KVM: PPC: booke: standard PPC floating point support
e500mc has a normal PPC FPU, rather than SPE which is found
on e500v1/v2.
Based on code from Liu Yu <yu.liu@freescale.com>.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 75dbaeb..0b77be1 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -457,6 +457,11 @@
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 @@
}
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: