[edk2-devel] [PATCH v2 04/14] OvmfPkg: provide a generic implementation of QemuLoadImageLib
Laszlo Ersek
lersek at redhat.com
Thu Mar 5 09:51:37 UTC 2020
On 03/04/20 10:52, Ard Biesheuvel wrote:
> Implement QemuLoadImageLib, and make it load the image provided by the
> QEMU_EFI_LOADER_FS_MEDIA_GUID/kernel device path that we implemented
> in a preceding patch in a separate DXE driver, using only the standard
> LoadImage and StartImage boot services.
>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2566
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---
> OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c | 278 ++++++++++++++++++++
> OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf | 38 +++
> 2 files changed, 316 insertions(+)
Reviewed-by: Laszlo Ersek <lersek at redhat.com>
Thanks,
Laszlo
> diff --git a/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c
> new file mode 100644
> index 000000000000..f5edb43cc0b9
> --- /dev/null
> +++ b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c
> @@ -0,0 +1,278 @@
> +/** @file
> + Generic implementation of QemuLoadImageLib library class interface.
> +
> + Copyright (c) 2020, ARM Ltd. All rights reserved.<BR>
> +
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include <Uefi.h>
> +
> +#include <Base.h>
> +#include <Guid/QemuKernelLoaderFsMedia.h>
> +#include <Library/DebugLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/PrintLib.h>
> +#include <Library/QemuFwCfgLib.h>
> +#include <Library/QemuLoadImageLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Protocol/DevicePath.h>
> +#include <Protocol/LoadedImage.h>
> +
> +#pragma pack (1)
> +typedef struct {
> + EFI_DEVICE_PATH_PROTOCOL FilePathHeader;
> + CHAR16 FilePath[ARRAY_SIZE (L"kernel")];
> +} KERNEL_FILE_DEVPATH;
> +
> +typedef struct {
> + VENDOR_DEVICE_PATH VenMediaNode;
> + KERNEL_FILE_DEVPATH FileNode;
> + EFI_DEVICE_PATH_PROTOCOL EndNode;
> +} KERNEL_VENMEDIA_FILE_DEVPATH;
> +#pragma pack ()
> +
> +STATIC CONST KERNEL_VENMEDIA_FILE_DEVPATH mKernelDevicePath = {
> + {
> + {
> + MEDIA_DEVICE_PATH, MEDIA_VENDOR_DP,
> + { sizeof (VENDOR_DEVICE_PATH) }
> + },
> + QEMU_KERNEL_LOADER_FS_MEDIA_GUID
> + }, {
> + {
> + MEDIA_DEVICE_PATH, MEDIA_FILEPATH_DP,
> + { sizeof (KERNEL_FILE_DEVPATH) }
> + },
> + L"kernel",
> + }, {
> + END_DEVICE_PATH_TYPE, END_ENTIRE_DEVICE_PATH_SUBTYPE,
> + { sizeof (EFI_DEVICE_PATH_PROTOCOL) }
> + }
> +};
> +
> +/**
> + Download the kernel, the initial ramdisk, and the kernel command line from
> + QEMU's fw_cfg. The kernel will be instructed via its command line to load
> + the initrd from the same Simple FileSystem where the kernel was loaded from.
> +
> + @param[out] ImageHandle The image handle that was allocated for
> + loading the image
> + @param[out] LoadedImage The loaded image protocol that was installed
> + on ImageHandle by the LoadImage boot service.
> +
> + @retval EFI_SUCCESS The image was loaded successfully.
> + @retval EFI_NOT_FOUND Kernel image was not found.
> + @retval EFI_OUT_OF_RESOURCES Memory allocation failed.
> + @retval EFI_PROTOCOL_ERROR Unterminated kernel command line.
> + @retval EFI_ACCESS_DENIED The underlying LoadImage boot service call
> + returned EFI_SECURITY_VIOLATION, and the image
> + was unloaded again.
> +
> + @return Error codes from any of the underlying
> + functions.
> +**/
> +EFI_STATUS
> +EFIAPI
> +QemuLoadKernelImage (
> + OUT EFI_HANDLE *ImageHandle
> + )
> +{
> + EFI_STATUS Status;
> + EFI_HANDLE KernelImageHandle;
> + EFI_LOADED_IMAGE_PROTOCOL *KernelLoadedImage;
> + UINTN CommandLineSize;
> + CHAR8 *CommandLine;
> + UINTN InitrdSize;
> +
> + //
> + // Load the image. This should call back into the QEMU EFI loader file system.
> + //
> + Status = gBS->LoadImage (
> + FALSE, // BootPolicy: exact match required
> + gImageHandle, // ParentImageHandle
> + (EFI_DEVICE_PATH_PROTOCOL *)&mKernelDevicePath,
> + NULL, // SourceBuffer
> + 0, // SourceSize
> + &KernelImageHandle
> + );
> + switch (Status) {
> + case EFI_SUCCESS:
> + break;
> +
> + case EFI_SECURITY_VIOLATION:
> + //
> + // In this case, the image was loaded but failed to authenticate.
> + //
> + Status = EFI_ACCESS_DENIED;
> + goto UnloadImage;
> +
> + default:
> + DEBUG ((DEBUG_ERROR, "%a: LoadImage(): %r\n", __FUNCTION__, Status));
> + return Status;
> + }
> +
> + //
> + // Construct the kernel command line.
> + //
> + Status = gBS->OpenProtocol (
> + KernelImageHandle,
> + &gEfiLoadedImageProtocolGuid,
> + (VOID **)&KernelLoadedImage,
> + gImageHandle, // AgentHandle
> + NULL, // ControllerHandle
> + EFI_OPEN_PROTOCOL_GET_PROTOCOL
> + );
> + ASSERT_EFI_ERROR (Status);
> +
> + QemuFwCfgSelectItem (QemuFwCfgItemCommandLineSize);
> + CommandLineSize = (UINTN)QemuFwCfgRead32 ();
> +
> + if (CommandLineSize == 0) {
> + KernelLoadedImage->LoadOptionsSize = 0;
> + } else {
> + CommandLine = AllocatePool (CommandLineSize);
> + if (CommandLine == NULL) {
> + Status = EFI_OUT_OF_RESOURCES;
> + goto UnloadImage;
> + }
> +
> + QemuFwCfgSelectItem (QemuFwCfgItemCommandLineData);
> + QemuFwCfgReadBytes (CommandLineSize, CommandLine);
> +
> + //
> + // Verify NUL-termination of the command line.
> + //
> + if (CommandLine[CommandLineSize - 1] != '\0') {
> + DEBUG ((DEBUG_ERROR, "%a: kernel command line is not NUL-terminated\n",
> + __FUNCTION__));
> + Status = EFI_PROTOCOL_ERROR;
> + goto FreeCommandLine;
> + }
> +
> + //
> + // Drop the terminating NUL, convert to UTF-16.
> + //
> + KernelLoadedImage->LoadOptionsSize = (CommandLineSize - 1) * 2;
> + }
> +
> + QemuFwCfgSelectItem (QemuFwCfgItemInitrdSize);
> + InitrdSize = (UINTN)QemuFwCfgRead32 ();
> +
> + if (InitrdSize > 0) {
> + //
> + // Append ' initrd=initrd' in UTF-16.
> + //
> + KernelLoadedImage->LoadOptionsSize += sizeof (L" initrd=initrd") - 2;
> + }
> +
> + if (KernelLoadedImage->LoadOptionsSize == 0) {
> + KernelLoadedImage->LoadOptions = NULL;
> + } else {
> + //
> + // NUL-terminate in UTF-16.
> + //
> + KernelLoadedImage->LoadOptionsSize += 2;
> +
> + KernelLoadedImage->LoadOptions = AllocatePool (
> + KernelLoadedImage->LoadOptionsSize);
> + if (KernelLoadedImage->LoadOptions == NULL) {
> + KernelLoadedImage->LoadOptionsSize = 0;
> + Status = EFI_OUT_OF_RESOURCES;
> + goto FreeCommandLine;
> + }
> +
> + UnicodeSPrintAsciiFormat (
> + KernelLoadedImage->LoadOptions,
> + KernelLoadedImage->LoadOptionsSize,
> + "%a%a",
> + (CommandLineSize == 0) ? "" : CommandLine,
> + (InitrdSize == 0) ? "" : " initrd=initrd"
> + );
> + DEBUG ((DEBUG_INFO, "%a: command line: \"%s\"\n", __FUNCTION__,
> + (CHAR16 *)KernelLoadedImage->LoadOptions));
> + }
> +
> + *ImageHandle = KernelImageHandle;
> + return EFI_SUCCESS;
> +
> +FreeCommandLine:
> + if (CommandLineSize > 0) {
> + FreePool (CommandLine);
> + }
> +UnloadImage:
> + gBS->UnloadImage (KernelImageHandle);
> +
> + return Status;
> +}
> +
> +/**
> + Transfer control to a kernel image loaded with QemuLoadKernelImage ()
> +
> + @param[in,out] ImageHandle Handle of image to be started. May assume a
> + different value on return if the image was
> + reloaded.
> +
> + @retval EFI_INVALID_PARAMETER ImageHandle is either an invalid image handle
> + or the image has already been initialized with
> + StartImage
> + @retval EFI_SECURITY_VIOLATION The current platform policy specifies that the
> + image should not be started.
> +
> + @return Error codes returned by the started image
> +**/
> +EFI_STATUS
> +EFIAPI
> +QemuStartKernelImage (
> + IN OUT EFI_HANDLE *ImageHandle
> + )
> +{
> + return gBS->StartImage (
> + *ImageHandle,
> + NULL, // ExitDataSize
> + NULL // ExitData
> + );
> +}
> +
> +/**
> + Unloads an image loaded with QemuLoadKernelImage ().
> +
> + @param ImageHandle Handle that identifies the image to be
> + unloaded.
> +
> + @retval EFI_SUCCESS The image has been unloaded.
> + @retval EFI_UNSUPPORTED The image has been started, and does not
> + support unload.
> + @retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
> +
> + @return Exit code from the image’s unload function.
> +**/
> +EFI_STATUS
> +EFIAPI
> +QemuUnloadKernelImage (
> + IN EFI_HANDLE ImageHandle
> + )
> +{
> + EFI_LOADED_IMAGE_PROTOCOL *KernelLoadedImage;
> + EFI_STATUS Status;
> +
> + Status = gBS->OpenProtocol (
> + ImageHandle,
> + &gEfiLoadedImageProtocolGuid,
> + (VOID **)&KernelLoadedImage,
> + gImageHandle, // AgentHandle
> + NULL, // ControllerHandle
> + EFI_OPEN_PROTOCOL_GET_PROTOCOL
> + );
> + if (EFI_ERROR (Status)) {
> + return EFI_INVALID_PARAMETER;
> + }
> +
> + if (KernelLoadedImage->LoadOptions != NULL) {
> + FreePool (KernelLoadedImage->LoadOptions);
> + KernelLoadedImage->LoadOptions = NULL;
> + }
> + KernelLoadedImage->LoadOptionsSize = 0;
> +
> + return gBS->UnloadImage (ImageHandle);
> +}
> diff --git a/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf
> new file mode 100644
> index 000000000000..b262cb926a4d
> --- /dev/null
> +++ b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf
> @@ -0,0 +1,38 @@
> +## @file
> +# Generic implementation of QemuLoadImageLib library class interface.
> +#
> +# Copyright (c) 2020, ARM Ltd. All rights reserved.<BR>
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> + INF_VERSION = 1.27
> + BASE_NAME = GenericQemuLoadImageLib
> + FILE_GUID = 9e3e28da-c7b5-4f85-841a-84e6a9a1f1a0
> + MODULE_TYPE = BASE
> + VERSION_STRING = 1.0
> + LIBRARY_CLASS = QemuLoadImageLib|DXE_DRIVER
> +
> +[Sources]
> + GenericQemuLoadImageLib.c
> +
> +[Packages]
> + MdeModulePkg/MdeModulePkg.dec
> + MdePkg/MdePkg.dec
> + OvmfPkg/OvmfPkg.dec
> +
> +[LibraryClasses]
> + DebugLib
> + MemoryAllocationLib
> + PrintLib
> + QemuFwCfgLib
> + UefiBootServicesTableLib
> +
> +[Protocols]
> + gEfiDevicePathProtocolGuid
> + gEfiLoadedImageProtocolGuid
> +
> +[Guids]
> + gQemuKernelLoaderFsMediaGuid
>
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