From: "Tian, Kevin" <kevin.tian@intel.com>
To: "Zhao, Yan Y" <yan.y.zhao@intel.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"jgg@nvidia.com" <jgg@nvidia.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"seanjc@google.com" <seanjc@google.com>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"luto@kernel.org" <luto@kernel.org>,
"peterz@infradead.org" <peterz@infradead.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"bp@alien8.de" <bp@alien8.de>, "hpa@zytor.com" <hpa@zytor.com>,
"corbet@lwn.net" <corbet@lwn.net>,
"joro@8bytes.org" <joro@8bytes.org>,
"will@kernel.org" <will@kernel.org>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>
Subject: RE: [PATCH 1/5] x86/pat: Let pat_pfn_immune_to_uc_mtrr() check MTRR for untracked PAT range
Date: Thu, 16 May 2024 07:42:33 +0000 [thread overview]
Message-ID: <BN9PR11MB527614E72C1DF467FF3F4C948CED2@BN9PR11MB5276.namprd11.prod.outlook.com> (raw)
In-Reply-To: <ZjnwiKcmdpDAjMQ5@yzhao56-desk.sh.intel.com>
> From: Zhao, Yan Y <yan.y.zhao@intel.com>
> Sent: Tuesday, May 7, 2024 5:13 PM
>
> On Tue, May 07, 2024 at 04:26:37PM +0800, Tian, Kevin wrote:
> > > From: Zhao, Yan Y <yan.y.zhao@intel.com>
> > > Sent: Tuesday, May 7, 2024 2:19 PM
> > >
> > > @@ -705,7 +705,17 @@ static enum page_cache_mode
> > > lookup_memtype(u64 paddr)
> > > */
> > > bool pat_pfn_immune_to_uc_mtrr(unsigned long pfn)
> > > {
> > > - enum page_cache_mode cm = lookup_memtype(PFN_PHYS(pfn));
> > > + u64 paddr = PFN_PHYS(pfn);
> > > + enum page_cache_mode cm;
> > > +
> > > + /*
> > > + * Check MTRR type for untracked pat range since lookup_memtype()
> > > always
> > > + * returns WB for this range.
> > > + */
> > > + if (x86_platform.is_untracked_pat_range(paddr, paddr + PAGE_SIZE))
> > > + cm = pat_x_mtrr_type(paddr, paddr + PAGE_SIZE,
> > > _PAGE_CACHE_MODE_WB);
> >
> > doing so violates the name of this function. The PAT of the untracked
> > range is still WB and not immune to UC MTRR.
> Right.
> Do you think we can rename this function to something like
> pfn_of_uncachable_effective_memory_type() and make it work
> under !pat_enabled()
> too?
let's hear from x86/kvm maintainers for their opinions.
My gut-feeling is that kvm_is_mmio_pfn() might be moved into the
x86 core as the logic there has nothing specific to kvm itself. Also
naming-wise it doesn't really matter whether the pfn is mmio. The
real point is to find the uncacheble memtype in the primary mmu
and then follow it in KVM.
from that point probably a pfn_memtype_uncacheable() reads clearer.
next prev parent reply other threads:[~2024-05-16 7:42 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 6:18 [PATCH 0/5] Enforce CPU cache flush for non-coherent device assignment Yan Zhao
2024-05-07 6:19 ` [PATCH 1/5] x86/pat: Let pat_pfn_immune_to_uc_mtrr() check MTRR for untracked PAT range Yan Zhao
2024-05-07 8:26 ` Tian, Kevin
2024-05-07 9:12 ` Yan Zhao
2024-05-08 22:14 ` Alex Williamson
2024-05-09 3:36 ` Yan Zhao
2024-05-16 7:42 ` Tian, Kevin [this message]
2024-05-16 14:07 ` Sean Christopherson
2024-05-20 2:36 ` Tian, Kevin
2024-05-07 6:20 ` [PATCH 2/5] KVM: x86/mmu: Fine-grained check of whether a invalid & RAM PFN is MMIO Yan Zhao
2024-05-07 8:39 ` Tian, Kevin
2024-05-07 9:19 ` Yan Zhao
2024-05-07 6:20 ` [PATCH 3/5] x86/mm: Introduce and export interface arch_clean_nonsnoop_dma() Yan Zhao
2024-05-07 8:51 ` Tian, Kevin
2024-05-07 9:40 ` Yan Zhao
2024-05-20 14:07 ` Christoph Hellwig
2024-05-21 15:49 ` Jason Gunthorpe
2024-05-21 16:00 ` Jason Gunthorpe
2024-05-22 3:41 ` Yan Zhao
2024-05-28 6:37 ` Christoph Hellwig
2024-06-01 19:46 ` Jason Gunthorpe
2024-05-07 6:21 ` [PATCH 4/5] vfio/type1: Flush CPU caches on DMA pages in non-coherent domains Yan Zhao
2024-05-09 18:10 ` Alex Williamson
2024-05-10 10:31 ` Yan Zhao
2024-05-10 16:57 ` Alex Williamson
2024-05-13 7:11 ` Yan Zhao
2024-05-16 7:53 ` Tian, Kevin
2024-05-16 8:34 ` Tian, Kevin
2024-05-16 20:31 ` Alex Williamson
2024-05-17 17:11 ` Jason Gunthorpe
2024-05-20 2:52 ` Tian, Kevin
2024-05-21 16:07 ` Jason Gunthorpe
2024-05-21 16:21 ` Alex Williamson
2024-05-21 16:34 ` Jason Gunthorpe
2024-05-21 18:19 ` Alex Williamson
2024-05-21 18:37 ` Jason Gunthorpe
2024-05-22 6:24 ` Tian, Kevin
2024-05-22 12:29 ` Jason Gunthorpe
2024-05-22 14:43 ` Alex Williamson
2024-05-22 16:52 ` Jason Gunthorpe
2024-05-22 18:22 ` Alex Williamson
2024-05-22 23:26 ` Tian, Kevin
2024-05-22 23:32 ` Jason Gunthorpe
2024-05-22 23:40 ` Tian, Kevin
2024-05-23 14:58 ` Jason Gunthorpe
2024-05-23 22:47 ` Alex Williamson
2024-05-24 0:30 ` Tian, Kevin
2024-05-24 13:50 ` Jason Gunthorpe
2024-05-22 3:33 ` Yan Zhao
2024-05-22 3:24 ` Yan Zhao
2024-05-22 12:26 ` Jason Gunthorpe
2024-05-24 3:07 ` Yan Zhao
2024-05-16 20:50 ` Alex Williamson
2024-05-17 3:11 ` Yan Zhao
2024-05-17 4:44 ` Alex Williamson
2024-05-17 5:00 ` Yan Zhao
2024-05-07 6:22 ` [PATCH 5/5] iommufd: " Yan Zhao
2024-05-09 14:13 ` Jason Gunthorpe
2024-05-10 8:03 ` Yan Zhao
2024-05-10 13:29 ` Jason Gunthorpe
2024-05-13 7:43 ` Yan Zhao
2024-05-14 15:11 ` Jason Gunthorpe
2024-05-15 7:06 ` Yan Zhao
2024-05-15 20:43 ` Jason Gunthorpe
2024-05-16 2:32 ` Yan Zhao
2024-05-16 8:38 ` Tian, Kevin
2024-05-16 9:48 ` Yan Zhao
2024-05-17 17:04 ` Jason Gunthorpe
2024-05-20 2:45 ` Yan Zhao
2024-05-21 16:04 ` Jason Gunthorpe
2024-05-22 3:17 ` Yan Zhao
2024-05-22 6:29 ` Yan Zhao
2024-05-22 17:01 ` Jason Gunthorpe
2024-05-27 7:15 ` Yan Zhao
2024-06-01 16:48 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=BN9PR11MB527614E72C1DF467FF3F4C948CED2@BN9PR11MB5276.namprd11.prod.outlook.com \
--to=kevin.tian@intel.com \
--cc=alex.williamson@redhat.com \
--cc=baolu.lu@linux.intel.com \
--cc=bp@alien8.de \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=iommu@lists.linux.dev \
--cc=jgg@nvidia.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=robin.murphy@arm.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
--cc=x86@kernel.org \
--cc=yan.y.zhao@intel.com \
--cc=yi.l.liu@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).