Re: [PATCH] kvm tools: adds a PCI device that exports a host shared segment as a PCI BAR in the guest

[Anthony Liguori <anthony@codemonkey.ws>]

On 08/24/2011 05:25 PM, David Evensky wrote:
>
>
> This patch adds a PCI device that provides PCI device memory to the
> guest. This memory in the guest exists as a shared memory segment in
> the host. This is similar memory sharing capability of Nahanni
> (ivshmem) available in QEMU. In this case, the shared memory segment
> is exposed as a PCI BAR only.
>
> A new command line argument is added as:
>      --shmem pci:0xc8000000:16MB:handle=/newmem:create
>
> diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/include/kvm/pci-shmem.h linux-kvm_pci_shmem/tools/kvm/include/kvm/pci-shmem.h
> --- linux-kvm/tools/kvm/include/kvm/pci-shmem.h	1969-12-31 16:00:00.000000000 -0800
> +++ linux-kvm_pci_shmem/tools/kvm/include/kvm/pci-shmem.h	2011-08-13 15:43:01.067953711 -0700
> @@ -0,0 +1,13 @@
> +#ifndef KVM__PCI_SHMEM_H
> +#define KVM__PCI_SHMEM_H
> +
> +#include<linux/types.h>
> +#include<linux/list.h>
> +
> +struct kvm;
> +struct shmem_info;
> +
> +int pci_shmem__init(struct kvm *self);
> +int pci_shmem__register_mem(struct shmem_info *si);
> +
> +#endif
> diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/include/kvm/virtio-pci-dev.h linux-kvm_pci_shmem/tools/kvm/include/kvm/virtio-pci-dev.h
> --- linux-kvm/tools/kvm/include/kvm/virtio-pci-dev.h	2011-08-09 15:38:48.760120973 -0700
> +++ linux-kvm_pci_shmem/tools/kvm/include/kvm/virtio-pci-dev.h	2011-08-18 10:06:12.171539230 -0700
> @@ -15,10 +15,13 @@
>   #define PCI_DEVICE_ID_VIRTIO_BLN		0x1005
>   #define PCI_DEVICE_ID_VIRTIO_P9			0x1009
>   #define PCI_DEVICE_ID_VESA			0x2000
> +#define PCI_DEVICE_ID_PCI_SHMEM			0x0001
>
>   #define PCI_VENDOR_ID_REDHAT_QUMRANET		0x1af4
> +#define PCI_VENDOR_ID_PCI_SHMEM			0x0001
>   #define PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET	0x1af4

FYI, that's not a valid vendor and device ID.

Perhaps the RH folks would be willing to reserve a portion of the device 
ID space in their vendor ID for ya'll to play around with.

Regards,

Anthony Liguori