diff options
Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 130 |
1 files changed, 97 insertions, 33 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 6861b74649ae..98df53c01343 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1283,21 +1283,54 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) return 0; } +/* + * Backs up the current FP/VX register save area on a particular + * destination. Used to switch between different register save + * areas. + */ +static inline void save_fpu_to(struct fpu *dst) +{ + dst->fpc = current->thread.fpu.fpc; + dst->flags = current->thread.fpu.flags; + dst->regs = current->thread.fpu.regs; +} + +/* + * Switches the FP/VX register save area from which to lazy + * restore register contents. + */ +static inline void load_fpu_from(struct fpu *from) +{ + current->thread.fpu.fpc = from->fpc; + current->thread.fpu.flags = from->flags; + current->thread.fpu.regs = from->regs; +} + void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { - save_fp_ctl(&vcpu->arch.host_fpregs.fpc); - 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); + /* Save host register state */ + save_fpu_regs(); + save_fpu_to(&vcpu->arch.host_fpregs); + 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 { - restore_fp_ctl(&vcpu->arch.guest_fpregs.fpc); - restore_fp_regs(vcpu->arch.guest_fpregs.fprs); - } + current->thread.fpu.fpc = vcpu->run->s.regs.fpc; + current->thread.fpu.flags = FPU_USE_VX; + /* + * Use the register save area in the SIE-control block + * for register restore and save in kvm_arch_vcpu_put() + */ + current->thread.fpu.vxrs = + (__vector128 *)&vcpu->run->s.regs.vrs; + /* Always enable the vector extension for KVM */ + __ctl_set_vx(); + } else + load_fpu_from(&vcpu->arch.guest_fpregs); + + if (test_fp_ctl(current->thread.fpu.fpc)) + /* User space provided an invalid FPC, let's clear it */ + current->thread.fpu.fpc = 0; + + save_access_regs(vcpu->arch.host_acrs); restore_access_regs(vcpu->run->s.regs.acrs); gmap_enable(vcpu->arch.gmap); atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags); @@ -1307,19 +1340,22 @@ 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 (test_kvm_facility(vcpu->kvm, 129)) { - save_fp_ctl(&vcpu->run->s.regs.fpc); - save_vx_regs((__vector128 *)&vcpu->run->s.regs.vrs); - } else { - save_fp_ctl(&vcpu->arch.guest_fpregs.fpc); - save_fp_regs(vcpu->arch.guest_fpregs.fprs); - } - save_access_regs(vcpu->run->s.regs.acrs); - restore_fp_ctl(&vcpu->arch.host_fpregs.fpc); + + save_fpu_regs(); + if (test_kvm_facility(vcpu->kvm, 129)) - restore_vx_regs((__vector128 *)&vcpu->arch.host_vregs->vrs); + /* + * kvm_arch_vcpu_load() set up the register save area to + * the &vcpu->run->s.regs.vrs and, thus, the vector registers + * are already saved. Only the floating-point control must be + * copied. + */ + vcpu->run->s.regs.fpc = current->thread.fpu.fpc; else - restore_fp_regs(vcpu->arch.host_fpregs.fprs); + save_fpu_to(&vcpu->arch.guest_fpregs); + load_fpu_from(&vcpu->arch.host_fpregs); + + save_access_regs(vcpu->run->s.regs.acrs); restore_access_regs(vcpu->arch.host_acrs); } @@ -1464,7 +1500,6 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, vcpu->arch.sie_block = &sie_page->sie_block; vcpu->arch.sie_block->itdba = (unsigned long) &sie_page->itdb; - vcpu->arch.host_vregs = &sie_page->vregs; vcpu->arch.sie_block->icpua = id; if (!kvm_is_ucontrol(kvm)) { @@ -1486,6 +1521,19 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, vcpu->arch.local_int.wq = &vcpu->wq; vcpu->arch.local_int.cpuflags = &vcpu->arch.sie_block->cpuflags; + /* + * Allocate a save area for floating-point registers. If the vector + * extension is available, register contents are saved in the SIE + * control block. The allocated save area is still required in + * particular places, for example, in kvm_s390_vcpu_store_status(). + */ + vcpu->arch.guest_fpregs.fprs = kzalloc(sizeof(freg_t) * __NUM_FPRS, + GFP_KERNEL); + if (!vcpu->arch.guest_fpregs.fprs) { + rc = -ENOMEM; + goto out_free_sie_block; + } + rc = kvm_vcpu_init(vcpu, kvm, id); if (rc) goto out_free_sie_block; @@ -1708,16 +1756,16 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) { if (test_fp_ctl(fpu->fpc)) return -EINVAL; - memcpy(&vcpu->arch.guest_fpregs.fprs, &fpu->fprs, sizeof(fpu->fprs)); + memcpy(vcpu->arch.guest_fpregs.fprs, &fpu->fprs, sizeof(fpu->fprs)); vcpu->arch.guest_fpregs.fpc = fpu->fpc; - restore_fp_ctl(&vcpu->arch.guest_fpregs.fpc); - restore_fp_regs(vcpu->arch.guest_fpregs.fprs); + save_fpu_regs(); + load_fpu_from(&vcpu->arch.guest_fpregs); return 0; } int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) { - memcpy(&fpu->fprs, &vcpu->arch.guest_fpregs.fprs, sizeof(fpu->fprs)); + memcpy(&fpu->fprs, vcpu->arch.guest_fpregs.fprs, sizeof(fpu->fprs)); fpu->fpc = vcpu->arch.guest_fpregs.fpc; return 0; } @@ -2268,8 +2316,21 @@ int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr) * copying in vcpu load/put. Lets update our copies before we save * it into the save area */ - save_fp_ctl(&vcpu->arch.guest_fpregs.fpc); - save_fp_regs(vcpu->arch.guest_fpregs.fprs); + save_fpu_regs(); + if (test_kvm_facility(vcpu->kvm, 129)) { + /* + * If the vector extension is available, the vector registers + * which overlaps with floating-point registers are saved in + * the SIE-control block. Hence, extract the floating-point + * registers and the FPC value and store them in the + * guest_fpregs structure. + */ + WARN_ON(!is_vx_task(current)); /* XXX remove later */ + vcpu->arch.guest_fpregs.fpc = current->thread.fpu.fpc; + convert_vx_to_fp(vcpu->arch.guest_fpregs.fprs, + current->thread.fpu.vxrs); + } else + save_fpu_to(&vcpu->arch.guest_fpregs); save_access_regs(vcpu->run->s.regs.acrs); return kvm_s390_store_status_unloaded(vcpu, addr); @@ -2296,10 +2357,13 @@ int kvm_s390_vcpu_store_adtl_status(struct kvm_vcpu *vcpu, unsigned long addr) /* * The guest VXRS are in the host VXRs due to the lazy - * copying in vcpu load/put. Let's update our copies before we save - * it into the save area. + * copying in vcpu load/put. We can simply call save_fpu_regs() + * to save the current register state because we are in the + * middle of a load/put cycle. + * + * Let's update our copies before we save it into the save area. */ - save_vx_regs((__vector128 *)&vcpu->run->s.regs.vrs); + save_fpu_regs(); return kvm_s390_store_adtl_status_unloaded(vcpu, addr); } |