Commit aabba3c6 authored by Radim Krčmář's avatar Radim Krčmář
Browse files

KVM: x86: add asm_safe wrapper 



Move the existing exception handling for inline assembly into a macro
and switch its return values to X86EMUL type.

Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 48520187

arch/x86/kvm/emulate.c

+23 −11
Original line number Diff line number Diff line
@@ -448,6 +448,26 @@ FOP_END; 
FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET

FOP_END;



/*

 * XXX: inoutclob user must know where the argument is being expanded.

 *      Relying on CC_HAVE_ASM_GOTO would allow us to remove _fault.

 */

#define asm_safe(insn, inoutclob...) \

({ \

	int _fault = 0; \

 \

	asm volatile("1:" insn "\n" \

	             "2:\n" \

	             ".pushsection .fixup, \"ax\"\n" \

	             "3: movl $1, %[_fault]\n" \

	             "   jmp  2b\n" \

	             ".popsection\n" \

	             _ASM_EXTABLE(1b, 3b) \

	             : [_fault] "+qm"(_fault) inoutclob ); \

 \

	_fault ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; \

})



static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,

				    enum x86_intercept intercept,

				    enum x86_intercept_stage stage)
@@ -5087,21 +5107,13 @@ static bool string_insn_completed(struct x86_emulate_ctxt *ctxt) 


static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)

{

	bool fault = false;

	int rc;



	ctxt->ops->get_fpu(ctxt);

	asm volatile("1: fwait \n\t"

		     "2: \n\t"

		     ".pushsection .fixup,\"ax\" \n\t"

		     "3: \n\t"

		     "movb $1, %[fault] \n\t"

		     "jmp 2b \n\t"

		     ".popsection \n\t"

		     _ASM_EXTABLE(1b, 3b)

		     : [fault]"+qm"(fault));

	rc = asm_safe("fwait");

	ctxt->ops->put_fpu(ctxt);



	if (unlikely(fault))

	if (unlikely(rc != X86EMUL_CONTINUE))

		return emulate_exception(ctxt, MF_VECTOR, 0, false);



	return X86EMUL_CONTINUE;