From 7ebad830d6ab61f0395f6f4bae4156664bbd8086 Mon Sep 17 00:00:00 2001

From: Laszlo Ersek <lersek@redhat.com>

Date: Thu, 17 May 2018 21:51:11 +0200

Subject: [PATCH] OvmfPkg/PlatformBootManagerLib: connect Virtio RNG devices

 again

Virtio RNG devices are never boot devices, so in commit 245c643cc8b7 we

stopped connecting them. This is a problem because an OS boot loader may

depend on EFI_RNG_PROTOCOL to seed the OS's RNG.

Connect Virtio RNG devices again. And, while commit 245c643cc8b7 removed

that from PlatformBootManagerAfterConsole(), reintroduce it now to

PlatformBootManagerBeforeConsole() -- this way Driver#### options launched

between both functions may access EFI_RNG_PROTOCOL too.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Cc: Jordan Justen <jordan.l.justen@intel.com>

Fixes: 245c643cc8b73240c3b88cb55b2911b285a8c10d

Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1579518

Contributed-under: TianoCore Contribution Agreement 1.1

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---

 .../PlatformBootManagerLib/BdsPlatform.h      |   1 +

 .../PlatformBootManagerLib/BdsPlatform.c      | 105 ++++++++++++++++++

 2 files changed, 106 insertions(+)

diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.h b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.h

index 97ffbb5148..4948ca6518 100644

--- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.h

+++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.h

@@ -30,6 +30,7 @@ Abstract:

 #include <IndustryStandard/Acpi.h>

 #include <IndustryStandard/SmBios.h>

 #include <IndustryStandard/PeImage.h>

+#include <IndustryStandard/Virtio095.h>

 #include <Library/DebugLib.h>

 #include <Library/BaseMemoryLib.h>

diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c

index 004b753f4d..5d4d323d73 100644

--- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c

+++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c

@@ -318,6 +318,15 @@ ConnectRootBridge (

   IN VOID        *Context

   );

+STATIC

+EFI_STATUS

+EFIAPI

+ConnectVirtioPciRng (

+  IN EFI_HANDLE Handle,

+  IN VOID       *Instance,

+  IN VOID       *Context

+  );

+

 STATIC

 VOID

 SaveS3BootScript (

@@ -399,6 +408,13 @@ PlatformBootManagerBeforeConsole (

   ASSERT_RETURN_ERROR (PcdStatus);

   PlatformRegisterOptionsAndKeys ();

+

+  //

+  // Install both VIRTIO_DEVICE_PROTOCOL and (dependent) EFI_RNG_PROTOCOL

+  // instances on Virtio PCI RNG devices.

+  //

+  VisitAllInstancesOfProtocol (&gEfiPciIoProtocolGuid, ConnectVirtioPciRng,

+    NULL);

 }

@@ -427,6 +443,95 @@ ConnectRootBridge (

 }

+STATIC

+EFI_STATUS

+EFIAPI

+ConnectVirtioPciRng (

+  IN EFI_HANDLE Handle,

+  IN VOID       *Instance,

+  IN VOID       *Context

+  )

+{

+  EFI_PCI_IO_PROTOCOL *PciIo;

+  EFI_STATUS          Status;

+  UINT16              VendorId;

+  UINT16              DeviceId;

+  UINT8               RevisionId;

+  BOOLEAN             Virtio10;

+  UINT16              SubsystemId;

+

+  PciIo = Instance;

+

+  //

+  // Read and check VendorId.

+  //

+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_VENDOR_ID_OFFSET,

+                        1, &VendorId);

+  if (EFI_ERROR (Status)) {

+    goto Error;

+  }

+  if (VendorId != VIRTIO_VENDOR_ID) {

+    return EFI_SUCCESS;

+  }

+

+  //

+  // Read DeviceId and RevisionId.

+  //

+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_DEVICE_ID_OFFSET,

+                        1, &DeviceId);

+  if (EFI_ERROR (Status)) {

+    goto Error;

+  }

+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint8, PCI_REVISION_ID_OFFSET,

+                        1, &RevisionId);

+  if (EFI_ERROR (Status)) {

+    goto Error;

+  }

+

+  //

+  // From DeviceId and RevisionId, determine whether the device is a

+  // modern-only Virtio 1.0 device. In case of Virtio 1.0, DeviceId can

+  // immediately be restricted to VIRTIO_SUBSYSTEM_ENTROPY_SOURCE, and

+  // SubsystemId will only play a sanity-check role. Otherwise, DeviceId can

+  // only be sanity-checked, and SubsystemId will decide.

+  //

+  if (DeviceId == 0x1040 + VIRTIO_SUBSYSTEM_ENTROPY_SOURCE &&

+      RevisionId >= 0x01) {

+    Virtio10 = TRUE;

+  } else if (DeviceId >= 0x1000 && DeviceId <= 0x103F && RevisionId == 0x00) {

+    Virtio10 = FALSE;

+  } else {

+    return EFI_SUCCESS;

+  }

+

+  //

+  // Read and check SubsystemId as dictated by Virtio10.

+  //

+  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16,

+                        PCI_SUBSYSTEM_ID_OFFSET, 1, &SubsystemId);

+  if (EFI_ERROR (Status)) {

+    goto Error;

+  }

+  if ((Virtio10 && SubsystemId >= 0x40) ||

+      (!Virtio10 && SubsystemId == VIRTIO_SUBSYSTEM_ENTROPY_SOURCE)) {

+    Status = gBS->ConnectController (

+                    Handle, // ControllerHandle

+                    NULL,   // DriverImageHandle -- connect all drivers

+                    NULL,   // RemainingDevicePath -- produce all child handles

+                    FALSE   // Recursive -- don't follow child handles

+                    );

+    if (EFI_ERROR (Status)) {

+      goto Error;

+    }

+  }

+  return EFI_SUCCESS;

+

+Error:

+  DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, Status));

+  return Status;

+}

+

+

 /**

   Add IsaKeyboard to ConIn; add IsaSerial to ConOut, ConIn, ErrOut.

-- 

2.17.0