lkml.org 
[lkml]   [2022]   [Feb]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH V2 1/2] Swiotlb: Add swiotlb_alloc_from_low_pages switch
From


On 2/23/2022 12:00 AM, Christoph Hellwig wrote:
> 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.

Yes, Hyper-V isolation VM uses ACPI. Devices are enumerated via vmbus
host and there is no child device information in ACPI table. The host
driver seems to be the right place to call new API.

\
 
 \ /
  Last update: 2022-02-23 10:47    [W:0.096 / U:1.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site