KVM: PPC: Teach MMIO Signedness

The guest I was trying to get to run uses the LHA and LHAU instructions.
Those instructions basically do a load, but also sign extend the result.

Since we need to fill our registers by hand when doing MMIO, we also need
to sign extend manually.

This patch implements sign extended MMIO and the LHA(U) instructions.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index fb87dcf418bf..119deb4750d9 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -270,6 +270,7 @@ struct kvm_vcpu_arch {
 
         u8 io_gpr; /* GPR used as IO source/target */
         u8 mmio_is_bigendian;
+        u8 mmio_sign_extend;
         u8 dcr_needed;
         u8 dcr_is_write;
 
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index c011170f572b..a288dd2fbb2c 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -48,6 +48,9 @@ extern void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu);
 extern int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
                               unsigned int rt, unsigned int bytes,
                               int is_bigendian);
+extern int kvmppc_handle_loads(struct kvm_run *run, struct kvm_vcpu *vcpu,
+                               unsigned int rt, unsigned int bytes,
+                               int is_bigendian);
 extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
                                u64 val, unsigned int bytes, int is_bigendian);