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OvmfPkg/PciHostBridgeUtilityLib: Initialize RootBridges apertures with spec 

Consume the host-provided specification of PCI host bridges if
available. Using the DxeHardwareInfoLib, populate a list of
hardware descriptors based on the content of the "hardware-info"
fw-cfg file, if provided. In the affirmative case, use the
resources and attributes specified by the hypervisor for each
Host Bridge to create the RootBridge elements.

In Ovmf platforms, the host can provide the specification of
non-discoverable hardware resources like PCI host bridges. If the
proper fw-cfg file is found, parse the contents provided by the
host into a linked list by using the Hardware Info library. Then,
using the list of PCI host bridges' descriptions, populate the
PCI_ROOT_BRIDGES array with the resources and attributes specified
by the host. If the file is not provided or no Host Bridge is found
in it, fold back to the legacy method based on pre-defined
apertures and rules.

In some use cases, the host requires additional control over the
hardware resources' configurations in the guest for performance and
discoverability reasons. For instance, to disclose information about
the PCI hierarchy to the guest so that this can profit from
optimized accesses. In this case, the host can decide to describe
multiple PCI Host Bridges and provide a specific set of resources
(e.g. MMIO apertures) so that the guest uses the values provided.
Using the provided values may entitle the guest to added performance,
for example by using specific MMIO mappings that can enable peer-to-peer
communication across the PCI hierarchy or by allocating memory closer
to a device for faster DMA transactions.

Cc: Alexander Graf <graf@amazon.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com>
This commit is contained in:
Nicolas Ojeda Leon 2021-06-29 17:52:13 +02:00 committed by mergify[bot]
parent 3497fd5c26
commit 3f5b1b9132
2 changed files with 328 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

332
OvmfPkg/Library/PciHostBridgeUtilityLib/PciHostBridgeUtilityLib.c
View File

@ -12,13 +12,16 @@
#include <IndustryStandard/Acpi10.h>
#include <IndustryStandard/Pci.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/DevicePathLib.h>
#include <Library/HardwareInfoLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PciHostBridgeUtilityLib.h>
#include <Library/PciLib.h>
#include <Library/QemuFwCfgLib.h>
#include <Protocol/PciHostBridgeResourceAllocation.h>
#pragma pack(1)
typedef struct {
@ -189,7 +192,9 @@ PciHostBridgeUtilityUninitRootBridge (
}
/**
Utility function to return all the root bridge instances in an array.
Utility function to scan PCI root bridges and create instances for those
that are found not empty. Populate their resources from the default
provided parameters and return all the root bridge instances in an array.
@param[out] Count The number of root bridge instances.
@ -217,9 +222,9 @@ PciHostBridgeUtilityUninitRootBridge (
@return All the root bridge instances in an array.
**/
STATIC
PCI_ROOT_BRIDGE *
EFIAPI
PciHostBridgeUtilityGetRootBridges (
PciHostBridgeUtilityGetRootBridgesBusScan (
OUT UINTN *Count,
IN UINT64 Attributes,
IN UINT64 AllocationAttributes,
@ -243,8 +248,6 @@ PciHostBridgeUtilityGetRootBridges (
UINTN LastRootBridgeNumber;
UINTN RootBridgeNumber;
*Count = 0;
if ((BusMin > BusMax) || (BusMax > PCI_MAX_BUS)) {
DEBUG ((
DEBUG_ERROR,
@ -403,6 +406,325 @@ FreeBridges:
return NULL;
}
/**
Utility function to read root bridges information from host-provided fw-cfg
file and return them in an array.
@param[out] Count The number of root bridge instances.
@return All the root bridge instances in an array parsed from
host-provided fw-cfg file (hardware-info).
**/
STATIC
PCI_ROOT_BRIDGE *
PciHostBridgeUtilityGetRootBridgesHostProvided (
OUT UINTN *Count
)
{
EFI_STATUS Status;
FIRMWARE_CONFIG_ITEM FwCfgItem;
UINTN FwCfgSize;
PCI_ROOT_BRIDGE *Bridges;
UINTN Initialized;
UINTN LastRootBridgeNumber;
UINTN RootBridgeNumber;
UINTN PciHostBridgeCount;
UINT8 *HardwareInfoBlob;
LIST_ENTRY HwInfoList;
LIST_ENTRY *HwLink;
HARDWARE_INFO *HwInfo;
UINT64 Attributes;
UINT64 AllocationAttributes;
BOOLEAN DmaAbove4G;
BOOLEAN NoExtendedConfigSpace;
BOOLEAN CombineMemPMem;
PCI_ROOT_BRIDGE_APERTURE Io;
PCI_ROOT_BRIDGE_APERTURE Mem;
PCI_ROOT_BRIDGE_APERTURE MemAbove4G;
PCI_ROOT_BRIDGE_APERTURE PMem;
PCI_ROOT_BRIDGE_APERTURE PMemAbove4G;
//
// Initialize the Hardware Info list head to start with an empty but valid
// list head.
//
InitializeListHead (&HwInfoList);
HardwareInfoBlob = NULL;
Initialized = 0;
Bridges = NULL;
PciHostBridgeCount = 0;
//
// Hypervisor can provide the specifications (resources) for one or more
// PCI host bridges. Such information comes through fw-cfg as part of
// the hardware-info file.
//
Status = QemuFwCfgFindFile ("etc/hardware-info", &FwCfgItem, &FwCfgSize);
if (EFI_ERROR (Status)) {
return NULL;
}
HardwareInfoBlob = AllocatePool (FwCfgSize);
if (HardwareInfoBlob == NULL) {
DEBUG ((
DEBUG_ERROR,
"%a: Failed to allocate memory for hardware resources info\n",
__FUNCTION__
));
return NULL;
}
QemuFwCfgSelectItem (FwCfgItem);
QemuFwCfgReadBytes (FwCfgSize, HardwareInfoBlob);
//
// Create the list of hardware info devices filtering for PCI host
// bridges
//
Status = CreateHardwareInfoList (
HardwareInfoBlob,
FwCfgSize,
HardwareInfoTypeHostBridge,
&HwInfoList
);
if (EFI_ERROR (Status)) {
DEBUG ((
DEBUG_ERROR,
"%a: Failed to create hardware info list to retrieve host "
"bridges information from fw-cfg\n",
__FUNCTION__
));
goto FreeBridges;
}
PciHostBridgeCount = GetHardwareInfoCountByType (
&HwInfoList,
HardwareInfoTypeHostBridge,
sizeof (HOST_BRIDGE_INFO)
);
if (PciHostBridgeCount == 0) {
goto FreeBridges;
}
DEBUG ((
DEBUG_INFO,
"%a: Host provided description for %Lu root bridges\n",
__FUNCTION__,
PciHostBridgeCount
));
//
// Allocate the root bridges
//
Bridges = AllocatePool (((UINTN)PciHostBridgeCount) * sizeof *Bridges);
if (Bridges == NULL) {
DEBUG ((DEBUG_ERROR, "%a: %r\n", __FUNCTION__, EFI_OUT_OF_RESOURCES));
goto FreeBridges;
}
//
// If Host Bridges' specification was obtained from fw-cfg, the list
// contains information to populate all root bridges in the system
// including resources and attributes.
//
HwLink = GetFirstHardwareInfoByType (
&HwInfoList,
HardwareInfoTypeHostBridge,
sizeof (HOST_BRIDGE_INFO)
);
while (!EndOfHardwareInfoList (&HwInfoList, HwLink)) {
HwInfo = HARDWARE_INFO_FROM_LINK (HwLink);
Status = HardwareInfoPciHostBridgeGet (
HwInfo->Data.PciHostBridge,
(UINTN)HwInfo->Header.Size,
&RootBridgeNumber,
&LastRootBridgeNumber,
&Attributes,
&DmaAbove4G,
&NoExtendedConfigSpace,
&CombineMemPMem,
&Io,
&Mem,
&MemAbove4G,
&PMem,
&PMemAbove4G,
NULL
);
if (EFI_ERROR (Status)) {
goto FreeBridges;
}
if ((RootBridgeNumber > LastRootBridgeNumber) || (LastRootBridgeNumber > PCI_MAX_BUS)) {
DEBUG ((
DEBUG_ERROR,
"%a: invalid bus range with BusMin %Lu and BusMax "
"%Lu\n",
__FUNCTION__,
(UINT64)RootBridgeNumber,
(UINT64)LastRootBridgeNumber
));
goto FreeBridges;
}
AllocationAttributes = 0;
if (CombineMemPMem) {
AllocationAttributes |= EFI_PCI_HOST_BRIDGE_COMBINE_MEM_PMEM;
}
if ((MemAbove4G.Limit > MemAbove4G.Base) ||
(PMemAbove4G.Limit > PMemAbove4G.Base))
{
AllocationAttributes |= EFI_PCI_HOST_BRIDGE_MEM64_DECODE;
}
Status = PciHostBridgeUtilityInitRootBridge (
Attributes,
Attributes,
AllocationAttributes,
DmaAbove4G,
NoExtendedConfigSpace,
(UINT8)RootBridgeNumber,
(UINT8)LastRootBridgeNumber,
&Io,
&Mem,
&MemAbove4G,
&PMem,
&PMemAbove4G,
&Bridges[Initialized]
);
if (EFI_ERROR (Status)) {
goto FreeBridges;
}
++Initialized;
HwLink = GetNextHardwareInfoByType (
&HwInfoList,
HwLink,
HardwareInfoTypeHostBridge,
sizeof (HOST_BRIDGE_INFO)
);
}
*Count = Initialized;
//
// If resources were allocated for host bridges info, release them
//
if (HardwareInfoBlob) {
FreePool (HardwareInfoBlob);
}
FreeHardwareInfoList (&HwInfoList);
return Bridges;
FreeBridges:
while (Initialized > 0) {
--Initialized;
PciHostBridgeUtilityUninitRootBridge (&Bridges[Initialized]);
}
if (Bridges) {
FreePool (Bridges);
}
if (HardwareInfoBlob) {
FreePool (HardwareInfoBlob);
}
FreeHardwareInfoList (&HwInfoList);
return NULL;
}
/**
Utility function to return all the root bridge instances in an array.
@param[out] Count The number of root bridge instances.
@param[in] Attributes Initial attributes.
@param[in] AllocAttributes Allocation attributes.
@param[in] DmaAbove4G DMA above 4GB memory.
@param[in] NoExtendedConfigSpace No Extended Config Space.
@param[in] BusMin Minimum Bus number, inclusive.
@param[in] BusMax Maximum Bus number, inclusive.
@param[in] Io IO aperture.
@param[in] Mem MMIO aperture.
@param[in] MemAbove4G MMIO aperture above 4G.
@param[in] PMem Prefetchable MMIO aperture.
@param[in] PMemAbove4G Prefetchable MMIO aperture above 4G.
@return All the root bridge instances in an array.
**/
PCI_ROOT_BRIDGE *
EFIAPI
PciHostBridgeUtilityGetRootBridges (
OUT UINTN *Count,
IN UINT64 Attributes,
IN UINT64 AllocationAttributes,
IN BOOLEAN DmaAbove4G,
IN BOOLEAN NoExtendedConfigSpace,
IN UINTN BusMin,
IN UINTN BusMax,
IN PCI_ROOT_BRIDGE_APERTURE *Io,
IN PCI_ROOT_BRIDGE_APERTURE *Mem,
IN PCI_ROOT_BRIDGE_APERTURE *MemAbove4G,
IN PCI_ROOT_BRIDGE_APERTURE *PMem,
IN PCI_ROOT_BRIDGE_APERTURE *PMemAbove4G
)
{
PCI_ROOT_BRIDGE *Bridges;
*Count = 0;
//
// First attempt to get the host provided descriptions of the Root Bridges
// if available.
//
Bridges = PciHostBridgeUtilityGetRootBridgesHostProvided (Count);
//
// If host did not provide Root Bridge information, scan the buses and
// auto populate them with default resources.
//
if (Bridges == NULL) {
Bridges = PciHostBridgeUtilityGetRootBridgesBusScan (
Count,
Attributes,
AllocationAttributes,
DmaAbove4G,
NoExtendedConfigSpace,
BusMin,
BusMax,
Io,
Mem,
MemAbove4G,
PMem,
PMemAbove4G
);
}
return Bridges;
}
/**
Utility function to free root bridge instances array from
PciHostBridgeUtilityGetRootBridges().

1
OvmfPkg/Library/PciHostBridgeUtilityLib/PciHostBridgeUtilityLib.inf
View File

@ -38,6 +38,7 @@
BaseMemoryLib
DebugLib
DevicePathLib
DxeHardwareInfoLib
MemoryAllocationLib
PciLib
QemuFwCfgLib