From patchwork Tue Mar 9 14:09:20 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 84286 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o29E9Z3W029212 for ; Tue, 9 Mar 2010 14:09:35 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752944Ab0CIOJd (ORCPT ); Tue, 9 Mar 2010 09:09:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22848 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752376Ab0CIOJ1 (ORCPT ); Tue, 9 Mar 2010 09:09:27 -0500 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o29E9QP1013465 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 9 Mar 2010 09:09:27 -0500 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by int-mx08.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o29E9PlI008231 for ; Tue, 9 Mar 2010 09:09:26 -0500 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 13519) id 778321339AD; Tue, 9 Mar 2010 16:09:23 +0200 (IST) From: Gleb Natapov To: kvm@vger.kernel.org Subject: [PATCH 22/24] KVM: x86 emulator: restart string instruction without going back to a guest. Date: Tue, 9 Mar 2010 16:09:20 +0200 Message-Id: <1268143762-4000-23-git-send-email-gleb@redhat.com> In-Reply-To: <1268143762-4000-1-git-send-email-gleb@redhat.com> References: <1268143762-4000-1-git-send-email-gleb@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.21 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 09 Mar 2010 14:09:35 +0000 (UTC) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 7d323d5..f74b4ad 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -193,6 +193,7 @@ struct x86_emulate_ctxt { /* interruptibility state, as a result of execution of STI or MOV SS */ int interruptibility; + bool restart; /* restart string instruction after writeback */ /* decode cache */ struct decode_cache decode; }; diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index ba1ce61..76ed77d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -925,8 +925,11 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) int mode = ctxt->mode; int def_op_bytes, def_ad_bytes, group; - /* Shadow copy of register state. Committed on successful emulation. */ + /* we cannot decode insn before we complete previous rep insn */ + WARN_ON(ctxt->restart); + + /* Shadow copy of register state. Committed on successful emulation. */ memset(c, 0, sizeof(struct decode_cache)); c->eip = ctxt->eip; ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS); @@ -2412,8 +2415,11 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) memop = c->modrm_ea; if (c->rep_prefix && (c->d & String)) { + ctxt->restart = true; /* All REP prefixes have the same first termination condition */ if (c->regs[VCPU_REGS_RCX] == 0) { + string_done: + ctxt->restart = false; kvm_rip_write(ctxt->vcpu, c->eip); goto done; } @@ -2425,17 +2431,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) * - if REPNE/REPNZ and ZF = 1 then done */ if ((c->b == 0xa6) || (c->b == 0xa7) || - (c->b == 0xae) || (c->b == 0xaf)) { + (c->b == 0xae) || (c->b == 0xaf)) { if ((c->rep_prefix == REPE_PREFIX) && - ((ctxt->eflags & EFLG_ZF) == 0)) { - kvm_rip_write(ctxt->vcpu, c->eip); - goto done; - } + ((ctxt->eflags & EFLG_ZF) == 0)) + goto string_done; if ((c->rep_prefix == REPNE_PREFIX) && - ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) { - kvm_rip_write(ctxt->vcpu, c->eip); - goto done; - } + ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) + goto string_done; } if (c->src.type == OP_MEM) memop = register_address(c, seg_override_base(ctxt, c), diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b25ef4b..82379e1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3724,6 +3724,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, return EMULATE_DONE; } +restart: r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops); shadow_mask = vcpu->arch.emulate_ctxt.interruptibility; @@ -3746,7 +3747,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, if (r) { if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) - return EMULATE_DONE; + goto done; if (!vcpu->mmio_needed) { kvm_report_emulation_failure(vcpu, "mmio"); return EMULATE_FAIL; @@ -3761,6 +3762,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu, return EMULATE_DO_MMIO; } +done: + if (vcpu->arch.emulate_ctxt.restart) + goto restart; + return EMULATE_DONE; } EXPORT_SYMBOL_GPL(emulate_instruction); @@ -4516,6 +4521,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) goto out; } } + if (vcpu->arch.emulate_ctxt.restart) { + vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + r = emulate_instruction(vcpu, 0, 0, EMULTYPE_NO_DECODE); + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); + if (r == EMULATE_DO_MMIO) { + r = 0; + goto out; + } + } if (kvm_run->exit_reason == KVM_EXIT_HYPERCALL) kvm_register_write(vcpu, VCPU_REGS_RAX, kvm_run->hypercall.ret);