ArmVirtPkg/PlatformBootManagerLib: connect Virtio RNG devices again

[mirror_edk2.git] / ArmVirtPkg / Library / PlatformBootManagerLib / PlatformBm.c

diff --git a/ArmVirtPkg/Library/PlatformBootManagerLib/PlatformBm.c b/ArmVirtPkg/Library/PlatformBootManagerLib/PlatformBm.c
index 5d5e51d8c870cec53f733cc3d71434443dd3397e..62cce6a01e1a8fb308380f643e7fd10cf59d6013 100644 (file)
--- a/ArmVirtPkg/Library/PlatformBootManagerLib/PlatformBm.c
+++ b/ArmVirtPkg/Library/PlatformBootManagerLib/PlatformBm.c
@@ -16,6 +16,7 @@
 **/\r
 \r
 #include <IndustryStandard/Pci22.h>\r
+#include <IndustryStandard/Virtio095.h>\r
 #include <Library/BootLogoLib.h>\r
 #include <Library/DevicePathLib.h>\r
 #include <Library/PcdLib.h>\r
@@ -27,6 +28,7 @@
 #include <Protocol/LoadedImage.h>\r
 #include <Protocol/PciIo.h>\r
 #include <Protocol/PciRootBridgeIo.h>\r
+#include <Protocol/VirtioDevice.h>\r
 #include <Guid/EventGroup.h>\r
 #include <Guid/RootBridgesConnectedEventGroup.h>\r
 \r
@@ -260,6 +262,121 @@ IsPciDisplay (
 }\r
 \r
 \r
+/**\r
+  This FILTER_FUNCTION checks if a handle corresponds to a Virtio RNG device at\r
+  the VIRTIO_DEVICE_PROTOCOL level.\r
+**/\r
+STATIC\r
+BOOLEAN\r
+EFIAPI\r
+IsVirtioRng (\r
+  IN EFI_HANDLE   Handle,\r
+  IN CONST CHAR16 *ReportText\r
+  )\r
+{\r
+  EFI_STATUS             Status;\r
+  VIRTIO_DEVICE_PROTOCOL *VirtIo;\r
+\r
+  Status = gBS->HandleProtocol (Handle, &gVirtioDeviceProtocolGuid,\r
+                  (VOID**)&VirtIo);\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+  return (BOOLEAN)(VirtIo->SubSystemDeviceId ==\r
+                   VIRTIO_SUBSYSTEM_ENTROPY_SOURCE);\r
+}\r
+\r
+\r
+/**\r
+  This FILTER_FUNCTION checks if a handle corresponds to a Virtio RNG device at\r
+  the EFI_PCI_IO_PROTOCOL level.\r
+**/\r
+STATIC\r
+BOOLEAN\r
+EFIAPI\r
+IsVirtioPciRng (\r
+  IN EFI_HANDLE   Handle,\r
+  IN CONST CHAR16 *ReportText\r
+  )\r
+{\r
+  EFI_STATUS          Status;\r
+  EFI_PCI_IO_PROTOCOL *PciIo;\r
+  UINT16              VendorId;\r
+  UINT16              DeviceId;\r
+  UINT8               RevisionId;\r
+  BOOLEAN             Virtio10;\r
+  UINT16              SubsystemId;\r
+\r
+  Status = gBS->HandleProtocol (Handle, &gEfiPciIoProtocolGuid,\r
+                  (VOID**)&PciIo);\r
+  if (EFI_ERROR (Status)) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Read and check VendorId.\r
+  //\r
+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_VENDOR_ID_OFFSET,\r
+                        1, &VendorId);\r
+  if (EFI_ERROR (Status)) {\r
+    goto PciError;\r
+  }\r
+  if (VendorId != VIRTIO_VENDOR_ID) {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Read DeviceId and RevisionId.\r
+  //\r
+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_DEVICE_ID_OFFSET,\r
+                        1, &DeviceId);\r
+  if (EFI_ERROR (Status)) {\r
+    goto PciError;\r
+  }\r
+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint8, PCI_REVISION_ID_OFFSET,\r
+                        1, &RevisionId);\r
+  if (EFI_ERROR (Status)) {\r
+    goto PciError;\r
+  }\r
+\r
+  //\r
+  // From DeviceId and RevisionId, determine whether the device is a\r
+  // modern-only Virtio 1.0 device. In case of Virtio 1.0, DeviceId can\r
+  // immediately be restricted to VIRTIO_SUBSYSTEM_ENTROPY_SOURCE, and\r
+  // SubsystemId will only play a sanity-check role. Otherwise, DeviceId can\r
+  // only be sanity-checked, and SubsystemId will decide.\r
+  //\r
+  if (DeviceId == 0x1040 + VIRTIO_SUBSYSTEM_ENTROPY_SOURCE &&\r
+      RevisionId >= 0x01) {\r
+    Virtio10 = TRUE;\r
+  } else if (DeviceId >= 0x1000 && DeviceId <= 0x103F && RevisionId == 0x00) {\r
+    Virtio10 = FALSE;\r
+  } else {\r
+    return FALSE;\r
+  }\r
+\r
+  //\r
+  // Read and check SubsystemId as dictated by Virtio10.\r
+  //\r
+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16,\r
+                        PCI_SUBSYSTEM_ID_OFFSET, 1, &SubsystemId);\r
+  if (EFI_ERROR (Status)) {\r
+    goto PciError;\r
+  }\r
+  if (Virtio10 && SubsystemId >= 0x40) {\r
+    return TRUE;\r
+  }\r
+  if (!Virtio10 && SubsystemId == VIRTIO_SUBSYSTEM_ENTROPY_SOURCE) {\r
+    return TRUE;\r
+  }\r
+  return FALSE;\r
+\r
+PciError:\r
+  DEBUG ((DEBUG_ERROR, "%a: %s: %r\n", __FUNCTION__, ReportText, Status));\r
+  return FALSE;\r
+}\r
+\r
+\r
 /**\r
   This CALLBACK_FUNCTION attempts to connect a handle non-recursively, asking\r
   the matching driver to produce all first-level child handles.\r
@@ -644,6 +761,18 @@ PlatformBootManagerBeforeConsole (
   // Register platform-specific boot options and keyboard shortcuts.\r
   //\r
   PlatformRegisterOptionsAndKeys ();\r
+\r
+  //\r
+  // At this point, VIRTIO_DEVICE_PROTOCOL instances exist only for Virtio MMIO\r
+  // transports. Install EFI_RNG_PROTOCOL instances on Virtio MMIO RNG devices.\r
+  //\r
+  FilterAndProcess (&gVirtioDeviceProtocolGuid, IsVirtioRng, Connect);\r
+\r
+  //\r
+  // Install both VIRTIO_DEVICE_PROTOCOL and (dependent) EFI_RNG_PROTOCOL\r
+  // instances on Virtio PCI RNG devices.\r
+  //\r
+  FilterAndProcess (&gEfiPciIoProtocolGuid, IsVirtioPciRng, Connect);\r
 }\r
 \r
 /**\r