[RFC PATCH v2 00/69] KVM: X86: TDX support

From: isaku . yamahata
Date: Fri Jul 02 2021 - 18:07:13 EST

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

* What's TDX?
TDX stands for Trust Domain Extensions which isolates VMs from the
virtual-machine manager (VMM)/hypervisor and any other software on the
platform. [1] For details, the specifications, [2], [3], [4], [5], [6], [7], are

* The goal of this RFC patch
The purpose of this post is to get feedback early on high level design issue of
KVM enhancement for TDX. The detailed coding (variable naming etc) is not cared
of. This patch series is incomplete (not working). So it's RFC. Although
multiple software components, not only KVM but also QEMU, guest Linux and
virtual bios, need to be updated, this includes only KVM VMM part. For those who
are curious to changes to other component, there are public repositories at
github. [8], [9]

* Patch organization
The patch 66 is main change. The preceding patches(1-65) The preceding
patches(01-61) are refactoring the code and introducing additional hooks.

- 01-12: They are preparations. introduce architecture constants, code
refactoring, export symbols for following patches.
- 13-40: start to introduce the new type of VM and allow the coexistence of
multiple type of VM. allow/disallow KVM ioctl where
appropriate. Especially make per-system ioctl to per-VM ioctl.
- 41-65: refactoring KVM VMX/MMU and adding new hooks for Secure EPT.
- 66: main patch to add "basic" support for building/running TDX.
- 67: trace points for
- 68-69: Documentation

Those major features are missing from this patch series to keep this patch
series small.

- load/initialize TDX module
split out from this patch series.
- unmapping private page
Will integrate Kirill's patch to show how kvm will utilize it.
- qemu gdb stub support
- Large page support
- guest PMU support
- TDP MMU support
- and more

Changes from v1:
- rebase to v5.13
- drop load/initialization of TDX module
- catch up the update of related specifications.
- rework on C-wrapper function to invoke seamcall
- various code clean up

[1] TDX specification
[2] Intel Trust Domain Extensions (Intel TDX)
[3] Intel CPU Architectural Extensions Specification
[4] Intel TDX Module 1.0 EAS
[5] Intel TDX Loader Interface Specification
[6] Intel TDX Guest-Hypervisor Communication Interface
[7] Intel TDX Virtual Firmware Design Guide
[8] intel public github
kvm TDX branch: https://github.com/intel/tdx/tree/kvm
TDX guest branch: https://github.com/intel/tdx/tree/guest
qemu TDX https://github.com/intel/qemu-tdx
[9] TDVF

Isaku Yamahata (11):
KVM: TDX: introduce config for KVM TDX support
KVM: X86: move kvm_cpu_vmxon() from vmx.c to virtext.h
KVM: X86: move out the definition vmcs_hdr/vmcs from kvm to x86
KVM: TDX: add a helper function for kvm to call seamcall
KVM: TDX: add trace point before/after TDX SEAMCALLs
KVM: TDX: Print the name of SEAMCALL status code
KVM: Add per-VM flag to mark read-only memory as unsupported
KVM: x86: add per-VM flags to disable SMI/INIT/SIPI
KVM: TDX: add trace point for TDVMCALL and SEPT operation
KVM: TDX: add document on TDX MODULE
Documentation/virtual/kvm: Add Trust Domain Extensions(TDX)

Kai Huang (2):
KVM: x86: Add per-VM flag to disable in-kernel I/O APIC and level
cpu/hotplug: Document that TDX also depends on booting CPUs once

Rick Edgecombe (1):
KVM: x86: Add infrastructure for stolen GPA bits

Sean Christopherson (53):
KVM: TDX: Add TDX "architectural" error codes
KVM: TDX: Add architectural definitions for structures and values
KVM: TDX: define and export helper functions for KVM TDX support
KVM: TDX: Add C wrapper functions for TDX SEAMCALLs
KVM: Export kvm_io_bus_read for use by TDX for PV MMIO
KVM: Enable hardware before doing arch VM initialization
KVM: x86: Split core of hypercall emulation to helper function
KVM: x86: Export kvm_mmio tracepoint for use by TDX for PV MMIO
KVM: x86/mmu: Zap only leaf SPTEs for deleted/moved memslot by default
KVM: Add infrastructure and macro to mark VM as bugged
KVM: Export kvm_make_all_cpus_request() for use in marking VMs as
KVM: x86: Use KVM_BUG/KVM_BUG_ON to handle bugs that are fatal to the
KVM: x86/mmu: Mark VM as bugged if page fault returns RET_PF_INVALID
KVM: Add max_vcpus field in common 'struct kvm'
KVM: x86: Add vm_type to differentiate legacy VMs from protected VMs
KVM: x86: Hoist kvm_dirty_regs check out of sync_regs()
KVM: x86: Introduce "protected guest" concept and block disallowed
KVM: x86: Add per-VM flag to disable direct IRQ injection
KVM: x86: Add flag to disallow #MC injection / KVM_X86_SETUP_MCE
KVM: x86: Add flag to mark TSC as immutable (for TDX)
KVM: Add per-VM flag to disable dirty logging of memslots for TDs
KVM: x86: Allow host-initiated WRMSR to set X2APIC regardless of CPUID
KVM: x86: Add kvm_x86_ops .cache_gprs() and .flush_gprs()
KVM: x86: Add support for vCPU and device-scoped KVM_MEMORY_ENCRYPT_OP
KVM: x86: Introduce vm_teardown() hook in kvm_arch_vm_destroy()
KVM: x86: Add a switch_db_regs flag to handle TDX's auto-switched
KVM: x86: Check for pending APICv interrupt in kvm_vcpu_has_events()
KVM: x86: Add option to force LAPIC expiration wait
KVM: x86: Add guest_supported_xss placholder
KVM: Export kvm_is_reserved_pfn() for use by TDX
KVM: x86/mmu: Explicitly check for MMIO spte in fast page fault
KVM: x86/mmu: Allow non-zero init value for shadow PTE
KVM: x86/mmu: Refactor shadow walk in __direct_map() to reduce
KVM: x86/mmu: Return old SPTE from mmu_spte_clear_track_bits()
KVM: x86/mmu: Frame in support for private/inaccessible shadow pages
KVM: x86/mmu: Move 'pfn' variable to caller of direct_page_fault()
KVM: x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by TDX
KVM: VMX: Modify NMI and INTR handlers to take intr_info as param
KVM: VMX: Move NMI/exception handler to common helper
KVM: x86/mmu: Allow per-VM override of the TDP max page level
KVM: VMX: Split out guts of EPT violation to common/exposed function
KVM: VMX: Define EPT Violation architectural bits
KVM: VMX: Define VMCS encodings for shared EPT pointer
KVM: VMX: Add 'main.c' to wrap VMX and TDX
KVM: VMX: Move setting of EPT MMU masks to common VT-x code
KVM: VMX: Move register caching logic to common code
KVM: TDX: Define TDCALL exit reason
KVM: TDX: Stub in tdx.h with structs, accessors, and VMCS helpers
KVM: VMX: Add macro framework to read/write VMCS for VMs and TDs
KVM: VMX: Move AR_BYTES encoder/decoder helpers to common.h
KVM: VMX: MOVE GDT and IDT accessors to common code
KVM: VMX: Move .get_interrupt_shadow() implementation to common VMX
KVM: TDX: Add "basic" support for building and running Trust Domains

Xiaoyao Li (2):
KVM: TDX: Introduce pr_seamcall_ex_ret_info() to print more info when
KVM: X86: Introduce initial_tsc_khz in struct kvm_arch

Documentation/virt/kvm/api.rst | 6 +-
Documentation/virt/kvm/intel-tdx.rst | 441 ++++++
Documentation/virt/kvm/tdx-module.rst | 48 +
arch/arm64/include/asm/kvm_host.h | 3 -
arch/arm64/kvm/arm.c | 7 +-
arch/arm64/kvm/vgic/vgic-init.c | 6 +-
arch/x86/Kbuild | 1 +
arch/x86/include/asm/cpufeatures.h | 2 +
arch/x86/include/asm/kvm-x86-ops.h | 8 +
arch/x86/include/asm/kvm_boot.h | 30 +
arch/x86/include/asm/kvm_host.h | 55 +-
arch/x86/include/asm/virtext.h | 25 +
arch/x86/include/asm/vmx.h | 17 +
arch/x86/include/uapi/asm/kvm.h | 60 +
arch/x86/include/uapi/asm/vmx.h | 7 +-
arch/x86/kernel/asm-offsets_64.c | 15 +
arch/x86/kvm/Kconfig | 11 +
arch/x86/kvm/Makefile | 3 +-
arch/x86/kvm/boot/Makefile | 6 +
arch/x86/kvm/boot/seam/tdx_common.c | 242 +++
arch/x86/kvm/boot/seam/tdx_common.h | 13 +
arch/x86/kvm/ioapic.c | 4 +
arch/x86/kvm/irq_comm.c | 13 +-
arch/x86/kvm/lapic.c | 7 +-
arch/x86/kvm/lapic.h | 2 +-
arch/x86/kvm/mmu.h | 31 +-
arch/x86/kvm/mmu/mmu.c | 526 +++++--
arch/x86/kvm/mmu/mmu_internal.h | 3 +
arch/x86/kvm/mmu/paging_tmpl.h | 25 +-
arch/x86/kvm/mmu/spte.c | 15 +-
arch/x86/kvm/mmu/spte.h | 18 +-
arch/x86/kvm/svm/svm.c | 18 +-
arch/x86/kvm/trace.h | 138 ++
arch/x86/kvm/vmx/common.h | 178 +++
arch/x86/kvm/vmx/main.c | 1098 ++++++++++++++
arch/x86/kvm/vmx/posted_intr.c | 6 +
arch/x86/kvm/vmx/seamcall.S | 64 +
arch/x86/kvm/vmx/seamcall.h | 68 +
arch/x86/kvm/vmx/tdx.c | 1958 +++++++++++++++++++++++++
arch/x86/kvm/vmx/tdx.h | 267 ++++
arch/x86/kvm/vmx/tdx_arch.h | 370 +++++
arch/x86/kvm/vmx/tdx_errno.h | 202 +++
arch/x86/kvm/vmx/tdx_ops.h | 218 +++
arch/x86/kvm/vmx/tdx_stubs.c | 45 +
arch/x86/kvm/vmx/vmcs.h | 11 -
arch/x86/kvm/vmx/vmenter.S | 146 ++
arch/x86/kvm/vmx/vmx.c | 509 ++-----
arch/x86/kvm/x86.c | 285 +++-
include/linux/kvm_host.h | 51 +-
include/uapi/linux/kvm.h | 2 +
kernel/cpu.c | 4 +
tools/arch/x86/include/uapi/asm/kvm.h | 55 +
tools/include/uapi/linux/kvm.h | 2 +
virt/kvm/kvm_main.c | 44 +-
54 files changed, 6717 insertions(+), 672 deletions(-)
create mode 100644 Documentation/virt/kvm/intel-tdx.rst
create mode 100644 Documentation/virt/kvm/tdx-module.rst
create mode 100644 arch/x86/include/asm/kvm_boot.h
create mode 100644 arch/x86/kvm/boot/Makefile
create mode 100644 arch/x86/kvm/boot/seam/tdx_common.c
create mode 100644 arch/x86/kvm/boot/seam/tdx_common.h
create mode 100644 arch/x86/kvm/vmx/common.h
create mode 100644 arch/x86/kvm/vmx/main.c
create mode 100644 arch/x86/kvm/vmx/seamcall.S
create mode 100644 arch/x86/kvm/vmx/seamcall.h
create mode 100644 arch/x86/kvm/vmx/tdx.c
create mode 100644 arch/x86/kvm/vmx/tdx.h
create mode 100644 arch/x86/kvm/vmx/tdx_arch.h
create mode 100644 arch/x86/kvm/vmx/tdx_errno.h
create mode 100644 arch/x86/kvm/vmx/tdx_ops.h
create mode 100644 arch/x86/kvm/vmx/tdx_stubs.c