From: Arun Menon <[email protected]> SWTPM will support backup and fsync of the state file. [1] and [2] Libvirt needs to support these options while launching a VM. This commit adds these optional attributes to the RNG schema, and updates the logic for both creation and parsing them from the XML.
[1] https://github.com/stefanberger/swtpm/commit/186f72a3a995fc68957ffc0b1438bb6e30d51ef0 [2] https://github.com/stefanberger/swtpm/commit/795c1973c913da59925fa6c2d688c5ef51cb5b73 Signed-off-by: Arun Menon <[email protected]> --- docs/formatdomain.rst | 15 +++++++++++++ src/conf/domain_conf.c | 22 +++++++++++++++++++ src/conf/domain_conf.h | 2 ++ src/conf/schemas/domaincommon.rng | 10 +++++++++ .../qemuxmlconfdata/tpm-emulator-tpm2-enc.xml | 2 +- 5 files changed, 50 insertions(+), 1 deletion(-) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index e4eb2d9ba3..402c3ab221 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -8932,6 +8932,21 @@ Example: usage of external TPM emulator :since:`Since 9.0.0` This attribute only works with the ``emulator`` backend. The accepted values are ``yes`` and ``no``. :since:`Since 7.0.0` +``backup`` + The optional ``backup`` attribute controls whether swtpm creates a + backup of its TPM state file before updating it. Enabling backup + protects against TPM state file corruption if swtpm process crashes + unexpectedly. Disabling backups avoids file-copying overhead. The + accepted values are ``yes`` and ``no``. :since:`Since 12.8.0` + +``fsync`` + The optional ``fsync`` attribute controls whether swtpm explicitly + flushes its state changes to the physical storage using fsync(). + Enabling fsync ensures data remains consistent across host power loss, + but might introduces I/O latency. Disabling fsync removes this latency + at the expense of host-level crash resilience. Acceptable + values are ``yes`` and ``no``. :since:`Since 12.8.0` + ``active_pcr_banks`` The ``active_pcr_banks`` node is used to define which of the PCR banks of a TPM 2.0 to activate. Valid names are for example sha1, sha256, sha384, diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 1327793b0a..283658849a 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -11449,6 +11449,11 @@ virDomainSmartcardDefParseXML(virDomainXMLOption *xmlopt, * </backend> * </tpm> * + * Emulator state backup and fsync is supported with the following: + * <tpm model='tpm-crb'> + * <backend type='emulator' version='2.0' backup='yes' fsync='yes'> + * </tpm> + * */ static virDomainTPMDef * virDomainTPMDefParseXML(virDomainXMLOption *xmlopt, @@ -11562,6 +11567,16 @@ virDomainTPMDefParseXML(virDomainXMLOption *xmlopt, } } + if (virXMLPropTristateBool(backends[0], "backup", + VIR_XML_PROP_NONE, + &def->data.emulator.backup) < 0) + goto error; + + if (virXMLPropTristateBool(backends[0], "fsync", + VIR_XML_PROP_NONE, + &def->data.emulator.fsync) < 0) + goto error; + if ((nnodes = virXPathNodeSet("./backend/active_pcr_banks/*", ctxt, &nodes)) < 0) break; if (nnodes > 0) @@ -26743,6 +26758,13 @@ virDomainTPMDefFormat(virBuffer *buf, } if (def->data.emulator.persistent_state) virBufferAddLit(&backendAttrBuf, " persistent_state='yes'"); + + if (def->data.emulator.backup) + virBufferAddLit(&backendAttrBuf, " backup='yes'"); + + if (def->data.emulator.fsync) + virBufferAddLit(&backendAttrBuf, " fsync='yes'"); + if (def->data.emulator.debug != 0) virBufferAsprintf(&backendAttrBuf, " debug='%u'", def->data.emulator.debug); diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index f7cbe7bf1d..fd022ea66f 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1546,6 +1546,8 @@ struct _virDomainTPMEmulatorDef { char *name; /* name read from active profile */ virDomainTPMProfileRemoveDisabled removeDisabled; } profile; + virTristateBool backup; + virTristateBool fsync; }; struct _virDomainTPMDef { diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng index 0c0a3597a9..13de7ce528 100644 --- a/src/conf/schemas/domaincommon.rng +++ b/src/conf/schemas/domaincommon.rng @@ -6208,6 +6208,16 @@ <ref name="uint8"/> </attribute> </optional> + <optional> + <attribute name="backup"> + <ref name="virYesNo"/> + </attribute> + </optional> + <optional> + <attribute name="fsync"> + <ref name="virYesNo"/> + </attribute> + </optional> </group> <group> <attribute name="type"> diff --git a/tests/qemuxmlconfdata/tpm-emulator-tpm2-enc.xml b/tests/qemuxmlconfdata/tpm-emulator-tpm2-enc.xml index e6746d5739..515831ab8c 100644 --- a/tests/qemuxmlconfdata/tpm-emulator-tpm2-enc.xml +++ b/tests/qemuxmlconfdata/tpm-emulator-tpm2-enc.xml @@ -28,7 +28,7 @@ <input type='mouse' bus='ps2'/> <input type='keyboard' bus='ps2'/> <tpm model='tpm-tis'> - <backend type='emulator' version='2.0'> + <backend type='emulator' version='2.0' backup='yes' fsync='yes'> <encryption secret='32ee7e76-2178-47a1-ab7b-269e6e348015'/> <source type='dir' path='/some/dir'/> </backend> -- 2.54.0
