Re: [PATCH V2 1/2] Swiotlb: Add swiotlb_alloc_from_low_pages switch

[Christoph Hellwig]

On Tue, Feb 22, 2022 at 11:07:19PM +0800, Tianyu Lan wrote:
> Thanks for your comment. That means we need to expose an 
> swiotlb_device_init() interface to allocate bounce buffer and initialize
> io tlb mem entry. DMA API Current  rmem_swiotlb_device_init() only works
> for platform with device tree. The new API should be called in the bus
> driver or new DMA API. Could you check whether this is a right way before 
> we start the work.

Do these VMs use ACPI?  We'd probably really want some kind of higher
level configuration and not have the drivers request it themselves.