From: Tom Lendacky <thomas.lendacky@amd.com>
To: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Richard Henderson <rth@twiddle.net>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
James E J Bottomley <James.Bottomley@HansenPartnership.com>,
Helge Deller <deller@gmx.de>,
"David S . Miller" <davem@davemloft.net>,
Arnd Bergmann <arnd@arndb.de>, Jonathan Corbet <corbet@lwn.net>,
"Michael S . Tsirkin" <mst@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
David Hildenbrand <david@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter H Anvin <hpa@zytor.com>,
Dave Hansen <dave.hansen@intel.com>,
Tony Luck <tony.luck@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Andi Kleen <ak@linux.intel.com>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>,
Sean Christopherson <seanjc@google.com>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, linux-alpha@vger.kernel.org,
linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org,
sparclinux@vger.kernel.org, linux-arch@vger.kernel.org,
linux-doc@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v5 01/16] x86/mm: Move force_dma_unencrypted() to common code
Date: Wed, 20 Oct 2021 11:11:13 -0500 [thread overview]
Message-ID: <72b8be39-b4e2-5d77-524c-a2ea0c750ab1@amd.com> (raw)
In-Reply-To: <20211009003711.1390019-2-sathyanarayanan.kuppuswamy@linux.intel.com>
On 10/8/21 7:36 PM, Kuppuswamy Sathyanarayanan wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
>
> Intel TDX doesn't allow VMM to access guest private memory. Any memory
> that is required for communication with VMM must be shared explicitly
> by setting the bit in page table entry. After setting the shared bit,
> the conversion must be completed with MapGPA hypercall. Details about
> MapGPA hypercall can be found in [1], sec 3.2.
>
> The call informs VMM about the conversion between private/shared
> mappings. The shared memory is similar to unencrypted memory in AMD
> SME/SEV terminology but the underlying process of sharing/un-sharing
> the memory is different for Intel TDX guest platform.
>
> SEV assumes that I/O devices can only do DMA to "decrypted" physical
> addresses without the C-bit set. In order for the CPU to interact with
> this memory, the CPU needs a decrypted mapping. To add this support,
> AMD SME code forces force_dma_unencrypted() to return true for
> platforms that support AMD SEV feature. It will be used for DMA memory
> allocation API to trigger set_memory_decrypted() for platforms that
> support AMD SEV feature.
>
> TDX is similar. So, to communicate with I/O devices, related pages need
> to be marked as shared. As mentioned above, shared memory in TDX
> architecture is similar to decrypted memory in AMD SME/SEV. So similar
> to AMD SEV, force_dma_unencrypted() has to forced to return true. This
> support is added in other patches in this series.
>
> So move force_dma_unencrypted() out of AMD specific code and call AMD
> specific (amd_force_dma_unencrypted()) initialization function from it.
> force_dma_unencrypted() will be modified by later patches to include
> Intel TDX guest platform specific initialization.
>
> Also, introduce new config option X86_MEM_ENCRYPT_COMMON that has to be
> selected by all x86 memory encryption features. This will be selected
> by both AMD SEV and Intel TDX guest config options.
>
> This is preparation for TDX changes in DMA code and it has no
> functional change.
Can force_dma_unencrypted() be moved to arch/x86/kernel/cc_platform.c,
instead of creating a new file? It might fit better with patch #6.
Thanks,
Tom
>
> [1] - https://software.intel.com/content/dam/develop/external/us/en/documents/intel-tdx-guest-hypervisor-communication-interface.pdf
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reviewed-by: Andi Kleen <ak@linux.intel.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> ---
>
> Changes since v4:
> * Removed used we/you from commit log.
>
> Change since v3:
> * None
>
> Changes since v1:
> * Removed sev_active(), sme_active() checks in force_dma_unencrypted().
>
> arch/x86/Kconfig | 8 ++++++--
> arch/x86/include/asm/mem_encrypt_common.h | 18 ++++++++++++++++++
> arch/x86/mm/Makefile | 2 ++
> arch/x86/mm/mem_encrypt.c | 3 ++-
> arch/x86/mm/mem_encrypt_common.c | 17 +++++++++++++++++
> 5 files changed, 45 insertions(+), 3 deletions(-)
> create mode 100644 arch/x86/include/asm/mem_encrypt_common.h
> create mode 100644 arch/x86/mm/mem_encrypt_common.c
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index af49ad084919..37b27412f52e 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1519,16 +1519,20 @@ config X86_CPA_STATISTICS
> helps to determine the effectiveness of preserving large and huge
> page mappings when mapping protections are changed.
>
> +config X86_MEM_ENCRYPT_COMMON
> + select ARCH_HAS_FORCE_DMA_UNENCRYPTED
> + select DYNAMIC_PHYSICAL_MASK
> + def_bool n
> +
> config AMD_MEM_ENCRYPT
> bool "AMD Secure Memory Encryption (SME) support"
> depends on X86_64 && CPU_SUP_AMD
> select DMA_COHERENT_POOL
> - select DYNAMIC_PHYSICAL_MASK
> select ARCH_USE_MEMREMAP_PROT
> - select ARCH_HAS_FORCE_DMA_UNENCRYPTED
> select INSTRUCTION_DECODER
> select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
> select ARCH_HAS_CC_PLATFORM
> + select X86_MEM_ENCRYPT_COMMON
> help
> Say yes to enable support for the encryption of system memory.
> This requires an AMD processor that supports Secure Memory
> diff --git a/arch/x86/include/asm/mem_encrypt_common.h b/arch/x86/include/asm/mem_encrypt_common.h
> new file mode 100644
> index 000000000000..697bc40a4e3d
> --- /dev/null
> +++ b/arch/x86/include/asm/mem_encrypt_common.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2020 Intel Corporation */
> +#ifndef _ASM_X86_MEM_ENCRYPT_COMMON_H
> +#define _ASM_X86_MEM_ENCRYPT_COMMON_H
> +
> +#include <linux/mem_encrypt.h>
> +#include <linux/device.h>
> +
> +#ifdef CONFIG_AMD_MEM_ENCRYPT
> +bool amd_force_dma_unencrypted(struct device *dev);
> +#else /* CONFIG_AMD_MEM_ENCRYPT */
> +static inline bool amd_force_dma_unencrypted(struct device *dev)
> +{
> + return false;
> +}
> +#endif /* CONFIG_AMD_MEM_ENCRYPT */
> +
> +#endif
> diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
> index 5864219221ca..b31cb52bf1bd 100644
> --- a/arch/x86/mm/Makefile
> +++ b/arch/x86/mm/Makefile
> @@ -52,6 +52,8 @@ obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) += pkeys.o
> obj-$(CONFIG_RANDOMIZE_MEMORY) += kaslr.o
> obj-$(CONFIG_PAGE_TABLE_ISOLATION) += pti.o
>
> +obj-$(CONFIG_X86_MEM_ENCRYPT_COMMON) += mem_encrypt_common.o
> +
> obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o
> obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_identity.o
> obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_boot.o
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 23d54b810f08..5d7fbed73949 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -31,6 +31,7 @@
> #include <asm/processor-flags.h>
> #include <asm/msr.h>
> #include <asm/cmdline.h>
> +#include <asm/mem_encrypt_common.h>
>
> #include "mm_internal.h"
>
> @@ -362,7 +363,7 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
> }
>
> /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
> -bool force_dma_unencrypted(struct device *dev)
> +bool amd_force_dma_unencrypted(struct device *dev)
> {
> /*
> * For SEV, all DMA must be to unencrypted addresses.
> diff --git a/arch/x86/mm/mem_encrypt_common.c b/arch/x86/mm/mem_encrypt_common.c
> new file mode 100644
> index 000000000000..f063c885b0a5
> --- /dev/null
> +++ b/arch/x86/mm/mem_encrypt_common.c
> @@ -0,0 +1,17 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Memory Encryption Support Common Code
> + *
> + * Copyright (C) 2021 Intel Corporation
> + *
> + * Author: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> + */
> +
> +#include <asm/mem_encrypt_common.h>
> +#include <linux/dma-mapping.h>
> +
> +/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
> +bool force_dma_unencrypted(struct device *dev)
> +{
> + return amd_force_dma_unencrypted(dev);
> +}
>
next prev parent reply other threads:[~2021-10-20 16:11 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-09 0:36 [PATCH v5 00/16] Add TDX Guest Support (shared-mm support) Kuppuswamy Sathyanarayanan
2021-10-09 0:36 ` [PATCH v5 01/16] x86/mm: Move force_dma_unencrypted() to common code Kuppuswamy Sathyanarayanan
2021-10-20 16:11 ` Tom Lendacky [this message]
2021-10-20 16:43 ` Sathyanarayanan Kuppuswamy
2021-10-09 0:36 ` [PATCH v5 02/16] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-10-09 0:36 ` [PATCH v5 03/16] x86/tdx: Exclude Shared bit from physical_mask Kuppuswamy Sathyanarayanan
2021-11-05 22:11 ` Sean Christopherson
2021-11-08 14:45 ` Kirill A. Shutemov
2021-10-09 0:36 ` [PATCH v5 04/16] x86/tdx: Make pages shared in ioremap() Kuppuswamy Sathyanarayanan
2021-10-20 16:03 ` Tom Lendacky
2021-10-20 16:41 ` Sathyanarayanan Kuppuswamy
2021-10-09 0:37 ` [PATCH v5 05/16] x86/tdx: Add helper to do MapGPA hypercall Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 06/16] x86/tdx: Make DMA pages shared Kuppuswamy Sathyanarayanan
2021-10-20 16:33 ` Tom Lendacky
2021-10-20 16:45 ` Sathyanarayanan Kuppuswamy
2021-10-20 17:22 ` Tom Lendacky
2021-10-20 17:26 ` Sathyanarayanan Kuppuswamy
2021-10-09 0:37 ` [PATCH v5 07/16] x86/kvm: Use bounce buffers for TD guest Kuppuswamy Sathyanarayanan
2021-10-20 16:39 ` Tom Lendacky
2021-10-20 16:50 ` Sathyanarayanan Kuppuswamy
2021-10-20 17:26 ` Tom Lendacky
2021-10-09 0:37 ` [PATCH v5 08/16] x86/tdx: ioapic: Add shared bit for IOAPIC base address Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 09/16] x86/tdx: Enable shared memory confidential guest flags for TDX guest Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 10/16] PCI: Consolidate pci_iomap_range(), pci_iomap_wc_range() Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 11/16] asm/io.h: Add ioremap_host_shared fallback Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 12/16] PCI: Add pci_iomap_host_shared(), pci_iomap_host_shared_range() Kuppuswamy Sathyanarayanan
2021-10-09 9:53 ` Michael S. Tsirkin
2021-10-09 20:39 ` Dan Williams
2021-10-10 22:11 ` Andi Kleen
2021-10-12 17:42 ` Dan Williams
2021-10-12 18:35 ` Andi Kleen
2021-10-12 21:14 ` Dan Williams
2021-10-12 21:18 ` Michael S. Tsirkin
2021-10-12 21:24 ` Andi Kleen
2021-10-12 21:28 ` Andi Kleen
2021-10-12 22:00 ` Dan Williams
2021-10-18 12:13 ` Greg KH
2021-10-12 18:36 ` Reshetova, Elena
2021-10-12 18:38 ` Andi Kleen
2021-10-12 18:57 ` Reshetova, Elena
2021-10-12 19:13 ` Dan Williams
2021-10-12 19:49 ` Andi Kleen
2021-10-12 21:11 ` Michael S. Tsirkin
2021-10-14 6:32 ` Reshetova, Elena
2021-10-14 6:57 ` Michael S. Tsirkin
2021-10-14 7:27 ` Reshetova, Elena
2021-10-14 9:26 ` Michael S. Tsirkin
2021-10-14 12:33 ` Reshetova, Elena
2021-10-17 22:17 ` Michael S. Tsirkin
2021-10-14 11:49 ` Michael S. Tsirkin
2021-10-17 21:52 ` Thomas Gleixner
2021-10-18 7:03 ` Reshetova, Elena
2021-10-18 0:55 ` Thomas Gleixner
2021-10-18 1:10 ` Thomas Gleixner
2021-10-18 12:08 ` Greg KH
2021-10-10 22:22 ` Andi Kleen
2021-10-11 11:59 ` Michael S. Tsirkin
2021-10-11 17:32 ` Andi Kleen
2021-10-11 18:22 ` Michael S. Tsirkin
2021-10-18 12:15 ` Greg KH
2021-10-18 13:17 ` Michael S. Tsirkin
2021-10-11 7:58 ` Christoph Hellwig
2021-10-11 17:23 ` Andi Kleen
2021-10-11 19:09 ` Michael S. Tsirkin
2021-10-12 5:31 ` Christoph Hellwig
2021-10-12 18:37 ` Andi Kleen
2021-10-09 0:37 ` [PATCH v5 13/16] PCI: Mark MSI data shared Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 14/16] virtio: Use shared mappings for virtio PCI devices Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 15/16] x86/tdx: Implement ioremap_host_shared for x86 Kuppuswamy Sathyanarayanan
2021-10-09 0:37 ` [PATCH v5 16/16] x86/tdx: Add cmdline option to force use of ioremap_host_shared Kuppuswamy Sathyanarayanan
2021-10-09 1:45 ` Randy Dunlap
2021-10-09 2:10 ` Kuppuswamy, Sathyanarayanan
2021-10-09 11:04 ` Michael S. Tsirkin
2021-10-11 2:39 ` Andi Kleen
2021-10-11 12:04 ` Michael S. Tsirkin
2021-10-11 17:35 ` Andi Kleen
2021-10-11 18:28 ` Michael S. Tsirkin
2021-10-12 17:55 ` Andi Kleen
2021-10-12 20:59 ` Michael S. Tsirkin
2021-10-12 21:18 ` Andi Kleen
2021-10-12 21:30 ` Michael S. Tsirkin
2021-10-15 5:50 ` Andi Kleen
2021-10-15 6:57 ` Michael S. Tsirkin
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