Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-14 Thread Pankaj Gupta
> > As this patch is dependent on PageReserved patch(which is in progress), > > just > > wondering if we are able to test the code path for hugepage with DAX. > > For testing, I used the following patch. It's not 100%, since it > intercepts at kvm_is_reserved_pfn(), and not PageReserved()

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread Paolo Bonzini
On 13/11/2018 17:21, Barret Rhoden wrote: > On 2018-11-12 at 20:31 Paolo Bonzini wrote: >> Looks good. What's the plan for removing PageReserved from DAX pages? > > I hear that's going on in this thread: > >

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread Barret Rhoden
On 2018-11-12 at 20:31 Paolo Bonzini wrote: > Looks good. What's the plan for removing PageReserved from DAX pages? I hear that's going on in this thread: https://lore.kernel.org/lkml/154145268025.30046.11742652345962594283.st...@ahduyck-desk1.jf.intel.com/ Though it looks like it's speeding

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread Barret Rhoden
On 2018-11-13 at 05:02 Pankaj Gupta wrote: > As this patch is dependent on PageReserved patch(which is in progress), just > wondering if we are able to test the code path for hugepage with DAX. For testing, I used the following patch. It's not 100%, since it intercepts at

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread Barret Rhoden
On 2018-11-13 at 10:36 David Hildenbrand wrote: > > Note that KVM already faulted in the page (or huge page) in the host's > > page table, and we hold the KVM mmu spinlock (grabbed before checking > > the mmu seq). > > I wonder if the KVM mmu spinlock is enough for walking (not KVM >

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread Paolo Bonzini
On 13/11/2018 11:02, Pankaj Gupta wrote: > >> >> On 09.11.18 21:39, Barret Rhoden wrote: >>> This change allows KVM to map DAX-backed files made of huge pages with >>> huge mappings in the EPT/TDP. >>> >>> DAX pages are not PageTransCompound. The existing check is trying to >>> determine if the

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread Pankaj Gupta
> > On 09.11.18 21:39, Barret Rhoden wrote: > > This change allows KVM to map DAX-backed files made of huge pages with > > huge mappings in the EPT/TDP. > > > > DAX pages are not PageTransCompound. The existing check is trying to > > determine if the mapping for the pfn is a huge mapping or

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-13 Thread David Hildenbrand
On 09.11.18 21:39, Barret Rhoden wrote: > This change allows KVM to map DAX-backed files made of huge pages with > huge mappings in the EPT/TDP. > > DAX pages are not PageTransCompound. The existing check is trying to > determine if the mapping for the pfn is a huge mapping or not. For >

Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-12 Thread Paolo Bonzini
On 09/11/2018 21:39, Barret Rhoden wrote: > This change allows KVM to map DAX-backed files made of huge pages with > huge mappings in the EPT/TDP. > > DAX pages are not PageTransCompound. The existing check is trying to > determine if the mapping for the pfn is a huge mapping or not. For >

[PATCH 2/2] kvm: Use huge pages for DAX-backed files

2018-11-09 Thread Barret Rhoden
This change allows KVM to map DAX-backed files made of huge pages with huge mappings in the EPT/TDP. DAX pages are not PageTransCompound. The existing check is trying to determine if the mapping for the pfn is a huge mapping or not. For non-DAX maps, e.g. hugetlbfs, that means checking