From aabba3c6abd50b05b1fc2c6ec44244aa6bcda576 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Date: Tue, 8 Nov 2016 20:54:18 +0100 Subject: [PATCH] KVM: x86: add asm_safe wrapper MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Move the existing exception handling for inline assembly into a macro and switch its return values to X86EMUL type. Signed-off-by: Radim Krčmář Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 14624d6bf112..6af3cac6ec89 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -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; -- 2.20.1