lkml.org 
[lkml]   [2018]   [Feb]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v2 08/15] KVM: s390: interface to enable AP execution mode
    From
    Date
    On 02/28/2018 04:44 AM, David Hildenbrand wrote:
    > On 27.02.2018 15:28, Tony Krowiak wrote:
    >> Introduces a new interface to enable AP interpretive
    >> execution (IE) mode for the KVM guest. When running
    >> with IE mode enabled, AP instructions executed on the
    >> KVM guest will be interpreted by the firmware and
    >> passed directly through to an AP device installed on
    >> the system. The CPU model feature for AP must
    >> be enabled for the KVM guest in order to enable
    >> interpretive execution mode.
    >>
    >> This interface will be used in a subsequent patch
    >> by the VFIO AP device driver.
    >>
    >> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
    >> ---
    >> arch/s390/include/asm/kvm-ap.h | 2 ++
    >> arch/s390/include/asm/kvm_host.h | 1 +
    >> arch/s390/kvm/kvm-ap.c | 27 +++++++++++++++++++++++++++
    >> arch/s390/kvm/kvm-s390.h | 1 +
    >> 4 files changed, 31 insertions(+), 0 deletions(-)
    >>
    >> diff --git a/arch/s390/include/asm/kvm-ap.h b/arch/s390/include/asm/kvm-ap.h
    >> index 46e7c5b..6bd6bfb 100644
    >> --- a/arch/s390/include/asm/kvm-ap.h
    >> +++ b/arch/s390/include/asm/kvm-ap.h
    >> @@ -51,4 +51,6 @@ struct kvm_ap_matrix {
    >>
    >> void kvm_ap_deconfigure_matrix(struct kvm *kvm);
    >>
    >> +int kvm_ap_enable_ie_mode(struct kvm *kvm);
    >> +
    >> #endif /* _ASM_KVM_AP */
    >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
    >> index a4c77d3..1eebdd6 100644
    >> --- a/arch/s390/include/asm/kvm_host.h
    >> +++ b/arch/s390/include/asm/kvm_host.h
    >> @@ -186,6 +186,7 @@ struct kvm_s390_sie_block {
    >> #define ECA_AIV 0x00200000
    >> #define ECA_VX 0x00020000
    >> #define ECA_PROTEXCI 0x00002000
    >> +#define ECA_APIE 0x00000008
    >> #define ECA_SII 0x00000001
    >> __u32 eca; /* 0x004c */
    >> #define ICPT_INST 0x04
    >> diff --git a/arch/s390/kvm/kvm-ap.c b/arch/s390/kvm/kvm-ap.c
    >> index bb29045..862e54b 100644
    >> --- a/arch/s390/kvm/kvm-ap.c
    >> +++ b/arch/s390/kvm/kvm-ap.c
    >> @@ -307,3 +307,30 @@ void kvm_ap_deconfigure_matrix(struct kvm *kvm)
    >> kvm_ap_clear_crycb_masks(kvm);
    >> }
    >> EXPORT_SYMBOL(kvm_ap_deconfigure_matrix);
    >> +
    >> +/**
    >> + * kvm_ap_enable_ie_mode
    >> + *
    >> + * Enable interpretrive execution of AP instructions for the guest. When
    >> + * enabled, AP instructions executed on the guest will be interpreted and
    >> + * passed through to an AP installed on the host system.
    >> + *
    >> + * Returns 0 if interpretrive execution is enabled. Returns -EOPNOTSUPP
    >> + * if AP facilities are not installed for the guest.
    >> + *
    >> + * @kvm: the guest's kvm structure
    >> + */
    >> +int kvm_ap_enable_ie_mode(struct kvm *kvm)
    >> +{
    >> + int i;
    >> + struct kvm_vcpu *vcpu;
    >> +
    >> + if (!test_kvm_cpu_feat(kvm, KVM_S390_VM_CPU_FEAT_AP))
    >> + return -EOPNOTSUPP;
    >> +
    >> + kvm_for_each_vcpu(i, vcpu, kvm)
    >> + vcpu->arch.sie_block->eca |= ECA_APIE;
    >> +
    >> + return 0;
    >> +}
    >> +EXPORT_SYMBOL(kvm_ap_enable_ie_mode);
    >> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
    >> index 1b5621f..3142541 100644
    >> --- a/arch/s390/kvm/kvm-s390.h
    >> +++ b/arch/s390/kvm/kvm-s390.h
    >> @@ -18,6 +18,7 @@
    >> #include <asm/facility.h>
    >> #include <asm/processor.h>
    >> #include <asm/sclp.h>
    >> +#include <asm/ap.h>
    >>
    >> /* Transactional Memory Execution related macros */
    >> #define IS_TE_ENABLED(vcpu) ((vcpu->arch.sie_block->ecb & ECB_TE))
    >>
    > And also, what about hot-plugged CPUs?
    I haven't considered that, do you have any suggestions?
    >

    \
     
     \ /
      Last update: 2018-02-28 21:40    [W:3.581 / U:0.092 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site