diff options
Diffstat (limited to 'OvmfPkg')
| -rw-r--r-- | OvmfPkg/IoMmuDxe/AmdSevIoMmu.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c b/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c index 34e1c6ee4a..6b7df8d8aa 100644 --- a/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c +++ b/OvmfPkg/IoMmuDxe/AmdSevIoMmu.c @@ -749,6 +749,107 @@ EDKII_IOMMU_PROTOCOL mAmdSev = { };
/**
+ Notification function that is queued when gBS->ExitBootServices() signals the
+ EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. This function signals another
+ event, received as Context, and returns.
+
+ Signaling an event in this context is safe. The UEFI spec allows
+ gBS->SignalEvent() to return EFI_SUCCESS only; EFI_OUT_OF_RESOURCES is not
+ listed, hence memory is not allocated. The edk2 implementation also does not
+ release memory (and we only have to care about the edk2 implementation
+ because EDKII_IOMMU_PROTOCOL is edk2-specific anyway).
+
+ @param[in] Event Event whose notification function is being invoked.
+ Event is permitted to request the queueing of this
+ function at TPL_CALLBACK or TPL_NOTIFY task
+ priority level.
+
+ @param[in] EventToSignal Identifies the EFI_EVENT to signal. EventToSignal
+ is permitted to request the queueing of its
+ notification function only at TPL_CALLBACK level.
+**/
+STATIC
+VOID
+EFIAPI
+AmdSevExitBoot (
+ IN EFI_EVENT Event,
+ IN VOID *EventToSignal
+ )
+{
+ //
+ // (1) The NotifyFunctions of all the events in
+ // EFI_EVENT_GROUP_EXIT_BOOT_SERVICES will have been queued before
+ // AmdSevExitBoot() is entered.
+ //
+ // (2) AmdSevExitBoot() is executing minimally at TPL_CALLBACK.
+ //
+ // (3) AmdSevExitBoot() has been queued in unspecified order relative to the
+ // NotifyFunctions of all the other events in
+ // EFI_EVENT_GROUP_EXIT_BOOT_SERVICES whose NotifyTpl is the same as
+ // Event's.
+ //
+ // Consequences:
+ //
+ // - If Event's NotifyTpl is TPL_CALLBACK, then some other NotifyFunctions
+ // queued at TPL_CALLBACK may be invoked after AmdSevExitBoot() returns.
+ //
+ // - If Event's NotifyTpl is TPL_NOTIFY, then some other NotifyFunctions
+ // queued at TPL_NOTIFY may be invoked after AmdSevExitBoot() returns; plus
+ // *all* NotifyFunctions queued at TPL_CALLBACK will be invoked strictly
+ // after all NotifyFunctions queued at TPL_NOTIFY, including
+ // AmdSevExitBoot(), have been invoked.
+ //
+ // - By signaling EventToSignal here, whose NotifyTpl is TPL_CALLBACK, we
+ // queue EventToSignal's NotifyFunction after the NotifyFunctions of *all*
+ // events in EFI_EVENT_GROUP_EXIT_BOOT_SERVICES.
+ //
+ DEBUG ((DEBUG_VERBOSE, "%a\n", __FUNCTION__));
+ gBS->SignalEvent (EventToSignal);
+}
+
+/**
+ Notification function that is queued after the notification functions of all
+ events in the EFI_EVENT_GROUP_EXIT_BOOT_SERVICES event group. The same memory
+ map restrictions apply.
+
+ This function unmaps all currently existing IOMMU mappings.
+
+ @param[in] Event Event whose notification function is being invoked. Event
+ is permitted to request the queueing of this function
+ only at TPL_CALLBACK task priority level.
+
+ @param[in] Context Ignored.
+**/
+STATIC
+VOID
+EFIAPI
+AmdSevUnmapAllMappings (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ LIST_ENTRY *Node;
+ LIST_ENTRY *NextNode;
+ MAP_INFO *MapInfo;
+
+ DEBUG ((DEBUG_VERBOSE, "%a\n", __FUNCTION__));
+
+ //
+ // All drivers that had set up IOMMU mappings have halted their respective
+ // controllers by now; tear down the mappings.
+ //
+ for (Node = GetFirstNode (&mMapInfos); Node != &mMapInfos; Node = NextNode) {
+ NextNode = GetNextNode (&mMapInfos, Node);
+ MapInfo = CR (Node, MAP_INFO, Link, MAP_INFO_SIG);
+ IoMmuUnmapWorker (
+ &mAmdSev, // This
+ MapInfo, // Mapping
+ TRUE // MemoryMapLocked
+ );
+ }
+}
+
+/**
Initialize Iommu Protocol.
**/
@@ -759,13 +860,57 @@ AmdSevInstallIoMmuProtocol ( )
{
EFI_STATUS Status;
+ EFI_EVENT UnmapAllMappingsEvent;
+ EFI_EVENT ExitBootEvent;
EFI_HANDLE Handle;
+ //
+ // Create the "late" event whose notification function will tear down all
+ // left-over IOMMU mappings.
+ //
+ Status = gBS->CreateEvent (
+ EVT_NOTIFY_SIGNAL, // Type
+ TPL_CALLBACK, // NotifyTpl
+ AmdSevUnmapAllMappings, // NotifyFunction
+ NULL, // NotifyContext
+ &UnmapAllMappingsEvent // Event
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // Create the event whose notification function will be queued by
+ // gBS->ExitBootServices() and will signal the event created above.
+ //
+ Status = gBS->CreateEvent (
+ EVT_SIGNAL_EXIT_BOOT_SERVICES, // Type
+ TPL_CALLBACK, // NotifyTpl
+ AmdSevExitBoot, // NotifyFunction
+ UnmapAllMappingsEvent, // NotifyContext
+ &ExitBootEvent // Event
+ );
+ if (EFI_ERROR (Status)) {
+ goto CloseUnmapAllMappingsEvent;
+ }
+
Handle = NULL;
Status = gBS->InstallMultipleProtocolInterfaces (
&Handle,
&gEdkiiIoMmuProtocolGuid, &mAmdSev,
NULL
);
+ if (EFI_ERROR (Status)) {
+ goto CloseExitBootEvent;
+ }
+
+ return EFI_SUCCESS;
+
+CloseExitBootEvent:
+ gBS->CloseEvent (ExitBootEvent);
+
+CloseUnmapAllMappingsEvent:
+ gBS->CloseEvent (UnmapAllMappingsEvent);
+
return Status;
}
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