On 04/27/2018 03:58 PM, Greg Kroah-Hartman wrote:
> 4.4-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
>
>
> From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>
> [ Upstream commit 35b3fde6203b932b2b1a5b53b3d8808abc9c4f60 ]
>
> The new firmware interfaces for branch prediction behaviour changes
> are transparently available for the guest. Nevertheless, there is
> new state attached that should be migrated and properly resetted.
> Provide a mechanism for handling reset, migration and VSIE.
>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> [Changed capability number to 152. - Radim]
> Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Something went wrong during the backport of this to 4.4
[...]
> ---
> arch/s390/include/asm/kvm_host.h | 3 ++-
> arch/s390/include/uapi/asm/kvm.h | 3 +++
> arch/s390/kvm/kvm-s390.c | 13 ++++++++++++-
> include/uapi/linux/kvm.h | 1 +
> 4 files changed, 18 insertions(+), 2 deletions(-)
>
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -1286,7 +1291,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu
> if (test_fp_ctl(current->thread.fpu.fpc))
> /* User space provided an invalid FPC, let's clear it */
> current->thread.fpu.fpc = 0;
> -
unrelated whitespace change
> save_access_regs(vcpu->arch.host_acrs);
> restore_access_regs(vcpu->run->s.regs.acrs);
> gmap_enable(vcpu->arch.gmap);
> @@ -1327,6 +1331,7 @@ static void kvm_s390_vcpu_initial_reset(
> current->thread.fpu.fpc = 0;
> vcpu->arch.sie_block->gbea = 1;
> vcpu->arch.sie_block->pp = 0;
> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
> vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
> kvm_clear_async_pf_completion_queue(vcpu);
> if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
> @@ -2162,6 +2167,7 @@ static void store_regs(struct kvm_vcpu *
> kvm_run->s.regs.pft = vcpu->arch.pfault_token;
> kvm_run->s.regs.pfs = vcpu->arch.pfault_select;
> kvm_run->s.regs.pfc = vcpu->arch.pfault_compare;
> + kvm_run->s.regs.bpbc = (vcpu->arch.sie_block->fpf & FPF_BPBC) == FPF_BPBC;
> }
>
> int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> @@ -2194,6 +2200,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v
> kvm_run->exit_reason = KVM_EXIT_INTR;
> rc = -EINTR;
> }
> + if ((kvm_run->kvm_dirty_regs & KVM_SYNC_BPBC) &&
> + test_kvm_facility(vcpu->kvm, 82)) {
> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC;
> + vcpu->arch.sie_block->fpf |= kvm_run->s.regs.bpbc ? FPF_BPBC : 0;
> + }
>
This looks misplaced and should go into the sync_regs function.