On Thu, 5 Dec 2019 18:34:32 +0100 Janosch Frank <fran...@linux.ibm.com> wrote:
> On 12/5/19 6:15 PM, Cornelia Huck wrote:
> > On Fri, 29 Nov 2019 04:48:02 -0500
> > Janosch Frank <fran...@linux.ibm.com> wrote:
> >
> >> Secure guests no longer intercept with code 4 for an instruction
> >> interception. Instead they have codes 104 and 108 for secure
> >> instruction interception and secure instruction notification
> >> respectively.
> >>
> >> The 104 mirrors the 4 interception.
> >>
> >> The 108 is a notification interception to let KVM and QEMU know that
> >> something changed and we need to update tracking information or
> >> perform specific tasks. It's currently taken for the following
> >> instructions:
> >>
> >> * stpx (To inform about the changed prefix location)
> >> * sclp (On incorrect SCCB values, so we can inject a IRQ)
> >> * sigp (All but "stop and store status")
> >> * diag308 (Subcodes 0/1)
> >>
> >> Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
> >> ---
> >> target/s390x/kvm.c | 6 ++++++
> >> 1 file changed, 6 insertions(+)
> >>
> >> @@ -1664,6 +1668,8 @@ static int handle_intercept(S390CPU *cpu)
> >> (long)cs->kvm_run->psw_addr);
> >> switch (icpt_code) {
> >> case ICPT_INSTRUCTION:
> >> + case ICPT_PV_INSTR:
> >> + case ICPT_PV_INSTR_NOTIFICATION:
> >> r = handle_instruction(cpu, run);
> >
> > I'm still a bit uneasy about going through the same path for both 104
> > and 108. How does the handler figure out whether it should emulate an
> > instruction, or just process a notification? Is it guaranteed that a
> > given instruction is always showing up as either a 104 or a 108, so
> > that the handler can check the pv state?
>
> diag 308 subcode 0/1 are 108, but all other subcodes are defined as a
> 104 (if they are an exit at all)...
I think that's a reason to really split 108 from 4/104, or at least add
an parameter...
>
> >
> > [Even if that works, it still feels a bit unclean to me.]
> >
> >> break;
> >> case ICPT_PROGRAM:
> >
> >
>
>
pgpbNTBJ3FvET.pgp
Description: OpenPGP digital signature
