[PATCH v4 00/31] Add AMD Secure Nested Paging (SEV-SNP) support

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These patches implement SEV-SNP base support along with CPUID enforcement
support for QEMU, and are also available at:

https://github.com/pagupta/qemu/tree/snp_v4

Latest version of kvm changes are posted here [2] and also queued in kvm/next.

Patch Layout
------------
01-03: 'error_setg' independent fix, kvm/next header sync & patch from
       Xiaoyao's TDX v5 patchset.
04-29: Introduction of sev-snp-guest object and various configuration
       requirements for SNP. Support for creating a cryptographic "launch" context
       and populating various OVMF metadata pages, BIOS regions, and vCPU/VMSA
       pages with the initial encrypted/measured/validated launch data prior to
       launching the SNP guest.
30-31: Handling for KVM_HC_MAP_GPA_RANGE hypercall for userspace VMEXIT.

Testing
-------
This series has been tested against the kvm/next tree and the
AMDSEV tree [1].

[1]  https://github.com/AMDESE/linux/commits/snp-host-latest/

Below version of OVMF is used to test the changes.

  https://github.com/mdroth/edk2/commits/apic-mmio-fix1d/

A basic command-line invocation for SNP would be:

 qemu-system-x86_64 -smp 32,maxcpus=255 -cpu EPYC-Milan-v2
  -machine q35,confidential-guest-support=sev0,memory-backend=ram1
  -object memory-backend-memfd,id=ram1,size=4G,share=true,reserve=false
  -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,id-auth=
  -bios OVMF_CODE-upstream-20240410-apic-mmio-fix1d-AmdSevX64.fd

With kernel-hashing and certificate data supplied:

 qemu-system-x86_64 -smp 32,maxcpus=255 -cpu EPYC-Milan-v2
  -machine q35,confidential-guest-support=sev0,memory-backend=ram1
  -object memory-backend-memfd,id=ram1,size=4G,share=true,reserve=false
  -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,id-auth=,kernel-hashes=on
  -bios OVMF_CODE-upstream-20240410-apic-mmio-fix1d-AmdSevX64.fd
  -kernel /boot/vmlinuz-$ver
  -initrd /boot/initrd.img-$ver
  -append "root=UUID=d72a6d1c-06cf-4b79-af43-f1bac4f620f9 ro console=ttyS0,115200n8"

With standard X64 OVMF package with separate image for persistent NVRAM:

 qemu-system-x86_64 -smp 32,maxcpus=255 -cpu EPYC-Milan-v2
  -machine q35,confidential-guest-support=sev0,memory-backend=ram1
  -object memory-backend-memfd,id=ram1,size=4G,share=true,reserve=false
  -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,id-auth=
  -bios OVMF_CODE-upstream-20240410-apic-mmio-fix1d.fd 
  -drive if=pflash,format=raw,unit=0,file=OVMF_VARS-upstream-20240410-apic-mmio-fix1d.fd,readonly=off:
 
 Any comments/feedback would be very much appreciated.

[2] https://lore.kernel.org/all/20240501085210.2213060-1-michael.roth@xxxxxxx/
--------------

Changes since rfc3:

- added class methods (SEV & SNP) for functions changes suggested in RFC v3:
  launch_start(), launch_update_data(), launch_finish(), kvm_init(), kvm_type() (Paolo) 
- improved qom.json, query-sev QAPI text suggestions (Daniel & Markus).
- moved 'pc_system_parse_sev_metadata' to 'target/i386/sev.c' (Isaku).
- moved SNP specific methods (set guest_mem_fd, no smm check, no disable block discard)
  to sev_snp_kvm_init().
- squashed qapi changes for SecCommonProperties into 'sev-guest-common' patch (Daniel, Markus)
- made legacy bios support to SNP only.
- switch to using KVM_HC_MAP_GPA_RANGE to handle page-state change
  requests rather than directly processing GHCB page-state change buffer
- drop attestation certificate support, will revisit once the KVM_EXIT_*
  event mechanism is finalized
- sync headers with kvm/next, which now contains base KVM SNP support
- some more fixes including missing 'return', length checks,
  monitor logs improvements. (Daniel, Markus)


Changes since rfc2:

- reworked on top of guest_memfd support
- added handling for various KVM_EXIT_VMGEXIT events
- various changes/considerations for PCI passthrough support
- general bugfixes/hardening/cleanups
- qapi cmdline doc fixes/rework (Dov, Markus)
- switch to qbase64_decode, more error-checking for cmdline opts (Dov)
- unset id_block_en for 0 input (Dov)
- use error_setg in snp init (Dov)
- report more info in trace_kvm_sev_init (Dov)
- rework bounds-checking for kvm_cpuid_info, rework existing checks for 
  readability, add additional checks (Dov)
- fixups for validated_ranges handling (Dov)
- rename 'policy' field to 'snp-policy' in query-sev when sev-type is SNP

Changes since rfc1:

 - rebased onto latest master
 - drop SNP config file in favor of a new 'sev-snp-guest' object where all
   SNP-related params are passed as strings/integers via command-line
 - report specific error if BIOS reports invalid address/len for
   reserved/pre-validated regions (Connor)
 - use Range helpers for handling validated region overlaps (Dave)
 - simplify error handling in sev_snp_launch_start, and report the correct
   return code when handling LAUNCH_START failures (Dov)
 - add SEV-SNP bit to CPUID 0x8000001f when SNP enabled
 - updated query-sev to handle differences between SEV and SEV-SNP
 - updated to work against v5 of SEV-SNP host kernel / hypervisor patches

Brijesh Singh (6):
  i386/sev: Introduce 'sev-snp-guest' object
  i386/sev: Add the SNP launch start context
  i386/sev: Add handling to encrypt/finalize guest launch data
  hw/i386/sev: Add function to get SEV metadata from OVMF header
  i386/sev: Add support for populating OVMF metadata pages
  hw/i386/sev: Add support to encrypt BIOS when SEV-SNP is enabled

Dov Murik (3):
  i386/sev: Extract build_kernel_loader_hashes
  i386/sev: Reorder struct declarations
  i386/sev: Allow measured direct kernel boot on SNP

Michael Roth (12):
  i386/sev: Introduce "sev-common" type to encapsulate common SEV state
  i386/sev: Add a sev_snp_enabled() helper
  i386/cpu: Set SEV-SNP CPUID bit when SNP enabled
  i386/sev: Don't return launch measurements for SEV-SNP guests
  i386/sev: Update query-sev QAPI format to handle SEV-SNP
  i386/sev: Set CPU state to protected once SNP guest payload is
    finalized
  i386/sev: Add support for SNP CPUID validation
  hw/i386/sev: Use guest_memfd for legacy ROMs
  hw/i386: Add support for loading BIOS using guest_memfd
  hw/i386/sev: Allow use of pflash in conjunction with -bios
  i386/kvm: Add KVM_EXIT_HYPERCALL handling for KVM_HC_MAP_GPA_RANGE
  i386/sev: Enable KVM_HC_MAP_GPA_RANGE hcall for SNP guests

Pankaj Gupta (9):
  i386/sev: Replace error_report with error_setg
  linux-headers: Update to current kvm/next
  i386/sev: Move sev_launch_update to separate class method
  i386/sev: Move sev_launch_finish to separate class method
  i386/sev: Add sev_kvm_init() override for SEV class
  i386/sev: Add snp_kvm_init() override for SNP class
  i386/sev: Add a class method to determine KVM VM type for SNP guests
  i386/sev: Invoke launch_updata_data() for SEV class
  i386/sev: Invoke launch_updata_data() for SNP class

Xiaoyao Li (1):
  memory: Introduce memory_region_init_ram_guest_memfd()

 docs/system/i386/amd-memory-encryption.rst |   70 +-
 hw/i386/pc.c                               |   14 +-
 hw/i386/pc_sysfw.c                         |   76 +-
 hw/i386/x86-common.c                       |   24 +-
 include/exec/memory.h                      |    6 +
 include/hw/i386/pc.h                       |   28 +
 include/hw/i386/x86.h                      |    2 +-
 linux-headers/asm-loongarch/bitsperlong.h  |   23 +
 linux-headers/asm-loongarch/kvm.h          |    4 +
 linux-headers/asm-loongarch/mman.h         |    9 +
 linux-headers/asm-riscv/kvm.h              |    1 +
 linux-headers/asm-riscv/mman.h             |   36 +-
 linux-headers/asm-s390/mman.h              |   36 +-
 linux-headers/asm-x86/kvm.h                |   52 +-
 linux-headers/linux/vhost.h                |   15 +-
 qapi/misc-target.json                      |   72 +-
 qapi/qom.json                              |   97 +-
 system/memory.c                            |   24 +
 target/i386/cpu.c                          |    1 +
 target/i386/kvm/kvm.c                      |   55 +
 target/i386/kvm/kvm_i386.h                 |    1 +
 target/i386/kvm/trace-events               |    1 +
 target/i386/sev-sysemu-stub.c              |    2 +-
 target/i386/sev.c                          | 1588 +++++++++++++++-----
 target/i386/sev.h                          |   13 +-
 target/i386/trace-events                   |    3 +
 26 files changed, 1833 insertions(+), 420 deletions(-)

-- 
2.34.1





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