[libvirt] [PATCH v3 19/20] Refactor qemuCapsParseDeviceStr to work from data tables

Daniel P. Berrange berrange at redhat.com
Tue Sep 25 18:00:12 UTC 2012


From: "Daniel P. Berrange" <berrange at redhat.com>

Currently the qemuCapsParseDeviceStr method has a bunch of open
coded string searches/comparisons to detect devices and their
properties. Soon this data will be obtained from QMP queries
instead of -device help output. Maintaining the list of device
and properties in two places is undesirable. Thus the existing
qemuCapsParseDeviceStr() method needs to be refactored to
separate the device types and properties from the actual
search code.

Thus the -device help output is now parsed to construct a
list of device names, and device properties. These are then
checked against a set of datatables to set the capability
flags

Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
 src/qemu/qemu_capabilities.c | 364 ++++++++++++++++++++++++++++++-------------
 src/qemu/qemu_capabilities.h |   3 +-
 tests/qemuhelptest.c         |   2 +-
 3 files changed, 259 insertions(+), 110 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 9c4f3be..c4d36f9 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -1233,6 +1233,262 @@ cleanup:
     return -1;
 }
 
+
+struct qemuCapsStringFlags {
+    const char *value;
+    int flag;
+};
+
+
+struct qemuCapsStringFlags qemuCapsObjectTypes[] = {
+    { "hda-duplex", QEMU_CAPS_HDA_DUPLEX },
+    { "hda-micro", QEMU_CAPS_HDA_MICRO },
+    { "ccid-card-emulated", QEMU_CAPS_CCID_EMULATED },
+    { "ccid-card-passthru", QEMU_CAPS_CCID_PASSTHRU },
+    { "piix3-usb-uhci", QEMU_CAPS_PIIX3_USB_UHCI },
+    { "piix4-usb-uhci", QEMU_CAPS_PIIX4_USB_UHCI },
+    { "usb-ehci", QEMU_CAPS_USB_EHCI },
+    { "ich9-usb-ehci1", QEMU_CAPS_ICH9_USB_EHCI1 },
+    { "vt82c686b-usb-uhci", QEMU_CAPS_VT82C686B_USB_UHCI },
+    { "pci-ohci", QEMU_CAPS_PCI_OHCI },
+    { "nec-usb-xhci", QEMU_CAPS_NEC_USB_XHCI },
+    { "usb-redir", QEMU_CAPS_USB_REDIR },
+    { "usb-hub", QEMU_CAPS_USB_HUB },
+    { "ich9-ahci", QEMU_CAPS_ICH9_AHCI },
+    { "virtio-blk-s390", QEMU_CAPS_VIRTIO_S390 },
+    { "lsi53c895a", QEMU_CAPS_SCSI_LSI },
+    { "virtio-scsi-pci", QEMU_CAPS_VIRTIO_SCSI_PCI },
+    { "spicevmc", QEMU_CAPS_DEVICE_SPICEVMC },
+    { "qxl-vga", QEMU_CAPS_DEVICE_QXL_VGA },
+    { "sga", QEMU_CAPS_SGA },
+    { "scsi-block", QEMU_CAPS_SCSI_BLOCK },
+    { "scsi-cd", QEMU_CAPS_SCSI_CD },
+    { "ide-cd", QEMU_CAPS_IDE_CD },
+};
+
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsVirtioBlk[] = {
+    { "multifunction", QEMU_CAPS_PCI_MULTIFUNCTION },
+    { "bootindex", QEMU_CAPS_BOOTINDEX },
+    { "ioeventfd", QEMU_CAPS_VIRTIO_IOEVENTFD },
+    { "event_idx", QEMU_CAPS_VIRTIO_BLK_EVENT_IDX },
+    { "scsi", QEMU_CAPS_VIRTIO_BLK_SCSI },
+    { "logical_block_size", QEMU_CAPS_BLOCKIO },
+};
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsVirtioNet[] = {
+    { "tx", QEMU_CAPS_VIRTIO_TX_ALG },
+    { "event_idx", QEMU_CAPS_VIRTIO_NET_EVENT_IDX },
+};
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsPciAssign[] = {
+    { "configfd", QEMU_CAPS_PCI_CONFIGFD },
+    { "bootindex", QEMU_CAPS_PCI_BOOTINDEX },
+};
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsScsiDisk[] = {
+    { "channel", QEMU_CAPS_SCSI_DISK_CHANNEL },
+    { "wwn", QEMU_CAPS_SCSI_DISK_WWN },
+};
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsIDEDrive[] = {
+    { "wwn", QEMU_CAPS_IDE_DRIVE_WWN },
+};
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsPixx4PM[] = {
+    { "disable_s3", QEMU_CAPS_DISABLE_S3 },
+    { "disable_s4", QEMU_CAPS_DISABLE_S4 },
+};
+
+static struct qemuCapsStringFlags qemuCapsObjectPropsUsbRedir[] = {
+    { "filter", QEMU_CAPS_USB_REDIR_FILTER },
+};
+
+struct qemuCapsObjectTypeProps {
+    const char *type;
+    struct qemuCapsStringFlags *props;
+    size_t nprops;
+};
+
+static struct qemuCapsObjectTypeProps qemuCapsObjectProps[] = {
+    { "virtio-blk-pci", qemuCapsObjectPropsVirtioBlk,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsVirtioBlk) },
+    { "virtio-net-pci", qemuCapsObjectPropsVirtioNet,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsVirtioNet) },
+    { "pci-assign", qemuCapsObjectPropsPciAssign,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsPciAssign) },
+    { "scsi-disk", qemuCapsObjectPropsScsiDisk,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsScsiDisk) },
+    { "ide-drive", qemuCapsObjectPropsIDEDrive,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsIDEDrive) },
+    { "PIIX4_PM", qemuCapsObjectPropsPixx4PM,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsPixx4PM) },
+    { "usb-redir", qemuCapsObjectPropsUsbRedir,
+      ARRAY_CARDINALITY(qemuCapsObjectPropsUsbRedir) },
+};
+
+
+static void
+qemuCapsProcessStringFlags(qemuCapsPtr caps,
+                           size_t nflags,
+                           struct qemuCapsStringFlags *flags,
+                           size_t nvalues,
+                           char *const*values)
+{
+    size_t i, j;
+    for (i = 0 ; i < nflags ; i++) {
+        for (j = 0 ; j < nvalues ; j++) {
+            if (STREQ(values[j], flags[i].value)) {
+                qemuCapsSet(caps, flags[i].flag);
+                break;
+            }
+        }
+    }
+}
+
+#define OBJECT_TYPE_PREFIX "name \""
+
+static int
+qemuCapsParseDeviceStrObjectTypes(const char *str,
+                                  char ***types)
+{
+    const char *tmp = str;
+    int ret = -1;
+    size_t ntypelist = 0;
+    char **typelist = NULL;
+
+    *types = NULL;
+
+    while ((tmp = strstr(tmp, OBJECT_TYPE_PREFIX))) {
+        char *end;
+        tmp += strlen(OBJECT_TYPE_PREFIX);
+        end = strstr(tmp, "\"");
+        if (!end) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("Malformed QEMU device list string, missing quote"));
+            goto cleanup;
+        }
+
+        if (VIR_EXPAND_N(typelist, ntypelist, 1) < 0) {
+            virReportOOMError();
+            goto cleanup;
+        }
+        if (!(typelist[ntypelist-1] = strndup(tmp, end-tmp))) {
+            virReportOOMError();
+            goto cleanup;
+        }
+    }
+
+    *types = typelist;
+    ret = ntypelist;
+
+cleanup:
+    return ret;
+}
+
+
+static int
+qemuCapsParseDeviceStrObjectProps(const char *str,
+                                  const char *type,
+                                  char ***props)
+{
+    const char *tmp = str;
+    int ret = -1;
+    size_t nproplist = 0;
+    char **proplist = NULL;
+
+    VIR_DEBUG("Extract type %s", type);
+    *props = NULL;
+
+    while ((tmp = strchr(tmp, '\n'))) {
+        char *end;
+        tmp += 1;
+
+        if (*tmp == '\0')
+            break;
+
+        if (STRPREFIX(tmp, OBJECT_TYPE_PREFIX))
+            continue;
+
+        if (!STRPREFIX(tmp, type))
+            continue;
+
+        tmp += strlen(type);
+        if (*tmp != '.')
+            continue;
+        tmp++;
+
+        end = strstr(tmp, "=");
+        if (!end) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("Malformed QEMU device list string, missing '='"));
+            goto cleanup;
+        }
+        if (VIR_EXPAND_N(proplist, nproplist, 1) < 0) {
+            virReportOOMError();
+            goto cleanup;
+        }
+        if (!(proplist[nproplist-1] = strndup(tmp, end-tmp))) {
+            virReportOOMError();
+            goto cleanup;
+        }
+    }
+
+    *props = proplist;
+    ret = nproplist;
+
+cleanup:
+    return ret;
+}
+
+
+static void
+qemuCapsFreeStringList(size_t len,
+                       char **values)
+{
+    size_t i;
+    for (i = 0 ; i < len ; i++)
+        VIR_FREE(values[i]);
+    VIR_FREE(values);
+}
+
+
+int
+qemuCapsParseDeviceStr(qemuCapsPtr caps, const char *str)
+{
+    int nvalues;
+    char **values;
+    size_t i;
+
+    if ((nvalues = qemuCapsParseDeviceStrObjectTypes(str, &values)) < 0)
+        return -1;
+    qemuCapsProcessStringFlags(caps,
+                               ARRAY_CARDINALITY(qemuCapsObjectTypes),
+                               qemuCapsObjectTypes,
+                               nvalues, values);
+    qemuCapsFreeStringList(nvalues, values);
+
+    for (i = 0 ; i < ARRAY_CARDINALITY(qemuCapsObjectProps); i++) {
+        const char *type = qemuCapsObjectProps[i].type;
+        if ((nvalues = qemuCapsParseDeviceStrObjectProps(str,
+                                                         type,
+                                                         &values)) < 0)
+            return -1;
+        qemuCapsProcessStringFlags(caps,
+                                   qemuCapsObjectProps[i].nprops,
+                                   qemuCapsObjectProps[i].props,
+                                   nvalues, values);
+        qemuCapsFreeStringList(nvalues, values);
+    }
+
+    /* Prefer -chardev spicevmc (detected earlier) over -device spicevmc */
+    if (qemuCapsGet(caps, QEMU_CAPS_CHARDEV_SPICEVMC))
+        qemuCapsClear(caps, QEMU_CAPS_DEVICE_SPICEVMC);
+
+    return 0;
+}
+
+
 static int
 qemuCapsExtractDeviceStr(const char *qemu,
                          qemuCapsPtr caps)
@@ -1266,7 +1522,7 @@ qemuCapsExtractDeviceStr(const char *qemu,
     if (virCommandRun(cmd, NULL) < 0)
         goto cleanup;
 
-    ret = qemuCapsParseDeviceStr(output, caps);
+    ret = qemuCapsParseDeviceStr(caps, output);
 
 cleanup:
     VIR_FREE(output);
@@ -1275,112 +1531,6 @@ cleanup:
 }
 
 
-int
-qemuCapsParseDeviceStr(const char *str, qemuCapsPtr caps)
-{
-    /* Which devices exist. */
-    if (strstr(str, "name \"hda-duplex\""))
-        qemuCapsSet(caps, QEMU_CAPS_HDA_DUPLEX);
-    if (strstr(str, "name \"hda-micro\""))
-        qemuCapsSet(caps, QEMU_CAPS_HDA_MICRO);
-    if (strstr(str, "name \"ccid-card-emulated\""))
-        qemuCapsSet(caps, QEMU_CAPS_CCID_EMULATED);
-    if (strstr(str, "name \"ccid-card-passthru\""))
-        qemuCapsSet(caps, QEMU_CAPS_CCID_PASSTHRU);
-
-    if (strstr(str, "name \"piix3-usb-uhci\""))
-        qemuCapsSet(caps, QEMU_CAPS_PIIX3_USB_UHCI);
-    if (strstr(str, "name \"piix4-usb-uhci\""))
-        qemuCapsSet(caps, QEMU_CAPS_PIIX4_USB_UHCI);
-    if (strstr(str, "name \"usb-ehci\""))
-        qemuCapsSet(caps, QEMU_CAPS_USB_EHCI);
-    if (strstr(str, "name \"ich9-usb-ehci1\""))
-        qemuCapsSet(caps, QEMU_CAPS_ICH9_USB_EHCI1);
-    if (strstr(str, "name \"vt82c686b-usb-uhci\""))
-        qemuCapsSet(caps, QEMU_CAPS_VT82C686B_USB_UHCI);
-    if (strstr(str, "name \"pci-ohci\""))
-        qemuCapsSet(caps, QEMU_CAPS_PCI_OHCI);
-    if (strstr(str, "name \"nec-usb-xhci\""))
-        qemuCapsSet(caps, QEMU_CAPS_NEC_USB_XHCI);
-    if (strstr(str, "name \"usb-redir\""))
-        qemuCapsSet(caps, QEMU_CAPS_USB_REDIR);
-    if (strstr(str, "usb-redir.filter"))
-        qemuCapsSet(caps, QEMU_CAPS_USB_REDIR_FILTER);
-    if (strstr(str, "name \"usb-hub\""))
-        qemuCapsSet(caps, QEMU_CAPS_USB_HUB);
-    if (strstr(str, "name \"ich9-ahci\""))
-        qemuCapsSet(caps, QEMU_CAPS_ICH9_AHCI);
-    if (strstr(str, "name \"virtio-blk-s390\"") ||
-        strstr(str, "name \"virtio-net-s390\"") ||
-        strstr(str, "name \"virtio-serial-s390\""))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_S390);
-
-    if (strstr(str, "name \"lsi53c895a\""))
-        qemuCapsSet(caps, QEMU_CAPS_SCSI_LSI);
-    if (strstr(str, "name \"virtio-scsi-pci\""))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_SCSI_PCI);
-
-    /* Prefer -chardev spicevmc (detected earlier) over -device spicevmc */
-    if (!qemuCapsGet(caps, QEMU_CAPS_CHARDEV_SPICEVMC) &&
-        strstr(str, "name \"spicevmc\""))
-        qemuCapsSet(caps, QEMU_CAPS_DEVICE_SPICEVMC);
-
-    /* Features of given devices. */
-    if (strstr(str, "pci-assign.configfd"))
-        qemuCapsSet(caps, QEMU_CAPS_PCI_CONFIGFD);
-    if (strstr(str, "virtio-blk-pci.multifunction"))
-        qemuCapsSet(caps, QEMU_CAPS_PCI_MULTIFUNCTION);
-    if (strstr(str, "virtio-blk-pci.bootindex")) {
-        qemuCapsSet(caps, QEMU_CAPS_BOOTINDEX);
-        if (strstr(str, "pci-assign.bootindex"))
-            qemuCapsSet(caps, QEMU_CAPS_PCI_BOOTINDEX);
-    }
-    if (strstr(str, "virtio-net-pci.tx="))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_TX_ALG);
-    if (strstr(str, "name \"qxl-vga\""))
-        qemuCapsSet(caps, QEMU_CAPS_DEVICE_QXL_VGA);
-    if (strstr(str, "virtio-blk-pci.ioeventfd"))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_IOEVENTFD);
-    if (strstr(str, "name \"sga\""))
-        qemuCapsSet(caps, QEMU_CAPS_SGA);
-    if (strstr(str, "virtio-blk-pci.event_idx"))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_BLK_EVENT_IDX);
-    if (strstr(str, "virtio-net-pci.event_idx"))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_NET_EVENT_IDX);
-    if (strstr(str, "virtio-blk-pci.scsi"))
-        qemuCapsSet(caps, QEMU_CAPS_VIRTIO_BLK_SCSI);
-    if (strstr(str, "scsi-disk.channel"))
-        qemuCapsSet(caps, QEMU_CAPS_SCSI_DISK_CHANNEL);
-    if (strstr(str, "scsi-disk.wwn"))
-        qemuCapsSet(caps, QEMU_CAPS_SCSI_DISK_WWN);
-    if (strstr(str, "scsi-block"))
-        qemuCapsSet(caps, QEMU_CAPS_SCSI_BLOCK);
-    if (strstr(str, "scsi-cd"))
-        qemuCapsSet(caps, QEMU_CAPS_SCSI_CD);
-    if (strstr(str, "ide-cd"))
-        qemuCapsSet(caps, QEMU_CAPS_IDE_CD);
-    if (strstr(str, "ide-drive.wwn"))
-        qemuCapsSet(caps, QEMU_CAPS_IDE_DRIVE_WWN);
-
-    /*
-     * the iolimit detection is not really straight forward:
-     * in qemu this is a capability of the block layer, if
-     * present any of -device scsi-disk, virtio-blk-*, ...
-     * will offer to specify logical and physical block size
-     * and other properties...
-     */
-    if (strstr(str, ".logical_block_size") &&
-        strstr(str, ".physical_block_size"))
-        qemuCapsSet(caps, QEMU_CAPS_BLOCKIO);
-    if (strstr(str, "PIIX4_PM.disable_s3="))
-        qemuCapsSet(caps, QEMU_CAPS_DISABLE_S3);
-    if (strstr(str, "PIIX4_PM.disable_s4="))
-        qemuCapsSet(caps, QEMU_CAPS_DISABLE_S4);
-
-    return 0;
-}
-
-
 static void
 uname_normalize (struct utsname *ut)
 {
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 31e39db..059a4bc 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -219,8 +219,7 @@ int qemuCapsParseHelpStr(const char *qemu,
                          unsigned int *kvm_version,
                          bool check_yajl);
 /* Only for use by test suite */
-int qemuCapsParseDeviceStr(const char *str,
-                           qemuCapsPtr caps);
+int qemuCapsParseDeviceStr(qemuCapsPtr caps, const char *str);
 
 VIR_ENUM_DECL(qemuCaps);
 
diff --git a/tests/qemuhelptest.c b/tests/qemuhelptest.c
index 079aef8..681f425 100644
--- a/tests/qemuhelptest.c
+++ b/tests/qemuhelptest.c
@@ -71,7 +71,7 @@ static int testHelpStrParsing(const void *data)
         if (virtTestLoadFile(path, &help) < 0)
             goto cleanup;
 
-        if (qemuCapsParseDeviceStr(help, flags) < 0)
+        if (qemuCapsParseDeviceStr(flags, help) < 0)
             goto cleanup;
     }
 
-- 
1.7.11.4




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