[RESEND,0/2] i386: Fix Hyper-V Gen1 guests stuck on boot with 'hv-passthrough'

Message

Vitaly Kuznetsov Sept. 22, 2023, 12:19 p.m. UTC

Hyper-V Gen1 guests are getting stuck on boot when 'hv-passthrough' is
used. While 'hv-passthrough' is a debug only feature, this significantly
limit its usefullness. While debugging the problem, I found that there are
two loosely connected issues:
- 'hv-passthrough' enables 'hv-syndbg' and this is undesired.
- 'hv-syndbg's support by KVM is detected incorrectly when !CONFIG_SYNDBG.

Fix both issues; exclude 'hv-syndbg' from 'hv-passthrough' and don't allow
to turn on 'hv-syndbg' for !CONFIG_SYNDBG builds. 

Vitaly Kuznetsov (2):
  i386: Fix conditional CONFIG_SYNDBG enablement
  i386: Exclude 'hv-syndbg' from 'hv-passthrough'

 docs/system/i386/hyperv.rst | 13 +++++++++----
 target/i386/cpu.c           |  2 ++
 target/i386/kvm/kvm.c       | 18 ++++++++++++------
 3 files changed, 23 insertions(+), 10 deletions(-)