Method, apparatus, and system for accessing storage device

Abstract

A method, an apparatus, and a system for accessing a storage device. The method includes: acquiring, by an I/O adapter, an access request from a virtual machine, where the access request carries virtual address information of a to-be-accessed storage area; generating an access instruction according to the access request, where the access instruction carries the virtual address information and an identifier of a virtual channel of the virtual machine, where the virtual channel corresponds to the virtual machine on a one-to-one basis and is used to connect the corresponding virtual machine to a storage device target, and the storage device target is configured to manage access to the storage device; and sending the access instruction to the storage device target.

What is claimed is: 
     
         1 . A method for accessing a storage device in a computer system having a plurality of virtual machines and an I/O adapter, wherein the method comprises:
 configuring, by a processor of the computer system, multiple virtual channels between the plurality of virtual machines and the I/O adapter;   assigning, by the processor, each of the multiple virtual channels for a respective virtual machine of the plurality of virtual machines; and   sending, by the processor, an access instruction from a virtual machine of the plurality of virtual machines to the I/O adapter through a virtual channel of the multiple virtual channels, wherein the virtual channel provides a uniquely identifiable transmission channel between the virtual machine and a storage device target.   
     
     
         2 . The method according to  claim 1 , wherein each of the virtual machines has an identifier, each of the virtual channels has an identifier, and the method further comprises:
 storing a correspondence between an identifier of a respective virtual machine of the plurality of virtual machines and an identifier of a respective virtual channel of the plurality of virtual channels.   
     
     
         3 . The method according to  claim 1 , wherein a plurality of cache queues are configured in the I/O adapter, wherein each cache queue of the plurality of cache queues corresponds to a respective virtual channel of a respective virtual machine on a one-to-one basis; and
 wherein the method further comprises: writing, by the I/O adapter, the access instruction of the virtual machine in a cache queue corresponding to the virtual channel of the virtual machine.   
     
     
         4 . The method according to  claim 1 , wherein access requests are acquired from at least two virtual machines, and an access instruction corresponding to a high-priority virtual machine is generated before an access instruction corresponding to a low-priority virtual machine. 
     
     
         5 . The method according to  claim 1 , wherein after sending the access instruction, the method further comprises:
 receiving, by the IO adapter, a feedback message from the storage device, wherein the feedback message comprises an execution result of the access instruction and an identifier of the virtual channel of the virtual machine;   determining, by the IO adapter, the virtual machine according to the identifier of the virtual channel; and   sending, by the IO adapter, the execution result of the access instruction to the virtual machine.   
     
     
         6 . The method according to  claim 5 , wherein the method further comprises:
 receiving, by the I/O adapter, a first notification from the virtual machine; and   acquiring, by the I/O adapter, an access request from an I/O shared ring that is shared with the virtual machine, wherein the access request is put in the I/O shared ring by the virtual machine, and the first notification indicates arrival of the access request at the I/O shared ring; and   wherein sending the execution result of the access instruction to the virtual machine comprises: putting the execution result of the access instruction in the I/O shared ring that is shared with the virtual machine, and sending a second notification to the virtual machine, wherein the second notification indicates arrival of the execution result at the I/O shared ring.   
     
     
         7 . A computer system comprising:
 a processor;   an I/O adapter; and   a storage device;   wherein the processor is configured to:
 configure multiple virtual channels between a plurality of virtual machines and the IO adapter; 
 assign each of the multiple virtual channels for a respective virtual machine of the plurality of virtual machines; and 
 send an access instruction from a virtual machine of the plurality of virtual machines to the I/O adapter through a virtual channel of the multiple virtual channels, wherein the virtual channel provides a uniquely identifiable transmission channel between the virtual machine and a storage device target. 
   
     
     
         8 . The computer system according to  claim 7 , wherein each of the virtual machines has an identifier, each of the virtual channels has an identifier, and a correspondence between an identifier of a respective virtual machine of the plurality of virtual machines and an identifier of a respective virtual channel of the plurality of virtual channels is stored in the computer system. 
     
     
         9 . The computer system according to  claim 7 , wherein a plurality of cache queues are configured in the I/O adapter, wherein each cache queue of the plurality of cache queues corresponds to a respective virtual channel of a respective virtual machine on a one-to-one basis; and
 wherein the I/O adapter is configured to write the access instruction of the virtual machine in a cache queue corresponding to the virtual channel of the virtual machine.   
     
     
         10 . The computer system according to  claim 7 , wherein the processor is further configured to:
 acquire access requests from at least two virtual machines; and   generate an access instruction corresponding to a high-priority virtual machine before generating an access instruction corresponding to a low-priority virtual machine.   
     
     
         11 . The computer system according to  claim 7 , wherein the I/O adapter is configured to:
 receive a feedback message from the storage device, wherein the feedback message comprises an execution result of the access instruction and an identifier of the virtual channel of the virtual machine;   determine the virtual machine according to the identifier of the virtual channel; and   send the execution result of the access instruction to the virtual machine.   
     
     
         12 . The computer system according to  claim 11 , wherein the I/O adapter is further configured to:
 receive a first notification from the virtual machine;   acquire an access request from an I/O shared ring that is shared with the virtual machine, wherein the access request is put in the I/O shared ring by the virtual machine, and the first notification indicates arrival of the access request at the I/O shared ring;   put the execution result of the access instruction in the I/O shared ring that is shared with the virtual machine, and   send a second notification to the virtual machine, wherein the second notification is used to indicate arrival of the execution result at the I/O shared ring.   
     
     
         13 . One or more non-transitory computer-readable mediums having processor-executable instructions stored thereon for accessing a storage device in a computer system having a plurality of virtual machines and an I/O adapter, wherein the processor-executable instructions, when executed, facilitate:
 configuring multiple virtual channels between the plurality of virtual machines and the  10  adapter;   assigning each of the multiple virtual channels for a respective virtual machine of the plurality of virtual machines; and   sending an access instruction from a virtual machine of the plurality of virtual machines to the I/O adapter through a virtual channel of the multiple virtual channels, wherein the virtual channel provides a uniquely identifiable transmission channel between the virtual machine and a storage device target.   
     
     
         14 . The one or more non-transitory computer-readable mediums according to  claim 13 , wherein each of the virtual machines has an identifier, each of the virtual channels has an identifier, and a correspondence between an identifier of a respective virtual machine of the plurality of virtual machines and an identifier of a respective virtual channel of the plurality of virtual channels is stored in the computer system. 
     
     
         15 . The one or more non-transitory computer-readable mediums according to  claim 13 , wherein a plurality of cache queues are configured in the I/O adapter, wherein each cache queue of the plurality of cache queues corresponds to a respective virtual channel of a respective virtual machine on a one-to-one basis; and
 wherein the processor-executable instructions, when executed, further facilitate: writing the access instruction of the virtual machine in a cache queue corresponding to the virtual channel of the virtual machine.   
     
     
         16 . The one or more non-transitory computer-readable mediums according to  claim 13 , wherein the processor-executable instructions, when executed, further facilitate:
 acquiring access requests from at least two virtual machines; and   generating an access instruction corresponding to a high-priority virtual machine before generating an access instruction corresponding to a low-priority virtual machine.   
     
     
         17 . The one or more non-transitory computer-readable mediums according to  claim 13 , wherein the processor-executable instructions, when executed, further facilitate:
 after the access instruction is sent, receiving a feedback message from the storage device, wherein the feedback message comprises an execution result of the access instruction and an identifier of the virtual channel of the virtual machine;   determining, according to the identifier of the virtual channel, the virtual machine; and   sending the execution result of the access instruction to the virtual machine.   
     
     
         18 . The one or more non-transitory computer-readable mediums according to  claim 17 , wherein the processor-executable instructions, when executed, further facilitate:
 receiving a first notification from the virtual machine; and   acquiring an access request from an I/O shared ring that is shared with the virtual machine, wherein the access request is put in the I/O shared ring by the virtual machine, and the first notification indicates arrival of the access request at the I/O shared ring; and   wherein sending the execution result of the access instruction to the virtual machine comprises: putting the execution result of the access instruction in the I/O shared ring that is shared with the virtual machine, and sending a second notification to the virtual machine, wherein the second notification indicates arrival of the execution result at the I/O shared ring.