linux-kernel - Re: [PATCH 1/2] KVM: MMU: Do not treat ZONE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8ba98630-9ca0-85c2-3c94-45d54a448fca@redhat.com>
Date:   Wed, 6 Nov 2019 18:14:40 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Radim Krčmář <rkrcmar@...hat.com>
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Adam Borowski <kilobyte@...band.pl>,
        David Hildenbrand <david@...hat.com>,
        Dan Williams <dan.j.williams@...el.com>
Subject: Re: [PATCH 1/2] KVM: MMU: Do not treat ZONE_DEVICE pages as being
 reserved

On 06/11/19 18:07, Sean Christopherson wrote:
>  void kvm_get_pfn(kvm_pfn_t pfn)
>  {
> -	if (!kvm_is_reserved_pfn(pfn))
> +	if (!kvm_is_reserved_pfn(pfn) && !WARN_ON(kvm_is_zone_device_pfn(pfn)))
>  		get_page(pfn_to_page(pfn));
>  }
>  EXPORT_SYMBOL_GPL(kvm_get_pfn);

Can you call remap_pfn_range with a source address that is ZONE_DEVICE?
 If so, you would get a WARN from the kvm_get_pfn call in
hva_to_pfn_remapped.

Paolo