From 05b6b6d0d034e0a2ecb9b826bf5052a3bada218d Mon Sep 17 00:00:00 2001

Message-Id: <05b6b6d0d034e0a2ecb9b826bf5052a3bada218d@dist-git>

From: Erik Skultety <eskultet@redhat.com>

Date: Mon, 20 Aug 2018 17:18:53 +0200

Subject: [PATCH] qemu: caps: Format SEV platform data into qemuCaps cache

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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@redhat.com>

Acked-by: Peter Krempa <pkrempa@redhat.com>

Tested-by: Brijesh Singh <brijesh.singh@amd.com>

(cherry picked from commit 77f51ab52049734d80a8ccb79b80189c7fb95c41)

https://bugzilla.redhat.com/show_bug.cgi?id=1612009

https://bugzilla.redhat.com/show_bug.cgi?id=1619150

Amend:

    - fixed the VIR_AUTOPTR bits which downstream doesn't support

    and wouldn't compile

Signed-off-by: Erik Skultety <eskultet@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/qemu/qemu_capabilities.c                  | 109 ++++++++++++++++++

 .../qemu_2.12.0.x86_64.xml                    |   5 +-

 .../caps_2.12.0.x86_64.xml                    |   6 +

 3 files changed, 119 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c

index 470f25a5a6..4f2051a2bb 100644

--- a/src/qemu/qemu_capabilities.c

+++ b/src/qemu/qemu_capabilities.c

@@ -1573,6 +1573,30 @@ virQEMUCapsHostCPUDataClear(virQEMUCapsHostCPUDataPtr cpuData)

 }

+static int

+virQEMUCapsSEVInfoCopy(virSEVCapabilityPtr *dst,

+                       virSEVCapabilityPtr src)

+{

+    int ret = -1;

+    virSEVCapabilityPtr tmp = NULL;

+

+    if (VIR_ALLOC(tmp) < 0 ||

+        VIR_STRDUP(tmp->pdh, src->pdh) < 0 ||

+        VIR_STRDUP(tmp->cert_chain, src->cert_chain) < 0)

+        goto cleanup;

+

+    tmp->cbitpos = src->cbitpos;

+    tmp->reduced_phys_bits = src->reduced_phys_bits;

+

+    VIR_STEAL_PTR(*dst, tmp);

+

+    ret = 0;

+ cleanup:

+    virSEVCapabilitiesFree(tmp);

+    return ret;

+}

+

+

 virQEMUCapsPtr virQEMUCapsNewCopy(virQEMUCapsPtr qemuCaps)

 {

     virQEMUCapsPtr ret = virQEMUCapsNew();

@@ -1635,6 +1659,11 @@ 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:

@@ -3273,6 +3302,62 @@ virQEMUCapsCachePrivFree(void *privData)

 }

+static int

+virQEMUCapsParseSEVInfo(virQEMUCapsPtr qemuCaps, xmlXPathContextPtr ctxt)

+{

+    int ret = -1;

+    virSEVCapabilityPtr 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"));

+        goto cleanup;

+    }

+

+    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"));

+        goto cleanup;

+    }

+

+    if (!(sev->pdh = virXPathString("string(./sev/pdh)", ctxt)))  {

+        virReportError(VIR_ERR_XML_ERROR, "%s",

+                       _("missing SEV pdh information "

+                         "in QEMU capabilities cache"));

+        goto cleanup;

+    }

+

+    if (!(sev->cert_chain = virXPathString("string(./sev/certChain)", ctxt))) {

+        virReportError(VIR_ERR_XML_ERROR, "%s",

+                       _("missing SEV certChain information "

+                         "in QEMU capabilities cache"));

+        goto cleanup;

+    }

+

+    VIR_STEAL_PTR(qemuCaps->sevCapabilities, sev);

+    ret = 0;

+ cleanup:

+    virSEVCapabilitiesFree(sev);

+    return ret;

+}

+

+

 /*

  * Parsing a doc that looks like

  *

@@ -3521,6 +3606,9 @@ 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);

@@ -3638,6 +3726,24 @@ 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)

 {

@@ -3719,6 +3825,9 @@ 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 78889facce..f0dc082640 100644

--- a/tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml

+++ b/tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml

@@ -1254,4 +1254,10 @@

   <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>

-- 

2.18.0