Commit 77ffe333 authored by Himadri Pandya's avatar Himadri Pandya Committed by David S. Miller
Browse files

hv_sock: use HV_HYP_PAGE_SIZE for Hyper-V communication 



Current code assumes PAGE_SIZE (the guest page size) is equal
to the page size used to communicate with Hyper-V (which is
always 4K). While this assumption is true on x86, it may not
be true for Hyper-V on other architectures. For example,
Linux on ARM64 may have PAGE_SIZE of 16K or 64K. A new symbol,
HV_HYP_PAGE_SIZE, has been previously introduced to use when
the Hyper-V page size is intended instead of the guest page size.

Make this code work on non-x86 architectures by using the new
HV_HYP_PAGE_SIZE symbol instead of PAGE_SIZE, where appropriate.
Also replace the now redundant PAGE_SIZE_4K with HV_HYP_PAGE_SIZE.
The change has no effect on x86, but lays the groundwork to run
on ARM64 and others.

Signed-off-by: default avatarHimadri Pandya <himadrispandya@gmail.com>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e17b9322

net/vmw_vsock/hyperv_transport.c

+12 −10
Original line number Diff line number Diff line
@@ -13,15 +13,16 @@ 
#include <linux/hyperv.h>

#include <net/sock.h>

#include <net/af_vsock.h>

#include <asm/hyperv-tlfs.h>



/* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some

 * stricter requirements on the hv_sock ring buffer size of six 4K pages. Newer

 * hosts don't have this limitation; but, keep the defaults the same for compat.

 * stricter requirements on the hv_sock ring buffer size of six 4K pages.

 * hyperv-tlfs defines HV_HYP_PAGE_SIZE as 4K. Newer hosts don't have this

 * limitation; but, keep the defaults the same for compat.

 */

#define PAGE_SIZE_4K		4096

#define RINGBUFFER_HVS_RCV_SIZE (PAGE_SIZE_4K * 6)

#define RINGBUFFER_HVS_SND_SIZE (PAGE_SIZE_4K * 6)

#define RINGBUFFER_HVS_MAX_SIZE (PAGE_SIZE_4K * 64)

#define RINGBUFFER_HVS_RCV_SIZE (HV_HYP_PAGE_SIZE * 6)

#define RINGBUFFER_HVS_SND_SIZE (HV_HYP_PAGE_SIZE * 6)

#define RINGBUFFER_HVS_MAX_SIZE (HV_HYP_PAGE_SIZE * 64)



/* The MTU is 16KB per the host side's design */

#define HVS_MTU_SIZE		(1024 * 16)
@@ -54,7 +55,8 @@ struct hvs_recv_buf { 
 * ringbuffer APIs that allow us to directly copy data from userspace buffer

 * to VMBus ringbuffer.

 */

#define HVS_SEND_BUF_SIZE (PAGE_SIZE_4K - sizeof(struct vmpipe_proto_header))

#define HVS_SEND_BUF_SIZE \

		(HV_HYP_PAGE_SIZE - sizeof(struct vmpipe_proto_header))



struct hvs_send_buf {

	/* The header before the payload data */
@@ -393,10 +395,10 @@ static void hvs_open_connection(struct vmbus_channel *chan) 
	} else {

		sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE);

		sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE);

		sndbuf = ALIGN(sndbuf, PAGE_SIZE);

		sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE);

		rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE);

		rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE);

		rcvbuf = ALIGN(rcvbuf, PAGE_SIZE);

		rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE);

	}



	ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb,
@@ -670,7 +672,7 @@ static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, 
	ssize_t ret = 0;

	ssize_t bytes_written = 0;



	BUILD_BUG_ON(sizeof(*send_buf) != PAGE_SIZE_4K);

	BUILD_BUG_ON(sizeof(*send_buf) != HV_HYP_PAGE_SIZE);



	send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL);

	if (!send_buf)

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