From 18280d8b4bcd4a2b174ee3cd748166c6190acacb Mon Sep 17 00:00:00 2001 From: Michael Mueller Date: Mon, 16 Mar 2015 16:05:41 +0100 Subject: [PATCH] KVM: s390: represent SIMD cap in kvm facility The patch represents capability KVM_CAP_S390_VECTOR_REGISTERS by means of the SIMD facility bit. This allows to a) disable the use of SIMD when used in conjunction with a not-SIMD-aware QEMU, b) to enable SIMD when used with a SIMD-aware version of QEMU and c) finally by means of a QEMU version using the future cpu model ioctls. Signed-off-by: Michael Mueller Reviewed-by: Eric Farman Tested-by: Eric Farman Reviewed-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/kvm_host.h | 1 - arch/s390/kvm/kvm-s390.c | 19 +++++++++++-------- arch/s390/kvm/kvm-s390.h | 11 +++++++++++ 3 files changed, 22 insertions(+), 9 deletions(-) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 2356a8c660b3..b8d1e97fb201 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -562,7 +562,6 @@ struct kvm_arch{ int css_support; int use_irqchip; int use_cmma; - int use_vectors; int user_cpu_state_ctrl; int user_sigp; int user_stsi; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 42b8a2595237..9072127bd51b 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -278,8 +278,12 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) r = 0; break; case KVM_CAP_S390_VECTOR_REGISTERS: - kvm->arch.use_vectors = MACHINE_HAS_VX; - r = MACHINE_HAS_VX ? 0 : -EINVAL; + if (MACHINE_HAS_VX) { + set_kvm_facility(kvm->arch.model.fac->mask, 129); + set_kvm_facility(kvm->arch.model.fac->list, 129); + r = 0; + } else + r = -EINVAL; break; case KVM_CAP_S390_USER_STSI: kvm->arch.user_stsi = 1; @@ -1084,7 +1088,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm->arch.css_support = 0; kvm->arch.use_irqchip = 0; - kvm->arch.use_vectors = 0; kvm->arch.epoch = 0; spin_lock_init(&kvm->arch.start_stop_lock); @@ -1186,12 +1189,12 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { save_fp_ctl(&vcpu->arch.host_fpregs.fpc); - if (vcpu->kvm->arch.use_vectors) + if (test_kvm_facility(vcpu->kvm, 129)) save_vx_regs((__vector128 *)&vcpu->arch.host_vregs->vrs); else save_fp_regs(vcpu->arch.host_fpregs.fprs); save_access_regs(vcpu->arch.host_acrs); - if (vcpu->kvm->arch.use_vectors) { + if (test_kvm_facility(vcpu->kvm, 129)) { restore_fp_ctl(&vcpu->run->s.regs.fpc); restore_vx_regs((__vector128 *)&vcpu->run->s.regs.vrs); } else { @@ -1207,7 +1210,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags); gmap_disable(vcpu->arch.gmap); - if (vcpu->kvm->arch.use_vectors) { + if (test_kvm_facility(vcpu->kvm, 129)) { save_fp_ctl(&vcpu->run->s.regs.fpc); save_vx_regs((__vector128 *)&vcpu->run->s.regs.vrs); } else { @@ -1216,7 +1219,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) } save_access_regs(vcpu->run->s.regs.acrs); restore_fp_ctl(&vcpu->arch.host_fpregs.fpc); - if (vcpu->kvm->arch.use_vectors) + if (test_kvm_facility(vcpu->kvm, 129)) restore_vx_regs((__vector128 *)&vcpu->arch.host_vregs->vrs); else restore_fp_regs(vcpu->arch.host_fpregs.fprs); @@ -1316,7 +1319,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->eca |= 1; if (sclp_has_sigpif()) vcpu->arch.sie_block->eca |= 0x10000000U; - if (vcpu->kvm->arch.use_vectors) { + if (test_kvm_facility(vcpu->kvm, 129)) { vcpu->arch.sie_block->eca |= 0x00020000; vcpu->arch.sie_block->ecd |= 0x20000000; } diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 5d54191e573e..c5aefef158e5 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -149,6 +149,17 @@ static inline int test_kvm_facility(struct kvm *kvm, unsigned long nr) __test_facility(nr, kvm->arch.model.fac->list); } +static inline int set_kvm_facility(u64 *fac_list, unsigned long nr) +{ + unsigned char *ptr; + + if (nr >= MAX_FACILITY_BIT) + return -EINVAL; + ptr = (unsigned char *) fac_list + (nr >> 3); + *ptr |= (0x80UL >> (nr & 7)); + return 0; +} + /* are cpu states controlled by user space */ static inline int kvm_s390_user_cpu_state_ctrl(struct kvm *kvm) { -- 2.30.2