Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754571AbZKHR1i (ORCPT ); Sun, 8 Nov 2009 12:27:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753905AbZKHR1i (ORCPT ); Sun, 8 Nov 2009 12:27:38 -0500 Received: from fmmailgate02.web.de ([217.72.192.227]:53482 "EHLO fmmailgate02.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751352AbZKHR1h (ORCPT ); Sun, 8 Nov 2009 12:27:37 -0500 Message-ID: <4AF6FEDE.5030807@web.de> Date: Sun, 08 Nov 2009 18:24:46 +0100 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Frederic Weisbecker CC: Ingo Molnar , LKML , Li Zefan , Prasad , Alan Stern , Peter Zijlstra , Arnaldo Carvalho de Melo , Steven Rostedt , Jiri Slaby , Avi Kivity , Paul Mackerras , Mike Galbraith , Masami Hiramatsu , Paul Mundt , Arjan van de Ven Subject: Re: [PATCH 5/7 v6] hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events References: <1257694141-5670-1-git-send-email-fweisbec@gmail.com> <1257694141-5670-6-git-send-email-fweisbec@gmail.com> In-Reply-To: <1257694141-5670-6-git-send-email-fweisbec@gmail.com> X-Enigmail-Version: 0.95.7 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig68DB5B809E08F6EB46238009" X-Provags-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2683 Lines: 77 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig68DB5B809E08F6EB46238009 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Frederic Weisbecker wrote: > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index fc2974a..22dee7a 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -42,6 +42,7 @@ > #define CREATE_TRACE_POINTS > #include "trace.h" > =20 > +#include > #include > #include > #include > @@ -3643,14 +3644,15 @@ static int vcpu_enter_guest(struct kvm_vcpu *vc= pu, struct kvm_run *kvm_run) > trace_kvm_entry(vcpu->vcpu_id); > kvm_x86_ops->run(vcpu, kvm_run); > =20 > - if (unlikely(vcpu->arch.switch_db_regs || test_thread_flag(TIF_DEBUG)= )) { > - set_debugreg(current->thread.debugreg[0], 0); > - set_debugreg(current->thread.debugreg[1], 1); > - set_debugreg(current->thread.debugreg[2], 2); > - set_debugreg(current->thread.debugreg[3], 3); > - set_debugreg(current->thread.debugreg6, 6); > - set_debugreg(current->thread.debugreg7, 7); > - } > + /* > + * If the guest has used debug registers, at least dr7 > + * will be disabled while returning to the host. > + * If we don't have active breakpoints in the host, we don't > + * care about the messed up debug address registers. But if > + * we have some of them active, restore the old state. > + */ > + if (__get_cpu_var(dr7) & DR_GLOBAL_ENABLE_MASK) Looks good, just a minor remark: Would be cleaner to wrap this into an inline function, say hw_breakpoint_active(), to abstract the precise condition away from KVM. > + hw_breakpoint_restore(); > =20 > set_bit(KVM_REQ_KICK, &vcpu->requests); > local_irq_enable(); Will see that I can give your series a try the next days, probably debugging qemu-kvm while running a guest that uses breakpoints. But I don't expect surprises. Jan --------------enig68DB5B809E08F6EB46238009 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkr2/ugACgkQitSsb3rl5xRkOQCfWtX+Rss4MnQpokliQd/9pnS+ XlcAoKzEmeVXKXTvI8GojLviCUjdpy// =caGC -----END PGP SIGNATURE----- --------------enig68DB5B809E08F6EB46238009-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/