Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

subbu kl wrote: Cam, just a wild though about alternative approach. Ideas are always good. Once specific set of address range of one guest is visible to other guest its just a matter of DMA/single memcpy will transfer the data across. My idea is to eliminate unnecessary copying. This

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

subbu kl wrote: correct me if wrong, can we do the sharing business by writing a non-transparent qemu PCI device in host and guests can access each other's address space ? Hi Subbu, I'm a bit confused by your question. Are you asking how this device works or suggesting an alternative

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Cameron Macdonell wrote: Hi Avi and Anthony, Sorry for the top-reply, but we haven't discussed this aspect here before. I've been thinking about how to implement interrupts. As far as I can tell, unix domain sockets in Qemu/KVM are used point-to-point with one VM being the server by

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Hi Avi and Anthony, Sorry for the top-reply, but we haven't discussed this aspect here before. I've been thinking about how to implement interrupts. As far as I can tell, unix domain sockets in Qemu/KVM are used point-to-point with one VM being the server by specifying server along

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Avi Kivity wrote: Cam Macdonell wrote: I think there is value for static memory sharing. It can be used for fast, simple synchronization and communication between guests (and the host) that use need to share data that needs to be updated frequently (such as a simple cache or notification

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Anthony Liguori wrote: I disagree with this. While virtio is excellent at exporting guest memory, it isn't so good at importing another guest's memory. First we need to separate static memory sharing and dynamic memory sharing. Static memory sharing has to be configured on start up. I

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Cam Macdonell wrote: I think there is value for static memory sharing. It can be used for fast, simple synchronization and communication between guests (and the host) that use need to share data that needs to be updated frequently (such as a simple cache or notification system). It may not

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Hi Cam, Cam Macdonell wrote: This patch supports sharing memory between VMs and between the host/VM. It's a first cut and comments are encouraged. The goal is to support simple Inter-VM communication with zero-copy access to shared memory. Nice work! I would suggest two design changes

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Anthony Liguori wrote: Hi Cam, Cam Macdonell wrote: This patch supports sharing memory between VMs and between the host/VM. It's a first cut and comments are encouraged. The goal is to support simple Inter-VM communication with zero-copy access to shared memory. Nice work! I would

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Avi Kivity wrote: Anthony Liguori wrote: Hi Cam, I would suggest two design changes to make here. The first is that I think you should use virtio. I disagree with this. While virtio is excellent at exporting guest memory, it isn't so good at importing another guest's memory. First we

Re: [PATCH] Add shared memory PCI device that shares a memory object betweens VMs

Hi Anthony and Avi, Anthony Liguori wrote: Avi Kivity wrote: Anthony Liguori wrote: Hi Cam, I would suggest two design changes to make here. The first is that I think you should use virtio. I disagree with this. While virtio is excellent at exporting guest memory, it isn't so good at