Hi Yi,
On 2020/9/10 18:56, Liu Yi L wrote:
The high-level architecture for SVA virtualization is as below, the key
design of vSVA support is to utilize the dual-stage IOMMU translation (
also known as IOMMU nesting translation) capability in host IOMMU.
.-------------. .---------------------------.
| vIOMMU | | Guest process CR3, FL only|
| | '---------------------------'
.----------------/
| PASID Entry |--- PASID cache flush -
'-------------' |
| | V
| | CR3 in GPA
'-------------'
Guest
------| Shadow |--------------------------|--------
v v v
Host
.-------------. .----------------------.
| pIOMMU | | Bind FL for GVA-GPA |
| | '----------------------'
.----------------/ |
| PASID Entry | V (Nested xlate)
'----------------\.------------------------------.
| ||SL for GPA-HPA, default domain|
| | '------------------------------'
'-------------'
A silly question: With nested mode, do we need to setup the second level
mappings (GPA->HPA) for devices before vm startup? If so, can you please
point me to the piece of code that achieves it?
On Arm, we setup the stage-2 mapping via the new prereg_listener [1].
[1]
https://patchwork.kernel.org/project/qemu-devel/patch/20210225105233.650545-15-eric.auger@xxxxxxxxxx/
Thanks,
Zenghui
