From: David Hildenbrand <david@redhat.com>
To: "Kalyazin, Nikita" <kalyazin@amazon.co.uk>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"shuah@kernel.org" <shuah@kernel.org>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kselftest@vger.kernel.org"
<linux-kselftest@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"michael.day@amd.com" <michael.day@amd.com>,
"jthoughton@google.com" <jthoughton@google.com>,
"Roy, Patrick" <roypat@amazon.co.uk>,
"Thomson, Jack" <jackabt@amazon.co.uk>,
"Manwaring, Derek" <derekmn@amazon.com>,
"Cali, Marco" <xmarcalx@amazon.co.uk>
Subject: Re: [PATCH v4 0/2] KVM: guest_memfd: use write for population
Date: Thu, 28 Aug 2025 22:07:35 +0200 [thread overview]
Message-ID: <ffe2f73a-6938-4079-b926-9d869f0642ca@redhat.com> (raw)
In-Reply-To: <20250828153049.3922-1-kalyazin@amazon.com>
On 28.08.25 17:30, Kalyazin, Nikita wrote:
> [ based on kvm/next ]
>
> Implement guest_memfd allocation and population via the write syscall.
> This is useful in non-CoCo use cases where the host can access guest
> memory. Even though the same can also be achieved via userspace mapping
> and memcpying from userspace, write provides a more performant option
> because it does not need to set page tables and it does not cause a page
> fault for every page like memcpy would. Note that memcpy cannot be
> accelerated via MADV_POPULATE_WRITE as it is not supported by
> guest_memfd and relies on GUP.
I also added this patch to the pile of guestmemfd preview patches located at
https://git.kernel.org/pub/scm/linux/kernel/git/david/linux.git/log/?h=guestmemfd-preview
There was only one minor conflict regarding setting file->f_mode.
--
Cheers
David / dhildenb
prev parent reply other threads:[~2025-08-28 20:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-28 15:30 [PATCH v4 0/2] KVM: guest_memfd: use write for population Kalyazin, Nikita
2025-08-28 15:31 ` [PATCH v4 1/2] KVM: guest_memfd: add generic population via write Kalyazin, Nikita
2025-08-28 20:01 ` David Hildenbrand
2025-09-01 14:29 ` Nikita Kalyazin
2025-09-01 15:38 ` David Hildenbrand
2025-08-30 18:56 ` kernel test robot
2025-09-01 10:09 ` David Hildenbrand
2025-09-01 14:29 ` Nikita Kalyazin
2025-08-28 15:31 ` [PATCH v4 2/2] KVM: selftests: update guest_memfd write tests Kalyazin, Nikita
2025-08-28 20:07 ` David Hildenbrand [this message]
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