Re: [Qemu-devel] [PATCH] intel_iommu: a fix to vtd_dev_get_trans_type()

[Peter Xu]

On Thu, Dec 21, 2017 at 02:15:19PM +0800, Liu, Yi L wrote:
> vtd_ce_get_type() returns uin32_t and vtd_dev_get_trans_type() returns
> the value from vtd_ce_get_type(). However, vtd_dev_get_trans_type()
> returns int. This patch switchs to return the translation type by
> parameter. It avoids unsigned to int transfer and also avoid potential
> reading confusion.

Frankly speaking I would still prefer the old way to do it: return
type when >=0 and error when <0.  After all we have a comment for
vtd_dev_get_trans_type() already:

/*
 * Fetch translation type for specific device. Returns <0 if error
 * happens, otherwise return the shifted type to check against
 * VTD_CONTEXT_TT_*.
 */

Thanks,

-- 
Peter Xu