From patchwork Sun Sep 7 16:31:32 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Madhavan Srinivasan X-Patchwork-Id: 4858771 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4A0CDC033A for ; Sun, 7 Sep 2014 16:31:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5D06B2010E for ; Sun, 7 Sep 2014 16:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 560962012D for ; Sun, 7 Sep 2014 16:31:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752670AbaIGQbu (ORCPT ); Sun, 7 Sep 2014 12:31:50 -0400 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:59241 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752647AbaIGQbs (ORCPT ); Sun, 7 Sep 2014 12:31:48 -0400 Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Sun, 7 Sep 2014 22:01:41 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 3579AE0054; Sun, 7 Sep 2014 22:04:04 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay01.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s87GVcOn58196062; Sun, 7 Sep 2014 22:01:38 +0530 Received: from d28av03.in.ibm.com (localhost [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s87GVdxx005797; Sun, 7 Sep 2014 22:01:40 +0530 Received: from SrihariMadhavan.ibm.com ([9.124.94.70]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s87GVb2B005731; Sun, 7 Sep 2014 22:01:38 +0530 From: Madhavan Srinivasan To: agraf@suse.de, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, Madhavan Srinivasan Subject: [PATCH 1/2 v5] powerpc/kvm: support to handle sw breakpoint Date: Sun, 7 Sep 2014 22:01:32 +0530 Message-Id: <1410107494-25556-2-git-send-email-maddy@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1410107494-25556-1-git-send-email-maddy@linux.vnet.ibm.com> References: <1410107494-25556-1-git-send-email-maddy@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14090716-0017-0000-0000-0000011E5B01 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-8.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds kernel side support for software breakpoint. Design is that, by using an illegal instruction, we trap to hypervisor via Emulation Assistance interrupt, where we check for the illegal instruction and accordingly we return to Host or Guest. Patch also adds support for software breakpoint in PR KVM. Signed-off-by: Madhavan Srinivasan --- arch/powerpc/include/asm/kvm_ppc.h | 6 ++++++ arch/powerpc/kvm/book3s.c | 3 ++- arch/powerpc/kvm/book3s_hv.c | 41 ++++++++++++++++++++++++++++++++++---- arch/powerpc/kvm/book3s_pr.c | 3 +++ arch/powerpc/kvm/emulate.c | 18 +++++++++++++++++ 5 files changed, 66 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index fb86a22..dd83c9a 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -38,6 +38,12 @@ #include #endif +/* + * KVMPPC_INST_SW_BREAKPOINT is debug Instruction + * for supporting software breakpoint. + */ +#define KVMPPC_INST_SW_BREAKPOINT 0x00dddd00 + enum emulation_result { EMULATE_DONE, /* no further processing */ EMULATE_DO_MMIO, /* kvm_run filled with MMIO request */ diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index dd03f6b..00e9c9f 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -778,7 +778,8 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) { - return -EINVAL; + vcpu->guest_debug = dbg->control; + return 0; } void kvmppc_decrementer_func(unsigned long data) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 27cced9..3a2414c 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -725,6 +725,30 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd) return kvmppc_hcall_impl_hv_realmode(cmd); } +static int kvmppc_emulate_debug_inst(struct kvm_run *run, + struct kvm_vcpu *vcpu) +{ + u32 last_inst; + + if(kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != + EMULATE_DONE) { + /* + * Fetch failed, so return to guest and + * try executing it again. + */ + return RESUME_GUEST; + } else { + if (last_inst == KVMPPC_INST_SW_BREAKPOINT) { + run->exit_reason = KVM_EXIT_DEBUG; + run->debug.arch.address = kvmppc_get_pc(vcpu); + return RESUME_HOST; + } else { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + return RESUME_GUEST; + } + } +} + static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, struct task_struct *tsk) { @@ -807,12 +831,18 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, break; /* * This occurs if the guest executes an illegal instruction. - * We just generate a program interrupt to the guest, since - * we don't emulate any guest instructions at this stage. + * If the guest debug is disabled, generate a program interrupt + * to the guest. If guest debug is enabled, we need to check + * whether the instruction is a software breakpoint instruction. + * Accordingly return to Guest or Host. */ case BOOK3S_INTERRUPT_H_EMUL_ASSIST: - kvmppc_core_queue_program(vcpu, SRR1_PROGILL); - r = RESUME_GUEST; + if(vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) { + r = kvmppc_emulate_debug_inst(run, vcpu); + } else { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + r = RESUME_GUEST; + } break; /* * This occurs if the guest (kernel or userspace), does something that @@ -922,6 +952,9 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id, long int i; switch (id) { + case KVM_REG_PPC_DEBUG_INST: + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); + break; case KVM_REG_PPC_HIOR: *val = get_reg_val(id, 0); break; diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index faffb27..6d73708 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1319,6 +1319,9 @@ static int kvmppc_get_one_reg_pr(struct kvm_vcpu *vcpu, u64 id, int r = 0; switch (id) { + case KVM_REG_PPC_DEBUG_INST: + *val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT); + break; case KVM_REG_PPC_HIOR: *val = get_reg_val(id, to_book3s(vcpu)->hior); break; diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index e96b50d..30f326b 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -274,6 +274,24 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) } break; + case 0: + /* + * Instruction with primary opcode 0. Based on PowerISA + * these are illegal instructions. + */ + if(inst == KVMPPC_INST_SW_BREAKPOINT) { + run->exit_reason = KVM_EXIT_DEBUG; + run->debug.arch.address = kvmppc_get_pc(vcpu); + emulated = EMULATE_EXIT_USER; + advance = 0; + printk(KERN_INFO "pr_emulate: debug instr \n"); + } else { + kvmppc_core_queue_program(vcpu, SRR1_PROGILL); + emulated = EMULATE_DONE; + advance = 0; + } + break; + default: emulated = EMULATE_FAIL; }