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OvmfPkg/CpuHotplugSmm: introduce Post-SMM Pen for hot-added CPUs

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Once a hot-added CPU finishes the SMBASE relocation, we need to pen it in
a HLT loop. Add the NASM implementation (with just a handful of
instructions, but much documentation), and some C language helper
functions.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200226221156.29589-12-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Laszlo Ersek
2020-02-26 23:11:51 +01:00
committed by mergify[bot]
parent 17cb8ddba3
commit 63c89da242
4 changed files with 297 additions and 0 deletions
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110
OvmfPkg/CpuHotplugSmm/Smbase.c Normal file
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/** @file
SMBASE relocation for hot-plugged CPUs.
Copyright (c) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h> // BASE_1MB
#include <Library/BaseMemoryLib.h> // CopyMem()
#include <Library/DebugLib.h> // DEBUG()
#include "Smbase.h"
extern CONST UINT8 mPostSmmPen[];
extern CONST UINT16 mPostSmmPenSize;
/**
Allocate a non-SMRAM reserved memory page for the Post-SMM Pen for hot-added
CPUs.
This function may only be called from the entry point function of the driver.
@param[out] PenAddress The address of the allocated (normal RAM) reserved
page.
@param[in] BootServices Pointer to the UEFI boot services table. Used for
allocating the normal RAM (not SMRAM) reserved page.
@retval EFI_SUCCESS Allocation successful.
@retval EFI_BAD_BUFFER_SIZE The Post-SMM Pen template is not smaller than
EFI_PAGE_SIZE.
@return Error codes propagated from underlying services.
DEBUG_ERROR messages have been logged. No
resources have been allocated.
**/
EFI_STATUS
SmbaseAllocatePostSmmPen (
OUT UINT32 *PenAddress,
IN CONST EFI_BOOT_SERVICES *BootServices
)
{
EFI_STATUS Status;
EFI_PHYSICAL_ADDRESS Address;
//
// The pen code must fit in one page, and the last byte must remain free for
// signaling the SMM Monarch.
//
if (mPostSmmPenSize >= EFI_PAGE_SIZE) {
Status = EFI_BAD_BUFFER_SIZE;
DEBUG ((DEBUG_ERROR, "%a: mPostSmmPenSize=%u: %r\n", __FUNCTION__,
mPostSmmPenSize, Status));
return Status;
}
Address = BASE_1MB - 1;
Status = BootServices->AllocatePages (AllocateMaxAddress,
EfiReservedMemoryType, 1, &Address);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "%a: AllocatePages(): %r\n", __FUNCTION__, Status));
return Status;
}
DEBUG ((DEBUG_INFO, "%a: Post-SMM Pen at 0x%Lx\n", __FUNCTION__, Address));
*PenAddress = (UINT32)Address;
return EFI_SUCCESS;
}
/**
Copy the Post-SMM Pen template code into the reserved page allocated with
SmbaseAllocatePostSmmPen().
Note that this effects an "SMRAM to normal RAM" copy.
The SMM Monarch is supposed to call this function from the root MMI handler.
@param[in] PenAddress The allocation address returned by
SmbaseAllocatePostSmmPen().
**/
VOID
SmbaseReinstallPostSmmPen (
IN UINT32 PenAddress
)
{
CopyMem ((VOID *)(UINTN)PenAddress, mPostSmmPen, mPostSmmPenSize);
}
/**
Release the reserved page allocated with SmbaseAllocatePostSmmPen().
This function may only be called from the entry point function of the driver,
on the error path.
@param[in] PenAddress The allocation address returned by
SmbaseAllocatePostSmmPen().
@param[in] BootServices Pointer to the UEFI boot services table. Used for
releasing the normal RAM (not SMRAM) reserved page.
**/
VOID
SmbaseReleasePostSmmPen (
IN UINT32 PenAddress,
IN CONST EFI_BOOT_SERVICES *BootServices
)
{
BootServices->FreePages (PenAddress, 1);
}