From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753395Ab3KSOy1 (ORCPT ); Tue, 19 Nov 2013 09:54:27 -0500 Received: from mail-ea0-f169.google.com ([209.85.215.169]:39496 "EHLO mail-ea0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753354Ab3KSOyI (ORCPT ); Tue, 19 Nov 2013 09:54:08 -0500 From: Dan Aloni To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, x86@kernel.org, gleb@redhat.com, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, Muli Ben-Yehuda Subject: [PATCH linux-next 2/2] kvm-x86: emulator: disable kgdb-x86 on fastop and fpe flush Date: Tue, 19 Nov 2013 16:53:30 +0200 Message-Id: <1384872810-29492-3-git-send-email-alonid@stratoscale.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1384872810-29492-1-git-send-email-alonid@stratoscale.com> References: <1384872810-29492-1-git-send-email-alonid@stratoscale.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We have seen that when kvm-unit-tests runs with kgdb enabled, the kernel halts on the debugger during the KVM x86 instruction emulation that performs a test of a division by zero, and also during fwait. This patch adds calls that temporarily disable the debugger trap. Signed-off-by: Dan Aloni Signed-off-by: Muli Ben-Yehuda --- arch/x86/kvm/emulate.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 07ffca0..05e8509 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -24,6 +24,7 @@ #include "kvm_cache_regs.h" #include #include +#include #include #include "x86.h" @@ -4438,6 +4439,7 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) { bool fault = false; + kgdb_ll_local_disable(); ctxt->ops->get_fpu(ctxt); asm volatile("1: fwait \n\t" "2: \n\t" @@ -4449,6 +4451,7 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) _ASM_EXTABLE(1b, 3b) : [fault]"+qm"(fault)); ctxt->ops->put_fpu(ctxt); + kgdb_ll_local_enable(); if (unlikely(fault)) return emulate_exception(ctxt, MF_VECTOR, 0, false); @@ -4468,10 +4471,14 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *)) ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; if (!(ctxt->d & ByteOp)) fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; + + kgdb_ll_local_disable(); asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n" : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags), [fastop]"+S"(fop) : "c"(ctxt->src2.val)); + kgdb_ll_local_enable(); + ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); if (!fop) /* exception is returned in fop variable */ return emulate_de(ctxt); -- 1.8.3.1