From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Marc Zyngier <maz@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Paolo Bonzini <pbonzini@redhat.com>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
David Hildenbrand <david@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org,
kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
linux-kernel@vger.kernel.org, Peter Feiner <pfeiner@google.com>,
Peter Shier <pshier@google.com>,
Junaid Shahid <junaids@google.com>,
Ben Gardon <bgardon@google.com>,
Christoffer Dall <christoffer.dall@arm.com>
Subject: Re: [PATCH 17/21] KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches
Date: Thu, 11 Jun 2020 08:43:59 -0700 [thread overview]
Message-ID: <20200611154359.GF29918@linux.intel.com> (raw)
In-Reply-To: <6cc08074c289cbea7b9c1deeaf18c63f@kernel.org>
On Thu, Jun 11, 2020 at 08:59:05AM +0100, Marc Zyngier wrote:
> >diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> >index 9398b66f8a87..688213ef34f0 100644
> >--- a/arch/arm64/kvm/mmu.c
> >+++ b/arch/arm64/kvm/mmu.c
> >@@ -131,7 +131,8 @@ static int mmu_topup_memory_cache(struct
> >kvm_mmu_memory_cache *cache, int min)
> > if (cache->nobjs >= min)
> > return 0;
> > while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
> >- page = (void *)__get_free_page(GFP_PGTABLE_USER);
> >+ page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT |
>
> This is definitely a change in the way we account for guest
> page tables allocation, although I find it bizarre that not
> all architectures account for it the same way.
It's not intended to be a functional change, i.e. the allocations should
still be accounted:
#define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
|
-> #define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO)
== GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO
versus
#define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
with __GFP_ZERO explicitly OR'd in
== GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO
I can put the above in the changelog, unless of course it's wrong and I've
missed something.
> It seems logical to me that nested page tables would be accounted
> against userspace, but I'm willing to be educated on the matter.
>
> Another possibility is that depending on the context, some allocations
> should be accounted on either the kernel or userspace (NV on arm64
> could definitely do something like that). If that was the case,
> maybe moving most of the GFP_* flags into the per-cache flags,
> and have the renaming that Ben suggested earlier.
>
> Thanks,
>
> M.
> --
> Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-06-11 15:44 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-05 21:38 [PATCH 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage Sean Christopherson
2020-06-05 21:38 ` [PATCH 01/21] KVM: x86/mmu: Track the associated kmem_cache in the MMU caches Sean Christopherson
2020-06-09 21:07 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 02/21] KVM: x86/mmu: Consolidate "page" variant of memory cache helpers Sean Christopherson
2020-06-09 22:54 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 03/21] KVM: x86/mmu: Use consistent "mc" name for kvm_mmu_memory_cache locals Sean Christopherson
2020-06-10 22:03 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 04/21] KVM: x86/mmu: Remove superfluous gotos from mmu_topup_memory_caches() Sean Christopherson
2020-06-09 22:57 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 05/21] KVM: x86/mmu: Try to avoid crashing KVM if a MMU memory cache is empty Sean Christopherson
2020-06-10 22:12 ` Ben Gardon
2020-06-17 0:53 ` Sean Christopherson
2020-06-17 16:36 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 06/21] KVM: x86/mmu: Move fast_page_fault() call above mmu_topup_memory_caches() Sean Christopherson
2020-06-09 23:03 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 07/21] KVM: x86/mmu: Topup memory caches after walking GVA->GPA Sean Christopherson
2020-06-10 22:34 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 08/21] KVM: x86/mmu: Clean up the gorilla math in mmu_topup_memory_caches() Sean Christopherson
2020-06-10 22:20 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 09/21] KVM: x86/mmu: Separate the memory caches for shadow pages and gfn arrays Sean Christopherson
2020-06-09 23:56 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 10/21] KVM: x86/mmu: Make __GFP_ZERO a property of the memory cache Sean Christopherson
2020-06-10 18:57 ` Ben Gardon
2020-06-22 19:40 ` Sean Christopherson
2020-06-05 21:38 ` [PATCH 11/21] KVM: x86/mmu: Zero allocate shadow pages (outside of mmu_lock) Sean Christopherson
2020-06-10 18:49 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 12/21] KVM: x86/mmu: Skip filling the gfn cache for guaranteed direct MMU topups Sean Christopherson
2020-06-10 18:52 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 13/21] KVM: x86/mmu: Prepend "kvm_" to memory cache helpers that will be global Sean Christopherson
2020-06-10 18:56 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 14/21] KVM: Move x86's version of struct kvm_mmu_memory_cache to common code Sean Christopherson
2020-06-10 19:01 ` Ben Gardon
2020-06-10 21:58 ` Ben Gardon
2020-06-22 16:57 ` Sean Christopherson
2020-06-11 7:42 ` Marc Zyngier
2020-06-05 21:38 ` [PATCH 15/21] KVM: Move x86's MMU memory cache helpers to common KVM code Sean Christopherson
2020-06-10 20:24 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 16/21] KVM: arm64: Drop @max param from mmu_topup_memory_cache() Sean Christopherson
2020-06-10 22:00 ` Ben Gardon
2020-06-11 15:59 ` Sean Christopherson
2020-06-05 21:38 ` [PATCH 17/21] KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches Sean Christopherson
2020-06-11 7:59 ` Marc Zyngier
2020-06-11 15:43 ` Sean Christopherson [this message]
2020-06-11 15:51 ` Marc Zyngier
2020-06-05 21:38 ` [PATCH 18/21] KVM: arm64: Use common KVM implementation of MMU " Sean Christopherson
2020-06-11 8:01 ` Marc Zyngier
2020-06-11 15:46 ` Sean Christopherson
2020-06-05 21:38 ` [PATCH 19/21] KVM: MIPS: Drop @max param from mmu_topup_memory_cache() Sean Christopherson
2020-06-08 8:56 ` Huacai Chen
2020-06-05 21:38 ` [PATCH 20/21] KVM: MIPS: Account pages used for GPA page tables Sean Christopherson
2020-06-08 8:56 ` Huacai Chen
2020-06-05 21:38 ` [PATCH 21/21] KVM: MIPS: Use common KVM implementation of MMU memory caches Sean Christopherson
2020-06-08 8:57 ` Huacai Chen
2020-06-11 8:06 ` [PATCH 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage Marc Zyngier
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=20200611154359.GF29918@linux.intel.com \
--to=sean.j.christopherson@intel.com \
--cc=bgardon@google.com \
--cc=borntraeger@de.ibm.com \
--cc=christoffer.dall@arm.com \
--cc=cohuck@redhat.com \
--cc=david@redhat.com \
--cc=frankja@linux.ibm.com \
--cc=imbrenda@linux.ibm.com \
--cc=james.morse@arm.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=julien.thierry.kdev@gmail.com \
--cc=junaids@google.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=maz@kernel.org \
--cc=paulus@ozlabs.org \
--cc=pbonzini@redhat.com \
--cc=pfeiner@google.com \
--cc=pshier@google.com \
--cc=suzuki.poulose@arm.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.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 NNTP newsgroup(s).