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
