A Static Measurement Method for Virtual Machine Instances Throughout Their Lifecycle Based on TPCM

Abstract

This invention relates to the fields of virtualization and trusted computing technology, and discloses a static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM. A novel virtual machine lifecycle model is defined, and based on this model, a request instance measurement module is added to the processing functions of each lifecycle stage of the virtual machine to implement the measurement request initiation function; a policy file located in the local protection component is constructed to specify how to organize the instance core data used for measurement, and the hardware trusted cryptography module located in the protection component is called to perform hash operations on the instance core data. This invention solves the following three problems existing in the static measurement schemes for virtual machine instances: (1) the static measurement operation of virtual machine instances fails to cover the entire lifecycle of the virtual machine; (2) the measurement overhead caused by the expansion of virtual machine instances is too large; (3) the trusted measurement service provided by TPM is at risk of being bypassed, making it difficult to guarantee the security of the measurement operation itself.

Description

Technical Field

[0001] This invention relates to the fields of virtualization and trusted computing technology, specifically to a static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM (Trusted Platform Control Module). Background Technology

[0002] Trusted computing technology uses immutable physical chips as the hardware root of trust, constructing a trust chain from power-on to operation through step-by-step measurement and trust chain transmission. Taking Trusted Computing 2.0 as a specific example, it uses the Trusted Platform Module (TPM) as the physical root of trust, building the trust chain from bottom to top to ultimately ensure the trustworthiness of the entire computing system. However, in its design philosophy, the TPM itself is a component mounted on the computing system, and its passive invocation method is vulnerable to malicious bypass, lacking proactive control over the computing platform. Therefore, my country proposed the concept of Trusted Computing 3.0—dividing the computing system into computing components and protection components, completely separating them. The TPM, as the protection component, starts before the computing components and provides security protection and control for the computing components through a measurement-as-you-go startup method. The two communicate through a shared memory area located in the computing components—this solves the security risks of the aforementioned TPM and is also more in line with my country's independent and controllable information technology innovation concept.

[0003] QCOW2 (Qemu Copy On Write Version 2) is a virtual machine instance format commonly used in QEMU (Quick Emulator) / KVM (Kernel-based Virtual Machine). Its internal data is composed of fixed-size data clusters, and its structure can be divided into: QCOW2 header cluster, partition table cluster, and data clusters.

[0004] The cloud management center is the control center of the entire cloud platform. One of its important tasks is the distribution of policy documents. These policy documents are distributed to the protection components in the computing system, and the protection components then perform refined management actions on the computing components according to the specific provisions of the policy documents.

[0005] The virtual machine lifecycle model defines the various stages a virtual machine may be in. Existing definitions of the lifecycle model generally include the startup, running, and shutdown states of the virtual machine, but do not encompass states such as creation, suspension, and resumption. Specifically, these virtual machine states can be further divided into dynamic and static categories. Dynamic refers to the state where the virtual machine uses the host's CPU, memory, and other resources to perform operations such as disk read / write and mathematical calculations; conversely, static refers to the state where the virtual machine relinquishes the host's CPU, memory, and other resources, ceasing all operations. Therefore, virtual machine state changes can be categorized as transitioning from dynamic to static and from static to dynamic.

[0006] Static metrics for virtual machine instances based on virtual machine lifecycle state transitions are defined as follows: When a virtual machine's lifecycle state transitions from static to dynamic, a hash function is used to measure the virtual machine instance file, and the obtained metric value is compared with a baseline value stored in a secure area to verify whether the file has been corrupted. Specifically, when the virtual machine's lifecycle state transitions from dynamic to static, the newly generated metric value does not perform a baseline value comparison operation; instead, the baseline value is updated, meaning the new metric value replaces the original baseline value. The initial baseline value for the virtual machine instance is typically provided by the cloud service provider.

[0007] The existing publicly available static measurement protection solutions for virtual machine instance files mainly have the following problems:

[0008] (1) Current virtual machine instance protection solutions only perform static measurement operations on virtual machines when they are in the startup and shutdown states, ignoring the life states of virtual machines such as creation, running, suspension, recovery, and destruction, and fail to achieve virtual machine instance measurement and protection based on the entire life cycle.

[0009] (2) The measurement operations used in existing static measurement schemes for virtual machine instance files are mostly based on the cryptographic module of TPM2.0 or by calling the hash function provided by the host operating system. This poses a risk of hijacking during the hash operation process.

[0010] (3) The existing static measurement scheme for virtual machine instances adopts a holistic measurement method for virtual machine instance files. This method does not take into account the actual situation that the instance file size expands rapidly due to the long-term operation of virtual machines, and thus causes problems such as low measurement efficiency and excessive system resources consumed by measurement operations. Summary of the Invention

[0011] The purpose of this invention is to provide a static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM, addressing the problems of static measurement of virtual machine instance files failing to cover the entire virtual machine lifecycle, the measurement operation being susceptible to hijacking, and the inefficiency and system performance loss caused by hashing the entire file. The technical solution is as follows:

[0012] A static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM includes the following steps:

[0013] Step 1: Add a function module for initiating instance metrics to the processing functions of each stage of the virtual machine lifecycle; the function module is used to implement the function of requesting metrics for virtual machine instances throughout the entire lifecycle, including virtual machine creation, startup, running, suspension, suspension resumption and shutdown.

[0014] Step 2: Generate and maintain a policy file located in the local protection component to specify the data reading and organization rules for virtual machine instance files;

[0015] Step 3: According to the policy file in the local protection component, organize the core data of the instance to be measured, place it in the shared memory, and call the SM3 algorithm of the hardware trusted cryptography module in the protection component to perform measurement operations on the data located in the shared memory area and generate measurement values.

[0016] Step 4: Perform baseline value comparison or metric value update operations on the generated metric values ​​according to the dynamic and static transformation of the virtual machine's lifecycle, and control the current virtual machine based on the comparison results.

[0017] Furthermore, step 1 specifically includes:

[0018] Step 1.1: Before executing the function logic for virtual machine creation, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine is created;

[0019] Step 1.2: Before executing the function logic for starting the virtual machine, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine starts;

[0020] Step 1.3: Before executing the function logic for virtual machine suspension and resumption, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine is suspended and resumed;

[0021] Step 1.4: After executing the virtual machine suspension function logic, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance after the virtual machine is suspended;

[0022] Step 1.5: After executing the virtual machine shutdown function logic, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance after the virtual machine has completed the shutdown operation.

[0023] Furthermore, in step 2, the policy file includes:

[0024] Cluster_num is a parameter issued by the cloud management center that specifies how many groups the data cluster portion of a virtual machine instance file can be divided into.

[0025] The random number N generated by the Trusted Cryptographic Module (TCM) in the local protection component is used to specify which cluster to select from each group to form the measurement data;

[0026] An algorithm for random cluster selection based on the parameter Cluster_num and the random number N.

[0027] Furthermore, step 2 specifically includes:

[0028] Step 2.1: The cloud management center distributes policy files to the protection components of the computing system. The policy files contain the parameter Cluster_num, which controls the parsing of virtual machine instances in QCOW2 format.

[0029] Step 2.2: The hardware trusted cryptographic module (TCM) located in the protection component generates a random number N and extends the random number N into the policy file in step 2.1;

[0030] Step 2.3: Determine the algorithm for reading N random clusters and using them as the core data of the instance, where the input parameters are the Cluster_num generated in Steps 2.1 and 2.2 and the random number N, respectively. The algorithm output is the starting address of the cluster to be selected in the instance file; this algorithm will also be extended to the policy file.

[0031] Furthermore, the specific steps of the algorithm in step 2.3 are as follows:

[0032] Step 2.3.1: Accept the parameter Cluse_num generated in Steps 2.1 and 2.2, the random number N, and the memory address of the instance file as three input parameters;

[0033] Step 2.3.2: Divide the data cluster portion of the instance file into Cluster_num groups;

[0034] Step 2.3.3: Return the memory address of the Nth cluster out of the Cluster_num groups.

[0035] Furthermore, step 3 specifically includes:

[0036] Step 3.1: Add an instance parsing module to the compute component to parse the file header cluster, partition table cluster, and data cluster of the QCOW2 format virtual machine instance; and divide the data cluster according to the Cluster_num parameter specified in the policy file;

[0037] Step 3.2: Take out the Nth data cluster from the divided Cluster_num groups, and combine the data cluster with the file header cluster and partition table cluster of the QCOW2 format virtual machine instance to form the instance core data, and store it in the memory area;

[0038] Step 3.3: Organize the instance measurement command to notify the hardware cryptographic module TCM in the local protection component to perform SM3 hash operation on the instance core data located in shared memory, thereby generating the instance's measurement value.

[0039] Furthermore, step 4 specifically includes:

[0040] Step 4.1: For instance measurement requests involving the transition of virtual machines from static to dynamic states, compare the instance measurement value generated in Step 3.3 with the instance baseline value stored in the protection component to determine whether the current instance has been tampered with. If it has not been tampered with, the virtual machine continues to run; otherwise, the virtual machine is controlled.

[0041] Step 4.2: For instance measurement requests involving the transition of a virtual machine from dynamic to static, perform a baseline value update operation on the instance measurement values ​​generated in Step 3.3, replacing the original instance measurement values ​​in the baseline library with the newly generated instance measurement values, and the virtual machine continues to run.

[0042] The beneficial effects of the present invention are:

[0043] 1. This invention achieves instance measurement functionality covering the entire lifecycle of a virtual machine by instrumenting code in various lifecycle processing functions of the virtual machine;

[0044] 2. This invention generates and maintains policy files in the local protection component to define the organization process of the core data of the virtual machine instance, thereby significantly reducing the volume of data to be measured and effectively improving measurement efficiency.

[0045] 3. This invention uses the SM3 hash algorithm provided by the hardware cryptographic module located in the protection component to perform measurement operations on the core data of the virtual machine instance, thus ensuring the security and reliability of the measurement operation itself. Attached Figure Description

[0046] Figure 1 This is a flowchart of the virtual machine instance measurement process in this invention.

[0047] Figure 2 This is a schematic diagram of the entire lifecycle state of the virtual machine in this invention.

[0048] Figure 3 This is a schematic diagram illustrating the construction of the strategy file in this invention.

[0049] Figure 4 This is a schematic diagram of the core data organization of a virtual machine instance in this invention. Detailed Implementation

[0050] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0051] This invention proposes a static measurement method for virtual machine instances based on TPCM throughout their entire lifecycle. This method is a static measurement scheme for virtual machine instances based on a novel virtual machine lifecycle model, integrating Trusted Computing 3.0 technology and the QCOW2 virtual disk file format. First, code instrumentation is performed in the processing functions of each stage of the novel virtual machine lifecycle model defined in this paper to initiate virtual machine instance measurement requests. Second, a policy file located in the local protection component is generated and maintained to specify the data reading and organization rules for virtual machine instance files. Then, according to the policy file in the local protection component, the core data of the instance to be measured is organized and placed in shared memory. Next, the SM3 algorithm of the Trusted Crypto Module (TCM) in the protection component is called to perform measurement operations on the data located in the shared memory area and generate measurement values. Finally, the newly generated instance measurement values ​​are compared with the baseline values ​​stored in the protection component, and the current virtual machine is controlled based on the comparison results.

[0052] like Figure 1 As shown in the diagram, the instance measurement process of this invention has the following basic flow:

[0053] (1) The virtual machine lifecycle state handling function initiates a request for instance measurement;

[0054] (2) The instance parsing module parses the virtual machine instance to obtain the header partition cluster, partition table cluster and data cluster;

[0055] (3) Organize the instance core data according to the policy file stored in the local protection component and place it in the shared memory area;

[0056] (4) Call the hardware cryptographic module TCM located in the local protection component to perform measurement operations on the core data of the instance;

[0057] (5) Determine whether the benchmark value comparison is performed for this instance measurement. If yes, proceed to steps (6) and (7); otherwise, proceed to step (8).

[0058] (6) Verify the obtained measurement values ​​against the baseline values ​​to determine whether the instance files have been tampered with;

[0059] (7) Intervene in the currently running virtual machine based on the verification results—if it is proven that the instance file has not been tampered with, the virtual machine continues to run; otherwise, the virtual machine is subject to appropriate control.

[0060] (8) Update the baseline value and the virtual machine continues to run.

[0061] The specific implementation steps are as follows:

[0062] Step 1: Add a function module for requesting instance measurement to the function logic of each stage of the virtual machine's lifecycle.

[0063] Analysis of the QEMU virtualization software source code revealed that by initiating a measurement request for the virtual machine instance before executing the function logic for creating, starting, suspending and resuming the virtual machine, and after executing the function logic for shutting down and suspending the virtual machine, instance protection can be achieved throughout the entire lifecycle of the virtual machine, including its creation, startup, suspension, suspension and resumption, and shutdown.

[0064] Step 1.1: Before executing the function logic for virtual machine creation, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine is created.

[0065] Step 1.2: Before executing the function logic for starting the virtual machine, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine starts.

[0066] Step 1.3: Before executing the function logic for virtual machine suspension and resumption, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine is suspended and resumed.

[0067] Step 1.4: After executing the virtual machine suspension function logic, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance after the virtual machine is suspended.

[0068] Step 1.5: After executing the virtual machine shutdown function logic, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance after the virtual machine has completed the shutdown operation.

[0069] like Figure 2 As shown in the diagram, the virtual machine's full lifecycle state is defined in this invention, and its basic principle is as follows:

[0070] The entire lifecycle of a virtual machine includes six states: creation, startup, running, suspension, suspension resume, and shutdown. Except for the creation and shutdown states, the other states exhibit a linear relationship—the transitions between states must be performed sequentially.

[0071] Step 2: Build and store the policy file in the protection component to control the reading of virtual machine instance data.

[0072] The policy file mainly consists of three parts: first, the parameter Cluster_num, issued by the cloud management center, which specifies how many groups the QCOW2 virtual disk file can be divided into; second, the random number N, randomly generated by the Trusted Cryptography Module (TCM) located in the local protection component, which specifies which cluster in each group is selected as the core data for measurement; and third, the algorithm for randomly selecting clusters based on the parameter Cluster_num and the random number N.

[0073] Step 2.1: The cloud management center distributes the policy file to the protection component of the computing system. The policy file contains the parameter Cluster_num, which controls the resolution of virtual machine instances (QCOW2 format) and specifies the number of groups that the virtual machine instance should be resolved to.

[0074] Step 2.2: The Hardware Trusted Cryptography Module (TCM) located in the protection component generates a random number N—used to control the offset of the cluster that the instance metric needs to read—and extends this random number into the policy file in Step 2.1.

[0075] Step 2.3: Determine the algorithm for reading the core data of N random clusters used as metrics, where the input parameters are Cluster_num and N generated in steps 2.1 and 2.2, respectively, and the algorithm output is the starting address of the cluster to be selected in the instance file. This algorithm will also be extended to the strategy file in step 2.1.

[0076] The specific steps of this algorithm are as follows:

[0077] Step 2.3.1: Accept the parameter Cluse_num generated in Steps 2.1 and 2.2, the random number N, and the memory address of the instance file as three input parameters;

[0078] Step 2.3.2: Divide the data cluster portion of the instance file into Cluster_num groups;

[0079] Step 2.3.3: Return the memory address of the Nth cluster out of the Cluster_num groups.

[0080] Step 3: Organize the core data of the virtual machine instances used for measurement according to the policy file generated in Step 2.

[0081] The QCOW2 format virtual machine instance file is divided into data clusters according to the policy file in step 2. Then, a random number of clusters are selected from each group to form the instance core data and placed in the shared memory area that communicates with the local protection component. The hardware trusted cryptographic module in the protection component reads the instance core data located in the shared memory through direct memory access technology and calls the SM3 hash algorithm to perform a hash operation to generate a metric value.

[0082] like Figure 3 As shown in the diagram, the basic principle of constructing the strategy file in this invention is as follows:

[0083] The policy file stored in the local protection component is used to instruct how to organize the core data of the instance in order to solve the problem of excessive overhead caused by the measurement operation of the entire instance file. The policy file consists of three parts: (1) a parameter Cluster_num issued by the cloud management center to set how many groups the data clusters in the original instance are divided into; (2) a random number N generated by the hardware TCM to randomly select the Nth data cluster from the divided Cluster_num groups; (3) an algorithm for random cluster selection based on parameters (1) and (2), and the algorithm output is the starting address of the selected cluster in the memory address space. The specific steps are as follows:

[0084] Step 3.1: Add an instance parsing module to the computing component. Its main functions are: (1) parsing the file header cluster and partition table cluster of the QCOW2 instance; (2) dividing the remaining data clusters according to the Cluster_num parameter specified in the strategy file in Step 2.1.

[0085] Step 3.2: From the divided Cluster_num groups, according to the policy file specified in Step 2.2, take out the Nth data cluster, and combine it with the file header cluster and partition table cluster of the QCOW2 instance to form the "instance core data", and store it in the memory area.

[0086] Step 3.3: Organize the instance measurement command to notify the hardware cryptographic module TCM in the local protection component to perform SM3 hash operation on the "instance core data" located in shared memory, thereby generating the measurement value.

[0087] Step 4: Perform either a baseline comparison operation or a metric update operation on the generated metrics according to the dynamic and static states of the virtual machine's lifecycle. The baseline comparison is used to verify whether the current virtual machine instance has been tampered with; the metric update operation replaces the baseline values ​​in the baseline library with the newly generated metrics.

[0088] Step 4.1: The virtual machine instance measurement requests initiated by Steps 1.1, 1.2, and 1.3 above involve the situation mentioned above where the virtual machine changes from static to dynamic. Therefore, the instance measurement value generated in Step 3.3 above will be compared with the instance baseline value stored in the protection component to determine whether the current virtual machine instance has been tampered with. If it has not been tampered with, the virtual machine will continue to run; otherwise, the virtual machine will be controlled.

[0089] Step 4.2: The instance measurement request initiated by Steps 1.4 and 1.5 above involves the situation of the virtual machine changing from dynamic to static as mentioned above. Therefore, the instance measurement value generated in Step 3.3 above will perform a baseline value update operation - the original instance measurement value located in the baseline library will be replaced with the new instance measurement value generated this time, and the virtual machine will continue to execute.

[0090] like Figure 4 This is a schematic diagram of the core data organization in an example of the present invention, and its basic principle is as follows:

[0091] (1) First, identify the header partition cluster, partition table cluster and data cluster of the QCOW2 virtual disk format instance file; (2) Divide and select the data cluster according to the policy file; (3) Organize the header partition cluster, partition table cluster and selected cluster into "instance core data".

Claims

1. A static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM, characterized in that, Includes the following steps: Step 1: Add a function module for initiating instance metrics to the processing functions of each stage of the virtual machine lifecycle; the function module is used to implement the function of requesting metrics for virtual machine instances throughout the entire lifecycle, including virtual machine creation, startup, running, suspension, suspension resumption and shutdown. Step 2: Generate and maintain a policy file located in the local protection component to specify the data reading and organization rules for virtual machine instance files; Step 3: According to the policy file in the local protection component, organize the core data of the instance to be measured, place it in the shared memory, and call the SM3 algorithm of the hardware trusted cryptography module in the protection component to perform measurement operations on the data located in the shared memory area and generate measurement values. Step 4: Perform baseline value comparison or metric value update operations on the generated metric values ​​according to the dynamic and static transformation of the virtual machine's lifecycle, and control the current virtual machine based on the comparison results.

2. The static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM according to claim 1, characterized in that, Step 1 specifically involves: Step 1.1: Before executing the function logic for virtual machine creation, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine is created; Step 1.2: Before executing the function logic for starting the virtual machine, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine starts; Step 1.3: Before executing the function logic for virtual machine suspension and resumption, add a function module for requesting virtual machine instance metrics, which is used to initiate a metric request to the instance before the virtual machine is suspended and resumed; Step 1.4: After executing the virtual machine suspension function logic, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance after the virtual machine is suspended; Step 1.5: After executing the virtual machine shutdown function logic, add a function module to request virtual machine instance metrics, which is used to initiate a metric request to the instance after the virtual machine has completed the shutdown operation.

3. The static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM according to claim 1, characterized in that, In step 2, the policy file includes: Cluster_num is a parameter issued by the cloud management center that specifies how many groups the data cluster portion of a virtual machine instance file can be divided into. The random number N generated by the Trusted Cryptographic Module (TCM) in the local protection component is used to specify which cluster to select from each group to form the measurement data; An algorithm for random cluster selection based on the parameter Cluster_num and the random number N.

4. The static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM according to claim 2, characterized in that, Step 2 specifically involves: Step 2.1: The cloud management center distributes policy files to the protection components of the computing system. The policy files contain the parameter Cluster_num, which controls the parsing of virtual machine instances in QCOW2 format. Step 2.2: The hardware trusted cryptographic module (TCM) located in the protection component generates a random number N and extends the random number N into the policy file in step 2.1; Step 2.3: Determine the algorithm for reading N random clusters and using them as the core data of the instance, where the input parameters are the Cluster_num generated in Steps 2.1 and 2.2 and the random number N, respectively. The algorithm output is the starting address of the cluster to be selected in the instance file; this algorithm will also be extended to the policy file.

5. The static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM according to claim 4, characterized in that, The specific steps of the algorithm in step 2.3 are as follows: Step 2.3.1: Accept the parameter Cluse_num generated in Steps 2.1 and 2.2, the random number N, and the memory address of the instance file as three input parameters; Step 2.3.2: Divide the data cluster portion of the instance file into Cluster_num groups; Step 2.3.3: Return the memory address of the Nth cluster out of the Cluster_num groups.

6. The static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM according to claim 4, characterized in that, Step 3 specifically involves: Step 3.1: Add an instance parsing module to the compute component to parse the file header cluster, partition table cluster, and data cluster of the QCOW2 format virtual machine instance; and divide the data cluster according to the Cluster_num parameter specified in the policy file; Step 3.2: Take out the Nth data cluster from the divided Cluster_num groups, and combine the data cluster with the file header cluster and partition table cluster of the QCOW2 format virtual machine instance to form the instance core data, and store it in the memory area; Step 3.3: Organize the instance measurement command to notify the hardware cryptographic module TCM in the local protection component to perform SM3 hash operation on the instance core data located in shared memory, thereby generating the instance's measurement value.

7. The static measurement method for virtual machine instances throughout their entire lifecycle based on TPCM according to claim 6, characterized in that, Step 4 specifically involves: Step 4.1: For instance measurement requests involving the transition of virtual machines from static to dynamic states, compare the instance measurement value generated in Step 3.3 with the instance baseline value stored in the protection component to determine whether the current instance has been tampered with. If it has not been tampered with, the virtual machine continues to run; otherwise, the virtual machine is controlled. Step 4.2: For instance measurement requests involving the transition of a virtual machine from dynamic to static, perform a baseline value update operation on the instance measurement values ​​generated in Step 3.3, replacing the original instance measurement values ​​in the baseline library with the newly generated instance measurement values, and the virtual machine continues to run.

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