From: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Tom Lendacky <thomas.lendacky@amd.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 09:43:43 -0700 [thread overview]
Message-ID: <f7ede3f4-7280-38da-3744-32ecd8fdfcb1@linux.intel.com> (raw)
In-Reply-To: <72b8be39-b4e2-5d77-524c-a2ea0c750ab1@amd.com>
On 10/20/21 9:11 AM, Tom Lendacky wrote:
>> 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.
Please check the final version of mem_encrypt_common.c
https://github.com/intel/tdx/blob/guest/arch/x86/mm/mem_encrypt_common.c
I am not sure whether it is alright to move mem_encrypt_init() and
arch_has_restricted_virtio_memory_access() to cc_platform.c
If this is fine, I can get rid of mem_encrypt_common.c
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
next prev parent reply other threads:[~2021-10-20 16:43 UTC|newest]
Thread overview: 85+ 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
2021-10-20 16:43 ` Sathyanarayanan Kuppuswamy [this message]
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
2021-10-15 13:34 ` Andi Kleen
2021-10-17 22:34 ` Michael S. Tsirkin
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