linux-kernel - [PATCH v1.1 0/2] Provide SEV-SNP support for unaccepted memory

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Message-ID: <cover.1659550264.git.thomas.lendacky@amd.com>
Date:   Wed, 3 Aug 2022 13:11:03 -0500
From:   Tom Lendacky <thomas.lendacky@....com>
To:     <linux-kernel@...r.kernel.org>, <x86@...nel.org>
CC:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "Kirill A. Shutemov" <kirill@...temov.name>,
        "H. Peter Anvin" <hpa@...or.com>,
        Michael Roth <michael.roth@....com>,
        Joerg Roedel <jroedel@...e.de>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH v1.1 0/2] Provide SEV-SNP support for unaccepted memory

This series adds SEV-SNP support for unaccepted memory to the patch series
titled:

  [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory

Currently, when changing the state of a page under SNP, the page state
change structure is kmalloc()'d. This lead to hangs during boot when
accepting memory because the allocation can trigger the need to accept
more memory. So this series consists of two patches:

  - A pre-patch to switch from a kmalloc()'d page state change structure
    to a static page state change structure proteced with access protected
    by a spinlock.

  - SNP support for unaccepted memory.

The series is based off of and tested against Kirill Shutemov's tree:
  https://github.com/intel/tdx.git guest-unaccepted-memory

---

This is what the static structure / spinlock method looks like. Let me
know if this approach is preferred over the per-CPU structure. If so,
I'll submit this as a v2.

Thanks,
Tom

Tom Lendacky (2):
  x86/sev: Use per-CPU PSC structure in prep for unaccepted memory
    support
  x86/sev: Add SNP-specific unaccepted memory support

 arch/x86/Kconfig                |  1 +
 arch/x86/boot/compressed/mem.c  |  3 ++
 arch/x86/boot/compressed/sev.c  | 10 ++++-
 arch/x86/boot/compressed/sev.h  | 23 +++++++++++
 arch/x86/include/asm/sev.h      |  3 ++
 arch/x86/kernel/sev.c           | 71 ++++++++++++++++++++++-----------
 arch/x86/mm/unaccepted_memory.c |  4 ++
 7 files changed, 91 insertions(+), 24 deletions(-)
 create mode 100644 arch/x86/boot/compressed/sev.h

-- 
2.36.1