[RFCv1 0/7] TDX and guest memory unmapping
From: Kirill A. Shutemov
Date: Fri Apr 02 2021 - 11:27:05 EST
TDX integrity check failures may lead to system shutdown host kernel must
not allow any writes to TD-private memory. This requirment clashes with
KVM design: KVM expects the guest memory to be mapped into host userspace
(e.g. QEMU).
This patchset aims to start discussion on how we can approach the issue.
The core of the change is in the last patch. Please see more detailed
description of the issue and proposoal of the solution there.
The patchset can also be found here:
git://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git kvm-unmapped-poison
Kirill A. Shutemov (7):
x86/mm: Move force_dma_unencrypted() to common code
x86/kvm: Introduce KVM memory protection feature
x86/kvm: Make DMA pages shared
x86/kvm: Use bounce buffers for KVM memory protection
x86/kvmclock: Share hvclock memory with the host
x86/realmode: Share trampoline area if KVM memory protection enabled
KVM: unmap guest memory using poisoned pages
arch/x86/Kconfig | 9 +-
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/io.h | 4 +-
arch/x86/include/asm/kvm_para.h | 5 +
arch/x86/include/asm/mem_encrypt.h | 7 +-
arch/x86/include/uapi/asm/kvm_para.h | 3 +-
arch/x86/kernel/kvm.c | 20 ++++
arch/x86/kernel/kvmclock.c | 2 +-
arch/x86/kernel/pci-swiotlb.c | 3 +-
arch/x86/kvm/Kconfig | 1 +
arch/x86/kvm/cpuid.c | 3 +-
arch/x86/kvm/mmu/mmu.c | 15 ++-
arch/x86/kvm/mmu/paging_tmpl.h | 10 +-
arch/x86/kvm/x86.c | 6 +
arch/x86/mm/Makefile | 2 +
arch/x86/mm/mem_encrypt.c | 74 ------------
arch/x86/mm/mem_encrypt_common.c | 87 ++++++++++++++
arch/x86/mm/pat/set_memory.c | 10 ++
arch/x86/realmode/init.c | 7 +-
include/linux/kvm_host.h | 12 ++
include/linux/swapops.h | 20 ++++
include/uapi/linux/kvm_para.h | 5 +-
mm/gup.c | 31 +++--
mm/memory.c | 45 +++++++-
mm/page_vma_mapped.c | 8 +-
mm/rmap.c | 2 +-
mm/shmem.c | 7 ++
virt/kvm/Kconfig | 3 +
virt/kvm/kvm_main.c | 164 ++++++++++++++++++++++++---
29 files changed, 442 insertions(+), 124 deletions(-)
create mode 100644 arch/x86/mm/mem_encrypt_common.c
--
2.26.3