diff options
Diffstat (limited to 'arch/powerpc/kvm/booke.c')
| -rw-r--r-- | arch/powerpc/kvm/booke.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index 074b7fc795b7..91e7217db9d9 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -124,6 +124,40 @@ static void kvmppc_vcpu_sync_spe(struct kvm_vcpu *vcpu) } #endif +/* + * Load up guest vcpu FP state if it's needed. + * It also set the MSR_FP in thread so that host know + * we're holding FPU, and then host can help to save + * guest vcpu FP state if other threads require to use FPU. + * This simulates an FP unavailable fault. + * + * It requires to be called with preemption disabled. + */ +static inline void kvmppc_load_guest_fp(struct kvm_vcpu *vcpu) +{ +#ifdef CONFIG_PPC_FPU + if (!(current->thread.regs->msr & MSR_FP)) { + enable_kernel_fp(); + load_fp_state(&vcpu->arch.fp); + current->thread.fp_save_area = &vcpu->arch.fp; + current->thread.regs->msr |= MSR_FP; + } +#endif +} + +/* + * Save guest vcpu FP state into thread. + * It requires to be called with preemption disabled. + */ +static inline void kvmppc_save_guest_fp(struct kvm_vcpu *vcpu) +{ +#ifdef CONFIG_PPC_FPU + if (current->thread.regs->msr & MSR_FP) + giveup_fpu(current); + current->thread.fp_save_area = NULL; +#endif +} + static void kvmppc_vcpu_sync_fpu(struct kvm_vcpu *vcpu) { #if defined(CONFIG_PPC_FPU) && !defined(CONFIG_KVM_BOOKE_HV) @@ -658,12 +692,8 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) /* * Since we can't trap on MSR_FP in GS-mode, we consider the guest - * as always using the FPU. Kernel usage of FP (via - * enable_kernel_fp()) in this thread must not occur while - * vcpu->fpu_active is set. + * as always using the FPU. */ - vcpu->fpu_active = 1; - kvmppc_load_guest_fp(vcpu); #endif @@ -687,8 +717,6 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) #ifdef CONFIG_PPC_FPU kvmppc_save_guest_fp(vcpu); - - vcpu->fpu_active = 0; #endif out: @@ -1194,6 +1222,7 @@ out: else { /* interrupts now hard-disabled */ kvmppc_fix_ee_before_entry(); + kvmppc_load_guest_fp(vcpu); } } |