linux-kernel - Re: [PATCH v5 05/12] KVM: Documentation: describe GUEST_MEMFD_FLAG_NO_DIRECT

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Message-ID: <786503d6-e58d-412a-a17b-f5e4e481c3fe@redhat.com>
Date: Thu, 28 Aug 2025 12:27:04 +0200
From: David Hildenbrand <david@...hat.com>
To: "Roy, Patrick" <roypat@...zon.co.uk>,
 "seanjc@...gle.com" <seanjc@...gle.com>
Cc: "tabba@...gle.com" <tabba@...gle.com>,
 "ackerleytng@...gle.com" <ackerleytng@...gle.com>,
 "pbonzini@...hat.com" <pbonzini@...hat.com>,
 "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
 "linux-arm-kernel@...ts.infradead.org"
 <linux-arm-kernel@...ts.infradead.org>,
 "kvmarm@...ts.linux.dev" <kvmarm@...ts.linux.dev>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "linux-mm@...ck.org" <linux-mm@...ck.org>, "rppt@...nel.org"
 <rppt@...nel.org>, "will@...nel.org" <will@...nel.org>,
 "vbabka@...e.cz" <vbabka@...e.cz>, "Cali, Marco" <xmarcalx@...zon.co.uk>,
 "Kalyazin, Nikita" <kalyazin@...zon.co.uk>,
 "Thomson, Jack" <jackabt@...zon.co.uk>, "Manwaring, Derek"
 <derekmn@...zon.com>
Subject: Re: [PATCH v5 05/12] KVM: Documentation: describe
 GUEST_MEMFD_FLAG_NO_DIRECT_MAP

On 28.08.25 11:39, Roy, Patrick wrote:
> Signed-off-by: Patrick Roy <roypat@...zon.co.uk>
> ---
>   Documentation/virt/kvm/api.rst | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index c17a87a0a5ac..b52c14d58798 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -6418,6 +6418,11 @@ When the capability KVM_CAP_GUEST_MEMFD_MMAP is supported, the 'flags' field
>   supports GUEST_MEMFD_FLAG_MMAP.  Setting this flag on guest_memfd creation
>   enables mmap() and faulting of guest_memfd memory to host userspace.
>   
> +When the capability KVM_CAP_GMEM_NO_DIRECT_MAP is supported, the 'flags' field
> +supports GUEST_MEMFG_FLAG_NO_DIRECT_MAP. Setting this flag makes the guest_memfd
> +instance behave similarly to memfd_secret, and unmaps the memory backing it from
> +the kernel's address space after allocation.
> +
>   When the KVM MMU performs a PFN lookup to service a guest fault and the backing
>   guest_memfd has the GUEST_MEMFD_FLAG_MMAP set, then the fault will always be
>   consumed from guest_memfd, regardless of whether it is a shared or a private

WARNING: Missing commit description - Add an appropriate one
WARNING: From:/Signed-off-by: email name mismatch: 'From: "Roy, Patrick" 
<roypat@...zon.co.uk>' != 'Signed-off-by: Patrick Roy <roypat@...zon.co.uk>'

-- 
Cheers

David / dhildenb