On Wed, 4 Dec 2019 10:00:45 +0100 Janosch Frank <fran...@linux.ibm.com> wrote:
> On 12/3/19 6:44 PM, Cornelia Huck wrote:
> > On Tue, 3 Dec 2019 08:28:11 -0500
> > Janosch Frank <fran...@linux.ibm.com> wrote:
> >
> >> Up to now we only had an ioctl to reset vcpu data QEMU couldn't reach
> >> for the initial reset, and that was also called for the clear
> >> reset. To be architecture compliant, we also need to clear local
> >> interrupts on a normal reset.
> >>
> >> Because of this and the upcoming protvirt support we need to add
> >> ioctls for the missing clear and normal resets.
> >>
> >> Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
> >> Reviewed-by: Thomas Huth <th...@redhat.com>
> >> Acked-by: David Hildenbrand <da...@redhat.com>
> >> ---
> >> target/s390x/cpu.c | 16 +++++++++++++--
> >> target/s390x/kvm-stub.c | 10 +++++++++-
> >> target/s390x/kvm.c | 42 ++++++++++++++++++++++++++++++++--------
> >> target/s390x/kvm_s390x.h | 4 +++-
> >> 4 files changed, 60 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> >> index 829ce6ad54..4973365d6c 100644
> >> --- a/target/s390x/cpu.c
> >> +++ b/target/s390x/cpu.c
> >> @@ -139,8 +139,20 @@ static void s390_cpu_reset(CPUState *s,
> >> cpu_reset_type type)
> >> }
> >>
> >> /* Reset state inside the kernel that we cannot access yet from QEMU.
> >> */
> >
> > For the last iteration, I asked about the 'yet' here...
>
> I have not written those comments, I merely refuse to delete them :)
> We still reset some state in the kernel, I'm not sure how much of that
> is already exposed via ioctls to QEMU, so I won't remove the comment.
>
> >
> >> - if (kvm_enabled() && type != S390_CPU_RESET_NORMAL) {
> >> - kvm_s390_reset_vcpu(cpu);
> >> + if (kvm_enabled()) {
> >> + switch (type) {
> >> + case S390_CPU_RESET_CLEAR:
> >> + kvm_s390_reset_vcpu_clear(cpu);
> >> + break;
> >> + case S390_CPU_RESET_INITIAL:
> >> + kvm_s390_reset_vcpu_initial(cpu);
> >> + break;
> >> + case S390_CPU_RESET_NORMAL:
> >> + kvm_s390_reset_vcpu_normal(cpu);
> >> + break;
> >> + default:
> >> + g_assert_not_reached();
> >> + }
> >> }
> >> }
> >>
> >
> > (...)
> >
> >> @@ -403,17 +405,41 @@ int kvm_arch_destroy_vcpu(CPUState *cs)
> >> return 0;
> >> }
> >>
> >> -void kvm_s390_reset_vcpu(S390CPU *cpu)
> >> +static void kvm_s390_reset_vcpu(S390CPU *cpu, unsigned long type)
> >> {
> >> CPUState *cs = CPU(cpu);
> >>
> >> - /* The initial reset call is needed here to reset in-kernel
> >> - * vcpu data that we can't access directly from QEMU
> >> - * (i.e. with older kernels which don't support sync_regs/ONE_REG).
> >> - * Before this ioctl cpu_synchronize_state() is called in common kvm
> >> - * code (kvm-all) */
> >> - if (kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
> >> - error_report("Initial CPU reset failed on CPU %i", cs->cpu_index);
> >> + /*
> >> + * The reset call is needed here to reset in-kernel vcpu data that
> >> + * we can't access directly from QEMU (i.e. with older kernels
> >> + * which don't support sync_regs/ONE_REG). Before this ioctl
> >
> > ...and this reference to 'older kernels' here.
> >
> > Are the comments still correct/relevant?
>
> See above
Fair enough, let's keep them for now and revisit this later.
>
> >
> >> + * cpu_synchronize_state() is called in common kvm code
> >> + * (kvm-all).
> >> + */
> >> + if (kvm_vcpu_ioctl(cs, type)) {
> >> + error_report("CPU reset failed on CPU %i type %lx",
> >> + cs->cpu_index, type);
> >> + }
> >> +}
> >
>
>
pgpHZKd3FGrTB.pgp
Description: OpenPGP digital signature
