JP2009157731A - Virtual computer system and control method of virtual computer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To share one network device from a plurality of OSs, to avoid performance deterioration by a copy operation also in transmission/reception of data, and to make an excess buffer unnecessary regarding a virtual machine system in which the plurality of OSs operate. <P>SOLUTION: The virtual machine system includes: the plurality of operating systems 1, 2; the network device 3 which transmits/receives the data with an external network; a plurality of device drivers 1a, 2a which are provided corresponding to each of the respective operating systems to control the network device based on instructions of the operating systems; and a virtual device 4 which receives the instructions from the respective device drivers to control the network device according to the respective instructions, and meanwhile, receives interruption instructions from the network devices to interrupt the respective device drivers. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a virtual computer system and a control method for the virtual computer system that can control the same peripheral device from a plurality of operating systems.

  In general, a virtual machine system in which a plurality of operating systems (hereinafter simply referred to as “OS”) operates is designed so that a plurality of OSs do not access the same peripheral device at the same time. In other words, either one of the OSs is always occupied and used, or each OS is used exclusively in a time division manner to share the peripheral device.

  As an example of the latter, for example, a technique disclosed in JP-A-7-225694 is known. In this technology, on the virtual machine monitor, each OS is monitored to access the peripheral device, and the management table storing the current usage status of the peripheral device is used to allow exclusive access in a time division manner. Peripheral devices can be shared by multiple OSs. An example of a virtual machine system is VMWARE (registered trademark), which allows a plurality of OSs to share peripheral devices.

  FIG. 5 is a block diagram showing an example of a conventional system configuration. This system includes an OS 40, a device driver for the OS 40, and a network device 42. The device driver 40 includes a buffer 41a, an interrupt management unit 41b, and a pointer management unit 41c. The network device 42 includes a register 42a, an interrupt management unit 42b, and a transmission / reception buffer 42c. The transmission / reception buffer 42c is a ring buffer in which the beginning and end of the memory array are logically connected. In FIG. 5, R is a device driver read start pointer, and W is a device driver write start pointer.

  FIG. 6 is a block diagram schematically showing a conventional system. In this system, a CPU 50, a main memory 51, and a network device 42 are connected via a system bus 52. The network device 42 includes a transmission / reception buffer 42c. The data transmission / reception process of the network device 42 is performed as follows. That is, as shown in FIG. 6, the data transmission / reception buffer secured in the main memory 51 by the system and the data transmission / reception buffer 42c of the network device 42 are connected via the system bus 52, and between the two buffers. Data is transmitted and received. The network device 42 is connected to an external network via the physical MAC / PHY layer of the network device 42 to transmit / receive data. Data transmission / reception by the system is realized by exchanging data between the buffer 51 secured by the system and the data transmission / reception buffer 42c of the network device 42, and the network device 42 transmits / receives data to / from an external network. The

In order to transmit data, the system copies data to be transmitted from the data transmission / reception buffer 51 of the system to the data transmission / reception buffer 42c of the network device 42. Then, the network device 42 transmits data to an external network. Conversely, in order for the system to acquire data, the data is copied from the data transmission / reception buffer 42 c of the network device 42 to the system data transmission / reception buffer 51. In advance, the network device 42 acquires data addressed to itself from an external network and stores it in the data transmission / reception buffer 42c for the network device.
JP-A-7-225694

  However, in the technique disclosed in Japanese Patent Laid-Open No. 7-225694, for example, a peripheral device such as a network device, I2C, IEEE, or FDDI performs processing for which OS when data is received. I can't decide what to do. For this reason, this technique cannot be applied when receiving data.

  In addition, VMWARE, which is an example of a virtual machine, can be shared by a plurality of OSs with respect to, for example, a network device. However, at the time of data transmission / reception, the network device buffer is not directly exchanged, and a copy operation is performed once for the virtual device. For this reason, performance degradation has occurred. In addition, it is necessary to secure an extra buffer for the copy operation in the virtual device.

  The present invention has been made in view of such circumstances, and relates to a virtual computer system in which a plurality of OSs operate. The same network device is shared from a plurality of OSs, and data is transmitted and received by a copy operation. It is an object of the present invention to provide a virtual machine system and a control method for the virtual machine system that do not cause performance degradation and can eliminate an unnecessary buffer.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, the virtual machine system of the present invention is provided corresponding to each of a plurality of operating systems, a network device for transmitting / receiving data to / from an external network, and each of the operating systems, and based on instructions of the operating system, A plurality of device drivers for controlling the network device and instructions from the device drivers, and controlling the network device according to the instructions, while receiving an interrupt instruction from the network device, the device drivers And a virtual device that interrupts the device.

  In this way, the virtual device receives instructions from each device driver and controls the network device according to each instruction, while receiving an interrupt instruction from the network device and interrupting each device driver, Data receiving operation can be performed by a plurality of operating systems.

  (2) A virtual machine system according to the present invention is provided corresponding to each of a plurality of operating systems, a network device for transmitting / receiving data to / from an external network, and each of the operating systems. A plurality of device drivers for controlling the network device, and the network device receives instructions from the device drivers and controls the network device according to the instructions, while the network device A virtual device that receives an interrupt instruction from the device and interrupts each of the device drivers.

  As described above, the virtual device included in the network device receives an instruction from each device driver and controls the network device according to each instruction, while receiving an interrupt instruction from the network device and interrupts each device driver. Therefore, it is possible to cause a plurality of operating systems to perform the data reception operation.

  (3) In the virtual computer system of the present invention, the virtual device is configured to set a value for a real register of the network device based on an instruction from each device driver; While receiving an interrupt registration setting from each device driver, an interrupt control unit that receives an interrupt from the network device and interrupts each device driver, and starts reading the real register of the network device from each device driver And a pointer management unit that receives an instruction about the value of the pointer and the write start pointer and determines the value of the read start pointer and the write start pointer set for the real register of the network device.

  With this configuration, data reception can be performed without performing a copy operation, so that it is possible to avoid performance degradation due to the copy operation. Further, since it is not necessary to provide an extra buffer, memory resources can be saved and effectively used.

  (4) In the virtual computer system of the present invention, the virtual register unit includes at least a first register that holds values of a read start pointer and a write start pointer designated by each device driver, and the network device. And a second register that holds the values of the read start pointer and the write start pointer set in the real register.

  With this configuration, the virtual device can perform processing for the network device in place of each device driver, and a plurality of operating systems can perform data reception operations.

  (5) In the virtual machine system of the present invention, the real register of the network device is a ring buffer.

  With this configuration, a fixed-length memory can be used effectively, and appropriate processing can be performed even when data is frequently updated.

  (6) In the virtual computer system of the present invention, the ring buffer includes a plurality of read pointers and at least one write pointer, and the virtual device is the rearmost read pointer with respect to the network device. Is set to a real register.

  With this configuration, it is possible to control so that data is not written before the rearmost read pointer. In addition, since data can be received without performing a copy operation, it is possible to avoid performance degradation due to the copy operation. Further, since it is not necessary to provide an extra buffer, memory resources can be saved and effectively used.

  (7) Also, the virtual computer system control method of the present invention is provided corresponding to each of a plurality of operating systems, a network device for transmitting / receiving data to / from an external network, and each of the operating systems. A virtual computer system control method comprising a plurality of device drivers for controlling the network device and a virtual device based on the instructions of the virtual device, wherein the virtual device receives instructions from the device drivers. And at least a step of controlling the network device according to each instruction, a step of receiving an interrupt instruction from the network device, and a step of interrupting each device driver. It is set to.

  In this way, the virtual device receives instructions from each device driver and controls the network device according to each instruction, while receiving an interrupt instruction from the network device and interrupting each device driver, Data receiving operation can be performed by a plurality of operating systems.

  According to the present invention, by accessing a peripheral device from a plurality of operating systems via a virtual device, the same peripheral device can be controlled from the plurality of operating systems. For example, when accessing a network device from a plurality of operating systems via a virtual device, it is possible to avoid performance degradation caused by performing a copying operation between data buffers in a data transmission / reception operation, and a buffer for the same. Need not be provided.

(First embodiment)
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a virtual machine system of the present invention. The virtual computer system includes a first OS 1 and a first device driver 1a, a second OS 2 and a second device driver 2a, a network device 3 that transmits and receives data to and from an external network, and a first OS 1 or And a virtual device 4 that allows the network device 3 to be shared from the second OS 2. The first device driver 1a and the second device driver 2a are composed of buffers 1b and 2b, pointer management units 1c and 2c, and interrupt management units 1d and 2d, respectively. The network device 3 includes a register 3a, a transmission / reception buffer 3b, and an interrupt management unit 3c. However, this is merely an example, and the OS and its device drivers are not limited to two. In this embodiment, a case where there are two OSs and two device drivers each will be described as an example.

  The virtual device 4 receives a request from the first device driver 1a or the second device driver 2a, and actually sets a value for the real register of the network device 3, and the first device An interrupt management unit 4b that performs an interrupt registration setting from the driver 1a or the second device driver 2a, receives an interrupt from the network device 3, and interrupts the first OS1 or the second OS2, and In response to the designation of the read start pointer or write start pointer of the buffer of the network device 3 from the first device driver 1a or the second device driver 2a, the read start pointer or write start of the buffer actually set for the network device 3 Determine the value of the pointer A pointer management section 4c, and a. In FIG. 1, r1 is a read start pointer for the first OS1, and r2 is a read start pointer for the second OS2. R is a read start pointer for each device driver, and W is a write start pointer for each device driver.

  The virtual register unit 4a includes a register that holds a read start pointer or a write start pointer designated by the first device driver 1a or the second device driver 2a, and further, a read start pointer that is actually set in the network device 3. And a register for holding the value of the write start pointer. Note that the virtual register unit 4a includes all of the real registers of the network device 3, such as an interrupt mask register.

  In the system configuration according to the present embodiment, the first device driver 1a or the second device driver 2a performs the settings performed on the normal real device, such as device initialization setting, data transmission / reception setting, register setting, and interrupt setting. In the same manner, the process is performed for the virtual device 4.

  When the virtual device 4 receives settings such as device initialization, data transmission / reception, and interrupt from the first device driver 1a or the second device driver 2a, the virtual device 4 performs these processes on the actual network device 3. For example, in the device initialization process, the network device 3 is not initialized a plurality of times for each of the first device driver 1a or the second device driver 2a, but the first device driver 1a or the second device driver. When the device initialization is set in the virtual device 4 by 2a, the virtual device 4 initializes the actual network device 3 only once.

  In the data transmission / reception processing, the first device driver 1a or the second device driver 2a sets the data transfer source, transfer destination, and transfer size for the virtual device 4, so that the virtual device 4 is actually Data transfer is performed with the network device 3. In the interrupt processing, when the first device driver 1 a or the second device driver 2 a performs interrupt registration setting for the virtual device 4, the virtual device 4 performs interrupt registration for the actual network device 3. When receiving an interrupt from the network device 3, the virtual device 4 interrupts the first device driver 1a or the second device driver 2a.

  Next, each process of initialization, data transmission / reception, and interruption of the network device 3 by the first device driver 1a or the second device driver 2a via the virtual device 4 will be described. In the present embodiment, the first device driver 1 a or the second device driver 2 a always transmits and receives data to and from the network device 3 via the virtual device 4. The first device driver 1a or the second device driver 2a performs the setting for the virtual device 4 that has been performed for the normal real device as before.

  An operation in which the first device driver 1a or the second device driver 2a transmits / receives data to / from the network device 3 via the virtual device 4 will be described. For example, as shown in FIG. 5 and FIG. 6 in the conventional transmission / reception using a virtual device such as VMWARE (registered trademark), a buffer is prepared in the virtual device, and once the data is transmitted / received to the virtual device The buffer was being copied. For this reason, the performance is degraded, and an extra buffer is required for the copy process in the virtual device.

  On the other hand, in the present embodiment, the virtual device 4 does not perform a copy operation, and the transmission / reception buffers of a plurality of OS device drivers (first device driver 1a or second device driver 2a) and the network device 3 Data is transferred between the transmission / reception buffers to perform data transmission / reception. For this reason, compared with the prior art, there is no deterioration in performance and no extra buffer is required. The transmission / reception buffer of the network device 3 is assumed to be a ring buffer.

  In order to perform data transmission / reception, the virtual device 4 performs initialization processing of the network device 3, interrupt processing of the network device 3, setting of a read start pointer and a write start pointer of the data transmission / reception buffer of the network device 3, and transmission / reception of the network device Buffer data transfer is required.

  The initialization process of the network device 3 via the virtual device 4 is performed according to the procedure shown in FIG. FIG. 2 is a flowchart showing a procedure of network device initialization processing. Even if the initialization setting is performed from the first device driver 1a or the second device driver 2a, the virtual device 4 performs the initialization setting for the actual network device 3 only once. If the initialization process has already been performed on the network device 3, the initialization process is not performed.

  As shown in FIG. 2, the device driver of the first or second OS 2 performs device initialization processing for the virtual device 4 (step S1). The virtual device 4 determines whether or not the initialization process is performed on the network device 3 (step S2), and only when the initialization process is not performed, the initialization process of the network device 3 is actually performed. . The initialization procedure of the network device 3 performed by the virtual device 4 is generally the same as the setting performed by the OS device driver for the network device.

  That is, first, as initialization processing of the network device, writing is performed to the reset register of the real register, and reset processing is performed (step S3). Next, each register of the network device such as the interrupt status register and the interrupt mask register is cleared (step S4). The MAC address is set in the physical address register (step S5).

  Next, to clear the transmission / reception buffer of the network device and use the transmission / reception buffer of the network device as a ring buffer, the storage start register indicating the storage start position of the buffer used for transmission / reception, the storage end register indicating the storage end position, the current Each register such as a write start register for storing a write start pointer indicating the write start position and a read start register for storing a read start pointer indicating the current read start position is cleared (step S6). In addition, in order to receive a data transmission / reception notification by an interrupt, an interrupt-related register is initialized, the interrupt mask is released, and an interrupt acceptance state is set (step S7).

  Next, interrupt processing will be described. FIG. 3 is a flowchart showing a procedure of interrupt processing according to the present embodiment. As shown in FIG. 3, first, the first device driver 1a or the second device driver 2a of the OS performs an interrupt setting such as registering an interrupt handler for the virtual device 4 (step T1). Next, the first device driver 1a or the second device driver 2a of the OS sets a read start pointer or a write start pointer for the virtual device 4 (step T2).

  Data transfer is performed between the buffer 3b of the network device 3 and the buffer 1b of the first device driver 1a or the buffer 2b of the second device driver 2a (step T3). The virtual device 4 updates the read start pointers of a plurality of managed device drivers (step T4). In the virtual device 4, the pointer management unit 4c determines a read start pointer to be set in the network device 3 from the read start pointers of a plurality of network drivers. The read start pointer to be set is the rearmost pointer among the plurality of network drivers (step T5). Finally, the virtual device 4 inputs the read start pointer to the register 3a of the network device 3 and updates it (Step T6).

  It is assumed that the transmission / reception buffer 3b of the network device 3 is a ring buffer. This "ring buffer" is a logical connection of the beginning and end of the memory array, and the buffer is configured so that the next to the end of the memory array returns to the beginning of the memory array. The buffer configuration is suitable for a case where a fixed-length memory can be used effectively and data is frequently updated. The ring buffer has a read start pointer and a write start pointer. The write start pointer cannot be written beyond the read start pointer.

  In general, in the reception buffer, the write start pointer is controlled by the hardware side, and the read start pointer is controlled by the software side. In the transmission buffer, the write start pointer is controlled by the software side, and the read start pointer is controlled by the hardware side.

  Next, processing when data is received by the network device 3 via the virtual device 4 will be described. In general, an OS network device driver determines whether the data is addressed to itself, and if it is not addressed to itself, discards packet data. In the present embodiment, the data acquired by the network device 3 is not determined to which OS on the virtual device 4 side, but data is transmitted to the network device drivers of both OSs for processing. .

  When data is received, an interrupt is generated from the network device 3 to the virtual device 4, and both the first device driver 1 a and the second device driver 2 a are transmitted from the virtual device to the network device driver of the OS. Interrupt, and transfer data between buffers to transfer data. Here, each of the first device driver 1a and the second device driver 2a performs reading, and discards the read data if it is not addressed to itself.

  The network receive buffer implemented in the present embodiment is a ring buffer having one read start pointer and one write start pointer, and does not write data through the virtual device beyond the rearmost read start pointer. To control.

  The virtual device 4 sets the network device to transfer data from the reception buffer of the network device 3 to the reception buffer of the device driver of each OS. Data transfer is directly performed between the reception buffer of the network device 3 and the reception buffer 1b or buffer 2b of the first device driver 1a or the second device driver 2a. Then, the virtual device 4 updates the read start pointer in the virtual register unit 4a of the virtual device 4 after the data reading process. Compared with the other reading start pointer, it is determined whether it is the most backward reading start pointer. When the reading start pointer is the most backward, the reading start pointer is updated to the actual register of the actual network device 3. .

  FIG. 4 is a flowchart showing processing at the time of data transmission of the network device 3 via the virtual device 4. The transmission buffer 3b of the network device 3 is a ring buffer having one read start pointer and one write start pointer, and controls so as not to write data beyond the read start pointer. First, when a data write request is received from the first device driver 1a or the second device driver 2a (step R1), the virtual device 4 transmits the transmission buffer 1b of the first device driver 1a or the second device driver 2a. Alternatively, the data is set to be transferred from the transmission buffer 2b to the transmission buffer of the actual network device 3 (step R2). Next, the virtual device 4 updates the write start pointer in the virtual register unit 4a of the virtual device 4 (step R3). Next, the value of the write start pointer is updated in the register 3a of the network device 3 (step R4).

  In this way, data transmission from a plurality of OS device drivers is performed sequentially. Data is transmitted by performing buffer transfer between the first device driver 1 a or the second device driver 2 a and the network device 3. The transmission completion interrupt is performed for each of the first device driver 1a or the second device driver 2a that has performed inter-buffer transfer.

(Second Embodiment)
In the first embodiment, sharing of the network device 3 is realized by separately providing the virtual device 4, but in the second embodiment, the network device 3 has the function of the virtual device 4. A register for storing read start pointers for a plurality of OSs is prepared in the network device, and data is transmitted and received under the control of the device drivers of the plurality of OSs. In addition to the conventional register, the network device shown in FIG. 1 has two registers: a register for storing the read start pointer for the first OS1 and a register for storing the read start pointer for the second OS2. To do. In addition, a pointer management unit for obtaining a read start pointer to be set in the network device is provided from the read start pointer for the first OS1 and the read start pointer for the second OS2. The read start pointer output from the pointer management unit is set for a register that stores the read start pointer of the network device.

  On the other hand, when writing, two registers, a register for storing the write start pointer for the first OS1 and a register for storing the write pointer for the second OS2, are prepared separately. A pointer output unit for obtaining a write start pointer to be set in the network device is provided from the two write start pointers for the first OS1 and the second OS2. The pointer management unit functions as this pointer output unit. The write start pointer output from the pointer management unit as the pointer output unit is stored in a register that stores the read start pointer of the network device. Since the flow of data transmission / reception processing is the same as that in the first embodiment, a description thereof will be omitted.

  As mentioned above, although embodiment of this invention was described, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, and includes meanings equivalent to the terms of the claims and all modifications within the scope.

It is a block diagram which shows schematic structure of the virtual computer system of this invention. It is a flowchart which shows the procedure of the initialization process of a network device. It is a flowchart which shows the procedure of the interrupt process which concerns on this embodiment. It is a flowchart which shows the process at the time of the data transmission of a network device via a virtual device. It is a block diagram which shows an example of the conventional system configuration. It is the block diagram which represented the conventional system typically.

Explanation of symbols

1 First OS
1a 1st device driver 1b buffer 1c pointer management unit 1d interrupt management unit 2 second OS
2a Second device driver 2b Buffer 2c Pointer manager 2d Interrupt manager 3 Network device 3a Register 3b Transmission / reception buffer 3c Interrupt manager 4 Virtual device 4a Virtual register 4b Interrupt manager 4c Pointer manager

Claims (7)

Multiple operating systems,
A network device that transmits and receives data to and from an external network;
A plurality of device drivers that are provided corresponding to each of the operating systems and that control the network device based on instructions of the operating system;
A virtual device that receives an instruction from each device driver and controls the network device according to each instruction, and receives an interrupt instruction from the network device and interrupts the device driver. Virtual computer system characterized by Multiple operating systems,
A network device that transmits and receives data to and from an external network;
A plurality of device drivers provided corresponding to each of the operating systems and controlling the network device based on instructions of the operating system;
The network device receives an instruction from each device driver and controls the network device according to each instruction, while receiving an interrupt instruction from the network device and interrupting each device driver A virtual computer system comprising: The virtual device is
Based on an instruction from each device driver, a virtual register unit that sets a value for a real register of the network device;
While receiving an interrupt registration setting from each device driver, an interrupt control unit that receives an interrupt from the network device and interrupts each device driver;
In response to instructions from the device drivers regarding the values of the read start pointer and the write start pointer of the real register of the network device, the values of the read start pointer and the write start pointer to be set for the real register of the network device are set. The virtual machine system according to claim 1, further comprising: a pointer management unit for determining.   The virtual register unit includes at least a first register that holds values of a read start pointer and a write start pointer designated by each device driver, and a read start pointer and a write start pointer that are set in a real register of the network device. The virtual machine system according to claim 3, further comprising: a second register that holds the value of   5. The virtual computer system according to claim 3, wherein the real register of the network device is a ring buffer. The ring buffer includes a plurality of read pointers and at least one write pointer;
6. The virtual computer system according to claim 5, wherein the virtual device sets a rearmost read pointer in the real register with respect to the network device. A plurality of operating systems, a network device that transmits / receives data to / from an external network, and a plurality of device drivers that are provided corresponding to each of the operating systems and that control the network device based on instructions from the operating system And a virtual computer system control method comprising a virtual device,
Receiving instructions from the device drivers in the virtual device;
Controlling the network device in response to each instruction;
Receiving an interrupt instruction from the network device;
A method of controlling the virtual machine system, comprising: at least interrupting each of the device drivers.

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