[Libguestfs] [PATCH] p2v: Use lscpu instead of libvirt to get CPU information.
Richard W.M. Jones
rjones at redhat.com
Thu Mar 23 14:31:36 UTC 2017
Don't get the CPU information from libvirt, because including libvirt
and all dependencies in the virt-p2v ISO bloats everything.
Instead get most of the information we need from the util-linux
program 'lscpu'.
Unfortunately the CPU model cannot be retrieved.
Example output:
$ ./run virt-p2v --cmdline="p2v.dump_config_and_exit"
[...]
cpu vendor . . . Intel
cpu sockets . . 2
cpu cores . . . 8
cpu threads . . 1
flags . . . . . acpi apic pae
This updates commit 963d6c3be7cd91c0373f67cfdd95c4f1dad1452f.
---
p2v/Makefile.am | 11 +-
p2v/cpuid.c | 331 ++++++++++++++++++++--------------------------------
p2v/dependencies.m4 | 5 -
3 files changed, 128 insertions(+), 219 deletions(-)
diff --git a/p2v/Makefile.am b/p2v/Makefile.am
index 726916027..94c649a8e 100644
--- a/p2v/Makefile.am
+++ b/p2v/Makefile.am
@@ -100,7 +100,6 @@ virt_p2v_CPPFLAGS = \
virt_p2v_CFLAGS = \
-pthread \
$(WARN_CFLAGS) $(WERROR_CFLAGS) \
- $(LIBVIRT_CFLAGS) \
$(PCRE_CFLAGS) \
$(LIBXML2_CFLAGS) \
$(GTK_CFLAGS) \
@@ -109,7 +108,6 @@ virt_p2v_CFLAGS = \
virt_p2v_LDADD = \
$(top_builddir)/common/utils/libutils.la \
$(top_builddir)/common/miniexpect/libminiexpect.la \
- $(LIBVIRT_LIBS) \
$(PCRE_LIBS) \
$(LIBXML2_LIBS) \
$(GTK_LIBS) \
@@ -126,16 +124,9 @@ dependencies_files = \
dependencies.redhat \
dependencies.suse
-if HAVE_LIBVIRT
-dependencies_have_libvirt = -DHAVE_LIBVIRT=1
-endif
-
$(dependencies_files): dependencies.m4
define=`echo $@ | $(SED) 's/dependencies.//;y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/'`; \
- m4 -D$$define=1 \
- -DGTK_VERSION=$(GTK_VERSION) \
- $(dependencies_have_libvirt) \
- $< > $@-t
+ m4 -D$$define=1 -DGTK_VERSION=$(GTK_VERSION) $< > $@-t
mv $@-t $@
# Support files needed by the virt-p2v-make-* scripts.
diff --git a/p2v/cpuid.c b/p2v/cpuid.c
index 13b61b050..12720552d 100644
--- a/p2v/cpuid.c
+++ b/p2v/cpuid.c
@@ -17,20 +17,17 @@
*/
/**
- * Process CPU capabilities into libvirt-compatible C<E<lt>cpuE<gt>> data.
+ * Find CPU vendor, topology and some CPU flags.
*
- * If libvirt is available at compile time then this is quite
- * simple - libvirt API C<virConnectGetCapabilities> provides
- * a C<E<lt>hostE<ge>> element which has mostly what we need.
+ * lscpu (from util-linux) provides CPU vendor, topology and flags.
*
- * Flags C<acpi>, C<apic>, C<pae> still have to be parsed out of
- * F</proc/cpuinfo> because these will not necessarily be present in
- * the libvirt capabilities directly (they are implied by the
- * processor model, requiring a complex lookup in the CPU map).
+ * ACPI can be read by seeing if F</sys/firmware/acpi> exists.
*
- * Note that #vCPUs and amount of RAM is handled by F<main.c>.
+ * CPU model is essentially impossible to get without using libvirt,
+ * but we cannot use libvirt for the reasons outlined in this message:
+ * https://www.redhat.com/archives/libvirt-users/2017-March/msg00071.html
*
- * See: L<https://libvirt.org/formatdomain.html#elementsCPU>
+ * Note that #vCPUs and amount of RAM is handled by F<main.c>.
*/
#include <config.h>
@@ -40,15 +37,10 @@
#include <stdarg.h>
#include <string.h>
#include <errno.h>
+#include <error.h>
#include <libintl.h>
-#ifdef HAVE_LIBVIRT
-#include <libvirt/libvirt.h>
-#include <libvirt/virterror.h>
-#endif
-
-#include <libxml/xpath.h>
-
+#include "c-ctype.h"
#include "getprogname.h"
#include "ignore-value.h"
@@ -65,235 +57,166 @@ free_cpu_config (struct cpu_config *cpu)
}
/**
- * Read flags from F</proc/cpuinfo>.
+ * Get the output of lscpu as a list of (key, value) pairs (as a
+ * flattened list of strings).
*/
-static void
-cpuinfo_flags (struct cpu_config *cpu)
+static char **
+get_lscpu (void)
{
const char *cmd;
CLEANUP_PCLOSE FILE *fp = NULL;
- CLEANUP_FREE char *flag = NULL;
+ CLEANUP_FREE char *line = NULL;
ssize_t len;
size_t buflen = 0;
+ char **ret = NULL;
+ size_t ret_size = 0;
- /* Get the flags, one per line. */
- cmd = "< /proc/cpuinfo "
-#if defined(__arm__)
- "grep ^Features"
-#else
- "grep ^flags"
-#endif
- " | awk '{ for (i = 3; i <= NF; ++i) { print $i }; exit }'";
+ cmd = "lscpu";
fp = popen (cmd, "re");
if (fp == NULL) {
- perror ("/proc/cpuinfo");
- return;
+ perror (cmd);
+ return NULL;
}
- while (errno = 0, (len = getline (&flag, &buflen, fp)) != -1) {
- if (len > 0 && flag[len-1] == '\n')
- flag[len-1] = '\0';
-
- if (STREQ (flag, "acpi"))
- cpu->acpi = 1;
- else if (STREQ (flag, "apic"))
- cpu->apic = 1;
- else if (STREQ (flag, "pae"))
- cpu->pae = 1;
+ ret = malloc (sizeof (char *));
+ if (ret == NULL) error (EXIT_FAILURE, errno, "malloc");
+ ret[0] = NULL;
+
+ while (errno = 0, (len = getline (&line, &buflen, fp)) != -1) {
+ char *p;
+ char *key, *value;
+
+ if (len > 0 && line[len-1] == '\n')
+ line[len-1] = '\0';
+
+ /* Split the line at the first ':' character. */
+ p = strchr (line, ':');
+ if (p == NULL)
+ continue;
+
+ *p = '\0';
+ key = strdup (line);
+ /* Skip leading whitespace in the value. */
+ for (++p; *p && c_isspace (*p); ++p)
+ ;
+ value = strdup (p);
+
+ /* Add key and value to the list, and trailing NULL pointer. */
+ ret_size += 2;
+ ret = realloc (ret, (ret_size + 1) * sizeof (char *));
+ if (ret == NULL) error (EXIT_FAILURE, errno, "realloc");
+ ret[ret_size-2] = key;
+ ret[ret_size-1] = value;
+ ret[ret_size] = NULL;
}
if (errno) {
- perror ("getline");
- return;
+ perror (cmd);
+ guestfs_int_free_string_list (ret);
+ return NULL;
}
+
+ return ret;
}
-#ifdef HAVE_LIBVIRT
+/**
+ * Read a single field from lscpu output.
+ *
+ * If the field does not exist, returns C<NULL>.
+ */
+static const char *
+get_field (char **lscpu, const char *key)
+{
+ size_t i;
+
+ for (i = 0; lscpu[i] != NULL; i += 2) {
+ if (STREQ (lscpu[i], key))
+ return lscpu[i+1];
+ }
+
+ return NULL;
+}
+/**
+ * Read the CPU vendor from lscpu output.
+ */
static void
-ignore_errors (void *ignore, virErrorPtr ignore2)
+get_vendor (char **lscpu, struct cpu_config *cpu)
{
- /* empty */
+ const char *vendor = get_field (lscpu, "Vendor ID");
+
+ if (vendor) {
+ /* Note this mapping comes from /usr/share/libvirt/cpu_map.xml */
+ if (STREQ (vendor, "GenuineIntel"))
+ cpu->vendor = strdup ("Intel");
+ else if (STREQ (vendor, "AuthenticAMD"))
+ cpu->vendor = strdup ("AMD");
+ /* Currently aarch64 lscpu has no Vendor ID XXX. */
+ }
}
-static void libvirt_error (const char *fs, ...) __attribute__((format (printf,1,2)));
-
+/**
+ * Read the CPU topology from lscpu output.
+ */
static void
-libvirt_error (const char *fs, ...)
+get_topology (char **lscpu, struct cpu_config *cpu)
{
- va_list args;
- CLEANUP_FREE char *msg = NULL;
- int len;
- virErrorPtr err;
-
- va_start (args, fs);
- len = vasprintf (&msg, fs, args);
- va_end (args);
-
- if (len < 0) goto fallback;
-
- /* In all recent libvirt, this retrieves the thread-local error. */
- err = virGetLastError ();
- if (err)
- fprintf (stderr,
- "%s: %s: %s [code=%d int1=%d]\n",
- getprogname (), msg, err->message, err->code, err->int1);
- else
- fallback:
- fprintf (stderr, "%s: %s\n", getprogname (), msg);
+ const char *v;
+
+ v = get_field (lscpu, "Socket(s)");
+ if (v)
+ ignore_value (sscanf (v, "%u", &cpu->sockets));
+ v = get_field (lscpu, "Core(s) per socket");
+ if (v)
+ ignore_value (sscanf (v, "%u", &cpu->cores));
+ v = get_field (lscpu, "Thread(s) per core");
+ if (v)
+ ignore_value (sscanf (v, "%u", &cpu->threads));
}
/**
- * Read the capabilities from libvirt and parse out the fields
- * we care about.
+ * Read some important flags from lscpu output.
*/
static void
-libvirt_capabilities (struct cpu_config *cpu)
+get_flags (char **lscpu, struct cpu_config *cpu)
{
- virConnectPtr conn;
- CLEANUP_FREE char *capabilities_xml = NULL;
- CLEANUP_XMLFREEDOC xmlDocPtr doc = NULL;
- CLEANUP_XMLXPATHFREECONTEXT xmlXPathContextPtr xpathCtx = NULL;
- CLEANUP_XMLXPATHFREEOBJECT xmlXPathObjectPtr xpathObj = NULL;
- const char *xpathexpr;
- xmlNodeSetPtr nodes;
- size_t nr_nodes, i;
- xmlNodePtr node;
-
- /* Connect to libvirt and get the capabilities XML. */
- conn = virConnectOpenReadOnly (NULL);
- if (!conn) {
- libvirt_error (_("could not connect to libvirt"));
- return;
- }
+ const char *flags;
- /* Suppress default behaviour of printing errors to stderr. Note
- * you can't set this to NULL to ignore errors; setting it to NULL
- * restores the default error handler ...
- */
- virConnSetErrorFunc (conn, NULL, ignore_errors);
-
- capabilities_xml = virConnectGetCapabilities (conn);
- if (!capabilities_xml) {
- libvirt_error (_("could not get libvirt capabilities"));
- virConnectClose (conn);
- return;
- }
-
- /* Parse the capabilities XML with libxml2. */
- doc = xmlReadMemory (capabilities_xml, strlen (capabilities_xml),
- NULL, NULL, XML_PARSE_NONET);
- if (doc == NULL) {
- fprintf (stderr,
- _("%s: unable to parse capabilities XML returned by libvirt\n"),
- getprogname ());
- virConnectClose (conn);
- return;
- }
-
- xpathCtx = xmlXPathNewContext (doc);
- if (xpathCtx == NULL) {
- fprintf (stderr, _("%s: unable to create new XPath context\n"),
- getprogname ());
- virConnectClose (conn);
- return;
- }
-
- /* Get the CPU vendor. */
- xpathexpr = "/capabilities/host/cpu/vendor/text()";
- xpathObj = xmlXPathEvalExpression (BAD_CAST xpathexpr, xpathCtx);
- if (xpathObj == NULL) {
- fprintf (stderr, _("%s: unable to evaluate xpath expression: %s\n"),
- getprogname (), xpathexpr);
- virConnectClose (conn);
- return;
- }
- nodes = xpathObj->nodesetval;
- nr_nodes = nodes->nodeNr;
- if (nr_nodes > 0) {
- node = nodes->nodeTab[0];
- cpu->vendor = (char *) xmlNodeGetContent (node);
- }
-
- /* Get the CPU model. */
- xmlXPathFreeObject (xpathObj);
- xpathexpr = "/capabilities/host/cpu/model/text()";
- xpathObj = xmlXPathEvalExpression (BAD_CAST xpathexpr, xpathCtx);
- if (xpathObj == NULL) {
- fprintf (stderr, _("%s: unable to evaluate xpath expression: %s\n"),
- getprogname (), xpathexpr);
- virConnectClose (conn);
- return;
- }
- nodes = xpathObj->nodesetval;
- nr_nodes = nodes->nodeNr;
- if (nr_nodes > 0) {
- node = nodes->nodeTab[0];
- cpu->model = (char *) xmlNodeGetContent (node);
- }
+ flags = get_field (lscpu, "Flags");
+ if (flags) {
+ cpu->apic = strstr (flags, " apic ") != NULL;
+ cpu->pae = strstr (flags, " pae ") != NULL;
- /* Get the topology. Note the XPath expression returns all
- * attributes of the <topology> node.
- */
- xmlXPathFreeObject (xpathObj);
- xpathexpr = "/capabilities/host/cpu/topology/@*";
- xpathObj = xmlXPathEvalExpression (BAD_CAST xpathexpr, xpathCtx);
- if (xpathObj == NULL) {
- fprintf (stderr, _("%s: unable to evaluate xpath expression: %s\n"),
- getprogname (), xpathexpr);
- virConnectClose (conn);
- return;
+ /* aarch64 /proc/cpuinfo has a "Features" field, but lscpu does
+ * not expose it. However aarch64 Features does not contain any
+ * of the interesting flags above.
+ */
}
- nodes = xpathObj->nodesetval;
- nr_nodes = nodes->nodeNr;
- /* Iterate over the attributes of the <topology> node. */
- for (i = 0; i < nr_nodes; ++i) {
- node = nodes->nodeTab[i];
-
- if (node->type == XML_ATTRIBUTE_NODE) {
- xmlAttrPtr attr = (xmlAttrPtr) node;
- CLEANUP_FREE char *content = NULL;
- unsigned *up;
-
- if (STREQ ((const char *) attr->name, "sockets")) {
- up = &cpu->sockets;
- parse_attr:
- *up = 0;
- content = (char *) xmlNodeListGetString (doc, attr->children, 1);
- if (content)
- ignore_value (sscanf (content, "%u", up));
- }
- else if (STREQ ((const char *) attr->name, "cores")) {
- up = &cpu->cores;
- goto parse_attr;
- }
- else if (STREQ ((const char *) attr->name, "threads")) {
- up = &cpu->threads;
- goto parse_attr;
- }
- }
- }
-
- virConnectClose (conn);
}
-#else /* !HAVE_LIBVIRT */
-
+/**
+ * Find out if the system uses ACPI.
+ */
static void
-libvirt_capabilities (struct cpu_config *cpu)
+get_acpi (struct cpu_config *cpu)
{
- fprintf (stderr,
- _("%s: program was compiled without libvirt support\n"),
- getprogname ());
+ cpu->acpi = access ("/sys/firmware/acpi", F_OK) == 0;
}
-#endif /* !HAVE_LIBVIRT */
-
void
get_cpu_config (struct cpu_config *cpu)
{
+ CLEANUP_FREE_STRING_LIST char **lscpu = NULL;
+
free_cpu_config (cpu);
- libvirt_capabilities (cpu);
- cpuinfo_flags (cpu);
+
+ lscpu = get_lscpu ();
+ if (lscpu != NULL) {
+ get_vendor (lscpu, cpu);
+ get_topology (lscpu, cpu);
+ get_flags (lscpu, cpu);
+ }
+
+ get_acpi (cpu);
}
diff --git a/p2v/dependencies.m4 b/p2v/dependencies.m4
index 0db2f85d4..02ca87c19 100644
--- a/p2v/dependencies.m4
+++ b/p2v/dependencies.m4
@@ -25,8 +25,6 @@ ifelse(REDHAT,1,
libxml2
gtk`'GTK_VERSION
dbus-libs
- dnl libvirt is optional, used just to parse the host CPU capabilities.
- ifdef(`HAVE_LIBVIRT', `libvirt-libs')
dnl Run as external programs by the p2v binary.
/usr/bin/ssh
@@ -66,7 +64,6 @@ ifelse(DEBIAN,1,
libxml2
ifelse(GTK_VERSION,2,libgtk`'GTK_VERSION`'.0-0,libgtk-`'GTK_VERSION`'-0)
libdbus-1-3
- ifdef(`HAVE_LIBVIRT', `libvirt0')
openssh-client
qemu-utils
debianutils
@@ -87,7 +84,6 @@ ifelse(ARCHLINUX,1,
libxml2
gtk`'GTK_VERSION
dbus
- ifdef(`HAVE_LIBVIRT', `libvirt')
openssh
qemu
which
@@ -110,7 +106,6 @@ ifelse(SUSE,1,
libxml2
gtk`'GTK_VERSION
libdbus-1-3
- ifdef(`HAVE_LIBVIRT', `libvirt-libs')
qemu-tools
openssh
dnl /usr/bin/which is in util-linux on SUSE
--
2.12.0
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