kvm/emulate: fix a -Werror=cast-function-type
arch/x86/kvm/emulate.c: In function 'x86_emulate_insn':
arch/x86/kvm/emulate.c:5686:22: error: cast between incompatible
function types from 'int (*)(struct x86_emulate_ctxt *)' to 'void
(*)(struct fastop *)' [-Werror=cast-function-type]
rc = fastop(ctxt, (fastop_t)ctxt->execute);
Fix it by using an unnamed union of a (*execute) function pointer and a
(*fastop) function pointer.
Fixes: 3009afc6e39e ("KVM: x86: Use a typedef for fastop functions")
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index ddbc619..dd19fb3 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -191,25 +191,6 @@
#define NR_FASTOP (ilog2(sizeof(ulong)) + 1)
#define FASTOP_SIZE 8
-/*
- * fastop functions have a special calling convention:
- *
- * dst: rax (in/out)
- * src: rdx (in/out)
- * src2: rcx (in)
- * flags: rflags (in/out)
- * ex: rsi (in:fastop pointer, out:zero if exception)
- *
- * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
- * different operand sizes can be reached by calculation, rather than a jump
- * table (which would be bigger than the code).
- *
- * fastop functions are declared as taking a never-defined fastop parameter,
- * so they can't be called from C directly.
- */
-
-struct fastop;
-
struct opcode {
u64 flags : 56;
u64 intercept : 8;
@@ -311,8 +292,19 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
#define ON64(x)
#endif
-typedef void (*fastop_t)(struct fastop *);
-
+/*
+ * fastop functions have a special calling convention:
+ *
+ * dst: rax (in/out)
+ * src: rdx (in/out)
+ * src2: rcx (in)
+ * flags: rflags (in/out)
+ * ex: rsi (in:fastop pointer, out:zero if exception)
+ *
+ * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
+ * different operand sizes can be reached by calculation, rather than a jump
+ * table (which would be bigger than the code).
+ */
static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);
#define __FOP_FUNC(name) \
@@ -5683,7 +5675,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
if (ctxt->execute) {
if (ctxt->d & Fastop)
- rc = fastop(ctxt, (fastop_t)ctxt->execute);
+ rc = fastop(ctxt, ctxt->fop);
else
rc = ctxt->execute(ctxt);
if (rc != X86EMUL_CONTINUE)