linux-kernel - Re: [PATCH v8 net-next 1/1] hv_sock: introduce Hyper-V Sockets

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: <1460078109.1800.16.camel@perches.com>
Date:	Thu, 07 Apr 2016 18:15:09 -0700
From:	Joe Perches <joe@...ches.com>
To:	Dexuan Cui <decui@...rosoft.com>, gregkh@...uxfoundation.org,
	davem@...emloft.net, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, devel@...uxdriverproject.org,
	olaf@...fle.de, apw@...onical.com, jasowang@...hat.com,
	cavery@...hat.com, kys@...rosoft.com, haiyangz@...rosoft.com
Cc:	vkuznets@...hat.com
Subject: Re: [PATCH v8 net-next 1/1] hv_sock: introduce Hyper-V Sockets

On Thu, 2016-04-07 at 18:36 -0700, Dexuan Cui wrote:
> Hyper-V Sockets (hv_sock) supplies a byte-stream based communication
> mechanism between the host and the guest. It's somewhat like TCP over
> VMBus, but the transportation layer (VMBus) is much simpler than IP.
[]
> diff --git a/include/net/af_hvsock.h b/include/net/af_hvsock.h
[]
> +#define VMBUS_RINGBUFFER_SIZE_HVSOCK_RECV (5 * PAGE_SIZE)
> +#define VMBUS_RINGBUFFER_SIZE_HVSOCK_SEND (5 * PAGE_SIZE)
> +
> +#define HVSOCK_RCV_BUF_SZ	VMBUS_RINGBUFFER_SIZE_HVSOCK_RECV
> +#define HVSOCK_SND_BUF_SZ	PAGE_SIZE
[]
> +struct hvsock_sock {
[]
> +	struct {
> +		struct vmpipe_proto_header hdr;
> +		char buf[HVSOCK_SND_BUF_SZ];
> +	} __packed send;
> +
> +	struct {
> +		struct vmpipe_proto_header hdr;
> +		char buf[HVSOCK_RCV_BUF_SZ];
> +		unsigned int data_len;
> +		unsigned int data_offset;
> +	} __packed recv;
> +};

These bufs are not page aligned and so can span pages.

Is there any value in allocating these bufs separately
as pages instead of as a kmalloc?