How to set `host_data` properly in QEMU

[cowbon]

Hi there, I'm trying to set host data on snp-v3 branch. I included the following in my QEMU command -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,host-data=b2l3bmNvd3FuY21wbXA. Both guest and host kernels were from here, and I could get a guest report using sev-guest. While I can set Report Data with sev-guest-get-report, Host data is still blank no matter what I passed to QEMU.
The following is the guest report I got with the Makefile in sev-guest used in hashing

[sev-guest]root@localhost# ./sev-guest-parse-report guest_report.bin                                          
Version: 2
Guest SVN: 0
Policy: 0xb0000
 - Debugging Allowed:       Yes
 - Migration Agent Allowed: No
 - SMT Allowed:             Yes
 - Min. ABI Major:          0
 - Min. ABI Minor:          0
Family ID:
    00000000000000000000000000000000
Image ID:
    00000000000000000000000000000000
VMPL: 0
Signature Algorithm: 1 (Invalid)
Platform Version: 03000000000008115
 - Boot Loader SVN:   3
 - TEE SVN:           0
 - SNP firmware SVN:  8
 - Microcode SVN:    115
Platform Info: 0x1
- SMT Enabled: Yes 
Author Key Enabled: Yes
Report Data:
    31bf7d4a0a9abf65d5184e53531661b8d67a83f2787a3e1a6bbe32fb235a158d
    a4daf7a92c20cc3ba538668c81b3519d6d0a07cae726a9694e30440b74cdf75b
Measurement:
    8b988c46fcc74422bce82fb42a481821ccc4dd667e5eb687
    328901e228009547340957823e0c4f96891d5cb5d0f996bc
Host Data:
    0000000000000000000000000000000000000000000000000000000000000000
ID Key Digest:
    000000000000000000000000000000000000000000000000
    000000000000000000000000000000000000000000000000
Author Key Digest:
    000000000000000000000000000000000000000000000000
    000000000000000000000000000000000000000000000000
Report ID:
    755ce22a77ba7d7ec99d6d904c7b15f71f2addcd34bf96ba6150a67409f1c0a5
Migration Agent Report ID:
    ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
Reported TCB: 03000000000008115
 - Boot Loader SVN:   3
 - TEE SVN:           0
 - SNP firmware SVN:  8
 - Microcode SVN:    115
Chip ID:
    c2a6528b7364e07e9f5c653ab3aa0dbd7384f9a80dfde54cc643ddbb89d89364
    25ff8a32568ca6ed771020dc39c33ccffb3b43cac0c501a0093cad6012dfd3ed
Signature:
  R:
    5068cb59b7dcbb3388594538b447b1dbd6396832395ad5bba3719c225e3839da3b98ed4c
    f3bca287f2a7abd7ea509595000000000000000000000000000000000000000000000000
  S:
    d7ffd39755b8fb1d3da4496d24ddcfcaf97d18bdc8ad5fc96b83d84f1c830e364f5aaa7f
    bc99a52233aa0ea03a026533000000000000000000000000000000000000000000000000

Please advise

[tlendacky]

It looks like the KVM support isn't copying the host data in snp_launch_finish() in arch/x86/kvm/svm/sev.c. I'll be sure to get that addressed.

[aep]

was that resolved?

[sza-1]

was that resolved?

I use host-data with the latest AMDESE/linux and AMDESE/qemu without any problems. So, yes, it seems that this feature is fully implemented.