[libvirt] [PATCH] RFC: qemu: add vmcoreinfo support

Marc-André Lureau marcandre.lureau at redhat.com
Thu Nov 16 14:27:52 UTC 2017


Hi

----- Original Message -----
> On Mon, Nov 06, 2017 at 01:09:09PM +0100, marcandre.lureau at redhat.com wrote:
> >From: Marc-André Lureau <marcandre.lureau at redhat.com>
> >
> >Starting from qemu 2.11, the `-device vmcoreinfo` will create a fw_cfg
> >entry for a guest to store dump details, necessary to process kernel
> >dump with KASLR enabled and providing additional kernel details.
> >
> >Since the device is a singleton and shouldn't use additional hardware
> >resources, I decided to map this to a <feature> element in the libvirt
> >domain XML. Feel free to argue and decide if it is better to have it
> >under <devices> instead.
> >
> 
> So is this similar to -fw_cfg name=etc/vmcoreinfo,file=X but in this case it
> is
> not backed by a file, but collected by QEMU itself?

correct

> 
> I'm OK with this being a feature.

Should I split the commit or can I resubmit like this without RFC?

Thanks

> 
> >The device is arm/x86 only for now (targets that support fw_cfg+dma).
> >
> >Related to:
> >https://bugzilla.redhat.com/show_bug.cgi?id=1395248
> >
> >Signed-off-by: Marc-André Lureau <marcandre.lureau at redhat.com>
> >---
> > docs/formatdomain.html.in                          |  4 +++
> > docs/schemas/domaincommon.rng                      |  5 +++
> > src/conf/domain_conf.c                             |  5 ++-
> > src/conf/domain_conf.h                             |  1 +
> > src/qemu/qemu_capabilities.c                       |  2 ++
> > src/qemu/qemu_capabilities.h                       |  1 +
> > src/qemu/qemu_command.c                            | 26 +++++++++++++++
> > .../qemuxml2argvdata/qemuxml2argv-vmcoreinfo.args  | 25 ++++++++++++++
> > tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.xml | 28 ++++++++++++++++
> > tests/qemuxml2argvtest.c                           |  1 +
> > .../qemuxml2xmlout-vmcoreinfo.xml                  | 38
> > ++++++++++++++++++++++
> > tests/qemuxml2xmltest.c                            |  1 +
> > 12 files changed, 136 insertions(+), 1 deletion(-)
> > create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.args
> > create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.xml
> > create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-vmcoreinfo.xml
> >
> >diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> >index 92e14a919..d87a32a89 100644
> >--- a/docs/formatdomain.html.in
> >+++ b/docs/formatdomain.html.in
> >@@ -1878,6 +1878,10 @@
> >           which is also known as a split I/O APIC mode.
> >           <span class="since">Since 3.4.0</span> (QEMU/KVM only)
> >       </dd>
> >+      <dt><code>vmcoreinfo</code></dt>
> >+      <dd>Enable QEMU vmcoreinfo device to let the guest kernel save debug
> >+          details. <span class="since">Since 3.10.0</span> (QEMU only)
> >+      </dd>
> >     </dl>
> >
> >     <h3><a id="elementsTime">Time keeping</a></h3>
> >diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> >index 9cec1a063..86cbe2c8c 100644
> >--- a/docs/schemas/domaincommon.rng
> >+++ b/docs/schemas/domaincommon.rng
> >@@ -4736,6 +4736,11 @@
> >           <optional>
> >             <ref name="ioapic"/>
> >           </optional>
> >+          <optional>
> >+            <element name="vmcoreinfo">
> >+              <empty/>
> >+            </element>
> >+          </optional>
> >         </interleave>
> >       </element>
> >     </optional>
> >diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> >index 400e90032..3a9b56cd2 100644
> >--- a/src/conf/domain_conf.c
> >+++ b/src/conf/domain_conf.c
> >@@ -148,7 +148,8 @@ VIR_ENUM_IMPL(virDomainFeature, VIR_DOMAIN_FEATURE_LAST,
> >               "vmport",
> >               "gic",
> >               "smm",
> >-              "ioapic")
> >+              "ioapic",
> >+              "vmcoreinfo")
> >
> > VIR_ENUM_IMPL(virDomainCapabilitiesPolicy,
> > VIR_DOMAIN_CAPABILITIES_POLICY_LAST,
> >               "default",
> >@@ -18710,6 +18711,7 @@ virDomainDefParseXML(xmlDocPtr xml,
> >         case VIR_DOMAIN_FEATURE_VIRIDIAN:
> >         case VIR_DOMAIN_FEATURE_PRIVNET:
> >         case VIR_DOMAIN_FEATURE_HYPERV:
> >+        case VIR_DOMAIN_FEATURE_VMCOREINFO:
> >         case VIR_DOMAIN_FEATURE_KVM:
> >             def->features[val] = VIR_TRISTATE_SWITCH_ON;
> >             break;
> >@@ -26052,6 +26054,7 @@ virDomainDefFormatInternal(virDomainDefPtr def,
> >             case VIR_DOMAIN_FEATURE_ACPI:
> >             case VIR_DOMAIN_FEATURE_PAE:
> >             case VIR_DOMAIN_FEATURE_VIRIDIAN:
> >+            case VIR_DOMAIN_FEATURE_VMCOREINFO:
> >             case VIR_DOMAIN_FEATURE_PRIVNET:
> >                 switch ((virTristateSwitch) def->features[i]) {
> >                 case VIR_TRISTATE_SWITCH_ABSENT:
> >diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> >index be38792c6..add668025 100644
> >--- a/src/conf/domain_conf.h
> >+++ b/src/conf/domain_conf.h
> >@@ -1723,6 +1723,7 @@ typedef enum {
> >     VIR_DOMAIN_FEATURE_GIC,
> >     VIR_DOMAIN_FEATURE_SMM,
> >     VIR_DOMAIN_FEATURE_IOAPIC,
> >+    VIR_DOMAIN_FEATURE_VMCOREINFO,
> >
> >     VIR_DOMAIN_FEATURE_LAST
> > } virDomainFeature;
> >diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> >index 7cb091056..44a2833a7 100644
> >--- a/src/qemu/qemu_capabilities.c
> >+++ b/src/qemu/qemu_capabilities.c
> >@@ -443,6 +443,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
> >               /* 270 */
> >               "vxhs",
> >               "virtio-blk.num-queues",
> >+              "vmcoreinfo",
> >     );
> >
> >
> >@@ -1670,6 +1671,7 @@ struct virQEMUCapsStringFlags virQEMUCapsObjectTypes[]
> >= {
> >     { "pcie-root-port", QEMU_CAPS_DEVICE_PCIE_ROOT_PORT },
> >     { "qemu-xhci", QEMU_CAPS_DEVICE_QEMU_XHCI },
> >     { "spapr-pci-host-bridge", QEMU_CAPS_DEVICE_SPAPR_PCI_HOST_BRIDGE },
> >+    { "vmcoreinfo", QEMU_CAPS_DEVICE_VMCOREINFO },
> > };
> >
> > static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsVirtioBalloon[]
> > = {
> >diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
> >index cacc2b77e..0cd9755a8 100644
> >--- a/src/qemu/qemu_capabilities.h
> >+++ b/src/qemu/qemu_capabilities.h
> >@@ -429,6 +429,7 @@ typedef enum {
> >     /* 270 */
> >     QEMU_CAPS_VXHS, /* -drive file.driver=vxhs via query-qmp-schema */
> >     QEMU_CAPS_VIRTIO_BLK_NUM_QUEUES, /* virtio-blk-*.num-queues */
> >+    QEMU_CAPS_DEVICE_VMCOREINFO, /* -device vmcoreinfo */
> >
> >     QEMU_CAPS_LAST /* this must always be the last item */
> > } virQEMUCapsFlags;
> >diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> >index 8708b79ed..b903b27b9 100644
> >--- a/src/qemu/qemu_command.c
> >+++ b/src/qemu/qemu_command.c
> >@@ -9727,6 +9727,29 @@ qemuBuildTPMCommandLine(virCommandPtr cmd,
> > }
> >
> >
> >+static int
> >+qemuBuildVMCoreInfoCommandLine(virCommandPtr cmd,
> >+                               const virDomainDef *def,
> >+                               virQEMUCapsPtr qemuCaps)
> >+{
> >+    virTristateSwitch vmci = def->features[VIR_DOMAIN_FEATURE_VMCOREINFO];
> >+
> >+    if (vmci != VIR_TRISTATE_SWITCH_ON) {
> >+        return 0;
> >+    }
> >+
> >+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VMCOREINFO)) {
> >+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> >+                       _("vmcoreinfo is not available "
> >+                         "with this QEMU binary"));
> >+        return -1;
> >+    }
> >+
> >+    virCommandAddArgList(cmd, "-device", "vmcoreinfo", NULL);
> >+    return 0;
> >+}
> >+
> >+
> > static int
> > qemuBuildPanicCommandLine(virCommandPtr cmd,
> >                           const virDomainDef *def,
> >@@ -10146,6 +10169,9 @@ qemuBuildCommandLine(virQEMUDriverPtr driver,
> >     if (qemuBuildNVRAMCommandLine(cmd, def, qemuCaps) < 0)
> >         goto error;
> >
> >+    if (qemuBuildVMCoreInfoCommandLine(cmd, def, qemuCaps) < 0)
> >+        goto error;
> >+
> >     if (snapshot)
> >         virCommandAddArgList(cmd, "-loadvm", snapshot->def->name, NULL);
> >
> >diff --git a/tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.args
> >b/tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.args
> >new file mode 100644
> >index 000000000..772e5a071
> >--- /dev/null
> >+++ b/tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.args
> >@@ -0,0 +1,25 @@
> >+LC_ALL=C \
> >+PATH=/bin \
> >+HOME=/home/test \
> >+USER=test \
> >+LOGNAME=test \
> >+QEMU_AUDIO_DRV=none \
> >+/usr/bin/qemu-system-i686 \
> >+-name QEMUGuest1 \
> >+-S \
> >+-M pc \
> >+-m 214 \
> >+-smp 1,sockets=1,cores=1,threads=1 \
> >+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
> >+-nographic \
> >+-nodefaults \
> >+-chardev
> >socket,id=charmonitor,path=/tmp/lib/domain--1-QEMUGuest1/monitor.sock,\
> >+server,nowait \
> >+-mon chardev=charmonitor,id=monitor,mode=readline \
> >+-no-acpi \
> >+-boot c \
> >+-usb \
> >+-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
> >+-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
> >+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 \
> >+-device vmcoreinfo
> >diff --git a/tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.xml
> >b/tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.xml
> >new file mode 100644
> >index 000000000..f8e586531
> >--- /dev/null
> >+++ b/tests/qemuxml2argvdata/qemuxml2argv-vmcoreinfo.xml
> >@@ -0,0 +1,28 @@
> >+<domain type='qemu'>
> >+  <name>QEMUGuest1</name>
> >+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> >+  <memory unit='KiB'>219100</memory>
> >+  <currentMemory unit='KiB'>219100</currentMemory>
> >+  <vcpu placement='static'>1</vcpu>
> >+  <os>
> >+    <type arch='i686' machine='pc'>hvm</type>
> >+    <boot dev='hd'/>
> >+  </os>
> >+  <features>
> >+    <vmcoreinfo/>
> >+  </features>
> >+  <clock offset='utc'/>
> >+  <on_poweroff>destroy</on_poweroff>
> >+  <on_reboot>restart</on_reboot>
> >+  <on_crash>destroy</on_crash>
> >+  <devices>
> >+    <emulator>/usr/bin/qemu-system-i686</emulator>
> >+    <disk type='block' device='disk'>
> >+      <source dev='/dev/HostVG/QEMUGuest1'/>
> >+      <target dev='hda' bus='ide'/>
> >+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
> >+    </disk>
> >+    <controller type='ide' index='0'/>
> >+    <memballoon model='virtio'/>
> >+  </devices>
> >+</domain>
> >diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
> >index 2e07b85aa..7b9b846ef 100644
> >--- a/tests/qemuxml2argvtest.c
> >+++ b/tests/qemuxml2argvtest.c
> >@@ -2810,6 +2810,7 @@ mymain(void)
> >     DO_TEST_PARSE_ERROR("cpu-cache-emulate-l2", QEMU_CAPS_KVM);
> >     DO_TEST_PARSE_ERROR("cpu-cache-passthrough3", QEMU_CAPS_KVM);
> >     DO_TEST_PARSE_ERROR("cpu-cache-passthrough-l3", QEMU_CAPS_KVM);
> >+    DO_TEST("vmcoreinfo", QEMU_CAPS_DEVICE_VMCOREINFO);
> >
> >     DO_TEST("user-aliases", QEMU_CAPS_KVM, QEMU_CAPS_DEVICE_CIRRUS_VGA,
> >             QEMU_CAPS_OBJECT_MEMORY_FILE, QEMU_CAPS_PIIX_DISABLE_S3,
> >diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-vmcoreinfo.xml
> >b/tests/qemuxml2xmloutdata/qemuxml2xmlout-vmcoreinfo.xml
> >new file mode 100644
> >index 000000000..a3922d630
> >--- /dev/null
> >+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-vmcoreinfo.xml
> >@@ -0,0 +1,38 @@
> >+<domain type='qemu'>
> >+  <name>QEMUGuest1</name>
> >+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
> >+  <memory unit='KiB'>219100</memory>
> >+  <currentMemory unit='KiB'>219100</currentMemory>
> >+  <vcpu placement='static'>1</vcpu>
> >+  <os>
> >+    <type arch='i686' machine='pc'>hvm</type>
> >+    <boot dev='hd'/>
> >+  </os>
> >+  <features>
> >+    <vmcoreinfo/>
> >+  </features>
> >+  <clock offset='utc'/>
> >+  <on_poweroff>destroy</on_poweroff>
> >+  <on_reboot>restart</on_reboot>
> >+  <on_crash>destroy</on_crash>
> >+  <devices>
> >+    <emulator>/usr/bin/qemu-system-i686</emulator>
> >+    <disk type='block' device='disk'>
> >+      <source dev='/dev/HostVG/QEMUGuest1'/>
> >+      <target dev='hda' bus='ide'/>
> >+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
> >+    </disk>
> >+    <controller type='ide' index='0'>
> >+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01'
> >function='0x1'/>
> >+    </controller>
> >+    <controller type='usb' index='0'>
> >+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01'
> >function='0x2'/>
> >+    </controller>
> >+    <controller type='pci' index='0' model='pci-root'/>
> >+    <input type='mouse' bus='ps2'/>
> >+    <input type='keyboard' bus='ps2'/>
> >+    <memballoon model='virtio'>
> >+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03'
> >function='0x0'/>
> >+    </memballoon>
> >+  </devices>
> >+</domain>
> >diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
> >index 5a282e5ff..9a7d460e5 100644
> >--- a/tests/qemuxml2xmltest.c
> >+++ b/tests/qemuxml2xmltest.c
> >@@ -1260,6 +1260,7 @@ mymain(void)
> >     DO_TEST("cpu-check-default-none2", NONE);
> >     DO_TEST("cpu-check-default-partial", NONE);
> >     DO_TEST("cpu-check-default-partial2", NONE);
> >+    DO_TEST("vmcoreinfo", NONE);
> >
> >     DO_TEST("smartcard-host", NONE);
> >     DO_TEST("smartcard-host-certificates", NONE);
> >--
> >2.15.0.rc0.40.gaefcc5f6f
> >
> >--
> >libvir-list mailing list
> >libvir-list at redhat.com
> >https://www.redhat.com/mailman/listinfo/libvir-list
> 




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