From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A326A30F545 for ; Fri, 15 May 2026 13:11:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778850677; cv=none; b=k/SCGaG6FX/UujMSX+2SrQ8maePXHFWuuvKeBdlNz7mwlxX7oFmDvBTMrOj6OVC+DU+2VxIYDXewJth5BtngLKDqUdxzM+pt9AAPs4mEu1FmeXenQVyRLvCxmqjXVYxO6OXMe8JH3/SsBZAqOv3ou7edhbmqpNxI1ihDMEeEBGw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778850677; c=relaxed/simple; bh=pXS7eAu4kOw07tJrJm2nhPzwFFvFajdpLr1l5U3L4RI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=pB7Sg8hXPYiEkSbAFkYqhe1g/vPzB+xQ8/N5hE5n91EzHZUIKE6kWc0eU2advfkTtqgvbXPcqL7uTaEdrsO5VGI2VPgXJ22auxcfLXKs6d3xfdDTo2OyZBeihvwUoV1Fi0DYTu0PsY7tzkQEFuIstl++hc6I+aARr/BazEPtOVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=B5KyL6d6; arc=none smtp.client-ip=209.85.215.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="B5KyL6d6" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-c82751074c8so8447126a12.0 for ; Fri, 15 May 2026 06:11:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778850676; x=1779455476; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=LGqc20rRiR6+FR8gmTl6hu3ZBwXxzWK7s/bG6re8fpg=; b=B5KyL6d6XkXUBJ9ajGh9nTURsMiSjnUIwwcCxQSXVzA6FXcOf4zpd6JC6QyHtquXHG JWurMOsvqS6obRC6iMi6qGk8WmN2epE5jbRSsKyiHntcdW3UgEoAtKdWXBXDkG+ltqLi 7WVnm3K2S3tTSBFmPmmipQEvC9Dd+OTXcG4z4T5VQel7ykoR7csNS/XuOZySg0KJprH6 FT1tu89v7b36y4R0f8lZ5/F+NMOdS5HdPa4pkFdcNdwUb5YX9+OmzlFxB2y3491dvcga pf1IDESQqemOWIXAwMTkhVy2pfTiDzqcr87TDsbSNrcS2gvwNXF07QfcWugVkzN6LQrV 5mcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778850676; x=1779455476; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LGqc20rRiR6+FR8gmTl6hu3ZBwXxzWK7s/bG6re8fpg=; b=n/Skdecj/vOzEP3Csqi9cU8WYqa2PP+fdQO6T6F8Wa3zGHRdSfenTgC3T1Y1YY89hQ NXSlFgrPbRASrjQdt7z+Vt/oxo5ebIhrH/SO/102f9/D/dQq+vLg29ti0VPdDtOZRmZW tf5qXk08MfXzPp1mu3uDVbS5M1dDi2Wu6wwaQagywzOevJvYlvp+a2ATd1G0h1YsWImW bHIzv6pvp+LhhZ7vRcABLJozpWfHbC1xmzKmW0072YAtGeTrllfgiQziU7h+wZujgk8d oxYh7ckUBiUST9PPvlIf+boX4dbZFRd6UTgK9g1neHfbLOlOR2G46JOZtmNVIY88hQ/F EQYg== X-Forwarded-Encrypted: i=1; AFNElJ/sVBPtuy/H1NSso0V6iMcJ29z2qqp6a4CZAyNecFC+fjqVOQ65IuymQm0I319imUEORYvMRtogmgpaTvI=@vger.kernel.org X-Gm-Message-State: AOJu0YybXU+6kqoZl8miJW/ihx5zoT3rBoFgbYwglSuIP9NzrBJhnjdr hcNYIj5v1hliHP5vbQu1lJNP8HscbZSSoErrLBKyUMmuFkS1gl+QvTYlSdP7eBvD6l3KkCn9/h0 Ze3JcVg== X-Received: from pfbhx24.prod.google.com ([2002:a05:6a00:8998:b0:831:2832:b2fc]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:440f:b0:824:374a:1407 with SMTP id d2e1a72fcca58-83f33c9e8dbmr4659692b3a.16.1778850675650; Fri, 15 May 2026 06:11:15 -0700 (PDT) Date: Fri, 15 May 2026 06:10:49 -0700 In-Reply-To: <20260508060139.850444-1-jun.miao@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260508060139.850444-1-jun.miao@intel.com> Message-ID: Subject: Re: [PATCH] KVM: Fix stale gfn_to_pfn() reference in kvm_invalidate_memslot() comment From: Sean Christopherson To: Jun Miao Cc: pbonzini@redhat.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Fri, May 08, 2026, Jun Miao wrote: > Commit 06cdaff80e50 ("KVM: Drop gfn_to_pfn() APIs now that all users are > gone") removed gfn_to_pfn(), but kvm_invalidate_memslot() still references > gfn_to_pfn() when describing how sp->gfn is validated for guest memory > accesses. > > Update the comment to reference __kvm_faultin_pfn(), which is the actual path > involved here. > > No functional change intended. > > Fixes: 06cdaff80e50 ("KVM: Drop gfn_to_pfn() APIs now that all users are gone") > Signed-off-by: Jun Miao > --- > virt/kvm/kvm_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 89489996fbc1..f4b3ea970a78 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1818,7 +1818,7 @@ static void kvm_invalidate_memslot(struct kvm *kvm, > /* > * From this point no new shadow pages pointing to a deleted, or moved, > * memslot will be created. Validation of sp->gfn happens in: > - * - gfn_to_hva (kvm_read_guest, gfn_to_pfn) > + * - gfn_to_hva (kvm_read_guest, __kvm_faultin_pfn) This isn't really accurate either. On x86, INVALID memslots don't even reach __kvm_faultin_pfn(), because they're filtered out early on by kvm_mmu_faultin_pfn(). Rather than simply fix the stale function reference, I think we should rewrite the comment to describe the mechanics of memslots in excruiating detail. The existing comment is painfully x86-centric, and IMO is unlikely to help anyone actually understand how all of this works; or at least, is supposed to work :-) > * - kvm_is_visible_gfn (mmu_check_root) > */ > kvm_arch_flush_shadow_memslot(kvm, old); > -- > 2.43.0 >