linux-kernel - Re: [PATCH v4 08/12] KVM: selftests: Add guest_memfd based vm_mem_backing_src

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]

Message-ID: <9e60449b-0d2f-43ef-a0b0-3cc999fa9d99@amazon.co.uk>
Date: Tue, 25 Feb 2025 14:12:27 +0000
From: Patrick Roy <roypat@...zon.co.uk>
To: <rppt@...nel.org>, <david@...hat.com>, <seanjc@...gle.com>
CC: <pbonzini@...hat.com>, <corbet@....net>, <willy@...radead.org>,
	<akpm@...ux-foundation.org>, <song@...nel.org>, <jolsa@...nel.org>,
	<ast@...nel.org>, <daniel@...earbox.net>, <andrii@...nel.org>,
	<martin.lau@...ux.dev>, <eddyz87@...il.com>, <yonghong.song@...ux.dev>,
	<john.fastabend@...il.com>, <kpsingh@...nel.org>, <sdf@...ichev.me>,
	<haoluo@...gle.com>, <Liam.Howlett@...cle.com>, <lorenzo.stoakes@...cle.com>,
	<vbabka@...e.cz>, <jannh@...gle.com>, <shuah@...nel.org>,
	<kvm@...r.kernel.org>, <linux-doc@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-fsdevel@...r.kernel.org>,
	<linux-mm@...ck.org>, <bpf@...r.kernel.org>,
	<linux-kselftest@...r.kernel.org>, <tabba@...gle.com>, <jgowans@...zon.com>,
	<graf@...zon.com>, <kalyazin@...zon.com>, <xmarcalx@...zon.com>,
	<derekmn@...zon.com>, <jthoughton@...gle.com>
Subject: Re: [PATCH v4 08/12] KVM: selftests: Add guest_memfd based
 vm_mem_backing_src_types

On Fri, 2025-02-21 at 16:07 +0000, Patrick Roy wrote:

...

> @@ -985,10 +1013,13 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type,
>  	if (alignment > 1)
>  		region->mmap_size += alignment;
>  
> -	region->fd = -1;
> -	if (backing_src_is_shared(src_type))
> +	if (backing_src_is_guest_memfd(src_type))
> +		region->fd = guest_memfd;
> +	else if (backing_src_is_guest_memfd(src_type))

Argh, this is nonsense. Should be 

+	else if (backing_src_is_shared(src_type))

instead.

>  		region->fd = kvm_memfd_alloc(region->mmap_size,
>  					     src_type == VM_MEM_SRC_SHARED_HUGETLB);
> +	else
> +		region->fd = -1;
>  
>  	region->mmap_start = mmap(NULL, region->mmap_size,
>  				  PROT_READ | PROT_WRITE,

...