1 files changed, 44 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 75dbaeb2efa3..0b77be187cf7 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -457,6 +457,11 @@ void kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
 int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 {
         int ret;
+#ifdef CONFIG_PPC_FPU
+        unsigned int fpscr;
+        int fpexc_mode;
+        u64 fpr[32];
+#endif
 
         if (!vcpu->arch.sane) {
                 kvm_run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
@@ -479,7 +484,46 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
         }
 
         kvm_guest_enter();
+
+#ifdef CONFIG_PPC_FPU
+        /* Save userspace FPU state in stack */
+        enable_kernel_fp();
+        memcpy(fpr, current->thread.fpr, sizeof(current->thread.fpr));
+        fpscr = current->thread.fpscr.val;
+        fpexc_mode = current->thread.fpexc_mode;
+
+        /* Restore guest FPU state to thread */
+        memcpy(current->thread.fpr, vcpu->arch.fpr, sizeof(vcpu->arch.fpr));
+        current->thread.fpscr.val = vcpu->arch.fpscr;
+
+        /*
+         * 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.
+         */
+        vcpu->fpu_active = 1;
+
+        kvmppc_load_guest_fp(vcpu);
+#endif
+
         ret = __kvmppc_vcpu_run(kvm_run, vcpu);
+
+#ifdef CONFIG_PPC_FPU
+        kvmppc_save_guest_fp(vcpu);
+
+        vcpu->fpu_active = 0;
+
+        /* Save guest FPU state from thread */
+        memcpy(vcpu->arch.fpr, current->thread.fpr, sizeof(vcpu->arch.fpr));
+        vcpu->arch.fpscr = current->thread.fpscr.val;
+
+        /* Restore userspace FPU state from stack */
+        memcpy(current->thread.fpr, fpr, sizeof(current->thread.fpr));
+        current->thread.fpscr.val = fpscr;
+        current->thread.fpexc_mode = fpexc_mode;
+#endif
+
         kvm_guest_exit();
 
 out: