[libvirt] [PATCH v2 4/4] qemu: caps: Format SEV platform data into qemuCaps cache
Erik Skultety
eskultet at redhat.com
Thu Aug 16 10:35:18 UTC 2018
Since we're not saving the platform-specific data into a cache, we're
not going to populate the structure, which in turn will cause a crash
upon calling virNodeGetSEVInfo because of a NULL pointer dereference.
Ultimately, we should start caching this data along with host-specific
capabilities like NUMA and SELinux stuff into a separate cache, but for
the time being, this is a semi-proper fix for a potential crash.
Backtrace (requires libvirtd restart to load qemu caps from cache):
#0 qemuGetSEVInfoToParams
#1 qemuNodeGetSEVInfo
#2 virNodeGetSEVInfo
#3 remoteDispatchNodeGetSevInfo
#4 remoteDispatchNodeGetSevInfoHelper
#5 virNetServerProgramDispatchCall
#6 virNetServerProgramDispatch
#7 virNetServerProcessMsg
#8 virNetServerHandleJob
#9 virThreadPoolWorker
#10 virThreadHelper
https: //bugzilla.redhat.com/show_bug.cgi?id=1612009
Signed-off-by: Erik Skultety <eskultet at redhat.com>
Acked-by: Peter Krempa <pkrempa at redhat.com>
---
src/qemu/qemu_capabilities.c | 100 ++++++++++++++++++++++
tests/domaincapsschemadata/qemu_2.12.0.x86_64.xml | 5 +-
tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml | 6 ++
3 files changed, 110 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index fc46a380f6..9edb4ca4d4 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -1570,6 +1570,25 @@ virQEMUCapsHostCPUDataClear(virQEMUCapsHostCPUDataPtr cpuData)
}
+static int
+virQEMUCapsSEVInfoCopy(virSEVCapabilityPtr *dst,
+ virSEVCapabilityPtr src)
+{
+ VIR_AUTOPTR(virSEVCapability) tmp = NULL;
+
+ if (VIR_ALLOC(tmp) < 0 ||
+ VIR_STRDUP(tmp->pdh, src->pdh) < 0 ||
+ VIR_STRDUP(tmp->cert_chain, src->cert_chain) < 0)
+ return -1;
+
+ tmp->cbitpos = src->cbitpos;
+ tmp->reduced_phys_bits = src->reduced_phys_bits;
+
+ VIR_STEAL_PTR(*dst, tmp);
+ return 0;
+}
+
+
virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps)
{
virQEMUCapsPtr ret = virQEMUCapsNew();
@@ -1632,6 +1651,11 @@ virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps)
for (i = 0; i < qemuCaps->ngicCapabilities; i++)
ret->gicCapabilities[i] = qemuCaps->gicCapabilities[i];
+ if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_SEV_GUEST) &&
+ virQEMUCapsSEVInfoCopy(&ret->sevCapabilities,
+ qemuCaps->sevCapabilities) < 0)
+ goto error;
+
return ret;
error:
@@ -3344,6 +3368,58 @@ virQEMUCapsCachePrivFree(void *privData)
}
+static int
+virQEMUCapsParseSEVInfo(virQEMUCapsPtr qemuCaps, xmlXPathContextPtr ctxt)
+{
+ VIR_AUTOPTR(virSEVCapability) sev = NULL;
+
+ if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_SEV_GUEST))
+ return 0;
+
+ if (virXPathBoolean("boolean(./sev)", ctxt) == 0) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("missing SEV platform data in QEMU "
+ "capabilities cache"));
+ return -1;
+ }
+
+ if (VIR_ALLOC(sev) < 0)
+ return -1;
+
+ if (virXPathUInt("string(./sev/cbitpos)", ctxt, &sev->cbitpos) < 0) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("missing or malformed SEV cbitpos information "
+ "in QEMU capabilities cache"));
+ return -1;
+ }
+
+ if (virXPathUInt("string(./sev/reducedPhysBits)", ctxt,
+ &sev->reduced_phys_bits) < 0) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("missing or malformed SEV reducedPhysBits information "
+ "in QEMU capabilities cache"));
+ return -1;
+ }
+
+ if (!(sev->pdh = virXPathString("string(./sev/pdh)", ctxt))) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("missing SEV pdh information "
+ "in QEMU capabilities cache"));
+ return -1;
+ }
+
+ if (!(sev->cert_chain = virXPathString("string(./sev/certChain)", ctxt))) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("missing SEV certChain information "
+ "in QEMU capabilities cache"));
+ return -1;
+ }
+
+ VIR_STEAL_PTR(qemuCaps->sevCapabilities, sev);
+ return 0;
+}
+
+
/*
* Parsing a doc that looks like
*
@@ -3592,6 +3668,9 @@ virQEMUCapsLoadCache(virArch hostArch,
}
VIR_FREE(nodes);
+ if (virQEMUCapsParseSEVInfo(qemuCaps, ctxt) < 0)
+ goto cleanup;
+
virQEMUCapsInitHostCPUModel(qemuCaps, hostArch, VIR_DOMAIN_VIRT_KVM);
virQEMUCapsInitHostCPUModel(qemuCaps, hostArch, VIR_DOMAIN_VIRT_QEMU);
@@ -3709,6 +3788,24 @@ virQEMUCapsFormatCPUModels(virQEMUCapsPtr qemuCaps,
}
+static void
+virQEMUCapsFormatSEVInfo(virQEMUCapsPtr qemuCaps, virBufferPtr buf)
+{
+ virSEVCapabilityPtr sev = virQEMUCapsGetSEVCapabilities(qemuCaps);
+
+ virBufferAddLit(buf, "<sev>\n");
+ virBufferAdjustIndent(buf, 2);
+ virBufferAsprintf(buf, "<cbitpos>%u</cbitpos>\n", sev->cbitpos);
+ virBufferAsprintf(buf, "<reducedPhysBits>%u</reducedPhysBits>\n",
+ sev->reduced_phys_bits);
+ virBufferEscapeString(buf, "<pdh>%s</pdh>\n", sev->pdh);
+ virBufferEscapeString(buf, "<certChain>%s</certChain>\n",
+ sev->cert_chain);
+ virBufferAdjustIndent(buf, -2);
+ virBufferAddLit(buf, "</sev>\n");
+}
+
+
char *
virQEMUCapsFormatCache(virQEMUCapsPtr qemuCaps)
{
@@ -3790,6 +3887,9 @@ virQEMUCapsFormatCache(virQEMUCapsPtr qemuCaps)
emulated ? "yes" : "no");
}
+ if (qemuCaps->sevCapabilities)
+ virQEMUCapsFormatSEVInfo(qemuCaps, &buf);
+
virBufferAdjustIndent(&buf, -2);
virBufferAddLit(&buf, "</qemuCaps>\n");
diff --git a/tests/domaincapsschemadata/qemu_2.12.0.x86_64.xml b/tests/domaincapsschemadata/qemu_2.12.0.x86_64.xml
index 7a1be4c093..a8d6a4d629 100644
--- a/tests/domaincapsschemadata/qemu_2.12.0.x86_64.xml
+++ b/tests/domaincapsschemadata/qemu_2.12.0.x86_64.xml
@@ -142,6 +142,9 @@
<gic supported='no'/>
<vmcoreinfo supported='yes'/>
<genid supported='yes'/>
- <sev supported='no'/>
+ <sev supported='yes'>
+ <cbitpos>47</cbitpos>
+ <reducedPhysBits>1</reducedPhysBits>
+ </sev>
</features>
</domainCapabilities>
diff --git a/tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml
index d34d762ca8..d134e5632d 100644
--- a/tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml
@@ -1253,4 +1253,10 @@
<machine name='pc-0.11' hotplugCpus='yes' maxCpus='255'/>
<machine name='pc-0.12' hotplugCpus='yes' maxCpus='255'/>
<machine name='pc-0.10' hotplugCpus='yes' maxCpus='255'/>
+ <sev>
+ <cbitpos>47</cbitpos>
+ <reducedPhysBits>1</reducedPhysBits>
+ <pdh>AQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAA</pdh>
+ <certChain>AQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAAAQAAAAAOAAA</certChain>
+ </sev>
</qemuCaps>
--
2.14.4
More information about the libvir-list
mailing list