linux-kernel - Re: [RFC v2 28/32] x86/tdx: Make pages shared in ioremap()

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 for Android: free password hash cracker in your pocket

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

Message-ID: <YLU1peNu/744jR/R@zn.tnic>
Date:   Mon, 31 May 2021 21:14:45 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Kuppuswamy, Sathyanarayanan" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
Cc:     Tom Lendacky <thomas.lendacky@....com>,
        Sean Christopherson <seanjc@...gle.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dan Williams <dan.j.williams@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        Raj Ashok <ashok.raj@...el.com>, linux-kernel@...r.kernel.org,
        Brijesh Singh <brijesh.singh@....com>
Subject: Re: [RFC v2 28/32] x86/tdx: Make pages shared in ioremap()

On Mon, May 31, 2021 at 11:45:38AM -0700, Kuppuswamy, Sathyanarayanan wrote:
> We can also use protected_guest_has(VM_VIRTIO_SECURE_FIX) or something
> similar for this purpose. Andi, any comments?

protected_guest_has() is enough for that - no need for two functions.

> IMHO, its better to use above generic config option in common header
> file (linux/protected_guest.h). Any architecture that implements
> protected guest feature can enable it. This will help is hide arch
> specific config options in arch specific header file.

You define empty function stubs for when the arch config option is not
enabled. Everything else is unnecessary. When another architecture needs
this, then another architecture will generalize it like it is usually
done.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette