KVM: PPC: Use load_fp/vr_state rather than load_up_fpu/altivec

The load_up_fpu and load_up_altivec functions were never intended to
be called from C, and do things like modifying the MSR value in their
callers' stack frames, which are assumed to be interrupt frames.  In
addition, on 32-bit Book S they require the MMU to be off.

This makes KVM use the new load_fp_state() and load_vr_state() functions
instead of load_up_fpu/altivec.  This means we can remove the assembler
glue in book3s_rmhandlers.S, and potentially fixes a bug on Book E,
where load_up_fpu was called directly from C.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 12 insertions, 6 deletions

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 21bf7c5c9545..d63a91f825d3 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -691,7 +691,8 @@ static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
 #endif
 		t->fp_state.fpscr = vcpu->arch.fpscr;
 		t->fpexc_mode = 0;
-		kvmppc_load_up_fpu();
+		enable_kernel_fp();
+		load_fp_state(&t->fp_state);
 	}
 
 	if (msr & MSR_VEC) {
@@ -699,7 +700,8 @@ static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
 		memcpy(t->vr_state.vr, vcpu->arch.vr, sizeof(vcpu->arch.vr));
 		t->vr_state.vscr = vcpu->arch.vscr;
 		t->vrsave = -1;
-		kvmppc_load_up_altivec();
+		enable_kernel_altivec();
+		load_vr_state(&t->vr_state);
 #endif
 	}
 
@@ -722,11 +724,15 @@ static void kvmppc_handle_lost_ext(struct kvm_vcpu *vcpu)
 	if (!lost_ext)
 		return;
 
-	if (lost_ext & MSR_FP)
-		kvmppc_load_up_fpu();
+	if (lost_ext & MSR_FP) {
+		enable_kernel_fp();
+		load_fp_state(&current->thread.fp_state);
+	}
 #ifdef CONFIG_ALTIVEC
-	if (lost_ext & MSR_VEC)
-		kvmppc_load_up_altivec();
+	if (lost_ext & MSR_VEC) {
+		enable_kernel_altivec();
+		load_vr_state(&current->thread.vr_state);
+	}
 #endif
 	current->thread.regs->msr |= lost_ext;
 }