Re: [kvm-devel] [PATCH 1/8] KVM: PVDMA Host: Handle reqeustsfor guest DMA mappings

[Joerg Roedel]

On Wed, Nov 07, 2007 at 04:21:02PM +0200, Amit Shah wrote:
> @@ -1649,6 +1913,15 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
>  	}
>  
>  	switch (nr) {
> +	case KVM_PV_DMA_MAP:
> +		ret = pv_map_hypercall(vcpu, a0, a1);
> +		break;
> +	case KVM_PV_DMA_UNMAP:
> +		ret = pv_unmap_hypercall(vcpu, a0);
> +		break;
> +	case KVM_PV_PCI_DEVICE:
> +		ret = pv_mapped_pci_device_hypercall(vcpu, a0);
> +		break;
>  	default:
>  		ret = -KVM_ENOSYS;
>  		break;

How does synchronization work with that design? I don't see a hypercall
to synchronize de DMA buffers. It will only work if GART is used as the
dma_ops backend on the host side and not with SWIOTLB. But GART can be
configured away.  Or do I miss something?

Joerg

-- 
           |           AMD Saxony Limited Liability Company & Co. KG
 Operating |         Wilschdorfer Landstr. 101, 01109 Dresden, Germany
 System    |                  Register Court Dresden: HRA 4896
 Research  |              General Partner authorized to represent:
 Center    |             AMD Saxony LLC (Wilmington, Delaware, US)
           | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/