kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-kernel@vger.kernel.org,
	Lai Jiangshan <jiangshan.ljs@antgroup.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	kvm@vger.kernel.org
Subject: Re: [PATCH V2 4/8] kvm: x86/mmu: Set mmu->sync_page as NULL for direct paging
Date: Fri, 10 Feb 2023 00:57:03 +0000	[thread overview]
Message-ID: <Y+WWX79I3acL1h5S@google.com> (raw)
In-Reply-To: <d5ff098a-731c-f336-efd4-b7405c5e776e@redhat.com>

On Tue, Feb 07, 2023, Paolo Bonzini wrote:
> On 2/7/23 16:57, Lai Jiangshan wrote:
> > From: Lai Jiangshan<jiangshan.ljs@antgroup.com>
> > 
> > mmu->sync_page for direct paging is never called.
> > 
> > And both mmu->sync_page and mm->invlpg only make sense in shadowpaging.
> > Setting mmu->sync_page as NULL for direct paging makes it consistent
> > with mm->invlpg which is set NULL for the case.
> > 
> > Signed-off-by: Lai Jiangshan<jiangshan.ljs@antgroup.com>
> 
> I'd rather have a WARN_ON_ONCE in kvm_sync_page(), otherwise looks good.

Agreed, there's even a WARN_ON_ONCE() to piggyback:

	if (WARN_ON_ONCE(sp->role.direct || !vcpu->arch.mmu->sync_spte ||
			 (sp->role.word ^ root_role.word) & ~sync_role_ign.word))
		return -1;

Of course, the direct + match checks on the role effectively do the same, but I
would rather be explicit.

  reply	other threads:[~2023-02-10  0:59 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20230207155735.2845-1-jiangshanlai@gmail.com>
2023-02-07 15:57 ` [PATCH V2 1/8] kvm: x86/mmu: Use KVM_MMU_ROOT_XXX for kvm_mmu_invalidate_gva() Lai Jiangshan
2023-02-10  0:50   ` Sean Christopherson
2023-02-07 15:57 ` [PATCH V2 2/8] kvm: x86/mmu: Use kvm_mmu_invalidate_gva() in kvm_mmu_invpcid_gva() Lai Jiangshan
2023-02-07 15:57 ` [PATCH V2 3/8] kvm: x86/mmu: Use kvm_mmu_invalidate_gva() in nested_ept_invalidate_addr() Lai Jiangshan
2023-02-10  0:52   ` Sean Christopherson
2023-02-07 15:57 ` [PATCH V2 4/8] kvm: x86/mmu: Set mmu->sync_page as NULL for direct paging Lai Jiangshan
2023-02-07 16:17   ` Paolo Bonzini
2023-02-10  0:57     ` Sean Christopherson [this message]
2023-02-07 15:57 ` [PATCH V2 5/8] kvm: x86/mmu: Move the code out of FNAME(sync_page)'s loop body into mmu.c Lai Jiangshan
2023-02-07 15:57 ` [PATCH V2 6/8] kvm: x86/mmu: Remove FNAME(invlpg) Lai Jiangshan
2023-02-10  1:10   ` Sean Christopherson
2023-02-16  4:16     ` Lai Jiangshan
2023-02-07 15:57 ` [PATCH V2 7/8] kvm: x86/mmu: Reduce the update to the spte in FNAME(sync_page) Lai Jiangshan
2023-02-07 15:57 ` [PATCH V2 8/8] kvm: x86/mmu: Remove @no_dirty_log from FNAME(prefetch_gpte) Lai Jiangshan

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=Y+WWX79I3acL1h5S@google.com \
    --to=seanjc@google.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=jiangshan.ljs@antgroup.com \
    --cc=jiangshanlai@gmail.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /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).