From patchwork Wed Nov 25 09:35:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Adalbert_Laz=C4=83r?= X-Patchwork-Id: 11930821 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A07DC8300E for ; Wed, 25 Nov 2020 09:42:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB060206F9 for ; Wed, 25 Nov 2020 09:42:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728583AbgKYJmG (ORCPT ); Wed, 25 Nov 2020 04:42:06 -0500 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:57140 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727682AbgKYJmC (ORCPT ); Wed, 25 Nov 2020 04:42:02 -0500 Received: from smtp.bitdefender.com (smtp01.buh.bitdefender.com [10.17.80.75]) by mx01.bbu.dsd.mx.bitdefender.com (Postfix) with ESMTPS id 62D96305D3EA; Wed, 25 Nov 2020 11:35:55 +0200 (EET) Received: from localhost.localdomain (unknown [91.199.104.27]) by smtp.bitdefender.com (Postfix) with ESMTPSA id 3EF253072785; Wed, 25 Nov 2020 11:35:55 +0200 (EET) From: =?utf-8?q?Adalbert_Laz=C4=83r?= To: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, Paolo Bonzini , =?utf-8?b?TmljdciZb3IgQ8OuyJt1?= , =?utf-8?q?Adalbert?= =?utf-8?q?_Laz=C4=83r?= Subject: [PATCH v10 77/81] KVM: introspection: add KVMI_VCPU_CONTROL_SINGLESTEP Date: Wed, 25 Nov 2020 11:35:56 +0200 Message-Id: <20201125093600.2766-78-alazar@bitdefender.com> In-Reply-To: <20201125093600.2766-1-alazar@bitdefender.com> References: <20201125093600.2766-1-alazar@bitdefender.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Nicușor Cîțu The next commit that adds the KVMI_VCPU_EVENT_SINGLESTEP event will make this command more useful. Signed-off-by: Nicușor Cîțu Co-developed-by: Adalbert Lazăr Signed-off-by: Adalbert Lazăr --- Documentation/virt/kvm/kvmi.rst | 33 +++++++++++ arch/x86/kvm/kvmi.c | 14 ++++- arch/x86/kvm/kvmi_msg.c | 56 +++++++++++++++---- arch/x86/kvm/x86.c | 12 +++- include/linux/kvmi_host.h | 7 +++ include/uapi/linux/kvmi.h | 30 ++++++---- .../testing/selftests/kvm/x86_64/kvmi_test.c | 39 +++++++++++++ virt/kvm/introspection/kvmi.c | 22 ++++++++ virt/kvm/introspection/kvmi_int.h | 2 + 9 files changed, 187 insertions(+), 28 deletions(-) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 991922897f1d..c8822912d8c8 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -791,6 +791,7 @@ exception. * -KVM_EINVAL - the selected vCPU is invalid * -KVM_EINVAL - the padding is not zero * -KVM_EAGAIN - the selected vCPU can't be introspected yet +* -KVM_EBUSY - the vCPU is switched in singlestep mode (*KVMI_VCPU_CONTROL_SINGLESTEP*) * -KVM_EBUSY - another *KVMI_VCPU_INJECT_EXCEPTION*-*KVMI_VCPU_EVENT_TRAP* pair is in progress @@ -1036,6 +1037,38 @@ In order to 'forget' an address, all three bits ('rwx') must be set. * -KVM_EAGAIN - the selected vCPU can't be introspected yet * -KVM_ENOMEM - there is not enough memory to add the page tracking structures +24. KVMI_VCPU_CONTROL_SINGLESTEP +-------------------------------- + +:Architectures: x86 (vmx) +:Versions: >= 1 +:Parameters: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_vcpu_control_singlestep { + __u8 enable; + __u8 padding[7]; + }; + +:Returns: + +:: + + struct kvmi_error_code; + +Enables/disables singlestep for the selected vCPU. + +The introspection tool should use *KVMI_GET_VERSION*, to check +if the hardware supports singlestep (see **KVMI_GET_VERSION**). + +:Errors: + +* -KVM_EOPNOTSUPP - the hardware doesn't support singlestep +* -KVM_EINVAL - the padding is not zero +* -KVM_EAGAIN - the selected vCPU can't be introspected yet + Events ====== diff --git a/arch/x86/kvm/kvmi.c b/arch/x86/kvm/kvmi.c index e0302883aec5..31a2de24de29 100644 --- a/arch/x86/kvm/kvmi.c +++ b/arch/x86/kvm/kvmi.c @@ -776,7 +776,9 @@ void kvmi_enter_guest(struct kvm_vcpu *vcpu) if (kvmi) { vcpui = VCPUI(vcpu); - if (vcpui->arch.exception.pending) + if (vcpui->singlestep.loop) + kvmi_arch_start_singlestep(vcpu); + else if (vcpui->arch.exception.pending) kvmi_inject_pending_exception(vcpu); kvmi_put(vcpu->kvm); @@ -1086,3 +1088,13 @@ void kvmi_arch_features(struct kvmi_features *feat) { feat->singlestep = !!kvm_x86_ops.control_singlestep; } + +void kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu) +{ + kvm_x86_ops.control_singlestep(vcpu, true); +} + +void kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu) +{ + kvm_x86_ops.control_singlestep(vcpu, false); +} diff --git a/arch/x86/kvm/kvmi_msg.c b/arch/x86/kvm/kvmi_msg.c index c961c5367a13..8b59f9f73c5d 100644 --- a/arch/x86/kvm/kvmi_msg.c +++ b/arch/x86/kvm/kvmi_msg.c @@ -166,7 +166,8 @@ static int handle_vcpu_inject_exception(const struct kvmi_vcpu_msg_job *job, else if (req->padding1 || req->padding2) ec = -KVM_EINVAL; else if (VCPUI(vcpu)->arch.exception.pending || - VCPUI(vcpu)->arch.exception.send_event) + VCPUI(vcpu)->arch.exception.send_event || + VCPUI(vcpu)->singlestep.loop) ec = -KVM_EBUSY; else ec = kvmi_arch_cmd_vcpu_inject_exception(vcpu, req); @@ -276,18 +277,49 @@ static int handle_vcpu_control_msr(const struct kvmi_vcpu_msg_job *job, return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); } +static int handle_vcpu_control_singlestep(const struct kvmi_vcpu_msg_job *job, + const struct kvmi_msg_hdr *msg, + const void *_req) +{ + const struct kvmi_vcpu_control_singlestep *req = _req; + struct kvm_vcpu *vcpu = job->vcpu; + int ec = 0; + + if (non_zero_padding(req->padding, ARRAY_SIZE(req->padding)) || + req->enable > 1) { + ec = -KVM_EINVAL; + goto reply; + } + + if (!kvm_x86_ops.control_singlestep) { + ec = -KVM_EOPNOTSUPP; + goto reply; + } + + if (req->enable) + kvmi_arch_start_singlestep(vcpu); + else + kvmi_arch_stop_singlestep(vcpu); + + VCPUI(vcpu)->singlestep.loop = !!req->enable; + +reply: + return kvmi_msg_vcpu_reply(job, msg, ec, NULL, 0); +} + static kvmi_vcpu_msg_job_fct const msg_vcpu[] = { - [KVMI_VCPU_CONTROL_CR] = handle_vcpu_control_cr, - [KVMI_VCPU_CONTROL_MSR] = handle_vcpu_control_msr, - [KVMI_VCPU_GET_CPUID] = handle_vcpu_get_cpuid, - [KVMI_VCPU_GET_INFO] = handle_vcpu_get_info, - [KVMI_VCPU_GET_MTRR_TYPE] = handle_vcpu_get_mtrr_type, - [KVMI_VCPU_GET_REGISTERS] = handle_vcpu_get_registers, - [KVMI_VCPU_GET_XCR] = handle_vcpu_get_xcr, - [KVMI_VCPU_GET_XSAVE] = handle_vcpu_get_xsave, - [KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception, - [KVMI_VCPU_SET_REGISTERS] = handle_vcpu_set_registers, - [KVMI_VCPU_SET_XSAVE] = handle_vcpu_set_xsave, + [KVMI_VCPU_CONTROL_CR] = handle_vcpu_control_cr, + [KVMI_VCPU_CONTROL_MSR] = handle_vcpu_control_msr, + [KVMI_VCPU_CONTROL_SINGLESTEP] = handle_vcpu_control_singlestep, + [KVMI_VCPU_GET_CPUID] = handle_vcpu_get_cpuid, + [KVMI_VCPU_GET_INFO] = handle_vcpu_get_info, + [KVMI_VCPU_GET_MTRR_TYPE] = handle_vcpu_get_mtrr_type, + [KVMI_VCPU_GET_REGISTERS] = handle_vcpu_get_registers, + [KVMI_VCPU_GET_XCR] = handle_vcpu_get_xcr, + [KVMI_VCPU_GET_XSAVE] = handle_vcpu_get_xsave, + [KVMI_VCPU_INJECT_EXCEPTION] = handle_vcpu_inject_exception, + [KVMI_VCPU_SET_REGISTERS] = handle_vcpu_set_registers, + [KVMI_VCPU_SET_XSAVE] = handle_vcpu_set_xsave, }; kvmi_vcpu_msg_job_fct kvmi_arch_vcpu_msg_handler(u16 id) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0ffa2e73284e..cc7292ee3b2d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8957,9 +8957,15 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) goto out; } - inject_pending_event(vcpu, &req_immediate_exit); - if (req_int_win) - kvm_x86_ops.enable_irq_window(vcpu); + if (!kvmi_vcpu_running_singlestep(vcpu)) { + /* + * We cannot inject events during single-stepping. + * Try again later. + */ + inject_pending_event(vcpu, &req_immediate_exit); + if (req_int_win) + kvm_x86_ops.enable_irq_window(vcpu); + } if (kvm_lapic_enabled(vcpu)) { update_cr8_intercept(vcpu); diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h index 14ac075a3ea9..e2103ab9d0d5 100644 --- a/include/linux/kvmi_host.h +++ b/include/linux/kvmi_host.h @@ -33,6 +33,10 @@ struct kvm_vcpu_introspection { bool waiting_for_reply; unsigned long *ev_enable_mask; + + struct { + bool loop; + } singlestep; }; struct kvm_introspection { @@ -76,6 +80,7 @@ int kvmi_ioctl_preunhook(struct kvm *kvm); void kvmi_handle_requests(struct kvm_vcpu *vcpu); bool kvmi_hypercall_event(struct kvm_vcpu *vcpu); bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len); +bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu); #else @@ -90,6 +95,8 @@ static inline void kvmi_handle_requests(struct kvm_vcpu *vcpu) { } static inline bool kvmi_hypercall_event(struct kvm_vcpu *vcpu) { return false; } static inline bool kvmi_breakpoint_event(struct kvm_vcpu *vcpu, u64 gva, u8 insn_len) { return true; } +static inline bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu) + { return false; } #endif /* CONFIG_KVM_INTROSPECTION */ diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index 43631ed2b06c..91126607b7eb 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -38,18 +38,19 @@ enum { enum { KVMI_VCPU_EVENT = KVMI_VCPU_MESSAGE_ID(0), - KVMI_VCPU_GET_INFO = KVMI_VCPU_MESSAGE_ID(1), - KVMI_VCPU_CONTROL_EVENTS = KVMI_VCPU_MESSAGE_ID(2), - KVMI_VCPU_GET_REGISTERS = KVMI_VCPU_MESSAGE_ID(3), - KVMI_VCPU_SET_REGISTERS = KVMI_VCPU_MESSAGE_ID(4), - KVMI_VCPU_GET_CPUID = KVMI_VCPU_MESSAGE_ID(5), - KVMI_VCPU_CONTROL_CR = KVMI_VCPU_MESSAGE_ID(6), - KVMI_VCPU_INJECT_EXCEPTION = KVMI_VCPU_MESSAGE_ID(7), - KVMI_VCPU_GET_XCR = KVMI_VCPU_MESSAGE_ID(8), - KVMI_VCPU_GET_XSAVE = KVMI_VCPU_MESSAGE_ID(9), - KVMI_VCPU_SET_XSAVE = KVMI_VCPU_MESSAGE_ID(10), - KVMI_VCPU_GET_MTRR_TYPE = KVMI_VCPU_MESSAGE_ID(11), - KVMI_VCPU_CONTROL_MSR = KVMI_VCPU_MESSAGE_ID(12), + KVMI_VCPU_GET_INFO = KVMI_VCPU_MESSAGE_ID(1), + KVMI_VCPU_CONTROL_EVENTS = KVMI_VCPU_MESSAGE_ID(2), + KVMI_VCPU_GET_REGISTERS = KVMI_VCPU_MESSAGE_ID(3), + KVMI_VCPU_SET_REGISTERS = KVMI_VCPU_MESSAGE_ID(4), + KVMI_VCPU_GET_CPUID = KVMI_VCPU_MESSAGE_ID(5), + KVMI_VCPU_CONTROL_CR = KVMI_VCPU_MESSAGE_ID(6), + KVMI_VCPU_INJECT_EXCEPTION = KVMI_VCPU_MESSAGE_ID(7), + KVMI_VCPU_GET_XCR = KVMI_VCPU_MESSAGE_ID(8), + KVMI_VCPU_GET_XSAVE = KVMI_VCPU_MESSAGE_ID(9), + KVMI_VCPU_SET_XSAVE = KVMI_VCPU_MESSAGE_ID(10), + KVMI_VCPU_GET_MTRR_TYPE = KVMI_VCPU_MESSAGE_ID(11), + KVMI_VCPU_CONTROL_MSR = KVMI_VCPU_MESSAGE_ID(12), + KVMI_VCPU_CONTROL_SINGLESTEP = KVMI_VCPU_MESSAGE_ID(13), KVMI_NEXT_VCPU_MESSAGE }; @@ -221,4 +222,9 @@ struct kvmi_vcpu_event_pf { __u32 padding3; }; +struct kvmi_vcpu_control_singlestep { + __u8 enable; + __u8 padding[7]; +}; + #endif /* _UAPI__LINUX_KVMI_H */ diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index 9984b0247ae9..d959216aac9d 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -1819,6 +1819,44 @@ static void test_event_pf(struct kvm_vm *vm) test_pf(vm, cbk_test_event_pf); } +static void cmd_vcpu_singlestep(struct kvm_vm *vm, __u8 enable, + int expected_err) +{ + struct { + struct kvmi_msg_hdr hdr; + struct kvmi_vcpu_hdr vcpu_hdr; + struct kvmi_vcpu_control_singlestep cmd; + } req = {}; + + req.cmd.enable = enable; + + test_vcpu0_command(vm, KVMI_VCPU_CONTROL_SINGLESTEP, + &req.hdr, sizeof(req), NULL, 0, expected_err); +} + +static void test_supported_singlestep(struct kvm_vm *vm) +{ + __u8 disable = 0, enable = 1, enable_inval = 2; + + cmd_vcpu_singlestep(vm, enable, 0); + cmd_vcpu_singlestep(vm, disable, 0); + + cmd_vcpu_singlestep(vm, enable_inval, -KVM_EINVAL); +} + +static void test_unsupported_singlestep(struct kvm_vm *vm) +{ + cmd_vcpu_singlestep(vm, 1, -KVM_EOPNOTSUPP); +} + +static void test_cmd_vcpu_control_singlestep(struct kvm_vm *vm) +{ + if (features.singlestep) + test_supported_singlestep(vm); + else + test_unsupported_singlestep(vm); +} + static void test_introspection(struct kvm_vm *vm) { srandom(time(0)); @@ -1853,6 +1891,7 @@ static void test_introspection(struct kvm_vm *vm) test_cmd_vcpu_control_msr(vm); test_cmd_vm_set_page_access(vm); test_event_pf(vm); + test_cmd_vcpu_control_singlestep(vm); unhook_introspection(vm); } diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index a228178ddba2..f620396d1887 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -436,6 +436,11 @@ static void kvmi_job_release_vcpu(struct kvm_vcpu *vcpu, void *ctx) atomic_set(&vcpui->pause_requests, 0); vcpui->waiting_for_reply = false; + + if (vcpui->singlestep.loop) { + kvmi_arch_stop_singlestep(vcpu); + vcpui->singlestep.loop = false; + } } static void kvmi_release_vcpus(struct kvm *kvm) @@ -1170,3 +1175,20 @@ void kvmi_remove_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); } + +bool kvmi_vcpu_running_singlestep(struct kvm_vcpu *vcpu) +{ + struct kvm_introspection *kvmi; + bool ret; + + kvmi = kvmi_get(vcpu->kvm); + if (!kvmi) + return false; + + ret = VCPUI(vcpu)->singlestep.loop; + + kvmi_put(vcpu->kvm); + + return ret; +} +EXPORT_SYMBOL(kvmi_vcpu_running_singlestep); diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index a51e7e4ed511..4815fa61b136 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -122,5 +122,7 @@ void kvmi_arch_update_page_tracking(struct kvm *kvm, void kvmi_arch_hook(struct kvm *kvm); void kvmi_arch_unhook(struct kvm *kvm); void kvmi_arch_features(struct kvmi_features *feat); +void kvmi_arch_start_singlestep(struct kvm_vcpu *vcpu); +void kvmi_arch_stop_singlestep(struct kvm_vcpu *vcpu); #endif