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OvmfPkg: AcpiPlatformDxe: download ACPI tables from QEMU 

Recent qemu versions compose all ACPI tables on the host side, according
to the target hardware configuration, and make the tables available to any
guest firmware over fw_cfg.

See version compatibility information below.

The feature moves the burden of keeping ACPI tables up-to-date from boot
firmware to qemu (which is the source of hardware configuration anyway).

This patch adds client code for this feature. Benefits of the
qemu-provided ACPI tables include PCI hotplug for example.

Qemu provides the following three fw_cfg files:
- etc/acpi/rsdp
- etc/acpi/tables
- etc/table-loader

"etc/acpi/rsdp" and "etc/acpi/tables" are similar, they are only kept
separate because they have different allocation requirements in SeaBIOS.

Both of these fw_cfg files contain preformatted ACPI payload.
"etc/acpi/rsdp" contains only the RSDP table, while "etc/acpi/tables"
contains all other tables, concatenated.

The tables in these two fw_cfg files are filled in by qemu, but two kinds
of fields are left incomplete in each table: pointers to other tables, and
checksums (which depend on the pointers).

Qemu initializes each pointer with a relative offset into the fw_cfg file
that contains the pointed-to ACPI table. The final pointer values depend
on where the fw_cfg files, holding the pointed-to ACPI tables, will be
placed in memory by the guest. That is, the pointer fields need to be
"relocated" (incremented) by the base addresses of where "/etc/acpi/rsdp"
and "/etc/acpi/tables" will be placed in guest memory.

This is where the third file, "/etc/table-loader" comes in the picture. It
is a linker/loader script that has several command types:

  One command type instructs the guest to download the other two files.

  Another command type instructs the guest to increment ("absolutize") a
  pointer field (having a relative initial value) in the pointing ACPI
  table, present in some fw_cfg file, with the dynamic base address of the
  same (or another) fw_cfg file, holding the pointed-to ACPI table.

  The third command type instructs the guest to compute checksums over
  ranges and to store them.

In edk2, EFI_ACPI_TABLE_PROTOCOL knows about table relationships -- it
handles linkage automatically when a table is installed. The protocol
takes care of checksumming too. RSDP is installed automatically. Hence we
only need to care about the "etc/acpi/tables" fw_cfg file, determining the
boundaries of each ACPI table inside it, and installing those tables.

Qemu compatibility information:

--------------+---------------------+-------------------------------------
 qemu version | qemu machine type   | effects of the patch
--------------+---------------------+-------------------------------------
 up to 1.6.x  | any pc-i440fx       | None. OVMF's built-in ACPI tables
              |                     | are used.
--------------+---------------------+-------------------------------------
 any          | up to pc-i440fx-1.6 | None. OVMF's built-in ACPI tables
              |                     | are used.
--------------+---------------------+-------------------------------------
 1.7.0        | pc-i440fx-1.7       | Potential guest OS crash, dependent
              | (default for 1.7.0) | on guest RAM size.
              |                     |
              |                     | DO NOT RUN OVMF on the (1.7.0,
              |                     | pc-i440fx-1.7) qemu / machine type
              |                     | combination.
--------------+---------------------+-------------------------------------
 1.7.1        | pc-i440fx-1.7       | OVMF downloads valid ACPI tables
              | (default for 1.7.1) | from qemu and passes them to the
              |                     | guest OS.
--------------+---------------------+-------------------------------------
 2.0.0-rc0    | pc-i440fx-1.7 or    | OVMF downloads valid ACPI tables
              | later               | from qemu and passes them to the
              |                     | guest OS.
 -------------+---------------------+-------------------------------------

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15420 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Laszlo Ersek 2014-03-31 20:36:06 +00:00 committed by jljusten
parent 209c3922b7
commit 96bbdbc856
3 changed files with 164 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
OvmfPkg/AcpiPlatformDxe/AcpiPlatform.c
View File

@ -256,16 +256,14 @@ AcpiPlatformEntryPoint (
if (XenDetected ()) {
Status = InstallXenTables (AcpiTable);
if (EFI_ERROR (Status)) {
Status = FindAcpiTablesInFv (AcpiTable);
}
} else {
Status = InstallQemuLinkedTables (AcpiTable);
}
if (EFI_ERROR (Status)) {
Status = FindAcpiTablesInFv (AcpiTable);
}
if (EFI_ERROR (Status)) {
return Status;
}
return EFI_SUCCESS;
return Status;
}

7
OvmfPkg/AcpiPlatformDxe/AcpiPlatform.h
View File

@ -10,7 +10,7 @@
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 _ACPI_PLATFORM_H_INCLUDED_
#define _ACPI_PLATFORM_H_INCLUDED_
@ -61,5 +61,10 @@ InstallXenTables (
IN EFI_ACPI_TABLE_PROTOCOL *AcpiProtocol
);
EFI_STATUS
EFIAPI
InstallQemuLinkedTables (
IN EFI_ACPI_TABLE_PROTOCOL *AcpiProtocol
);
#endif

153
OvmfPkg/AcpiPlatformDxe/Qemu.c
View File

@ -515,3 +515,156 @@ QemuInstallAcpiTable (
);
}
/**
Download the ACPI table data file from QEMU and interpret it.
@param[in] AcpiProtocol The ACPI table protocol used to install tables.
@retval EFI_UNSUPPORTED Firmware configuration is unavailable.
@retval EFI_NOT_FOUND The host doesn't export the required fw_cfg
files.
@retval EFI_OUT_OF_RESOURCES Memory allocation failed.
@retval EFI_PROTOCOL_ERROR Found truncated or invalid ACPI table header
in the fw_cfg contents.
@return Status codes returned by
AcpiProtocol->InstallAcpiTable().
**/
//
// We'll be saving the keys of installed tables so that we can roll them back
// in case of failure. 128 tables should be enough for anyone (TM).
//
#define INSTALLED_TABLES_MAX 128
EFI_STATUS
EFIAPI
InstallQemuLinkedTables (
IN EFI_ACPI_TABLE_PROTOCOL *AcpiProtocol
)
{
EFI_STATUS Status;
FIRMWARE_CONFIG_ITEM TablesFile;
UINTN TablesFileSize;
UINT8 *Tables;
UINTN *InstalledKey;
UINTN Processed;
INT32 Installed;
Status = QemuFwCfgFindFile ("etc/acpi/tables", &TablesFile, &TablesFileSize);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_INFO, "%a: \"etc/acpi/tables\" interface unavailable: %r\n",
__FUNCTION__, Status));
return Status;
}
Tables = AllocatePool (TablesFileSize);
if (Tables == NULL) {
return EFI_OUT_OF_RESOURCES;
}
QemuFwCfgSelectItem (TablesFile);
QemuFwCfgReadBytes (TablesFileSize, Tables);
InstalledKey = AllocatePool (INSTALLED_TABLES_MAX * sizeof *InstalledKey);
if (InstalledKey == NULL) {
Status = EFI_OUT_OF_RESOURCES;
goto FreeTables;
}
Processed = 0;
Installed = 0;
while (Processed < TablesFileSize) {
UINTN Remaining;
EFI_ACPI_DESCRIPTION_HEADER *Probe;
Remaining = TablesFileSize - Processed;
if (Remaining < sizeof *Probe) {
Status = EFI_PROTOCOL_ERROR;
break;
}
Probe = (EFI_ACPI_DESCRIPTION_HEADER *) (Tables + Processed);
if (Remaining < Probe->Length || Probe->Length < sizeof *Probe) {
Status = EFI_PROTOCOL_ERROR;
break;
}
DEBUG ((EFI_D_VERBOSE, "%a: offset 0x%016Lx:"
" Signature=\"%-4.4a\" Length=0x%08x\n",
__FUNCTION__, (UINT64) Processed,
(CONST CHAR8 *) &Probe->Signature, Probe->Length));
//
// skip automatically handled "root" tables: RSDT, XSDT
//
if (Probe->Signature !=
EFI_ACPI_1_0_ROOT_SYSTEM_DESCRIPTION_TABLE_SIGNATURE &&
Probe->Signature !=
EFI_ACPI_2_0_EXTENDED_SYSTEM_DESCRIPTION_TABLE_SIGNATURE) {
if (Installed == INSTALLED_TABLES_MAX) {
DEBUG ((EFI_D_ERROR, "%a: can't install more than %d tables\n",
__FUNCTION__, INSTALLED_TABLES_MAX));
Status = EFI_OUT_OF_RESOURCES;
break;
}
Status = AcpiProtocol->InstallAcpiTable (AcpiProtocol, Probe,
Probe->Length, &InstalledKey[Installed]);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR,
"%a: failed to install table \"%-4.4a\" at offset 0x%Lx: %r\n",
__FUNCTION__, (CONST CHAR8 *) &Probe->Signature, (UINT64) Processed,
Status));
break;
}
++Installed;
}
Processed += Probe->Length;
}
//
// NUL-padding at the end is accepted
//
if (Status == EFI_PROTOCOL_ERROR) {
UINTN ErrorLocation;
ErrorLocation = Processed;
while (Processed < TablesFileSize && Tables[Processed] == '\0') {
++Processed;
}
if (Processed < TablesFileSize) {
DEBUG ((EFI_D_ERROR, "%a: truncated or invalid ACPI table header at "
"offset 0x%Lx\n", __FUNCTION__, (UINT64) ErrorLocation));
}
}
if (Processed == TablesFileSize) {
DEBUG ((EFI_D_INFO, "%a: installed %d tables\n", __FUNCTION__, Installed));
Status = EFI_SUCCESS;
} else {
ASSERT (EFI_ERROR (Status));
//
// Roll back partial installation.
//
while (Installed > 0) {
--Installed;
AcpiProtocol->UninstallAcpiTable (AcpiProtocol, InstalledKey[Installed]);
}
}
FreePool (InstalledKey);
FreeTables:
FreePool (Tables);
return Status;
}