror (errno));
+ goto done;
+ }
+
+ /* XXX The following test fails for LVM devices for a couple
+ * of reasons: (1) They are commonly symlinks to /dev/mapper/foo
+ * and despite the man page for fstat, fstat stats the link not
+ * the file. (2) Stat even on the block device returns st_size==0.
+ *
+ * Anyhow, it should be safe to ignore this test since we are
+ * in O_RDONLY mode.
+ */
+#if 0
+ /* NB we know offset > 0, size >= 0 */
+ if (offset + size > statbuf.st_size) {
+ virXendError (domain->conn, VIR_ERR_INVALID_ARG, "offset");
+ goto done;
+ }
+#endif
+
+ /* Seek and read. */
+ /* NB. Because we configure with AC_SYS_LARGEFILE, off_t should
+ * be 64 bits on all platforms.
+ */
+ if (lseek (fd, offset, SEEK_SET) == (off_t) -1 ||
+ saferead (fd, buffer, size) == (ssize_t) -1) {
+ virXendError (domain->conn, VIR_ERR_SYSTEM_ERROR, strerror (errno));
+ goto done;
+ }
+
+ ret = 0;
+ done:
+ if (fd >= 0) close (fd);
+ return ret;
+}
+
#endif /* ! PROXY */
#endif /* WITH_XEN */
Index: src/xend_internal.h
===================================================================
RCS file: /data/cvs/libvirt/src/xend_internal.h,v
retrieving revision 1.40
diff -u -r1.40 xend_internal.h
--- src/xend_internal.h 10 Apr 2008 16:54:54 -0000 1.40
+++ src/xend_internal.h 16 Apr 2008 15:18:26 -0000
@@ -228,6 +228,8 @@
int xenDaemonDomainMigratePrepare (virConnectPtr dconn, char **cookie, int *cookielen, const char *uri_in, char **uri_out, unsigned long flags, const char *dname, unsigned long resource);
int xenDaemonDomainMigratePerform (virDomainPtr domain, const char *cookie, int cookielen, const char *uri, unsigned long flags, const char *dname, unsigned long resource);
+int xenDaemonDomainBlockPeek (virDomainPtr domain, const char *path, long long offset, size_t size, void *buffer);
+
#ifdef __cplusplus
}
#endif
Index: src/xm_internal.c
===================================================================
RCS file: /data/cvs/libvirt/src/xm_internal.c,v
retrieving revision 1.70
diff -u -r1.70 xm_internal.c
--- src/xm_internal.c 10 Apr 2008 16:54:54 -0000 1.70
+++ src/xm_internal.c 16 Apr 2008 15:18:29 -0000
@@ -3160,4 +3160,15 @@
return (ret);
}
+int
+xenXMDomainBlockPeek (virDomainPtr dom,
+ const char *path ATTRIBUTE_UNUSED,
+ long long offset ATTRIBUTE_UNUSED,
+ size_t size ATTRIBUTE_UNUSED,
+ void *buffer ATTRIBUTE_UNUSED)
+{
+ xenXMError (dom->conn, VIR_ERR_NO_SUPPORT, __FUNCTION__);
+ return -1;
+}
+
#endif /* WITH_XEN */
Index: src/xm_internal.h
===================================================================
RCS file: /data/cvs/libvirt/src/xm_internal.h,v
retrieving revision 1.11
diff -u -r1.11 xm_internal.h
--- src/xm_internal.h 10 Apr 2008 16:54:54 -0000 1.11
+++ src/xm_internal.h 16 Apr 2008 15:18:29 -0000
@@ -60,6 +60,7 @@
virConfPtr xenXMParseXMLToConfig(virConnectPtr conn, const char *xml);
char *xenXMDomainFormatXML(virConnectPtr conn, virConfPtr conf);
+int xenXMDomainBlockPeek (virDomainPtr dom, const char *path, long long offset, size_t size, void *buffer);
#ifdef __cplusplus
}
Index: tests/sexpr2xmldata/sexpr2xml-curmem.xml
===================================================================
RCS file: /data/cvs/libvirt/tests/sexpr2xmldata/sexpr2xml-curmem.xml,v
retrieving revision 1.4
diff -u -r1.4 sexpr2xml-curmem.xml
--- tests/sexpr2xmldata/sexpr2xml-curmem.xml 21 Aug 2007 08:54:07 -0000 1.4
+++ tests/sexpr2xmldata/sexpr2xml-curmem.xml 16 Apr 2008 15:18:29 -0000
@@ -15,17 +15,17 @@
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
+ <disk type='file' device='disk'>
+ <driver name='tap' type='aio'/>
+ <source file='/xen/rhel5.img'/>
+ <target dev='xvda:disk'/>
+ </disk>
<interface type='bridge'>
<source bridge='xenbr0'/>
<target dev='vif5.0'/>
<mac address='00:16:3e:1d:06:15'/>
<script path='vif-bridge'/>
</interface>
- <disk type='file' device='disk'>
- <driver name='tap' type='aio'/>
- <source file='/xen/rhel5.img'/>
- <target dev='xvda:disk'/>
- </disk>
<input type='mouse' bus='xen'/>
<graphics type='vnc' port='5905'/>
</devices>
Index: tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml
===================================================================
RCS file: /data/cvs/libvirt/tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml,v
retrieving revision 1.8
diff -u -r1.8 sexpr2xml-no-source-cdrom.xml
--- tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml 30 Sep 2007 15:36:47 -0000 1.8
+++ tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml 16 Apr 2008 15:18:29 -0000
@@ -20,11 +20,6 @@
<clock offset='utc'/>
<devices>
<emulator>/usr/lib/xen/bin/qemu-dm</emulator>
- <interface type='bridge'>
- <source bridge='xenbr0'/>
- <target dev='vif6.0'/>
- <mac address='00:16:3e:0a:7b:39'/>
- </interface>
<disk type='block' device='disk'>
<driver name='phy'/>
<source dev='/dev/sda8'/>
@@ -34,6 +29,11 @@
<target dev='hdc'/>
<readonly/>
</disk>
+ <interface type='bridge'>
+ <source bridge='xenbr0'/>
+ <target dev='vif6.0'/>
+ <mac address='00:16:3e:0a:7b:39'/>
+ </interface>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='5906'/>
</devices>
--
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