From patchwork Wed Nov 25 09:35:29 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: 11930799 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 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 403ACC63777 for ; Wed, 25 Nov 2020 09:41:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8A21206F9 for ; Wed, 25 Nov 2020 09:41:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727942AbgKYJl4 (ORCPT ); Wed, 25 Nov 2020 04:41:56 -0500 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:57094 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726620AbgKYJlz (ORCPT ); Wed, 25 Nov 2020 04:41:55 -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 E785C305D49A; Wed, 25 Nov 2020 11:35:50 +0200 (EET) Received: from localhost.localdomain (unknown [91.199.104.27]) by smtp.bitdefender.com (Postfix) with ESMTPSA id C5CE63072784; Wed, 25 Nov 2020 11:35:50 +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?q?Adalbert_Laz=C4=83r?= Subject: [PATCH v10 50/81] KVM: introspection: add KVMI_VCPU_EVENT_PAUSE Date: Wed, 25 Nov 2020 11:35:29 +0200 Message-Id: <20201125093600.2766-51-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 This event is sent by the vCPU thread as a response to the KVMI_VM_PAUSE_VCPU command, but it has a lower priority, being sent after any other introspection event and when no other introspection command is queued. The number of KVMI_VCPU_EVENT_PAUSE will match the number of successful KVMI_VM_PAUSE_VCPU commands. Signed-off-by: Adalbert Lazăr --- Documentation/virt/kvm/kvmi.rst | 26 ++++++++ include/uapi/linux/kvmi.h | 2 + .../testing/selftests/kvm/x86_64/kvmi_test.c | 65 ++++++++++++++++++- virt/kvm/introspection/kvmi.c | 26 +++++++- virt/kvm/introspection/kvmi_int.h | 1 + virt/kvm/introspection/kvmi_msg.c | 18 +++++ 6 files changed, 136 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 5e99baf7e2f3..c86c83566c3d 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -596,3 +596,29 @@ the guest (see **Unhooking**) and the introspection has been enabled for this event (see **KVMI_VM_CONTROL_EVENTS**). The introspection tool has a chance to unhook and close the introspection socket (signaling that the operation can proceed). + +2. KVMI_VCPU_EVENT_PAUSE +------------------------ + +:Architectures: all +:Versions: >= 1 +:Actions: CONTINUE, CRASH +:Parameters: + +:: + + struct kvmi_event_hdr; + struct kvmi_vcpu_event; + +:Returns: + +:: + + struct kvmi_vcpu_hdr; + struct kvmi_vcpu_event_reply; + +This event is sent in response to a *KVMI_VCPU_PAUSE* command and +cannot be controlled with *KVMI_VCPU_CONTROL_EVENTS*. +Because it has a low priority, it will be sent after any other vCPU +introspection event and when no other vCPU introspection command is +queued. diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index 6a57efb5664d..757d4b84f473 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -50,6 +50,8 @@ enum { }; enum { + KVMI_VCPU_EVENT_PAUSE = KVMI_VCPU_EVENT_ID(0), + KVMI_NEXT_VCPU_EVENT }; diff --git a/tools/testing/selftests/kvm/x86_64/kvmi_test.c b/tools/testing/selftests/kvm/x86_64/kvmi_test.c index 52765ca3f9c8..4c9dc6560ad9 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -34,6 +34,17 @@ static vm_paddr_t test_gpa; static int page_size; +struct vcpu_event { + struct kvmi_event_hdr hdr; + struct kvmi_vcpu_event common; +}; + +struct vcpu_reply { + struct kvmi_msg_hdr hdr; + struct kvmi_vcpu_hdr vcpu_hdr; + struct kvmi_vcpu_event_reply reply; +}; + struct vcpu_worker_data { struct kvm_vm *vm; int vcpu_id; @@ -690,14 +701,66 @@ static void pause_vcpu(void) cmd_vcpu_pause(1, 0); } +static void reply_to_event(struct kvmi_msg_hdr *ev_hdr, struct vcpu_event *ev, + __u8 action, struct vcpu_reply *rpl, size_t rpl_size) +{ + ssize_t r; + + rpl->hdr.id = ev_hdr->id; + rpl->hdr.seq = ev_hdr->seq; + rpl->hdr.size = rpl_size - sizeof(rpl->hdr); + + rpl->vcpu_hdr.vcpu = ev->common.vcpu; + + rpl->reply.action = action; + rpl->reply.event = ev->hdr.event; + + r = send(Userspace_socket, rpl, rpl_size, 0); + TEST_ASSERT(r == rpl_size, + "send() failed, sending %zd, result %zd, errno %d (%s)\n", + rpl_size, r, errno, strerror(errno)); +} + +static void receive_vcpu_event(struct kvmi_msg_hdr *msg_hdr, + struct vcpu_event *ev, + size_t ev_size, u16 ev_id) +{ + receive_event(msg_hdr, KVMI_VCPU_EVENT, + &ev->hdr, ev_id, ev_size); +} + +static void discard_pause_event(struct kvm_vm *vm) +{ + struct vcpu_worker_data data = {.vm = vm, .vcpu_id = VCPU_ID}; + struct vcpu_reply rpl = {}; + struct kvmi_msg_hdr hdr; + pthread_t vcpu_thread; + struct vcpu_event ev; + + vcpu_thread = start_vcpu_worker(&data); + + receive_vcpu_event(&hdr, &ev, sizeof(ev), KVMI_VCPU_EVENT_PAUSE); + + reply_to_event(&hdr, &ev, KVMI_EVENT_ACTION_CONTINUE, + &rpl, sizeof(rpl)); + + wait_vcpu_worker(vcpu_thread); +} + static void test_pause(struct kvm_vm *vm) { - __u8 wait = 1, wait_inval = 2; + __u8 no_wait = 0, wait = 1, wait_inval = 2; pause_vcpu(); + discard_pause_event(vm); cmd_vcpu_pause(wait, 0); + discard_pause_event(vm); cmd_vcpu_pause(wait_inval, -KVM_EINVAL); + + disallow_event(vm, KVMI_VCPU_EVENT_PAUSE); + cmd_vcpu_pause(no_wait, -KVM_EPERM); + allow_event(vm, KVMI_VCPU_EVENT_PAUSE); } static void test_introspection(struct kvm_vm *vm) diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index 771e6b545698..3d26a7319fb7 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -103,6 +103,7 @@ static void kvmi_init_known_events(void) bitmap_zero(Kvmi_known_vcpu_events, KVMI_NUM_EVENTS); kvmi_arch_init_vcpu_events_mask(Kvmi_known_vcpu_events); + set_bit(KVMI_VCPU_EVENT_PAUSE, Kvmi_known_vcpu_events); bitmap_or(Kvmi_known_events, Kvmi_known_vm_events, Kvmi_known_vcpu_events, KVMI_NUM_EVENTS); @@ -740,12 +741,35 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu) } } +static void kvmi_handle_unsupported_event_action(struct kvm *kvm) +{ + kvmi_sock_shutdown(KVMI(kvm)); +} + +void kvmi_handle_common_event_actions(struct kvm_vcpu *vcpu, u32 action) +{ + struct kvm *kvm = vcpu->kvm; + + switch (action) { + default: + kvmi_handle_unsupported_event_action(kvm); + } +} + static void kvmi_vcpu_pause_event(struct kvm_vcpu *vcpu) { struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu); + u32 action; atomic_dec(&vcpui->pause_requests); - /* to be implemented */ + + action = kvmi_msg_send_vcpu_pause(vcpu); + switch (action) { + case KVMI_EVENT_ACTION_CONTINUE: + break; + default: + kvmi_handle_common_event_actions(vcpu, action); + } } void kvmi_handle_requests(struct kvm_vcpu *vcpu) diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index 65d8c1c37796..0876740dfa24 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -38,6 +38,7 @@ int kvmi_send_vcpu_event(struct kvm_vcpu *vcpu, u32 ev_id, int kvmi_msg_vcpu_reply(const struct kvmi_vcpu_msg_job *job, const struct kvmi_msg_hdr *msg, int err, const void *rpl, size_t rpl_size); +u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu); /* kvmi.c */ void *kvmi_msg_alloc(void); diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c index 467c88185be1..71a28e26d382 100644 --- a/virt/kvm/introspection/kvmi_msg.c +++ b/virt/kvm/introspection/kvmi_msg.c @@ -258,6 +258,11 @@ static int handle_vm_pause_vcpu(struct kvm_introspection *kvmi, goto reply; } + if (!kvmi_is_event_allowed(kvmi, KVMI_VCPU_EVENT_PAUSE)) { + err = -KVM_EPERM; + goto reply; + } + vcpu = kvmi_get_vcpu(kvmi, req->vcpu); if (!vcpu) err = -KVM_EINVAL; @@ -697,3 +702,16 @@ int kvmi_send_vcpu_event(struct kvm_vcpu *vcpu, u32 ev_id, return err; } + +u32 kvmi_msg_send_vcpu_pause(struct kvm_vcpu *vcpu) +{ + u32 action; + int err; + + err = kvmi_send_vcpu_event(vcpu, KVMI_VCPU_EVENT_PAUSE, NULL, 0, + NULL, 0, &action); + if (err) + return KVMI_EVENT_ACTION_CONTINUE; + + return action; +}