Hi All,
On 2/5/21 3:38 PM, Kuppuswamy Sathyanarayanan wrote:
Hi All,
NOTE: This series is not ready for wide public review. It is being
specifically posted so that Peter Z and other experts on the entry
code can look for problems with the new exception handler (#VE).
That's also why x86@ is not being spammed.
We are currently working on a solution to fix the issues raised in
"Add #VE support for TDX guest" patch. While we fix that issue, I would
like to know if there are issues in other patches in this series. So if
possible can you please review other patches in the series and let us
know your comments?.
If you want me to rebase the series on top of v5.12-rcX kernel and repost it,
please let me know.
Intel's Trust Domain Extensions (TDX) protect guest VMs from malicious
hosts and some physical attacks. This series adds the bare-minimum
support to run a TDX guest. The host-side support will be submitted
separately. Also support for advanced TD guest features like attestation
or debug-mode will be submitted separately. Also, at this point it is not
secure with some known holes in drivers, and also hasn’t been fully audited
and fuzzed yet.
TDX has a lot of similarities to SEV. It enhances confidentiality and
of guest memory and state (like registers) and includes a new exception
(#VE) for the same basic reasons as SEV-ES. Like SEV-SNP (not merged
yet), TDX limits the host's ability to effect changes in the guest
physical address space.
In contrast to the SEV code in the kernel, TDX guest memory is integrity
protected and isolated; the host is prevented from accessing guest
memory (even ciphertext).
The TDX architecture also includes a new CPU mode called
Secure-Arbitration Mode (SEAM). The software (TDX module) running in this
mode arbitrates interactions between host and guest and implements many of
the guarantees of the TDX architecture.
Some of the key differences between TD and regular VM is,
1. Multi CPU bring-up is done using the ACPI MADT wake-up table.
2. A new #VE exception handler is added. The TDX module injects #VE exception
to the guest TD in cases of instructions that need to be emulated,
disallowed
MSR accesses, subset of CPUID leaves, etc.
3. By default memory is marked as private, and TD will selectively share it with
VMM based on need.
4. Remote attestation is supported to enable a third party (either the owner of
the workload or a user of the services provided by the workload) to
establish
that the workload is running on an Intel-TDX-enabled platform located
within a
TD prior to providing that workload data.
You can find TDX related documents in the following link.
https://software.intel.com/content/www/br/pt/develop/articles/intel-trust-domain-extensions.html
This RFC series has been reviewed by Dave Hansen.
Kirill A. Shutemov (16):
x86/paravirt: Introduce CONFIG_PARAVIRT_XL
x86/tdx: Get TD execution environment information via TDINFO
x86/traps: Add #VE support for TDX guest
x86/tdx: Add HLT support for TDX guest
x86/tdx: Wire up KVM hypercalls
x86/tdx: Add MSR support for TDX guest
x86/tdx: Handle CPUID via #VE
x86/io: Allow to override inX() and outX() implementation
x86/tdx: Handle port I/O
x86/tdx: Handle in-kernel MMIO
x86/mm: Move force_dma_unencrypted() to common code
x86/tdx: Exclude Shared bit from __PHYSICAL_MASK
x86/tdx: Make pages shared in ioremap()
x86/tdx: Add helper to do MapGPA TDVMALL
x86/tdx: Make DMA pages shared
x86/kvm: Use bounce buffers for TD guest
Kuppuswamy Sathyanarayanan (6):
x86/cpufeatures: Add TDX Guest CPU feature
x86/cpufeatures: Add is_tdx_guest() interface
x86/tdx: Handle MWAIT, MONITOR and WBINVD
ACPI: tables: Add multiprocessor wake-up support
x86/topology: Disable CPU hotplug support for TDX platforms.
x86/tdx: Introduce INTEL_TDX_GUEST config option
Sean Christopherson (4):
x86/boot: Add a trampoline for APs booting in 64-bit mode
x86/boot: Avoid #VE during compressed boot for TDX platforms
x86/boot: Avoid unnecessary #VE during boot process
x86/tdx: Forcefully disable legacy PIC for TDX guests
arch/x86/Kconfig | 28 +-
arch/x86/boot/compressed/Makefile | 2 +
arch/x86/boot/compressed/head_64.S | 10 +-
arch/x86/boot/compressed/misc.h | 1 +
arch/x86/boot/compressed/pgtable.h | 2 +-
arch/x86/boot/compressed/tdx.c | 32 ++
arch/x86/boot/compressed/tdx_io.S | 9 +
arch/x86/include/asm/apic.h | 3 +
arch/x86/include/asm/asm-prototypes.h | 1 +
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/idtentry.h | 4 +
arch/x86/include/asm/io.h | 25 +-
arch/x86/include/asm/irqflags.h | 42 +-
arch/x86/include/asm/kvm_para.h | 21 +
arch/x86/include/asm/paravirt.h | 22 +-
arch/x86/include/asm/paravirt_types.h | 3 +-
arch/x86/include/asm/pgtable.h | 3 +
arch/x86/include/asm/realmode.h | 1 +
arch/x86/include/asm/tdx.h | 114 +++++
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/acpi/boot.c | 56 +++
arch/x86/kernel/apic/probe_32.c | 8 +
arch/x86/kernel/apic/probe_64.c | 8 +
arch/x86/kernel/head64.c | 3 +
arch/x86/kernel/head_64.S | 13 +-
arch/x86/kernel/idt.c | 6 +
arch/x86/kernel/paravirt.c | 4 +-
arch/x86/kernel/pci-swiotlb.c | 2 +-
arch/x86/kernel/smpboot.c | 5 +
arch/x86/kernel/tdx-kvm.c | 116 +++++
arch/x86/kernel/tdx.c | 560 +++++++++++++++++++++++
arch/x86/kernel/tdx_io.S | 143 ++++++
arch/x86/kernel/topology.c | 3 +-
arch/x86/kernel/traps.c | 73 ++-
arch/x86/mm/Makefile | 2 +
arch/x86/mm/ioremap.c | 8 +-
arch/x86/mm/mem_encrypt.c | 74 ---
arch/x86/mm/mem_encrypt_common.c | 83 ++++
arch/x86/mm/mem_encrypt_identity.c | 1 +
arch/x86/mm/pat/set_memory.c | 23 +-
arch/x86/realmode/rm/header.S | 1 +
arch/x86/realmode/rm/trampoline_64.S | 49 +-
arch/x86/realmode/rm/trampoline_common.S | 5 +-
drivers/acpi/tables.c | 9 +
include/acpi/actbl2.h | 21 +-
45 files changed, 1444 insertions(+), 157 deletions(-)
create mode 100644 arch/x86/boot/compressed/tdx.c
create mode 100644 arch/x86/boot/compressed/tdx_io.S
create mode 100644 arch/x86/include/asm/tdx.h
create mode 100644 arch/x86/kernel/tdx-kvm.c
create mode 100644 arch/x86/kernel/tdx.c
create mode 100644 arch/x86/kernel/tdx_io.S
create mode 100644 arch/x86/mm/mem_encrypt_common.c
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
