From patchwork Fri Apr 8 16:05:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 608081 X-Patchwork-Delegate: paulus@samba.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qhPTN3RxVz9t42 for ; Sat, 9 Apr 2016 02:06:16 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3qhPTN2d6VzDqMt for ; Sat, 9 Apr 2016 02:06:16 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qhPSF44XzzDq6Y for ; Sat, 9 Apr 2016 02:05:16 +1000 (AEST) Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 165D96436D; Fri, 8 Apr 2016 16:05:15 +0000 (UTC) Received: from thinkpad.redhat.com (ovpn-112-41.ams2.redhat.com [10.36.112.41]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u38G5AG8029483; Fri, 8 Apr 2016 12:05:10 -0400 From: Laurent Vivier To: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH v2] kvm-pr: manage single-step mode Date: Fri, 8 Apr 2016 18:05:00 +0200 Message-Id: <1460131500-19560-1-git-send-email-lvivier@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 08 Apr 2016 16:05:15 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , thuth@redhat.com, dgibson@redhat.com, Gleb Natapov , linux-kernel@vger.kernel.org, Paul Mackerras , Paolo Bonzini , linuxppc-dev@lists.ozlabs.org, Alexander Graf MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Until now, when we connect gdb to the QEMU gdb-server, the single-step mode is not managed. This patch adds this, only for kvm-pr: If KVM_GUESTDBG_SINGLESTEP is set, we enable single-step trace bit in the MSR (MSR_SE) just before the __kvmppc_vcpu_run(), and disable it just after. In kvmppc_handle_exit_pr, instead of routing the interrupt to the guest, we return to host, with KVM_EXIT_DEBUG reason. Signed-off-by: Laurent Vivier Reviewed-by: David Gibson Reviewed-by: Thomas Huth --- v2: split BOOK3S_INTERRUPT_MACHINE_CHECK and BOOK3S_INTERRUPT_TRACE arch/powerpc/kvm/book3s_pr.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 95bceca..8129b0d 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -882,6 +882,24 @@ void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr) } #endif +static void kvmppc_setup_debug(struct kvm_vcpu *vcpu) +{ + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) { + u64 msr = kvmppc_get_msr(vcpu); + + kvmppc_set_msr(vcpu, msr | MSR_SE); + } +} + +static void kvmppc_clear_debug(struct kvm_vcpu *vcpu) +{ + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) { + u64 msr = kvmppc_get_msr(vcpu); + + kvmppc_set_msr(vcpu, msr & ~MSR_SE); + } +} + int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned int exit_nr) { @@ -1207,10 +1225,18 @@ program_interrupt: break; #endif case BOOK3S_INTERRUPT_MACHINE_CHECK: - case BOOK3S_INTERRUPT_TRACE: kvmppc_book3s_queue_irqprio(vcpu, exit_nr); r = RESUME_GUEST; break; + case BOOK3S_INTERRUPT_TRACE: + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) { + run->exit_reason = KVM_EXIT_DEBUG; + r = RESUME_HOST; + } else { + kvmppc_book3s_queue_irqprio(vcpu, exit_nr); + r = RESUME_GUEST; + } + break; default: { ulong shadow_srr1 = vcpu->arch.shadow_srr1; @@ -1479,6 +1505,8 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) goto out; } + kvmppc_setup_debug(vcpu); + /* * Interrupts could be timers for the guest which we have to inject * again, so let's postpone them until we're in the guest and if we @@ -1501,6 +1529,8 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) ret = __kvmppc_vcpu_run(kvm_run, vcpu); + kvmppc_clear_debug(vcpu); + /* No need for kvm_guest_exit. It's done in handle_exit. We also get here with interrupts enabled. */