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 96CC7381EA9 for ; Mon, 14 Sep 2026 18:24:16 +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=1789410257; cv=none; b=Cuc7PdM4LDrYJHs+Uqh7fZRU8Fea4Mk7FkAfjrLipPupJgTtL3dNMsQ3NS/CmaXgwTo6o4zGIoP6jwH4ribceDDoYP7LPjcPderS+omy/DdbN3hKMwnz3WON4aPaacXSb8pcPwd6wonNfrS4ZcgujGNToxIRR85+JTftLBU9cBQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789410257; c=relaxed/simple; bh=dGW+X/liPfgw64pPe+WajoEJA9nILyzUVSIP75uQkRg=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=EBbo0wV99PWtFCHDCZ9JnMYTjanqMFk+FYaQoa4baY4VS6TDI56zWjq2IKFf+AzlHTDgk0+rXFtyEUK5oGHsWzHPXreNDlY9S0Ko9M3zDpaE/3E4ePE5OJHtiBiZTvBWMijb9+pYaQhAgkaiUFF3/PB5HFxhHWx7dWNr7CIvzQA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fG+EeLGM; 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="fG+EeLGM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D4011F000FF; Mon, 14 Sep 2026 18:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789410256; bh=yWPc5MBaUgrrDgZ6ixZIstffpF0yrQ9HrwrFNUkJQI8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=fG+EeLGM3/pII7eZIBtuLRkjPmjEuc+s0AC86AoqEkwx/OCuXNg4ZLQehllqyBFiB vBMTzJFvq8BpfxqapQys84XE88ZydyNoI4a9lYz7XkLFX9th+GWQGxYbC5PU/xKahz ++UluP7rqQBWKcrPMIFkVmEyaENNag2SxzLjfdbioPj82nsDqtmZCwCa0Tvd1yoWb7 jhx5rfDggTeDQyltRhAxO2XfOcNkRfXBT/wZoXO1xkyMaBq+qgUwunRTZsW7bP13E9 w1WNwmHm60JV3pLpdulIqmMUHzDWIKZQCttd/7KE8m0Jnm1FTYJY4M88TTf17zZwJT UWND3U9jsSJdw== From: sashiko-bot@kernel.org Subject: Re: [PATCH 1/5] KVM: Reject attempts to lock all vCPUs if vCPU creation is in-progress Reply-To: sashiko-reviews@lists.linux.dev To: "Sean Christopherson" Cc: kvm@vger.kernel.org In-Reply-To: <20260914181223.289061-2-seanjc@google.com> References: <20260914181223.289061-1-seanjc@google.com> <20260914181223.289061-2-seanjc@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 14 Sep 2026 18:24:15 +0000 Message-Id: <20260914182416.4D4011F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Low] Redundant manual check for vCPU creation left behind in ARM VGIC in= itialization. -- commit 62db20a1fe5b1f9f44f668c005957e7cf68b7547 Author: Sean Christopherson KVM: Reject attempts to lock all vCPUs if vCPU creation is in-progress This commit updates KVM to reject attempts to lock all vCPUs while vCPU creation is in progress by adding checks inside kvm_trylock_all_vcpus() and kvm_lock_all_vcpus(). It also opportunistically drops existing manual checks that precede or follow locking all vCPUs. > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 65eb26a0520d8..78cc090435be5 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1363,6 +1363,9 @@ int kvm_trylock_all_vcpus(struct kvm *kvm) > =20 > lockdep_assert_held(&kvm->lock); > =20 > + if (kvm_is_vcpu_creation_in_progress(kvm)) > + return -EBUSY; > + [Severity: Low] Was the manual check in arch/arm64/kvm/vgic/vgic-init.c missed during the cleanup of redundant in-progress vCPU creation checks? The commit message notes that existing manual checks are being dropped, but in kvm_vgic_create(), there is still a manual check immediately following t= he kvm_trylock_all_vcpus() call: arch/arm64/kvm/vgic/vgic-init.c:kvm_vgic_create() { ... ret =3D kvm_trylock_all_vcpus(kvm); if (ret) return ret; ret =3D -EBUSY; if (kvm->created_vcpus !=3D atomic_read(&kvm->online_vcpus)) goto out_unlock; ... } Because this condition is now evaluated inside the preceding kvm_trylock_all_vcpus() call, this manual check in kvm_vgic_create() appears to be left as dead code and will never evaluate to true. > kvm_for_each_vcpu(i, vcpu, kvm) > if (!mutex_trylock_nest_lock(&vcpu->mutex, &kvm->lock)) > goto out_unlock; --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260914181223.2890= 61-1-seanjc@google.com?part=3D1