From: Matthew Wilcox <willy@infradead.org>
To: "Gowans, James" <jgowans@amazon.com>
Cc: "seanjc@google.com" <seanjc@google.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"Roy, Patrick" <roypat@amazon.co.uk>,
"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
"Manwaring, Derek" <derekmn@amazon.com>,
"rppt@kernel.org" <rppt@kernel.org>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"Woodhouse, David" <dwmw@amazon.co.uk>,
"Kalyazin, Nikita" <kalyazin@amazon.co.uk>,
"lstoakes@gmail.com" <lstoakes@gmail.com>,
"Liam.Howlett@oracle.com" <Liam.Howlett@oracle.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"kirill.shutemov@linux.intel.com"
<kirill.shutemov@linux.intel.com>,
"vbabka@suse.cz" <vbabka@suse.cz>,
"mst@redhat.com" <mst@redhat.com>,
"somlo@cmu.edu" <somlo@cmu.edu>, "Graf (AWS),
Alexander" <graf@amazon.de>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-coco@lists.linux.dev" <linux-coco@lists.linux.dev>
Subject: Re: Unmapping KVM Guest Memory from Host Kernel
Date: Sat, 9 Mar 2024 05:01:45 +0000 [thread overview]
Message-ID: <ZevtORMrVbTsauzn@casper.infradead.org> (raw)
In-Reply-To: <cc1bb8e9bc3e1ab637700a4d3defeec95b55060a.camel@amazon.com>
On Fri, Mar 08, 2024 at 03:50:05PM +0000, Gowans, James wrote:
> Currently when using anonymous memory for KVM guest RAM, the memory all
> remains mapped into the kernel direct map. We are looking at options to
> get KVM guest memory out of the kernel’s direct map as a principled
> approach to mitigating speculative execution issues in the host kernel.
> Our goal is to more completely address the class of issues whose leak
> origin is categorized as "Mapped memory" [1].
One of the things that is holding Linux back is the inability to do I/O
to memory which is not part of memmap. _So Much_ of our infrastructure
is based on having a struct page available to stick into an sglist, bio,
skb_frag, or whatever. The solution to this is to move to a (phys_addr,
length) tuple instead of (page, offset, len) tuple. I call this "phyr"
and I've written about it before. I'm not working on this as I have
quite enough to do with the folio work, but I hope somebody works on it
before I get time to.
next prev parent reply other threads:[~2024-03-09 5:02 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AQHacXBJeX10YUH0O0SiQBg1zQLaEw==>
2024-03-08 15:50 ` Unmapping KVM Guest Memory from Host Kernel Gowans, James
2024-03-08 16:25 ` Brendan Jackman
2024-03-08 17:35 ` David Matlack
2024-03-08 17:45 ` David Woodhouse
2024-03-08 22:47 ` Sean Christopherson
2024-03-09 2:45 ` Manwaring, Derek
2024-03-18 14:11 ` Brendan Jackman
2024-03-08 23:22 ` Sean Christopherson
2024-03-09 11:14 ` Mike Rapoport
2024-05-13 10:31 ` Patrick Roy
2024-05-13 15:39 ` Sean Christopherson
2024-05-13 16:01 ` Gowans, James
2024-05-13 17:09 ` Sean Christopherson
2024-05-13 19:43 ` Gowans, James
2024-05-13 20:36 ` Sean Christopherson
2024-05-13 22:01 ` Manwaring, Derek
2024-03-14 21:45 ` Manwaring, Derek
2024-03-09 5:01 ` Matthew Wilcox [this message]
2024-03-08 21:05 Manwaring, Derek
2024-03-11 9:26 ` Fuad Tabba
2024-03-11 9:29 ` Fuad Tabba
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