KVM: SVM: Treat exit_code as an unsigned 64-bit value through all of KVM

Fix KVM's long-standing buggy handling of SVM's exit_code as a 32-bit
value.  Per the APM and Xen commit d1bd157fbc ("Big merge the HVM
full-virtualisation abstractions.") (which is arguably more trustworthy
than KVM), offset 0x70 is a single 64-bit value:

  070h 63:0 EXITCODE

Track exit_code as a single u64 to prevent reintroducing bugs where KVM
neglects to correctly set bits 63:32.

Fixes: 6aa8b732ca ("[PATCH] kvm: userspace interface")
Cc: Jim Mattson <jmattson@google.com>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230211347.4099600-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson 2025-12-30 13:13:44 -08:00
commit d7507a94a0
11 changed files with 42 additions and 69 deletions