Re: [PATCH 0/2] KVM: MMU: support VMAs that got remap_pfn_range-ed

[Paolo Bonzini]

On 04/07/2016 08:39, Xiao Guangrong wrote:
> Why the memory mapped by this mmap() is not a portion of MMIO from
> underlayer physical device? If it is a valid system memory, is this
> interface
> really needed to implemented in vfio? (you at least need to set VM_MIXEDMAP
> if it mixed system memory with MMIO)

The KVM code does not care if VM_MIXEDMAP is set or not, it works in
either case.

Paolo

> IIUC, the kernel assumes that VM_PFNMAP is a continuous memory, e.g, like
> current KVM and vaddr_get_pfn() in vfio, but it seems nvdia's patchset
> breaks this semantic as ops->validate_map_request() can adjust the physical
> address arbitrarily. (again, the name 'validate' should be changed to match
> the thing as it is really doing)
> 
> 
> -- 
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>