Re: [libvirt] [PATCH v6 2/9] qemu: introduce SEV feature in hypervisor capabilities

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 (PDH) 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. Signed-off-by: Brijesh Singh <brijesh.singh(a)amd.com&gt; ---

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 b68ae4b4f1f3..f37b059ba6b1 100644 --- a/docs/formatdomaincaps.html.in +++ b/docs/formatdomaincaps.html.in @@ -434,6 +434,12 @@ &lt;/enum&gt; &lt;/gic&gt; &lt;vmcoreinfo supported='yes'/&gt; + &lt;sev&gt; + &lt;pdh&gt;UWxKSlNrVlRTRk5KVGtkSVFVMUU=&lt;/pdh&gt; + &lt;cert-chain&gt;VVd4S1NsTnJWbFJUUms1S1ZHdGtTVkZWTVVVPQ==&lt;/cert-chain&gt; + &lt;cbitpos&gt;47&lt;/cbitpos&gt; + &lt;reduced-phys-bits&gt;1&lt;/reduced-phys-bits&gt; + &lt;/sev&gt; &lt;/features&gt; &lt;/domainCapabilities&gt; </pre> @@ -462,5 +468,39 @@ <p>Reports whether the vmcoreinfo feature can be enabled</p> + <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.</p> + + <p> + For more details on SEV feature see: + <a href="https://support.amd.com/TechDocs/55766_SEV-KM%20API_Specificat... + SEV API spec</a> and <a href="http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12... + SEV White Paper</a> + </p> + + <dl> + <dt><code>pdh</code></dt> + <dd>A base64 encoded platform Diffie-Hellman public key which can be + exported to remote entities that desire to establish a secure transport + context with the SEV platform in order to transmit data securely.</dd> + <dt><code>cert-chain</code></dt> + <dd> A base64 encoded platform certificate chain that includes the platform + endorsement key (PEK), owners certificate authority (OCD), and chip + endorsement key (CEK).</dd> + <dt><code>cbitpos</code></dt> + <dd>When memory encryption is enabled, one of the physical address bits + (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 lose certain bits in physical + address space. The number of bits we lose is hypervisor dependent.</dd> + </dl> + </body> </html> diff --git a/docs/schemas/domaincaps.rng b/docs/schemas/domaincaps.rng index 5913d711a3fe..26265645b82a 100644 --- a/docs/schemas/domaincaps.rng +++ b/docs/schemas/domaincaps.rng @@ -184,6 +184,9 @@ <interleave> <ref name='gic'/> <ref name='vmcoreinfo'/> + <optional> + <ref name='sev'/>

+ </optional> </interleave> </element> </define> @@ -201,6 +204,23 @@ </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 6e2ab0a28796..3b767c45cbb3 100644 --- a/src/conf/domain_capabilities.c +++ b/src/conf/domain_capabilities.c @@ -542,6 +542,25 @@ 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); + virBufferEscapeString(buf, "<pdh>%s</pdh>\n", sev->pdh); + virBufferEscapeString(buf, "<cert-chain>%s</cert-chain>\n", + sev->cert_chain);

+ virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</sev>\n"); +} + char * virDomainCapsFormat(virDomainCapsPtr const caps) @@ -585,6 +604,7 @@ virDomainCapsFormat(virDomainCapsPtr const caps) virDomainCapsFeatureGICFormat(&buf, &caps->gic); virBufferAsprintf(&buf, "<vmcoreinfo supported='%s'/>\n", caps->vmcoreinfo ? "yes" : "no"); + 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 c1093234ceb8..e33bef525ef4 100644 --- a/src/conf/domain_capabilities.h +++ b/src/conf/domain_capabilities.h @@ -172,6 +172,7 @@ struct _virDomainCaps { virDomainCapsFeatureGIC gic; bool vmcoreinfo; + virSEVCapabilityPtr sev; /* add new domain features here */ }; diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 49b74f7e12c1..3345b09fa384 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -4998,6 +4998,8 @@ virQEMUCapsFillDomainCaps(virCapsPtr caps, virQEMUCapsFillDomainDeviceHostdevCaps(qemuCaps, hostdev) < 0 || virQEMUCapsFillDomainFeatureGICCaps(qemuCaps, domCaps) < 0) return -1; + + domCaps->sev = qemuCaps->sevCapabilities;