From fadbaa23757ff9dca329bdb8d3447c27599f6884 Mon Sep 17 00:00:00 2001 From: Jim Fehlig Date: Wed, 15 Apr 2020 16:34:54 -0600 Subject: [PATCH] conf: add xen hypervisor feature 'passthrough' 'passthrough' is Xen-Specific guest configuration option new to Xen 4.13 that enables IOMMU mappings for a guest and hence whether it supports PCI passthrough. The default is disabled. See the xl.cfg(5) man page and xen.git commit babde47a3fe for more details. The default state of disabled prevents hotlugging PCI devices. However, if the guest configuration contains a PCI passthrough device at time of creation, libxl will automatically enable 'passthrough' and subsequent hotplugging of PCI devices will also be possible. It is not possible to unconditionally enable 'passthrough' since it would introduce a migration incompatibility due to guest ABI change. Instead, introduce another Xen hypervisor feature that can be used to enable guest PCI passthrough To allow finer control over how IOMMU maps to guest P2M table, the passthrough element also supports a 'mode' attribute with values restricted to snyc_pt and share_pt, similar to xl.cfg(5) 'passthrough' setting . Signed-off-by: Jim Fehlig Reviewed-by: Michal Privoznik --- docs/formatdomain.html.in | 7 ++ docs/schemas/domaincommon.rng | 12 ++++ src/conf/domain_conf.c | 123 +++++++++++++++++++++++++--------- src/conf/domain_conf.h | 11 +++ 4 files changed, 123 insertions(+), 30 deletions(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 81060d6730..9ccae54e04 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -2063,6 +2063,7 @@ </kvm> <xen> <e820_host state='on'/> + <passthrough state='on' mode='share_pt'/> </xen> <pvspinlock state='on'/> <gic version='2'/> @@ -2260,6 +2261,12 @@ on, off 6.3.0 + + passthrough + Enable IOMMU mappings allowing PCI passthrough) + on, off; mode - optional string sync_pt or share_pt + 6.3.0 +
pmu
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 2b5f844658..a6f6e8ab83 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -6349,6 +6349,18 @@ + + + + + + + (sync_pt|share_pt) + + + + + diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index dabbceb265..9f3362c934 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -209,7 +209,15 @@ VIR_ENUM_IMPL(virDomainKVM, VIR_ENUM_IMPL(virDomainXen, VIR_DOMAIN_XEN_LAST, - "e820_host" + "e820_host", + "passthrough", +); + +VIR_ENUM_IMPL(virDomainXenPassthroughMode, + VIR_DOMAIN_XEN_PASSTHROUGH_MODE_LAST, + "default", + "sync_pt", + "share_pt", ); VIR_ENUM_IMPL(virDomainMsrsUnknown, @@ -21182,6 +21190,8 @@ virDomainDefParseXML(xmlDocPtr xml, if (def->features[VIR_DOMAIN_FEATURE_XEN] == VIR_TRISTATE_SWITCH_ON) { int feature; int value; + g_autofree char *ptval = NULL; + if ((n = virXPathNodeSet("./features/xen/*", ctxt, &nodes)) < 0) goto error; @@ -21194,28 +21204,54 @@ virDomainDefParseXML(xmlDocPtr xml, goto error; } + if (!(tmp = virXMLPropString(nodes[i], "state"))) { + virReportError(VIR_ERR_XML_ERROR, + _("missing 'state' attribute for " + "Xen feature '%s'"), + nodes[i]->name); + goto error; + } + + if ((value = virTristateSwitchTypeFromString(tmp)) < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("invalid value of state argument " + "for Xen feature '%s'"), + nodes[i]->name); + goto error; + } + + VIR_FREE(tmp); + def->xen_features[feature] = value; + switch ((virDomainXen) feature) { case VIR_DOMAIN_XEN_E820_HOST: - if (!(tmp = virXMLPropString(nodes[i], "state"))) { - virReportError(VIR_ERR_XML_ERROR, - _("missing 'state' attribute for " - "Xen feature '%s'"), - nodes[i]->name); - goto error; - } - - if ((value = virTristateSwitchTypeFromString(tmp)) < 0) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("invalid value of state argument " - "for Xen feature '%s'"), - nodes[i]->name); - goto error; - } - - VIR_FREE(tmp); - def->xen_features[feature] = value; break; + case VIR_DOMAIN_XEN_PASSTHROUGH: + if (value != VIR_TRISTATE_SWITCH_ON) + break; + + if ((ptval = virXMLPropString(nodes[i], "mode"))) { + int mode = virDomainXenPassthroughModeTypeFromString(ptval); + + if (mode < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unsupported mode '%s' for Xen passthrough feature"), + ptval); + goto error; + } + + if (mode != VIR_DOMAIN_XEN_PASSTHROUGH_MODE_SYNC_PT && + mode != VIR_DOMAIN_XEN_PASSTHROUGH_MODE_SHARE_PT) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("'mode' attribute for Xen feature " + "'passthrough' must be 'sync_pt' or 'share_pt'")); + goto error; + } + def->xen_passthrough_mode = mode; + } + break; + /* coverity[dead_error_begin] */ case VIR_DOMAIN_XEN_LAST: break; @@ -23400,18 +23436,28 @@ virDomainDefFeaturesCheckABIStability(virDomainDefPtr src, /* xen */ if (src->features[VIR_DOMAIN_FEATURE_XEN] == VIR_TRISTATE_SWITCH_ON) { for (i = 0; i < VIR_DOMAIN_XEN_LAST; i++) { + if (src->xen_features[i] != dst->xen_features[i]) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("State of Xen feature '%s' differs: " + "source: '%s', destination: '%s'"), + virDomainXenTypeToString(i), + virTristateSwitchTypeToString(src->xen_features[i]), + virTristateSwitchTypeToString(dst->xen_features[i])); + return false; + } switch ((virDomainXen) i) { case VIR_DOMAIN_XEN_E820_HOST: - if (src->xen_features[i] != dst->xen_features[i]) { + break; + + case VIR_DOMAIN_XEN_PASSTHROUGH: + if (src->xen_passthrough_mode != dst->xen_passthrough_mode) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("State of Xen feature '%s' differs: " + _("'mode' of Xen passthrough feature differs: " "source: '%s', destination: '%s'"), - virDomainXenTypeToString(i), - virTristateSwitchTypeToString(src->xen_features[i]), - virTristateSwitchTypeToString(dst->xen_features[i])); + virDomainXenPassthroughModeTypeToString(src->xen_passthrough_mode), + virDomainXenPassthroughModeTypeToString(dst->xen_passthrough_mode)); return false; } - break; /* coverity[dead_error_begin] */ @@ -29047,13 +29093,30 @@ virDomainDefFormatFeatures(virBufferPtr buf, virBufferAddLit(&childBuf, "\n"); virBufferAdjustIndent(&childBuf, 2); for (j = 0; j < VIR_DOMAIN_XEN_LAST; j++) { + if (def->xen_features[j] == VIR_TRISTATE_SWITCH_ABSENT) + continue; + + virBufferAsprintf(&childBuf, "<%s state='%s'", + virDomainXenTypeToString(j), + virTristateSwitchTypeToString( + def->xen_features[j])); + switch ((virDomainXen) j) { case VIR_DOMAIN_XEN_E820_HOST: - if (def->xen_features[j]) - virBufferAsprintf(&childBuf, "<%s state='%s'/>\n", - virDomainXenTypeToString(j), - virTristateSwitchTypeToString( - def->xen_features[j])); + virBufferAddLit(&childBuf, "/>\n"); + break; + case VIR_DOMAIN_XEN_PASSTHROUGH: + if (def->xen_features[j] != VIR_TRISTATE_SWITCH_ON) { + virBufferAddLit(&childBuf, "/>\n"); + break; + } + if (def->xen_passthrough_mode == VIR_DOMAIN_XEN_PASSTHROUGH_MODE_SYNC_PT || + def->xen_passthrough_mode == VIR_DOMAIN_XEN_PASSTHROUGH_MODE_SHARE_PT) { + virBufferEscapeString(&childBuf, " mode='%s'/>\n", + virDomainXenPassthroughModeTypeToString(def->xen_passthrough_mode)); + } else { + virBufferAddLit(&childBuf, "/>\n"); + } break; /* coverity[dead_error_begin] */ diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index fde88b7389..bfd1bbb532 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1862,10 +1862,19 @@ typedef enum { typedef enum { VIR_DOMAIN_XEN_E820_HOST = 0, + VIR_DOMAIN_XEN_PASSTHROUGH, VIR_DOMAIN_XEN_LAST } virDomainXen; +typedef enum { + VIR_DOMAIN_XEN_PASSTHROUGH_MODE_DEFAULT = 0, + VIR_DOMAIN_XEN_PASSTHROUGH_MODE_SYNC_PT, + VIR_DOMAIN_XEN_PASSTHROUGH_MODE_SHARE_PT, + + VIR_DOMAIN_XEN_PASSTHROUGH_MODE_LAST +} virDomainXenPassthroughMode; + typedef enum { VIR_DOMAIN_CAPABILITIES_POLICY_DEFAULT = 0, VIR_DOMAIN_CAPABILITIES_POLICY_ALLOW, @@ -2492,6 +2501,7 @@ struct _virDomainDef { int kvm_features[VIR_DOMAIN_KVM_LAST]; int msrs_features[VIR_DOMAIN_MSRS_LAST]; int xen_features[VIR_DOMAIN_XEN_LAST]; + int xen_passthrough_mode; unsigned int hyperv_spinlocks; int hyperv_stimer_direct; virGICVersion gic_version; @@ -3538,6 +3548,7 @@ VIR_ENUM_DECL(virDomainGraphicsVNCSharePolicy); VIR_ENUM_DECL(virDomainHyperv); VIR_ENUM_DECL(virDomainKVM); VIR_ENUM_DECL(virDomainXen); +VIR_ENUM_DECL(virDomainXenPassthroughMode); VIR_ENUM_DECL(virDomainMsrsUnknown); VIR_ENUM_DECL(virDomainRNGModel); VIR_ENUM_DECL(virDomainRNGBackend);