Re: [PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-12-13 Thread Jan Beulich
On 13.12.2021 11:33, Roger Pau Monné wrote: > On Mon, Dec 13, 2021 at 11:00:23AM +0100, Jan Beulich wrote: >> On 13.12.2021 10:45, Roger Pau Monné wrote: >>> It would be better if we could somehow account this in a per-vCPU way, >>> kind of similar to what we do with vPCI BAR mappings. >> >> But re

Re: [PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-12-13 Thread Roger Pau Monné
On Mon, Dec 13, 2021 at 11:00:23AM +0100, Jan Beulich wrote: > On 13.12.2021 10:45, Roger Pau Monné wrote: > > On Mon, Dec 13, 2021 at 09:49:50AM +0100, Jan Beulich wrote: > >> On 10.12.2021 16:06, Roger Pau Monné wrote: > >>> On Fri, Sep 24, 2021 at 11:52:14AM +0200, Jan Beulich wrote: > ---

Re: [PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-12-13 Thread Jan Beulich
On 13.12.2021 10:45, Roger Pau Monné wrote: > On Mon, Dec 13, 2021 at 09:49:50AM +0100, Jan Beulich wrote: >> On 10.12.2021 16:06, Roger Pau Monné wrote: >>> On Fri, Sep 24, 2021 at 11:52:14AM +0200, Jan Beulich wrote: --- I'm not fully sure about allowing 512G mappings: The scheduling-fo

Re: [PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-12-13 Thread Roger Pau Monné
On Mon, Dec 13, 2021 at 09:49:50AM +0100, Jan Beulich wrote: > On 10.12.2021 16:06, Roger Pau Monné wrote: > > On Fri, Sep 24, 2021 at 11:52:14AM +0200, Jan Beulich wrote: > >> --- > >> I'm not fully sure about allowing 512G mappings: The scheduling-for- > >> freeing of intermediate page tables can

Re: [PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-12-13 Thread Jan Beulich
On 10.12.2021 16:06, Roger Pau Monné wrote: > On Fri, Sep 24, 2021 at 11:52:14AM +0200, Jan Beulich wrote: >> --- >> I'm not fully sure about allowing 512G mappings: The scheduling-for- >> freeing of intermediate page tables can take quite a while when >> replacing a tree of 4k mappings by a single

Re: [PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-12-10 Thread Roger Pau Monné
On Fri, Sep 24, 2021 at 11:52:14AM +0200, Jan Beulich wrote: > No separate feature flags exist which would control availability of > these; the only restriction is HATS (establishing the maximum number of > page table levels in general), and even that has a lower bound of 4. > Thus we can unconditi

[PATCH v2 12/18] AMD/IOMMU: allow use of superpage mappings

2021-09-24 Thread Jan Beulich
No separate feature flags exist which would control availability of these; the only restriction is HATS (establishing the maximum number of page table levels in general), and even that has a lower bound of 4. Thus we can unconditionally announce 2M, 1G, and 512G mappings. (Via non-default page size