Abstract: Disclosed is a virtual machine system where hardware timer interrupts are processed by a first virtual machine. The first virtual machine writes a timer value to a shared memory location while processing the hardware timer interrupt. The timer value may be based on a kernel timing parameter maintained by the operating system of the first virtual machine. A second virtual machine may read the shared timer value from the shared memory location in order to time inter-virtual machine processes such as I/O processing and I/O requests.

Abstract: Disclosed is a system with multiple virtual machines passing I/O requests via a shared memory space. A flag in shared memory is set to a first state in response to a first hypervisor I/O interrupt to indicate that an I/O processing routine is active (running). I/O requests are retrieved from an I/O queue in the shared memory by the I/O processing routine. Based on an indicator that there are no I/O requests remaining in said I/O queue, the shared flag is set to a second state to indicate that the I/O processing routine is deactivated (sleeping). In response to said shared flag being in the second state, when new I/O requests are going to be made, a second hypervisor I/O interrupt is generated. In response to said shared flag being in said first state, I/O requests are inserted into the I/O queue without generating a second hypervisor I/O interrupt.

Abstract: Disclosed is a method of booting a virtual machine. A file, accessible by a privileged domain that includes an index file image and a plurality of other file images is stored. The index file image is of a predetermined, fixed size and includes a file name and a file size for each of the other images in the file. The privileged domain provides the file to one or more non-privileged virtual machines as a single disk image of the fixed size mounted on the non-privileged virtual machine. The other file images are extracted by the virtual machines based on the file names and file sizes stored in the index file image.

Abstract: Disclosed is a virtual machine system where hardware timer interrupts are processed by a first virtual machine. The first virtual machine writes a timer value to a shared memory location while processing the hardware timer interrupt. The timer value may be based on a kernel timing parameter maintained by the operating system of the first virtual machine. A second virtual machine may read the shared timer value from the shared memory location in order to time inter-virtual machine processes such as I/O processing and I/O requests.

Abstract: Disclosed is a system with multiple virtual machines passing I/O requests via a shared memory space. A flag in shared memory is set to a first state in response to a first hypervisor I/O interrupt to indicate that an I/O processing routine is active (running). I/O requests are retrieved from an I/O queue in the shared memory by the I/O processing routine. Based on an indicator that there are no I/O requests remaining in said I/O queue, the shared flag is set to a second state to indicate that the I/O processing routine is deactivated (sleeping). In response to said shared flag being in the second state, when new I/O requests are going to be made, a second hypervisor I/O interrupt is generated. In response to said shared flag being in said first state, I/O requests are inserted into the I/O queue without generating a second hypervisor I/O interrupt.