[libvirt] [PATCH v3 2/9] qemu: introduce SEV feature in hypervisor capabilities
Brijesh Singh
brijesh.singh at amd.com
Wed Mar 14 15:44:28 UTC 2018
Extend hypervisor capabilities to include sev feature. When available,
hypervisor supports launching an encrypted VM on AMD platform. The
sev feature tag provides additional details like platform diffie-hellman
key and certificate chain which can be used by the guest owner to
establish a cryptographic session with the SEV firmware to negotiate
keys used for attestation or to provide secret during launch.
Reviewed-by: "Daniel P. Berrangé" <berrange at redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh at amd.com>
---
docs/formatdomaincaps.html.in | 40 ++++++++++++++++++++++++++++++++++++++++
docs/schemas/domaincaps.rng | 20 ++++++++++++++++++++
src/conf/domain_capabilities.c | 20 ++++++++++++++++++++
src/conf/domain_capabilities.h | 1 +
src/qemu/qemu_capabilities.c | 2 ++
5 files changed, 83 insertions(+)
diff --git a/docs/formatdomaincaps.html.in b/docs/formatdomaincaps.html.in
index 6bfcaf61caae..f38314166ac3 100644
--- a/docs/formatdomaincaps.html.in
+++ b/docs/formatdomaincaps.html.in
@@ -417,6 +417,12 @@
<value>3</value>
</enum>
</gic>
+ <sev>
+ <pdh> </pdh>
+ <cert-chain> </cert-chain>
+ <cbitpos> </cbitpos>
+ <reduced-phys-bits> </reduced-phys-bits>
+ </sev>
</features>
</domainCapabilities>
</pre>
@@ -441,5 +447,39 @@
<code>gic</code> element.</dd>
</dl>
+ <h4><a id="elementsSEV">SEV capabilities</a></h4>
+
+ <p>AMD Secure Encrypted Virtualization (SEV) capabilities are exposed under
+ the <code>sev</code> element.
+ SEV is an extension to the AMD-V architecture which supports running
+ virtual machines (VMs) under the control of a hypervisor. When supported,
+ guest owner can create a VM whose memory contents will be transparently
+ encrypted with a key unique to that VM.
+
+ For more details on SEV feature see:
+ <a href="https://support.amd.com/TechDocs/55766_SEV-KM%20API_Specification.pdf">
+ SEV API spec</a> and <a href="http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf">
+ SEV White Paper</a>
+
+ </p>
+
+ <dl>
+ <dt><code>pdh</code></dt>
+ <dd>Platform diffie-hellman key, which can be exported to remote entities
+ which wish to establish a secure transport context with the SEV platform
+ in order to transmit data securely. The key is encoded in base64</dd>
+ <dt><code>cert-chain</code></dt>
+ <dd> Platform certificate chain -- which includes platform endorsement key
+ (PEK), owners certificate authory (OCA) and chip endorsement key (CEK).
+ The certificate chain is encoded in base64.</dd>
+ <dt><code>cbitpos</code></dt>
+ <dd>When memory encryption is enabled, one of the physical address bit
+ (aka the C-bit) is utilized to mark if a memory page is protected. The
+ C-bit position is Hypervisor dependent.</dd>
+ <dt><code>reduced-phys-bits</code></dt>
+ <dd>When memory encryption is enabled, we loose certain bits in physical
+ address space. The number of bits we loose is hypervisor dependent.</dd>
+ </dl>
+
</body>
</html>
diff --git a/docs/schemas/domaincaps.rng b/docs/schemas/domaincaps.rng
index 39053181eb9a..53b33eb83c1f 100644
--- a/docs/schemas/domaincaps.rng
+++ b/docs/schemas/domaincaps.rng
@@ -173,6 +173,9 @@
<element name='features'>
<interleave>
<ref name='gic'/>
+ <optional>
+ <ref name='sev'/>
+ </optional>
</interleave>
</element>
</define>
@@ -184,6 +187,23 @@
</element>
</define>
+ <define name='sev'>
+ <element name='sev'>
+ <element name='pdh'>
+ <data type='string'/>
+ </element>
+ <element name='cert-chain'>
+ <data type='string'/>
+ </element>
+ <element name='cbitpos'>
+ <data type='unsignedInt'/>
+ </element>
+ <element name='reduced-phys-bits'>
+ <data type='unsignedInt'/>
+ </element>
+ </element>
+ </define>
+
<define name='value'>
<zeroOrMore>
<element name='value'>
diff --git a/src/conf/domain_capabilities.c b/src/conf/domain_capabilities.c
index f7d9be50f82d..082065fb4733 100644
--- a/src/conf/domain_capabilities.c
+++ b/src/conf/domain_capabilities.c
@@ -549,6 +549,25 @@ virDomainCapsFeatureGICFormat(virBufferPtr buf,
FORMAT_EPILOGUE(gic);
}
+static void
+virDomainCapsFeatureSEVFormat(virBufferPtr buf,
+ virSEVCapabilityPtr const sev)
+{
+ if (!sev)
+ return;
+
+ virBufferAddLit(buf, "<sev supported='yes'>\n");
+ virBufferAdjustIndent(buf, 2);
+ virBufferAsprintf(buf, "<cbitpos>%d</cbitpos>\n", sev->cbitpos);
+ virBufferAsprintf(buf, "<reduced-phys-bits>%d</reduced-phys-bits>\n",
+ sev->reduced_phys_bits);
+ virBufferAsprintf(buf, "<pdh>%s</pdh>\n", sev->pdh);
+ virBufferAsprintf(buf, "<cert-chain>%s</cert-chain>\n",
+ sev->cert_chain);
+ virBufferAdjustIndent(buf, -2);
+ virBufferAddLit(buf, "</sev>\n");
+}
+
char *
virDomainCapsFormat(virDomainCapsPtr const caps)
@@ -587,6 +606,7 @@ virDomainCapsFormat(virDomainCapsPtr const caps)
virBufferAdjustIndent(&buf, 2);
virDomainCapsFeatureGICFormat(&buf, &caps->gic);
+ virDomainCapsFeatureSEVFormat(&buf, caps->sev);
virBufferAdjustIndent(&buf, -2);
virBufferAddLit(&buf, "</features>\n");
diff --git a/src/conf/domain_capabilities.h b/src/conf/domain_capabilities.h
index 72e9daf9120f..2e8596ceea58 100644
--- a/src/conf/domain_capabilities.h
+++ b/src/conf/domain_capabilities.h
@@ -170,6 +170,7 @@ struct _virDomainCaps {
/* add new domain devices here */
virDomainCapsFeatureGIC gic;
+ virSEVCapabilityPtr sev;
/* add new domain features here */
};
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 6da7cf7477c7..4517ea19224d 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -5925,6 +5925,8 @@ virQEMUCapsFillDomainCaps(virCapsPtr caps,
virQEMUCapsFillDomainDeviceHostdevCaps(qemuCaps, hostdev) < 0 ||
virQEMUCapsFillDomainFeatureGICCaps(qemuCaps, domCaps) < 0)
return -1;
+
+ domCaps->sev = qemuCaps->sevCapabilities;
return 0;
}
--
2.14.3
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