Method, apparatus, and system for accessing storage device

Patent metadata

Field	Value
Publication number	US-10713074-B2
Application number	US-201715666306-A
Country	US
Kind code	B2
Filing date	Aug 1, 2017
Priority date	Oct 21, 2015
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

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.

First claim

What is claimed is:

1. A method for accessing a storage device in a computer system having a virtual machine and an I/O adapter, wherein the method comprises:
acquiring, by the I/O adapter, an access request from the virtual machine, wherein the access request carries virtual address information of a to-be-accessed physical storage area of the storage device;
generating, by the I/O adapter, an access instruction according to the access request, wherein the access instruction carries the virtual address information of the to-be-accessed physical storage area and an identifier of a virtual channel configured between the I/O adapter and the storage device, wherein the virtual channel corresponds to the virtual machine on a one-to-one basis such that the virtual channel provides the virtual machine with a uniquely identifiable transmission channel between the virtual machine, the I/O adapter, and a storage device target, wherein the storage device target is configured to manage access to the storage device; and
sending, by the I/O adapter, the access instruction to the storage device target to facilitate the storage device target uniquely determining a physical address of the to-be-accessed physical storage area according to the virtual address information of the to-be-accessed physical storage area and the identifier of the virtual channel that are carried in the access instruction.

2. The method according to claim 1 , wherein before generating the access instruction, the method further comprises:
querying, by the I/O adapter, a preset first correspondence according to an identifier of the virtual machine to determine the identifier of the virtual channel, wherein the preset first correspondence comprises a correspondence between an identifier of each virtual machine of a plurality of virtual machines and an identifier of each virtual channel of a plurality of virtual channels.

3. The method according to claim 2 , wherein the method further comprises:
maintaining, by the I/O adapter, the one-to-one basis between the virtual channel and the virtual machine by storing an entry comprising the identifier of the virtual channel and the identifier of the virtual machine, and
wherein querying the preset first correspondence to determine the identifier of the virtual channel is based on the stored entry indicating the one-to-one basis between the virtual channel and the virtual machine.

4. The method according to claim 1 , wherein a plurality of cache queues are configured in the I/O adapter, each cache queue of the plurality of cache queues corresponds to a respective virtual channel of a respective virtual machine based on the one-to-one basis; and
wherein after acquiring the access request, the method further comprises: writing, by the I/O adapter, the access request of the virtual machine in a first cache queue of the plurality of cache queues corresponding to the virtual channel of the virtual machine.

5. The method according to claim 1 , wherein if the I/O adapter acquires access requests from at least two virtual machines, an access instruction corresponding to a high-priority virtual machine is generated before an access instruction corresponding to a low-priority virtual machine.

6. The method according to claim 1 , wherein the method further comprises:
receiving, by the I/O adapter, a first doorbell notification from the virtual machine indicating arrival of the access request from the virtual machine in an I/O shared ring that is shared between the virtual machine and the I/O adapter, and
wherein acquiring the access request is in response to receiving the first doorbell notification and from the virtual machine via the I/O shared ring.

7. The method according to claim 1 , wherein the method further comprises:
in response to determining the virtual machine has been created, creating the one-to-one basis between the virtual channel and the virtual machine; and
storing an entry indicating the one-to-one basis between the virtual channel and the virtual machine in memory of the I/O adapter.

8. The method of according to claim 7 , wherein the method further comprises:
dynamically adjusting the entry indicating the one-to-one basis between the virtual channel and the virtual machine by associating the virtual machine with a different virtual channel.

9. The method of claim 7 , wherein the method further comprises:
in response to determining the virtual machine has been deleted, deleting the entry indicating the one-to-one basis between the virtual channel and the virtual machine.

10. A method for accessing a storage device, comprising:
acquiring, by a storage device target, an access instruction from an I/O adapter, wherein the access instruction carries virtual address information of a to-be-accessed physical storage area of the storage device and an identifier of a virtual channel configured between the I/O adapter and the storage device, wherein the virtual channel corresponds to the virtual machine on a one-to-one basis such that the virtual channel provides the virtual machine with a uniquely identifiable transmission channel between the virtual machine, the I/O adapter, and the storage device target;
uniquely determining, by the storage device target, a physical address of the to-be-accessed physical storage area according to the virtual address information of the to-be-accessed physical storage area and the identifier of the virtual channel that are carried in the access instruction; and
performing, by the storage device target, an operation on the to-be-accessed physical storage area according to the access instruction and the physical address of the to-be-accessed physical storage area;
wherein the virtual channel is one of a plurality of virtual channels, wherein each virtual channel is associated with a plurality of virtual addresses, wherein the virtual addresses for the virtual channel associated with the virtual machine overlap with the virtual addresses of a second virtual channel associated with another virtual machine such that a respective virtual address of the virtual channel is the same as a respective virtual address of the second virtual channel, and wherein each virtual channel-virtual address pair corresponds to a different, unique physical address.

11. The method according to claim 10 , wherein uniquely determining the physical address of the to-be-accessed physical storage area comprises:
querying, by the storage device target, a preset second correspondence according to the virtual address information of the to-be-accessed physical storage area and the identifier of the virtual channel that are carried in the access instruction to uniquely determine the physical address of the to-be-accessed physical storage area, wherein the preset second correspondence comprises a correspondence between an identifier of each virtual channel of a plurality of virtual channels and a respective physical address of a physical storage area allocated to each virtual channel.

12. The method according to claim 10 , wherein a plurality of cache queues are configured in the storage device target, each cache queue of the plurality of cache queues corresponds to a respective virtual channel of a respective virtual machine based on the one-to-one basis; and
wherein after acquiring the access instruction, the method further comprises: writing, by the storage device target, the access instruction in a second cache queue of the plurality of cache queues corresponding to the virtual channel of the virtual machine.

13. The method according to claim 10 , wherein if the storage device target acquires access instructions from at least two virtual machin

Assignees

• Huawei Tech Co Ltd

Inventors

• Li Langbo

Classifications

• G06F2009/45579

  I/O management, e.g. providing access to device drivers or storage · CPC title

• G06F2009/45583

  Memory management, e.g. access or allocation · CPC title

• G06F9/45558 Primary

  Hypervisor-specific management and integration aspects · CPC title

• G06F12/109

  for multiple virtual address spaces, e.g. segmentation (G06F12/1036 takes precedence) · CPC title

• G06F12/1009

  using page tables, e.g. page table structures · CPC title