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(+)
>
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index ad6e38c876..3d9c44ba9d 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -115,6 +115,8 @@
> #define ICPT_CPU_STOP 0x28
> #define ICPT_OPEREXC 0x2c
> #define ICPT_IO 0x40
> +#define ICPT_PV_INSTR 0x68
> +#define ICPT_PV_INSTR_NOTIFICATION 0x6c
>
> #define NR_LOCAL_IRQS 32
> /*
> @@ -151,6 +153,7 @@ static int cap_s390_irq;
> static int cap_ri;
> static int cap_gs;
> static int cap_hpage_1m;
> +static int cap_protvirt;
>
> static int active_cmma;
>
> @@ -342,6 +345,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
> cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
> cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
> cap_s390_irq = kvm_check_extension(s, KVM_CAP_S390_INJECT_IRQ);
> + cap_protvirt = kvm_check_extension(s, KVM_CAP_S390_PROTECTED);
>
> if (!kvm_check_extension(s, KVM_CAP_S390_GMAP)
> || !kvm_check_extension(s, KVM_CAP_S390_COW)) {
> @@ -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?
[Even if that works, it still feels a bit unclean to me.]
> break;
> case ICPT_PROGRAM:
