The IPA space of a Realm is divided into two halves: - Protected IPA space and - Unprotected IPA space.
Software in a Realm should treat the most significant bit of an IPA as a protection attribute. The Unprotected IPA space is used for sharing memory and for performing MMIO accesses with the Host. An Unprotected IPA is an address in the upper half of a Realm's IPA space. The most significant bit of an Unprotected IPA is 1. Therefore, the page tables for the MMIO regions must be updated to set the most significant bit of the IPA space. To facilitate this define ArmCcaConfigureMmio () that can be called during the early firmware startup. Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org> Cc: Leif Lindholm <quic_llind...@quicinc.com> Cc: Gerd Hoffmann <kra...@redhat.com> Signed-off-by: Sami Mujawar <sami.muja...@arm.com> --- ArmVirtPkg/Include/Library/ArmVirtMemInfoLib.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/ArmVirtPkg/Include/Library/ArmVirtMemInfoLib.h b/ArmVirtPkg/Include/Library/ArmVirtMemInfoLib.h index 7812c2e28657ca9525880dcc0d16d7bca90cc334..b70a96ed923e8c2654e51c9714074744a4d5f0c2 100644 --- a/ArmVirtPkg/Include/Library/ArmVirtMemInfoLib.h +++ b/ArmVirtPkg/Include/Library/ArmVirtMemInfoLib.h @@ -1,6 +1,6 @@ /** @file - Copyright (c) 2011-2013, ARM Limited. All rights reserved. + Copyright (c) 2011-2023, Arm Limited. All rights reserved. Copyright (c) 2017, Linaro, Ltd. All rights reserved. SPDX-License-Identifier: BSD-2-Clause-Patent @@ -32,4 +32,21 @@ ArmVirtGetMemoryMap ( OUT ARM_MEMORY_REGION_DESCRIPTOR **VirtualMemoryMap ); +/** + Configure the MMIO regions as shared with the VMM. + + Set the protection attribute for the MMIO regions as Unprotected IPA. + + @param[in] IpaWidth IPA width of the Realm. + + @retval RETURN_SUCCESS Success. + @retval RETURN_INVALID_PARAMETER A parameter is invalid. + @retval RETURN_UNSUPPORTED The execution context is not in a Realm. +**/ +EFI_STATUS +EFIAPI +ArmCcaConfigureMmio ( + IN UINT64 IpaWidth + ); + #endif -- 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)' -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#117687): https://edk2.groups.io/g/devel/message/117687 Mute This Topic: https://groups.io/mt/105483426/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
