From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C7CA549365; Wed, 23 Sep 2026 15:24:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790177076; cv=none; b=AxeY9edOKDi/rwTGojKn8DmKNbil09M8lPDZ7T/tZ4fLtbqEW1E7+S+BuIKys5G6XYP9BB3z5BEvhNUBdWVqbZSaho2rzndrO6a1ecXatNF8zJDKMTWYZ7qOFjv2SmcCFjbHjT10+KDu7g/wGqctTN9GAgCtqps9/51KgJ4B+88= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790177076; c=relaxed/simple; bh=42vuhSvBe5+j0EauPTIpEX+X3pMtcFz/th1Ds2wldRo=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=RMT5TM3s3Eau9MTMk7kpDhN5QldmlD0ObZ6zbpgthghKieDnkdyeNQaBFhCJ9LWcEYWXzMmKiePtX6/h8wUJ5sBiGKqq8etfR9O8baMJ1Xm9ei8tKnRixwLIl2NgYGjZYH8zfPOoDreGD89KtnuRhZiAGP2cchj6rqL/T716SPY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HqzAnR8p; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HqzAnR8p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 245CF1F00898; Wed, 23 Sep 2026 15:24:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790177074; bh=42vuhSvBe5+j0EauPTIpEX+X3pMtcFz/th1Ds2wldRo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=HqzAnR8pJfJv5bnArM8/t5yRof2VhnxPvOTJto7LnQZ3h6C7VlZIfzwM3ACMTxRxA OOuHJe1zsqqIDFNtJzktb+LmspCnFdaIv9c7i41shp1Vfaw9VD5m68Lcj8Wnh0KexS StstuQkUFNvYlhJ1bAZRJTi2dcEJLTetUiP+9gpnTo4nMVLWbtTXCBJ+otZ9yfUaWR WcSMs6vNd83ibOMqENmCQBi7vn2XprOQ/VGVzQewQwNePuHbNZiQhn6mx+HsJX27PL uUER8yk+k6VRmw6UZZ53Eq+UMThTT8AiSObzZPxoZ6QEXe7szSTC0ENLhFM+CzELS9 4CvR3H4aTMsEw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 01/14] KVM: Allow architectures to disallow pre-fault Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: kvm@vger.kernel.org, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , kvmarm@lists.linux.dev, "Marc Zyngier" , linux-s390@vger.kernel.org, "Oliver Upton" , "Christian Borntraeger" In-Reply-To: <20260923-kvm-arm-prefault-v4-1-d4b0b4dfa8c3@kernel.org> References: <20260923-kvm-arm-prefault-v4-0-d4b0b4dfa8c3@kernel.org> <20260923-kvm-arm-prefault-v4-1-d4b0b4dfa8c3@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 23 Sep 2026 15:24:33 +0000 Message-Id: <20260923152434.245CF1F00898@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > All existing architectures which implement KVM pre-fault (x86, s390) have > mechanisms for disallowing pre-faulting. >=20 > Currently these are open coded as part of kvm_arch_vcpu_pre_fault_memory(= ). >=20 > Formalise this by moving them into a new kvm_arch_pre_fault_allowed() hoo= k, > which every architecture selecting CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY mu= st > implement, returning an error code if the operation is disallowed or 0 > otherwise. >=20 > The hook is called early in the generic code, allowing architectures to > disallow the operation prior to vCPU load. >=20 > This is important, as kvm_vcpu_pre_fault_memory() is the only place where > generic code can call vcpu_load() on a vCPU that has not yet been > initialised. >=20 > This lays the foundation for a future change which implements pre-faulting > for arm64 which needs to disallow the mechanism for uninitialised vCPUs. >=20 > Suggested-by: Oliver Upton > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260923-kvm-arm-pr= efault-v4-0-d4b0b4dfa8c3@kernel.org?part=3D1