From patchwork Mon Dec 7 20:45:49 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: 11956737 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=-13.7 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 13FBEC4167B for ; Mon, 7 Dec 2020 20:48:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4D22238A0 for ; Mon, 7 Dec 2020 20:48:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727320AbgLGUs3 (ORCPT ); Mon, 7 Dec 2020 15:48:29 -0500 Received: from mx01.bbu.dsd.mx.bitdefender.com ([91.199.104.161]:42562 "EHLO mx01.bbu.dsd.mx.bitdefender.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727293AbgLGUs2 (ORCPT ); Mon, 7 Dec 2020 15:48:28 -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 4CC1A305D46F; Mon, 7 Dec 2020 22:46:20 +0200 (EET) Received: from localhost.localdomain (unknown [91.199.104.27]) by smtp.bitdefender.com (Postfix) with ESMTPSA id 291BC3072784; Mon, 7 Dec 2020 22:46:20 +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 v11 48/81] KVM: introspection: add KVMI_VM_PAUSE_VCPU Date: Mon, 7 Dec 2020 22:45:49 +0200 Message-Id: <20201207204622.15258-49-alazar@bitdefender.com> In-Reply-To: <20201207204622.15258-1-alazar@bitdefender.com> References: <20201207204622.15258-1-alazar@bitdefender.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This command increments a pause requests counter for a vCPU and kicks it out of guest. The introspection tool can pause a VM by sending this command for all vCPUs. If it sets 'wait=1', it can consider that the VM is paused when it receives the reply for the last KVMI_VM_PAUSE_VCPU command. Signed-off-by: Adalbert Lazăr --- Documentation/virt/kvm/kvmi.rst | 39 +++++++++++++++ include/linux/kvmi_host.h | 2 + include/uapi/linux/kvmi.h | 8 ++++ .../testing/selftests/kvm/x86_64/kvmi_test.c | 30 ++++++++++++ virt/kvm/introspection/kvmi.c | 47 +++++++++++++++++-- virt/kvm/introspection/kvmi_int.h | 1 + virt/kvm/introspection/kvmi_msg.c | 24 ++++++++++ 7 files changed, 147 insertions(+), 4 deletions(-) diff --git a/Documentation/virt/kvm/kvmi.rst b/Documentation/virt/kvm/kvmi.rst index 902ced4dd0c4..a71fb78d546e 100644 --- a/Documentation/virt/kvm/kvmi.rst +++ b/Documentation/virt/kvm/kvmi.rst @@ -470,6 +470,45 @@ Returns the TSC frequency (in HZ) for the specified vCPU if available * -KVM_EINVAL - the selected vCPU is invalid * -KVM_EAGAIN - the selected vCPU can't be introspected yet +9. KVMI_VM_PAUSE_VCPU +--------------------- + +:Architectures: all +:Versions: >= 1 +:Parameters: + +:: + + struct kvmi_vm_pause_vcpu { + __u16 vcpu; + __u8 wait; + __u8 padding1; + __u32 padding2; + }; + +:Returns: + +:: + + struct kvmi_error_code; + +Kicks the vCPU out of guest. + +If `wait` is 1, the command will wait for vCPU to acknowledge the IPI. + +The vCPU will handle the pending commands/events and send the +*KVMI_VCPU_EVENT_PAUSE* event (one for every successful *KVMI_VM_PAUSE_VCPU* +command) before returning to guest. + +:Errors: + +* -KVM_EINVAL - the padding is not zero +* -KVM_EINVAL - the selected vCPU is invalid +* -KVM_EAGAIN - the selected vCPU can't be introspected yet +* -KVM_EBUSY - the selected vCPU has too many queued + *KVMI_VCPU_EVENT_PAUSE* events +* -KVM_EPERM - the *KVMI_VCPU_EVENT_PAUSE* event is disallowed + Events ====== diff --git a/include/linux/kvmi_host.h b/include/linux/kvmi_host.h index 736edb400c05..59e645d9ea34 100644 --- a/include/linux/kvmi_host.h +++ b/include/linux/kvmi_host.h @@ -18,6 +18,8 @@ struct kvm_vcpu_introspection { struct list_head job_list; spinlock_t job_lock; + + atomic_t pause_requests; }; struct kvm_introspection { diff --git a/include/uapi/linux/kvmi.h b/include/uapi/linux/kvmi.h index da766427231e..bb90d03f059b 100644 --- a/include/uapi/linux/kvmi.h +++ b/include/uapi/linux/kvmi.h @@ -26,6 +26,7 @@ enum { KVMI_VM_CONTROL_EVENTS = KVMI_VM_MESSAGE_ID(5), KVMI_VM_READ_PHYSICAL = KVMI_VM_MESSAGE_ID(6), KVMI_VM_WRITE_PHYSICAL = KVMI_VM_MESSAGE_ID(7), + KVMI_VM_PAUSE_VCPU = KVMI_VM_MESSAGE_ID(8), KVMI_NEXT_VM_MESSAGE }; @@ -115,4 +116,11 @@ struct kvmi_vcpu_hdr { __u32 padding2; }; +struct kvmi_vm_pause_vcpu { + __u16 vcpu; + __u8 wait; + __u8 padding1; + __u32 padding2; +}; + #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 9350ba8b7f9b..52765ca3f9c8 100644 --- a/tools/testing/selftests/kvm/x86_64/kvmi_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvmi_test.c @@ -671,6 +671,35 @@ static void test_cmd_vcpu_get_info(struct kvm_vm *vm) &rpl, sizeof(rpl), -KVM_EINVAL); } +static void cmd_vcpu_pause(__u8 wait, int expected_err) +{ + struct { + struct kvmi_msg_hdr hdr; + struct kvmi_vm_pause_vcpu cmd; + } req = {}; + __u16 vcpu_idx = 0; + + req.cmd.wait = wait; + req.cmd.vcpu = vcpu_idx; + + test_vm_command(KVMI_VM_PAUSE_VCPU, &req.hdr, sizeof(req), NULL, 0, expected_err); +} + +static void pause_vcpu(void) +{ + cmd_vcpu_pause(1, 0); +} + +static void test_pause(struct kvm_vm *vm) +{ + __u8 wait = 1, wait_inval = 2; + + pause_vcpu(); + + cmd_vcpu_pause(wait, 0); + cmd_vcpu_pause(wait_inval, -KVM_EINVAL); +} + static void test_introspection(struct kvm_vm *vm) { srandom(time(0)); @@ -686,6 +715,7 @@ static void test_introspection(struct kvm_vm *vm) test_cmd_vm_control_events(vm); test_memory_access(vm); test_cmd_vcpu_get_info(vm); + test_pause(vm); unhook_introspection(vm); } diff --git a/virt/kvm/introspection/kvmi.c b/virt/kvm/introspection/kvmi.c index 95677cb9a657..904362d00e62 100644 --- a/virt/kvm/introspection/kvmi.c +++ b/virt/kvm/introspection/kvmi.c @@ -17,6 +17,8 @@ #define KVMI_MSG_SIZE_ALLOC (sizeof(struct kvmi_msg_hdr) + KVMI_MAX_MSG_SIZE) +#define MAX_PAUSE_REQUESTS 1001 + static DECLARE_BITMAP(Kvmi_always_allowed_commands, KVMI_NUM_COMMANDS); static DECLARE_BITMAP(Kvmi_known_events, KVMI_NUM_EVENTS); static DECLARE_BITMAP(Kvmi_known_vm_events, KVMI_NUM_EVENTS); @@ -124,10 +126,14 @@ void kvmi_uninit(void) kvmi_cache_destroy(); } -static void kvmi_make_request(struct kvm_vcpu *vcpu) +static void kvmi_make_request(struct kvm_vcpu *vcpu, bool wait) { kvm_make_request(KVM_REQ_INTROSPECTION, vcpu); - kvm_vcpu_kick(vcpu); + + if (wait) + kvm_vcpu_kick_and_wait(vcpu); + else + kvm_vcpu_kick(vcpu); } static int __kvmi_add_job(struct kvm_vcpu *vcpu, @@ -162,7 +168,7 @@ int kvmi_add_job(struct kvm_vcpu *vcpu, err = __kvmi_add_job(vcpu, fct, ctx, free_fct); if (!err) - kvmi_make_request(vcpu); + kvmi_make_request(vcpu, false); return err; } @@ -359,6 +365,9 @@ static int __kvmi_hook(struct kvm *kvm, static void kvmi_job_release_vcpu(struct kvm_vcpu *vcpu, void *ctx) { + struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu); + + atomic_set(&vcpui->pause_requests, 0); } static void kvmi_release_vcpus(struct kvm *kvm) @@ -731,15 +740,45 @@ void kvmi_run_jobs(struct kvm_vcpu *vcpu) } } +static void kvmi_vcpu_pause_event(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu); + + atomic_dec(&vcpui->pause_requests); + /* to be implemented */ +} + void kvmi_handle_requests(struct kvm_vcpu *vcpu) { + struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu); struct kvm_introspection *kvmi; kvmi = kvmi_get(vcpu->kvm); if (!kvmi) return; - kvmi_run_jobs(vcpu); + for (;;) { + kvmi_run_jobs(vcpu); + + if (atomic_read(&vcpui->pause_requests)) + kvmi_vcpu_pause_event(vcpu); + else + break; + } kvmi_put(vcpu->kvm); } + +int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait) +{ + struct kvm_vcpu_introspection *vcpui = VCPUI(vcpu); + + if (atomic_read(&vcpui->pause_requests) > MAX_PAUSE_REQUESTS) + return -KVM_EBUSY; + + atomic_inc(&vcpui->pause_requests); + + kvmi_make_request(vcpu, wait); + + return 0; +} diff --git a/virt/kvm/introspection/kvmi_int.h b/virt/kvm/introspection/kvmi_int.h index 126e72201518..f1caa67dbdc3 100644 --- a/virt/kvm/introspection/kvmi_int.h +++ b/virt/kvm/introspection/kvmi_int.h @@ -55,6 +55,7 @@ int kvmi_cmd_read_physical(struct kvm *kvm, u64 gpa, size_t size, const struct kvmi_msg_hdr *ctx); int kvmi_cmd_write_physical(struct kvm *kvm, u64 gpa, size_t size, const void *buf); +int kvmi_cmd_vcpu_pause(struct kvm_vcpu *vcpu, bool wait); /* arch */ void kvmi_arch_init_vcpu_events_mask(unsigned long *supported); diff --git a/virt/kvm/introspection/kvmi_msg.c b/virt/kvm/introspection/kvmi_msg.c index 0c12b7c53a9e..8d87ba16eb12 100644 --- a/virt/kvm/introspection/kvmi_msg.c +++ b/virt/kvm/introspection/kvmi_msg.c @@ -245,6 +245,29 @@ static int handle_vm_write_physical(struct kvm_introspection *kvmi, return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0); } +static int handle_vm_pause_vcpu(struct kvm_introspection *kvmi, + const struct kvmi_msg_hdr *msg, + const void *_req) +{ + const struct kvmi_vm_pause_vcpu *req = _req; + struct kvm_vcpu *vcpu; + int ec; + + if (req->wait > 1 || req->padding1 || req->padding2) { + ec = -KVM_EINVAL; + goto reply; + } + + vcpu = kvmi_get_vcpu(kvmi, req->vcpu); + if (!vcpu) + ec = -KVM_EINVAL; + else + ec = kvmi_cmd_vcpu_pause(vcpu, req->wait == 1); + +reply: + return kvmi_msg_vm_reply(kvmi, msg, ec, NULL, 0); +} + /* * These commands are executed by the receiving thread. */ @@ -254,6 +277,7 @@ static kvmi_vm_msg_fct const msg_vm[] = { [KVMI_VM_CHECK_EVENT] = handle_vm_check_event, [KVMI_VM_CONTROL_EVENTS] = handle_vm_control_events, [KVMI_VM_GET_INFO] = handle_vm_get_info, + [KVMI_VM_PAUSE_VCPU] = handle_vm_pause_vcpu, [KVMI_VM_READ_PHYSICAL] = handle_vm_read_physical, [KVMI_VM_WRITE_PHYSICAL] = handle_vm_write_physical, };