Direct access to host memory for guests

A method comprising:

• receiving, by a filesystem daemon of a hypervisor executing on a processor, a first file retrieval request associated with a file stored in a host memory from a first storage controller of a first guest via a first filesystem queue and a second file retrieval request associated with the file from a second storage controller of a second guest via a second filesystem queue, wherein the first file retrieval request includes an identifier of an identified part of the file to be accessed;
• causing, by the filesystem daemon, a host memory address (HMA) associated with the file to be mapped to a first guest memory address (GMA) of the first guest and a second GMA of the second guest;
• accessing, by a first application of the first guest, the file in the host memory with the first GMA;
• updating, by the first application, the file with changes;
• responsive to the file being updated by the first application, modifying, by a second application of the second guest, an execution state of the second application based on the changes;
• determining, by the filesystem daemon, a memory offset associated with a starting position of the identified part in the host memory;
• and
• adjusting, by the filesystem daemon, the first HMA with the memory offset allowing the application to directly access the identified part via the first GMA, wherein the first application's access to the file is limited to a segment of the file that includes the identified part.

A non-transitory computer readable medium storing instructions which, when executed, cause a processor to execute to:

• receive, by a filesystem daemon of a hypervisor, a first file retrieval request associated with a file stored in a host memory from a first storage controller of a first guest via a first filesystem queue and a second file retrieval request associated with the file from a second storage controller of a second guest via a second filesystem queue, wherein the first file retrieval request includes an identifier of an identified part of the file to be accessed;
• cause, by the filesystem daemon, a host memory address (HMA) associated with the file to be mapped to a first guest memory address (GMA) of the first guest and a second GMA of the second guest;
• access, by a first application of the first guest, the file in the host memory with the first GMA;
• update, by the first application, the file with changes;
• responsive to the file being updated by the first application, modify, by a second application of the second guest, an execution state of the second application based on the changes;
• determine, by the filesystem daemon, a memory offset associated with a starting position of the identified part in the host memory;
• and
• adjust, by the filesystem daemon, the first HMA with the memory offset allowing the application to directly access the identified part via the first GMA, wherein the first application's access to the file is limited to a segment of the file that includes the identified part.