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]
Date: Thu, 1 Feb 2024 09:16:03 +0530
From: Vishal Annapurve <vannapurve@...gle.com>
To: Dave Hansen <dave.hansen@...el.com>
Cc: x86@...nel.org, linux-kernel@...r.kernel.org, pbonzini@...hat.com, 
	rientjes@...gle.com, seanjc@...gle.com, erdemaktas@...gle.com, 
	ackerleytng@...gle.com, jxgao@...gle.com, sagis@...gle.com, oupton@...gle.com, 
	peterx@...hat.com, vkuznets@...hat.com, dmatlack@...gle.com, 
	pgonda@...gle.com, michael.roth@....com, kirill@...temov.name, 
	thomas.lendacky@....com, dave.hansen@...ux.intel.com, 
	linux-coco@...ts.linux.dev, chao.p.peng@...ux.intel.com, 
	isaku.yamahata@...il.com, andrew.jones@...ux.dev, corbet@....net, hch@....de, 
	m.szyprowski@...sung.com, rostedt@...dmis.org, iommu@...ts.linux.dev
Subject: Re: [RFC V1 5/5] x86: CVMs: Ensure that memory conversions happen at
 2M alignment

On Wed, Jan 31, 2024 at 10:03 PM Dave Hansen <dave.hansen@...el.com> wrote:
>
> On 1/11/24 21:52, Vishal Annapurve wrote:
> > @@ -2133,8 +2133,10 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
> >       int ret;
> >
> >       /* Should not be working on unaligned addresses */
> > -     if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
> > -             addr &= PAGE_MASK;
> > +     if (WARN_ONCE(addr & ~HPAGE_MASK, "misaligned address: %#lx\n", addr)
> > +             || WARN_ONCE((numpages << PAGE_SHIFT) & ~HPAGE_MASK,
> > +                     "misaligned numpages: %#lx\n", numpages))
> > +             return -EINVAL;
>
> This series is talking about swiotlb and DMA, then this applies a
> restriction to what I *thought* was a much more generic function:
> __set_memory_enc_pgtable().  What prevents this function from getting
> used on 4k mappings?
>
>

The end goal here is to limit the conversion granularity to hugepage
sizes. SWIOTLB allocations are the major source of unaligned
allocations(and so the conversions) that need to be fixed before
achieving this goal.

This change will ensure that conversion fails for unaligned ranges, as
I don't foresee the need for 4K aligned conversions apart from DMA
allocations.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ