The fw_cfg file "etc/acpi/tables" is not a stable guest interface -- QEMU
could rename it in the future, and/or introduce additional fw_cfg files
with ACPI payload. Only the higher-level "etc/table-loader" file is
considered stable, which contains a sequence of commands to assist
firmware with reading QEMU ACPI tables from the FwCfg interface.
Because edk2 provides publishing support for ACPI tables, OVMF only uses
the Allocate command to find the names of FwCfg files to read and publish
as ACPI tables.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.jus...@intel.com>
---
Notes:
v2:
- incorporated suggested wording in commit message [Jordan]
- documented origin of QEMU_LOADER_FNAME_SIZE by rebasing it on new
fw_cfg macro introduced in v2 1/4 (this follows the qemu source code,
see "hw/i386/bios-linker-loader.c") [Jordan]
- added comment before the QEMU_LOADER_COMMAND_TYPE enum type that we
only care about Allocate [Jordan]
OvmfPkg/AcpiPlatformDxe/QemuLoader.h | 90 ++++++++++++++++++++++++++++++++++++
OvmfPkg/AcpiPlatformDxe/Qemu.c | 54 ++++++++++++++++++++--
2 files changed, 139 insertions(+), 5 deletions(-)
create mode 100644 OvmfPkg/AcpiPlatformDxe/QemuLoader.h
diff --git a/OvmfPkg/AcpiPlatformDxe/QemuLoader.h
b/OvmfPkg/AcpiPlatformDxe/QemuLoader.h
new file mode 100644
index 0000000..6d1dfa3
--- /dev/null
+++ b/OvmfPkg/AcpiPlatformDxe/QemuLoader.h
@@ -0,0 +1,90 @@
+/** @file
+ Command structures for the QEMU linker/loader interface.
+
+ Copyright (C) 2014, Red Hat, Inc.
+
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License which accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+ WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef __QEMU_LOADER_H__
+#define __QEMU_LOADER_H__
+
+#include <Include/Base.h>
+#include <Library/QemuFwCfgLib.h>
+
+//
+// The types and the documentation reflects the SeaBIOS interface. In OVMF we
+// use a minimal subset of it.
+//
+#define QEMU_LOADER_FNAME_SIZE QEMU_FW_CFG_FNAME_SIZE
+
+//
+// We only look at the Allocate command, and only to get FwCfg filenames.
+//
+typedef enum {
+ QemuLoaderCmdAllocate = 1,
+ QemuLoaderCmdAddPointer,
+ QemuLoaderCmdAddChecksum
+} QEMU_LOADER_COMMAND_TYPE;
+
+typedef enum {
+ QemuLoaderAllocHigh = 1,
+ QemuLoaderAllocFSeg
+} QEMU_LOADER_ALLOC_ZONE;
+
+#pragma pack (1)
+//
+// QemuLoaderCmdAllocate: download the fw_cfg file named File, to a buffer
+// allocated in the zone specified by Zone, aligned at a multiple of Alignment.
+//
+typedef struct {
+ UINT8 File[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
+ UINT32 Alignment; // power of two
+ UINT8 Zone; // QEMU_LOADER_ALLOC_ZONE values
+} QEMU_LOADER_ALLOCATE;
+
+//
+// QemuLoaderCmdAddPointer: the bytes at
+// [PointerOffset..PointerOffset+PointerSize) in the file PointerFile contain a
+// relative pointer (an offset) into PointeeFile. Increment the relative
+// pointer's value by the base address of where PointeeFile's contents have
+// been placed (when QemuLoaderCmdAllocate has been executed for PointeeFile).
+//
+typedef struct {
+ UINT8 PointerFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
+ UINT8 PointeeFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
+ UINT32 PointerOffset;
+ UINT8 PointerSize; // one of 1, 2, 4, 8
+} QEMU_LOADER_ADD_POINTER;
+
+//
+// QemuLoaderCmdAddChecksum: calculate the UINT8 checksum (as per
+// CalculateChecksum8()) of the range [Start..Start+Length) in File. Store the
+// UINT8 result at ResultOffset in the same File.
+//
+typedef struct {
+ UINT8 File[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
+ UINT32 ResultOffset;
+ UINT32 Start;
+ UINT32 Length;
+} QEMU_LOADER_ADD_CHECKSUM;
+
+typedef struct {
+ UINT32 Type; // QEMU_LOADER_COMMAND_TYPE values
+ union {
+ QEMU_LOADER_ALLOCATE Allocate;
+ QEMU_LOADER_ADD_POINTER AddPointer;
+ QEMU_LOADER_ADD_CHECKSUM AddChecksum;
+ UINT8 Padding[124];
+ } Command;
+} QEMU_LOADER_ENTRY;
+#pragma pack ()
+
+#endif
diff --git a/OvmfPkg/AcpiPlatformDxe/Qemu.c b/OvmfPkg/AcpiPlatformDxe/Qemu.c
index 5a96d76..70f3ff6 100644
--- a/OvmfPkg/AcpiPlatformDxe/Qemu.c
+++ b/OvmfPkg/AcpiPlatformDxe/Qemu.c
@@ -15,8 +15,9 @@
**/
#include "AcpiPlatform.h"
+#include "QemuLoader.h"
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/QemuFwCfgLib.h>
#include <Library/DxeServicesTableLib.h>
@@ -794,10 +795,9 @@ InstallQemuLinkedTables (
@retval EFI_OUT_OF_RESOURCES Memory allocation failed, or more than
INSTALLED_TABLES_MAX tables found.
- @retval EFI_PROTOCOL_ERROR Found truncated or invalid ACPI table header
- in the fw_cfg contents.
+ @retval EFI_PROTOCOL_ERROR Found invalid fw_cfg contents.
@return Status codes returned by
AcpiProtocol->InstallAcpiTable().
@@ -811,19 +811,62 @@ InstallAllQemuLinkedTables (
{
UINTN *InstalledKey;
INT32 Installed;
EFI_STATUS Status;
+ FIRMWARE_CONFIG_ITEM LoaderItem;
+ UINTN LoaderSize;
+ UINT8 *Loader;
+ QEMU_LOADER_ENTRY *Entry, *End;
InstalledKey = AllocatePool (INSTALLED_TABLES_MAX * sizeof *InstalledKey);
if (InstalledKey == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Installed = 0;
- Status = InstallQemuLinkedTables ("etc/acpi/tables", AcpiProtocol,
- InstalledKey, &Installed);
+ Status = QemuFwCfgFindFile ("etc/table-loader", &LoaderItem, &LoaderSize);
+ if (EFI_ERROR (Status)) {
+ goto FreeInstalledKey;
+ }
+ if (LoaderSize % sizeof *Entry != 0) {
+ Status = EFI_PROTOCOL_ERROR;
+ goto FreeInstalledKey;
+ }
+
+ Loader = AllocatePool (LoaderSize);
+ if (Loader == NULL) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto FreeInstalledKey;
+ }
+
+ QemuFwCfgSelectItem (LoaderItem);
+ QemuFwCfgReadBytes (LoaderSize, Loader);
+
+ Entry = (QEMU_LOADER_ENTRY *)Loader;
+ End = (QEMU_LOADER_ENTRY *)(Loader + LoaderSize);
+ while (Entry < End) {
+ if (Entry->Type == QemuLoaderCmdAllocate) {
+ QEMU_LOADER_ALLOCATE *Allocate;
+
+ Allocate = &Entry->Command.Allocate;
+ if (Allocate->File[sizeof Allocate->File - 1] != '\0') {
+ Status = EFI_PROTOCOL_ERROR;
+ break;
+ }
+
+ Status = InstallQemuLinkedTables ((CHAR8 *)Allocate->File, AcpiProtocol,
+ InstalledKey, &Installed);
+ if (EFI_ERROR (Status)) {
+ ASSERT (Status != EFI_INVALID_PARAMETER);
+ break;
+ }
+ }
+ ++Entry;
+ }
+
+ FreePool (Loader);
+
if (EFI_ERROR (Status)) {
- ASSERT (Status != EFI_INVALID_PARAMETER);
//
// Roll back partial installation.
//
while (Installed > 0) {
@@ -833,7 +876,8 @@ InstallAllQemuLinkedTables (
} else {
DEBUG ((EFI_D_INFO, "%a: installed %d tables\n", __FUNCTION__, Installed));
}
+FreeInstalledKey:
FreePool (InstalledKey);
return Status;
}
--
1.8.3.1
------------------------------------------------------------------------------
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