[PATCH v2 0/9] Support TDX guests on Hyper-V (the Hyper-V specific part)

[Dexuan Cui]

Hyper-V provides two modes for running Intel TDX VMs:

1) TD Partitioning mode with a paravisor (see [1]).
2) In "fully enlightened" mode with normal TDX shared bit control
   over page encryption, and no paravisor

The first mode is similar to AMD SEV-SNP's vTOM mode (see [2]).
The second is similar to AMD SEV-SNP's C-bit mode(see [2]).

For #2, the v6 patchset was [3], which is later split into 2 parts:
the generic TDX part (see [4][5]), and the Hyper-V specific part, i.e.
the first 5 patches of this patchset. For the second part, I rebased
the patches to Tianyu's fully enlighted SNP v7 patchset [2]. Since this
is a straightforward rebasing, I keep the existing Acked-by and
Reviewed-by in the v6 patchset [3].

The next 3 patches of this patchset add the support for #1.

The last patch (the 9th patch) just makes some cleanup.

Please review all the 9 patches, which are also on my github
branch [6].

I tested the patches for a regular VM, a VBS VM, a SNP VM
with the paravisor, and a TDX VM with the paravisor and a TDX
VM without the paravisor, and an ARM64 VM. All the VMs worked
as expected.

If the patches all look good, I expect that Tianyu's patches [2]
are merged into the Hyper-V tree's hyperv-next branch first, then
these 9 patches can be merged afterwards.

Compared with v1, the difference is trivial: the v2 is mainly a rebase
to Tianyu's v7.

Thanks,
Dexuan

References:
[1] Intel TDX Module v1.5 TD Partitioning Architecture Specification
[2] https://lwn.net/ml/linux-kernel/20230818102919.1318039-1-ltykernel@xxxxxxxxx/
[3] https://lwn.net/ml/linux-kernel/20230504225351.10765-1-decui@xxxxxxxxxxxxx/
[4] https://lwn.net/ml/linux-kernel/20230811214826.9609-1-decui%40microsoft.com/
[5] https://github.com/dcui/tdx/commits/decui/mainline/x86/tdx/v10
[6] https://github.com/dcui/tdx/commits/decui/mainline/x86/hyperv/tdx-v2 

Dexuan Cui (9):
  x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests
  x86/hyperv: Support hypercalls for fully enlightened TDX guests
  Drivers: hv: vmbus: Support fully enlightened TDX guests
  x86/hyperv: Fix serial console interrupts for fully enlightened TDX
    guests
  Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VM
  x86/hyperv: Introduce a global variable hyperv_paravisor_present
  Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the
    paravisor
  x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the
    paravisor
  x86/hyperv: Remove hv_isolation_type_en_snp

 arch/x86/hyperv/hv_apic.c          |  15 +++-
 arch/x86/hyperv/hv_init.c          |  59 +++++++++++---
 arch/x86/hyperv/ivm.c              | 120 ++++++++++++++++++++++++++---
 arch/x86/include/asm/hyperv-tlfs.h |   3 +-
 arch/x86/include/asm/mshyperv.h    |  42 +++++++---
 arch/x86/kernel/cpu/mshyperv.c     |  75 +++++++++++++++---
 drivers/hv/connection.c            |   2 +-
 drivers/hv/hv.c                    |  88 +++++++++++++++++----
 drivers/hv/hv_common.c             |  46 ++++++++---
 drivers/hv/hyperv_vmbus.h          |  11 +++
 include/asm-generic/mshyperv.h     |   6 +-
 11 files changed, 391 insertions(+), 76 deletions(-)

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2.25.1