Re: [PATCH v2 06/14] arm64: Override set_fixmap_io

Catalin Marinas
2024-05-13T16:14:10Z

On Fri, Apr 12, 2024 at 09:42:05AM +0100, Steven Price wrote:
> Override the set_fixmap_io to set shared permission for the host
> in case of a CC guest. For now we mark it shared unconditionally.
> Future changes could filter the physical address and make the
> decision accordingly.
[...]
> +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys)
> +{
> + pgprot_t prot = FIXMAP_PAGE_IO;
> +
> + /*
> + * For now we consider all I/O as non-secure. For future
> + * filter the I/O base for setting appropriate permissions.
> + */
> + prot = __pgprot(pgprot_val(prot) | PROT_NS_SHARED);
> +
> + return __set_fixmap(idx, phys, prot);
> +}

I looked through the patches and could not find any place where this
function does anything different as per the commit log suggestion. Can
we just update FIXMAP_PAGE_IO for now until you have a clear use-case?

--
Catalin