target-arm: Provide mechanism for getting KVM constants even if not CONFIG_KVM

There are a number of places where it would be convenient for ARM
code to have working definitions of KVM constants even in code
which is compiled with CONFIG_KVM not set. In this situation we
can't simply include the kernel KVM headers (which might conflict
with host header definitions or not even compile on the compiler
we're using) so we have to redefine equivalent constants.
Provide a mechanism for doing this and checking that the values
match, and use it for the constants we're currently exposing
via an ad-hoc mechanism.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Message-id: 1385140638-10444-2-git-send-email-peter.maydell@linaro.org

3 files changed, 43 insertions, 20 deletions

diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index 9f110f15b6..c3f007fc53 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -21,6 +21,8 @@
 
 #include "config.h"
 
+#include "kvm-consts.h"
+
 #if defined(TARGET_AARCH64)
   /* AArch64 definitions */
 #  define TARGET_LONG_BITS 64
@@ -497,17 +499,6 @@ void armv7m_nvic_complete_irq(void *opaque, int irq);
     (((cp) << 16) | ((is64) << 15) | ((crn) << 11) |    \
      ((crm) << 7) | ((opc1) << 3) | (opc2))
 
-/* Note that these must line up with the KVM/ARM register
- * ID field definitions (kvm.c will check this, but we
- * can't just use the KVM defines here as the kvm headers
- * are unavailable to non-KVM-specific files)
- */
-#define CP_REG_SIZE_SHIFT 52
-#define CP_REG_SIZE_MASK       0x00f0000000000000ULL
-#define CP_REG_SIZE_U32        0x0020000000000000ULL
-#define CP_REG_SIZE_U64        0x0030000000000000ULL
-#define CP_REG_ARM             0x4000000000000000ULL
-
 /* Convert a full 64 bit KVM register ID to the truncated 32 bit
  * version used as a key for the coprocessor register hashtable
  */
diff --git a/target-arm/kvm-consts.h b/target-arm/kvm-consts.h
new file mode 100644
index 0000000000..6f56f726d3
--- /dev/null
+++ b/target-arm/kvm-consts.h
@@ -0,0 +1,41 @@
+/*
+ * KVM ARM ABI constant definitions
+ *
+ * Copyright (c) 2013 Linaro Limited
+ *
+ * Provide versions of KVM constant defines that can be used even
+ * when CONFIG_KVM is not set and we don't have access to the
+ * KVM headers. If CONFIG_KVM is set, we do a compile-time check
+ * that we haven't got out of sync somehow.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#ifndef ARM_KVM_CONSTS_H
+#define ARM_KVM_CONSTS_H
+
+#ifdef CONFIG_KVM
+#include "qemu/compiler.h"
+#include <linux/kvm.h>
+
+#define MISMATCH_CHECK(X, Y) QEMU_BUILD_BUG_ON(X != Y)
+
+#else
+#define MISMATCH_CHECK(X, Y)
+#endif
+
+#define CP_REG_SIZE_SHIFT 52
+#define CP_REG_SIZE_MASK       0x00f0000000000000ULL
+#define CP_REG_SIZE_U32        0x0020000000000000ULL
+#define CP_REG_SIZE_U64        0x0030000000000000ULL
+#define CP_REG_ARM             0x4000000000000000ULL
+
+MISMATCH_CHECK(CP_REG_SIZE_SHIFT, KVM_REG_SIZE_SHIFT)
+MISMATCH_CHECK(CP_REG_SIZE_MASK, KVM_REG_SIZE_MASK)
+MISMATCH_CHECK(CP_REG_SIZE_U32, KVM_REG_SIZE_U32)
+MISMATCH_CHECK(CP_REG_SIZE_U64, KVM_REG_SIZE_U64)
+MISMATCH_CHECK(CP_REG_ARM, KVM_REG_ARM)
+
+#undef MISMATCH_CHECK
+
+#endif
diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index 6e5cd36fae..309845630b 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -23,15 +23,6 @@
 #include "cpu.h"
 #include "hw/arm/arm.h"
 
-/* Check that cpu.h's idea of coprocessor fields matches KVM's */
-#if (CP_REG_SIZE_SHIFT != KVM_REG_SIZE_SHIFT) || \
-    (CP_REG_SIZE_MASK != KVM_REG_SIZE_MASK) ||   \
-    (CP_REG_SIZE_U32 != KVM_REG_SIZE_U32) || \
-    (CP_REG_SIZE_U64 != KVM_REG_SIZE_U64) || \
-    (CP_REG_ARM != KVM_REG_ARM)
-#error mismatch between cpu.h and KVM header definitions
-#endif
-
 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
 };