From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (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 E20A1386571 for ; Tue, 12 May 2026 23:41:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778629283; cv=none; b=dArLqg6f6RZFfLMC1IwHJmFJ+mSSP4lLCtmUro4WbC/NGZlsMr17utjCYcWFZAvTLUl+hFVYBUz7GsPVL6GBW2BMIvDNDX0oC/3MnjFzEVFOtQT6VZjoLkdvPc+tvN+WFqw6zJUhDEXvVrPZJ35OB0nhBd7+iKJullCoU6bk6UY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778629283; c=relaxed/simple; bh=k6glw0fa1xZbNCk2CI4tGQalB7KYR7msKvRtehm/sOc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=cWypenwLE05dy0JlCybxBTsH3aS8jQw6vSZlVZQyhUJPlEISgademFtnj3tRfcbVLuWtcZeXf+JLUxNM/3Dp0TQNobK5yoy66p9i5cuzPImpNYvKpb2JJEJmHn23T7I6Q7RRow5nv0khwWCkF7do3wHlb8fBwE4ceVkdlyiFp5I= 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=eeqjakIH; arc=none smtp.client-ip=209.85.214.201 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="eeqjakIH" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2b9b8137828so64686405ad.0 for ; Tue, 12 May 2026 16:41:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778629281; x=1779234081; 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=Q4JJQhnqYlnKPfDWfphBogFKjvhlthhr+yORGRRz1NM=; b=eeqjakIHRSXldr3Pwxv2NfbIN17luRsYkUf3KAQCLkSBxYdPLZF5SEPAeZD4XQ8RSs K/4uF5q44nOdn+bYVFi03Iwl1CKuCHelH36Nf8yDHJs0x9ZMrZbdluA39HnvqHQNkXFh te1q/jXa09fsLU7rykCDmLMzXfmoAhTmp6Tv3DUFhG7I0vfIXs2FY2DTZYaruAkQkfaQ 4K9gAOdJm4st8gb/wEbb+RDERXpRgkBqCei1a0z0qOjoo6LbyhwFVJ8sQWvOajj0vni+ Wt/hywSPPMlLhB7DzRF+13EyOUmcp4o4LV5Z3iLo92C+hgbX470s8CYjhiGHJHle/8M1 hmqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778629281; x=1779234081; 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=Q4JJQhnqYlnKPfDWfphBogFKjvhlthhr+yORGRRz1NM=; b=ne6RvAj5hn/881dWov/c5b5e4H1vP3dIjzg4axH3MkLFv1qCUssA6eGcjWILeOCK/S Is73ixgKHQqGkxdbOeKTYk2qggyGnKrbVtU9cbASEG7QnFrCFo2JXtrBlXJSlDiux5jT dgKpeDCfrWrtEGBJoloSrUZd/3Ok7SADmIH7jWOGMG6ekpQGQNIaZapNFPeTOxUfzYuE eH4tfOf4J6F+SwA9AzydOoyPUHMWpBmqtGeDf3i+g0vQMaSsn3hnRqojgHyoT92uXm2w yrhkbOcOQ7zmBl+TjAgjsBDxypEF/qJDyc0UbGN60z6iXhOgylKBX+rPZTndrBEPbAT4 NdNg== X-Forwarded-Encrypted: i=1; AFNElJ+qeYltBjlqZFqCrgJ9IN2QvPDIlo/8AV1xGY/j9C41EZowa3Hy19VEmrOwT9wPOcK82qhQBXb+7o3xyaM=@vger.kernel.org X-Gm-Message-State: AOJu0YwdGYfA2Ff3zamY4eZz3Bqy/WYiM+1VMH0jR8uHXPLPfSdSZFnO TQEwAo0+b5bPopcJMh6Ewx6tdZ2gCtzx1XQUCDFH+A2+vYue9ypq5KoFwDy3Kaw36WCHzE/Nazb vbvDW8Q== X-Received: from plhv6.prod.google.com ([2002:a17:903:2386:b0:2ba:b55d:244c]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:d585:b0:2bc:ffe1:c380 with SMTP id d9443c01a7336-2bd2f4dbbbcmr3504675ad.8.1778629280961; Tue, 12 May 2026 16:41:20 -0700 (PDT) Date: Tue, 12 May 2026 16:41:20 -0700 In-Reply-To: <20260508015013.4108345-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260508015013.4108345-1-maobibo@loongson.cn> Message-ID: Subject: Re: [PATCH] KVM: selftests: Check guest memfd validity with flags From: Sean Christopherson To: Bibo Mao Cc: Paolo Bonzini , Oliver Upton , Marc Zyngier , kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Fri, May 08, 2026, Bibo Mao wrote: > The type of guest_memfd in structure kvm_userspace_memory_region2 > is __u32, it is not correct to assign it with -1 and check whether > it is smaller than 0. Here check flags with KVM_MEM_GUEST_MEMFD > set. > > Signed-off-by: Bibo Mao > --- > tools/testing/selftests/kvm/lib/kvm_util.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > index 2a76eca7029d..9d3553f7e6a5 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -817,7 +817,7 @@ static void __vm_mem_region_delete(struct kvm_vm *vm, > kvm_munmap(region->mmap_alias, region->mmap_size); > close(region->fd); > } > - if (region->region.guest_memfd >= 0) > + if (region->region.flags & KVM_MEM_GUEST_MEMFD) Hmm, it's a bit gross, but this is probably more robust? if ((int)region->region.guest_memfd < 0) E.g. if we somehow end up in a state where KVM_MEM_GUEST_MEMFD is either stale or the guest_memfd file was already closed. I highly doubt either of those things will happen, but logically it's the correct fix (the only reason guest_memfd is a u32 is being it's part of the kernel's uAPI).