Linux-kselftest Archive on lore.kernel.org
 help / color / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>,
	Ben Gardon <bgardon@google.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	linux-kselftest@vger.kernel.org
Cc: Peter Xu <peterx@redhat.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Peter Shier <pshier@google.com>, Oliver Upton <oupton@google.com>
Subject: Re: [PATCH 3/3] kvm: mmu: Separate pte generation from set_spte
Date: Wed, 5 Feb 2020 15:53:41 +0100
Message-ID: <1adc4784-8567-d008-4d78-957fd33585ed@redhat.com> (raw)
In-Reply-To: <87pnetkuov.fsf@vitty.brq.redhat.com>

On 05/02/20 14:52, Vitaly Kuznetsov wrote:
>> +	spte = make_spte(vcpu, pte_access, level, gfn, pfn, *sptep, speculative,
>> +			 can_unsync, host_writable, sp_ad_disabled(sp), &ret);
> I'm probably missing something, but in make_spte() I see just one place
> which writes to '*ret' so at the end, this is either
> SET_SPTE_WRITE_PROTECTED_PT or 0 (which we got only because we
> initialize it to 0 in set_spte()). Unless this is preparation to some
> other change, I don't see much value in the complication.
> 
> Can we actually reverse the logic, pass 'spte' by reference and return
> 'ret'?
> 

It gives a similar calling convention between make_spte and
make_mmio_spte.  It's not the most beautiful thing but I think I prefer it.

But the overwhelming function parameters are quite ugly, especially
old_spte.  I don't think it's an improvement, let's consider it together
with the rest of your changes instead.

Paolo


  reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-03 23:09 [PATCH 1/3] kvm: mmu: Replace unsigned with unsigned int for PTE access Ben Gardon
2020-02-03 23:09 ` [PATCH 2/3] kvm: mmu: Separate generating and setting mmio ptes Ben Gardon
2020-02-05 13:37   ` Vitaly Kuznetsov
2020-02-05 14:37     ` Paolo Bonzini
2020-02-03 23:09 ` [PATCH 3/3] kvm: mmu: Separate pte generation from set_spte Ben Gardon
2020-02-05 13:52   ` Vitaly Kuznetsov
2020-02-05 14:53     ` Paolo Bonzini [this message]
2020-02-05 12:00 ` [PATCH 1/3] kvm: mmu: Replace unsigned with unsigned int for PTE access Vitaly Kuznetsov
2020-02-05 16:46 ` Peter Xu

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=1adc4784-8567-d008-4d78-957fd33585ed@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=bgardon@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=oupton@google.com \
    --cc=peterx@redhat.com \
    --cc=pshier@google.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=vkuznets@redhat.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

Linux-kselftest Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-kselftest/0 linux-kselftest/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-kselftest linux-kselftest/ https://lore.kernel.org/linux-kselftest \
		linux-kselftest@vger.kernel.org
	public-inbox-index linux-kselftest

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kselftest


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git