On Tue, Jun 14, 2022 at 1:47 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > Deliberately truncate the exception error code when shoving it into the > VMCS (VM-Entry field for vmcs01 and vmcs02, VM-Exit field for vmcs12). > Intel CPUs are incapable of handling 32-bit error codes and will never Never say "never." :-) > generate an error code with bits 31:16, but userspace can provide an > arbitrary error code via KVM_SET_VCPU_EVENTS. Failure to drop the bits > on exception injection results in failed VM-Entry, as VMX disallows > setting bits 31:16. Setting the bits on VM-Exit would at best confuse > L1, and at worse induce a nested VM-Entry failure, e.g. if L1 decided to > reinject the exception back into L2. > > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
