sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

OvmfPkg: Add TdxDxe driver

Browse Source 
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

TdxDxe driver is dispatched early in DXE, due to being list in APRIORI.
This module is responsible for below features:
 - Sets max logical cpus based on TDINFO
 - Sets PCI PCDs based on resource hobs
 - Set shared bit in MMIO region
 - Relocate Td mailbox and set its address in MADT table.

1. Set shared bit in MMIO region

Qemu allows a ROM device to set to ROMD mode (default) or MMIO mode.
When it is in ROMD mode, the device is mapped to guest memory and
satisfies read access directly.

In EDK2 Option ROM is treated as MMIO region. So Tdx guest access
Option ROM via TDVMCALL(MMIO). But as explained above, since Qemu set
the Option ROM to ROMD mode, the call of TDVMCALL(MMIO) always return
INVALID_OPERAND. Tdvf then falls back to direct access. This requires
to set the shared bit to corresponding PageTable entry. Otherwise it
triggers GP fault.

TdxDxe's entry point is the right place to set the shared bit in MMIO
region because Option ROM has not been discoverd yet.

2. Relocate Td mailbox and set the new address in MADT Mutiprocessor
Wakeup Table.

In TDX the guest firmware is designed to publish a multiprocessor-wakeup
structure to let the guest-bootstrap processor wake up guest-application
processors with a mailbox. The mailbox is memory that the guest firmware
can reserve so each guest virtual processor can have the guest OS send
a message to them. The address of the mailbox is recorded in the MADT
table. See [ACPI].

TdxDxe registers for protocol notification
(gQemuAcpiTableNotifyProtocolGuid) to call the AlterAcpiTable(), in
which MADT table is altered by the above Mailbox address. The protocol
will be installed in AcpiPlatformDxe when the MADT table provided by
Qemu is ready. This is to maintain the simplicity of the AcpiPlatformDxe.

AlterAcpiTable is the registered function which traverses the ACPI
table list to find the original MADT from Qemu. After the new MADT is
configured and installed, the original one will be uninstalled.

[ACPI] https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model
/ACPI_Software_Programming_Model.html#multiprocessor-wakeup-structure

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
This commit is contained in:
Min Xu
2021-09-22 13:26:01 +08:00
committed by mergify[bot]
parent 5aa8018639
commit fae5c1464d
8 changed files with 694 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

261
OvmfPkg/TdxDxe/TdxDxe.c Normal file
View File

@@ -0,0 +1,261 @@
/** @file
TDX Dxe driver. This driver is dispatched early in DXE, due to being list
in APRIORI.
This module is responsible for:
- Sets max logical cpus based on TDINFO
- Sets PCI PCDs based on resource hobs
- Alter MATD table to record address of Mailbox
Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/DxeServicesTableLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PcdLib.h>
#include <Library/UefiLib.h>
#include <Library/HobLib.h>
#include <Protocol/Cpu.h>
#include <Library/UefiBootServicesTableLib.h>
#include <IndustryStandard/Tdx.h>
#include <Library/PlatformInitLib.h>
#include <Library/TdxLib.h>
#include <TdxAcpiTable.h>
#include <Library/MemEncryptTdxLib.h>
/**
Location of resource hob matching type and starting address
@param[in] Type The type of resource hob to locate.
@param[in] Start The resource hob must at least begin at address.
@retval pointer to resource Return pointer to a resource hob that matches or NULL.
**/
STATIC
EFI_HOB_RESOURCE_DESCRIPTOR *
GetResourceDescriptor (
EFI_RESOURCE_TYPE Type,
EFI_PHYSICAL_ADDRESS Start,
EFI_PHYSICAL_ADDRESS End
)
{
EFI_PEI_HOB_POINTERS Hob;
EFI_HOB_RESOURCE_DESCRIPTOR *ResourceDescriptor = NULL;
Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
while (Hob.Raw != NULL) {
DEBUG ((
DEBUG_INFO,
"%a:%d: resource type 0x%x %llx %llx\n",
__func__,
__LINE__,
Hob.ResourceDescriptor->ResourceType,
Hob.ResourceDescriptor->PhysicalStart,
Hob.ResourceDescriptor->ResourceLength
));
if ((Hob.ResourceDescriptor->ResourceType == Type) &&
(Hob.ResourceDescriptor->PhysicalStart >= Start) &&
((Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength) < End))
{
ResourceDescriptor = Hob.ResourceDescriptor;
break;
}
Hob.Raw = GET_NEXT_HOB (Hob);
Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
}
return ResourceDescriptor;
}
/**
Location of resource hob matching type and highest address below end
@param[in] Type The type of resource hob to locate.
@param[in] End The resource hob return is the closest to the End address
@retval pointer to resource Return pointer to a resource hob that matches or NULL.
**/
STATIC
EFI_HOB_RESOURCE_DESCRIPTOR *
GetHighestResourceDescriptor (
EFI_RESOURCE_TYPE Type,
EFI_PHYSICAL_ADDRESS End
)
{
EFI_PEI_HOB_POINTERS Hob;
EFI_HOB_RESOURCE_DESCRIPTOR *ResourceDescriptor = NULL;
Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
while (Hob.Raw != NULL) {
if ((Hob.ResourceDescriptor->ResourceType == Type) &&
(Hob.ResourceDescriptor->PhysicalStart < End))
{
if (!ResourceDescriptor ||
(ResourceDescriptor->PhysicalStart < Hob.ResourceDescriptor->PhysicalStart))
{
ResourceDescriptor = Hob.ResourceDescriptor;
}
}
Hob.Raw = GET_NEXT_HOB (Hob);
Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
}
return ResourceDescriptor;
}
/**
Set the shared bit for mmio region in Tdx guest.
In Tdx guest there are 2 ways to access mmio, TdVmcall or direct access.
For direct access, the shared bit of the PageTableEntry should be set.
The mmio region information is retrieved from hob list.
@retval EFI_SUCCESS The shared bit is set successfully.
@retval EFI_UNSUPPORTED Setting the shared bit of memory region
is not supported
**/
EFI_STATUS
SetMmioSharedBit (
VOID
)
{
EFI_PEI_HOB_POINTERS Hob;
Hob.Raw = (UINT8 *)GetHobList ();
//
// Parse the HOB list until end of list or matching type is found.
//
while (!END_OF_HOB_LIST (Hob)) {
if ( (Hob.Header->HobType == EFI_HOB_TYPE_RESOURCE_DESCRIPTOR)
&& (Hob.ResourceDescriptor->ResourceType == EFI_RESOURCE_MEMORY_MAPPED_IO))
{
MemEncryptTdxSetPageSharedBit (
0,
Hob.ResourceDescriptor->PhysicalStart,
EFI_SIZE_TO_PAGES (Hob.ResourceDescriptor->ResourceLength)
);
}
Hob.Raw = GET_NEXT_HOB (Hob);
}
return EFI_SUCCESS;
}
EFI_STATUS
EFIAPI
TdxDxeEntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
RETURN_STATUS PcdStatus;
EFI_HOB_RESOURCE_DESCRIPTOR *Res = NULL;
EFI_HOB_RESOURCE_DESCRIPTOR *MemRes = NULL;
EFI_HOB_PLATFORM_INFO *PlatformInfo = NULL;
EFI_HOB_GUID_TYPE *GuidHob;
UINT32 CpuMaxLogicalProcessorNumber;
TD_RETURN_DATA TdReturnData;
EFI_EVENT QemuAcpiTableEvent;
void *Registration;
GuidHob = GetFirstGuidHob (&gUefiOvmfPkgPlatformInfoGuid);
if (GuidHob == NULL) {
return EFI_UNSUPPORTED;
}
//
// Both Td and Non-Td guest have PlatformInfoHob which contains the HostBridgePciDevId
//
PlatformInfo = (EFI_HOB_PLATFORM_INFO *)GET_GUID_HOB_DATA (GuidHob);
ASSERT (PlatformInfo->HostBridgeDevId != 0);
PcdStatus = PcdSet16S (PcdOvmfHostBridgePciDevId, PlatformInfo->HostBridgeDevId);
ASSERT_RETURN_ERROR (PcdStatus);
if (!TdIsEnabled ()) {
return EFI_UNSUPPORTED;
}
SetMmioSharedBit ();
//
// Call TDINFO to get actual number of cpus in domain
//
Status = TdCall (TDCALL_TDINFO, 0, 0, 0, &TdReturnData);
ASSERT (Status == EFI_SUCCESS);
CpuMaxLogicalProcessorNumber = PcdGet32 (PcdCpuMaxLogicalProcessorNumber);
//
// Adjust PcdCpuMaxLogicalProcessorNumber, if needed. If firmware is configured for
// more than number of reported cpus, update.
//
if (CpuMaxLogicalProcessorNumber > TdReturnData.TdInfo.NumVcpus) {
PcdStatus = PcdSet32S (PcdCpuMaxLogicalProcessorNumber, TdReturnData.TdInfo.NumVcpus);
ASSERT_RETURN_ERROR (PcdStatus);
}
//
// Register for protocol notifications to call the AlterAcpiTable(),
// the protocol will be installed in AcpiPlatformDxe when the ACPI
// table provided by Qemu is ready.
//
Status = gBS->CreateEvent (
EVT_NOTIFY_SIGNAL,
TPL_CALLBACK,
AlterAcpiTable,
NULL,
&QemuAcpiTableEvent
);
Status = gBS->RegisterProtocolNotify (
&gQemuAcpiTableNotifyProtocolGuid,
QemuAcpiTableEvent,
&Registration
);
#define INIT_PCDSET(NAME, RES) do {\
PcdStatus = PcdSet64S (NAME##Base, (RES)->PhysicalStart); \
ASSERT_RETURN_ERROR (PcdStatus); \
PcdStatus = PcdSet64S (NAME##Size, (RES)->ResourceLength); \
ASSERT_RETURN_ERROR (PcdStatus); \
} while(0)
if (PlatformInfo) {
PcdSet16S (PcdOvmfHostBridgePciDevId, PlatformInfo->HostBridgeDevId);
if ((Res = GetResourceDescriptor (EFI_RESOURCE_MEMORY_MAPPED_IO, (EFI_PHYSICAL_ADDRESS)0x100000000, (EFI_PHYSICAL_ADDRESS)-1)) != NULL) {
INIT_PCDSET (PcdPciMmio64, Res);
}
if ((Res = GetResourceDescriptor (EFI_RESOURCE_IO, 0, 0x10001)) != NULL) {
INIT_PCDSET (PcdPciIo, Res);
}
//
// To find low mmio, first find top of low memory, and then search for io space.
//
if ((MemRes = GetHighestResourceDescriptor (EFI_RESOURCE_SYSTEM_MEMORY, 0xffc00000)) != NULL) {
if ((Res = GetResourceDescriptor (EFI_RESOURCE_MEMORY_MAPPED_IO, MemRes->PhysicalStart, 0x100000000)) != NULL) {
INIT_PCDSET (PcdPciMmio32, Res);
}
}
}
return EFI_SUCCESS;
}