ARM64: KVM: MMIO support BE host running LE code

In case of guest CPU running in LE mode and host runs in
BE mode we need byteswap data, so read/write is emulated correctly.

Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index dd8ecfc3f995..fdc3e21abd8d 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -213,6 +213,17 @@ static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
                 default:
                         return be64_to_cpu(data);
                 }
+        } else {
+                switch (len) {
+                case 1:
+                        return data & 0xff;
+                case 2:
+                        return le16_to_cpu(data & 0xffff);
+                case 4:
+                        return le32_to_cpu(data & 0xffffffff);
+                default:
+                        return le64_to_cpu(data);
+                }
         }
 
         return data;            /* Leave LE untouched */
@@ -233,6 +244,17 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
                 default:
                         return cpu_to_be64(data);
                 }
+        } else {
+                switch (len) {
+                case 1:
+                        return data & 0xff;
+                case 2:
+                        return cpu_to_le16(data & 0xffff);
+                case 4:
+                        return cpu_to_le32(data & 0xffffffff);
+                default:
+                        return cpu_to_le64(data);
+                }
         }
 
         return data;            /* Leave LE untouched */