[edk2-devel] [PATCH v1 2/3] OvmfPkg/GenericQemuLoadImageLib: Read cmdline from QemuKernelLoaderFs
Dov Murik
dovmurik at linux.ibm.com
Wed Jun 9 12:18:27 UTC 2021
Remove the QemuFwCfgLib interface used to read the QEMU cmdline
(-append argument) and the initrd size. Instead, use the synthetic
filesystem QemuKernelLoaderFs which has three files: "kernel", "initrd",
and "cmdline".
Cc: Laszlo Ersek <lersek at redhat.com>
Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Tobin Feldman-Fitzthum <tobin at linux.ibm.com>
Signed-off-by: Dov Murik <dovmurik at linux.ibm.com>
---
OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf | 2 +-
OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c | 132 ++++++++++++++++++--
2 files changed, 126 insertions(+), 8 deletions(-)
diff --git a/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf
index b262cb926a4d..f462fd6922cf 100644
--- a/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf
+++ b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf
@@ -27,12 +27,12 @@ [LibraryClasses]
DebugLib
MemoryAllocationLib
PrintLib
- QemuFwCfgLib
UefiBootServicesTableLib
[Protocols]
gEfiDevicePathProtocolGuid
gEfiLoadedImageProtocolGuid
+ gEfiSimpleFileSystemProtocolGuid
[Guids]
gQemuKernelLoaderFsMediaGuid
diff --git a/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c
index 114db7e8441f..7d26c912e14f 100644
--- a/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c
+++ b/OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.c
@@ -11,9 +11,9 @@
#include <Base.h>
#include <Guid/QemuKernelLoaderFsMedia.h>
#include <Library/DebugLib.h>
+#include <Library/FileHandleLib.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>
@@ -30,6 +30,11 @@ typedef struct {
KERNEL_FILE_DEVPATH FileNode;
EFI_DEVICE_PATH_PROTOCOL EndNode;
} KERNEL_VENMEDIA_FILE_DEVPATH;
+
+typedef struct {
+ VENDOR_DEVICE_PATH VenMediaNode;
+ EFI_DEVICE_PATH_PROTOCOL EndNode;
+} SINGLE_VENMEDIA_NODE_DEVPATH;
#pragma pack ()
STATIC CONST KERNEL_VENMEDIA_FILE_DEVPATH mKernelDevicePath = {
@@ -51,6 +56,78 @@ STATIC CONST KERNEL_VENMEDIA_FILE_DEVPATH mKernelDevicePath = {
}
};
+STATIC CONST SINGLE_VENMEDIA_NODE_DEVPATH mQemuKernelLoaderFileSystemDevicePath = {
+ {
+ {
+ MEDIA_DEVICE_PATH, MEDIA_VENDOR_DP,
+ { sizeof (VENDOR_DEVICE_PATH) }
+ },
+ QEMU_KERNEL_LOADER_FS_MEDIA_GUID
+ }, {
+ END_DEVICE_PATH_TYPE, END_ENTIRE_DEVICE_PATH_SUBTYPE,
+ { sizeof (EFI_DEVICE_PATH_PROTOCOL) }
+ }
+};
+
+STATIC
+EFI_STATUS
+GetQemuKernelBlobSize (
+ IN EFI_FILE_HANDLE Root,
+ IN CHAR16 *FileName,
+ OUT UINTN *Size
+ )
+{
+ EFI_STATUS Status;
+ EFI_FILE_HANDLE FileHandle;
+ UINT64 FileSize;
+
+ Status = Root->Open (Root, &FileHandle, FileName, EFI_FILE_MODE_READ, 0);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ Status = FileHandleGetSize (FileHandle, &FileSize);
+ if (EFI_ERROR (Status)) {
+ goto CloseFile;
+ }
+ *Size = FileSize;
+ Status = EFI_SUCCESS;
+CloseFile:
+ FileHandle->Close (FileHandle);
+ return Status;
+}
+
+STATIC
+EFI_STATUS
+ReadWholeQemuKernelBlob (
+ IN EFI_FILE_HANDLE Root,
+ IN CHAR16 *FileName,
+ IN UINTN Size,
+ OUT VOID *Buffer
+ )
+{
+ EFI_STATUS Status;
+ EFI_FILE_HANDLE FileHandle;
+ UINTN ReadSize;
+
+ Status = Root->Open (Root, &FileHandle, FileName, EFI_FILE_MODE_READ, 0);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ ReadSize = Size;
+ Status = FileHandle->Read (FileHandle, &ReadSize, Buffer);
+ if (EFI_ERROR (Status)) {
+ goto CloseFile;
+ }
+ if (ReadSize != Size) {
+ Status = EFI_PROTOCOL_ERROR;
+ goto CloseFile;
+ }
+ Status = EFI_SUCCESS;
+CloseFile:
+ FileHandle->Close (FileHandle);
+ return Status;
+}
+
/**
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
@@ -79,6 +156,10 @@ QemuLoadKernelImage (
EFI_STATUS Status;
EFI_HANDLE KernelImageHandle;
EFI_LOADED_IMAGE_PROTOCOL *KernelLoadedImage;
+ EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;
+ EFI_HANDLE FsVolumeHandle;
+ EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *FsProtocol;
+ EFI_FILE_HANDLE Root;
UINTN CommandLineSize;
CHAR8 *CommandLine;
UINTN InitrdSize;
@@ -124,8 +205,38 @@ QemuLoadKernelImage (
);
ASSERT_EFI_ERROR (Status);
- QemuFwCfgSelectItem (QemuFwCfgItemCommandLineSize);
- CommandLineSize = (UINTN)QemuFwCfgRead32 ();
+ //
+ // Open the Qemu Kernel Loader abstract filesystem (volume) which will be
+ // used to read the "initrd" and "cmdline" synthetic files.
+ //
+ DevicePathNode = (EFI_DEVICE_PATH_PROTOCOL *) &mQemuKernelLoaderFileSystemDevicePath;
+ Status = gBS->LocateDevicePath (
+ &gEfiSimpleFileSystemProtocolGuid,
+ &DevicePathNode,
+ &FsVolumeHandle
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = gBS->HandleProtocol (
+ FsVolumeHandle,
+ &gEfiSimpleFileSystemProtocolGuid,
+ (VOID **)&FsProtocol
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = FsProtocol->OpenVolume (FsVolumeHandle, &Root);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = GetQemuKernelBlobSize (Root, L"cmdline", &CommandLineSize);
+ if (EFI_ERROR (Status)) {
+ goto CloseRoot;
+ }
if (CommandLineSize == 0) {
KernelLoadedImage->LoadOptionsSize = 0;
@@ -136,8 +247,10 @@ QemuLoadKernelImage (
goto UnloadImage;
}
- QemuFwCfgSelectItem (QemuFwCfgItemCommandLineData);
- QemuFwCfgReadBytes (CommandLineSize, CommandLine);
+ Status = ReadWholeQemuKernelBlob (Root, L"cmdline", CommandLineSize, CommandLine);
+ if (EFI_ERROR (Status)) {
+ goto FreeCommandLine;
+ }
//
// Verify NUL-termination of the command line.
@@ -155,8 +268,10 @@ QemuLoadKernelImage (
KernelLoadedImage->LoadOptionsSize = (UINT32)((CommandLineSize - 1) * 2);
}
- QemuFwCfgSelectItem (QemuFwCfgItemInitrdSize);
- InitrdSize = (UINTN)QemuFwCfgRead32 ();
+ Status = GetQemuKernelBlobSize (Root, L"initrd", &InitrdSize);
+ if (EFI_ERROR (Status)) {
+ goto FreeCommandLine;
+ }
if (InitrdSize > 0) {
//
@@ -193,6 +308,7 @@ QemuLoadKernelImage (
}
*ImageHandle = KernelImageHandle;
+ Root->Close (Root);
return EFI_SUCCESS;
FreeCommandLine:
@@ -201,6 +317,8 @@ FreeCommandLine:
}
UnloadImage:
gBS->UnloadImage (KernelImageHandle);
+CloseRoot:
+ Root->Close (Root);
return Status;
}
--
2.25.1
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