freebsd-skq/sys/net/netmap_virt.h
2016-10-16 18:27:41 +00:00

326 lines
11 KiB
C

/*
* Copyright (C) 2013-2016 Luigi Rizzo
* Copyright (C) 2013-2016 Giuseppe Lettieri
* Copyright (C) 2013-2016 Vincenzo Maffione
* Copyright (C) 2015 Stefano Garzarella
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef NETMAP_VIRT_H
#define NETMAP_VIRT_H
#define NETMAP_VIRT_CSB_SIZE 4096
/* ptnetmap features */
#define PTNETMAP_F_BASE 1
#define PTNETMAP_F_FULL 2 /* not used */
#define PTNETMAP_F_VNET_HDR 4
/*
* ptnetmap_memdev: device used to expose memory into the guest VM
*
* These macros are used in the hypervisor frontend (QEMU, bhyve) and in the
* guest device driver.
*/
/* PCI identifiers and PCI BARs for the ptnetmap memdev
* and ptnetmap network interface. */
#define PTNETMAP_MEMDEV_NAME "ptnetmap-memdev"
#define PTNETMAP_PCI_VENDOR_ID 0x3333 /* TODO change vendor_id */
#define PTNETMAP_PCI_DEVICE_ID 0x0001 /* memory device */
#define PTNETMAP_PCI_NETIF_ID 0x0002 /* ptnet network interface */
#define PTNETMAP_IO_PCI_BAR 0
#define PTNETMAP_MEM_PCI_BAR 1
#define PTNETMAP_MSIX_PCI_BAR 2
/* Registers for the ptnetmap memdev */
/* 32 bit r/o */
#define PTNETMAP_IO_PCI_FEATURES 0 /* XXX should be removed */
/* 32 bit r/o */
#define PTNETMAP_IO_PCI_MEMSIZE 4 /* size of the netmap memory shared
* between guest and host */
/* 16 bit r/o */
#define PTNETMAP_IO_PCI_HOSTID 8 /* memory allocator ID in netmap host */
#define PTNETMAP_IO_SIZE 10
/*
* ptnetmap configuration
*
* The hypervisor (QEMU or bhyve) sends this struct to the host netmap
* module through an ioctl() command when it wants to start the ptnetmap
* kthreads.
*/
struct ptnetmap_cfg {
#define PTNETMAP_CFG_FEAT_CSB 0x0001
#define PTNETMAP_CFG_FEAT_EVENTFD 0x0002
#define PTNETMAP_CFG_FEAT_IOCTL 0x0004
uint32_t features;
void *ptrings; /* ptrings inside CSB */
uint32_t num_rings; /* number of entries */
struct ptnet_ring_cfg entries[0]; /* per-ptring configuration */
};
/*
* Functions used to write ptnetmap_cfg from/to the nmreq.
* The user-space application writes the pointer of ptnetmap_cfg
* (user-space buffer) starting from nr_arg1 field, so that the kernel
* can read it with copyin (copy_from_user).
*/
static inline void
ptnetmap_write_cfg(struct nmreq *nmr, struct ptnetmap_cfg *cfg)
{
uintptr_t *nmr_ptncfg = (uintptr_t *)&nmr->nr_arg1;
*nmr_ptncfg = (uintptr_t)cfg;
}
/* ptnetmap control commands */
#define PTNETMAP_PTCTL_CONFIG 1
#define PTNETMAP_PTCTL_FINALIZE 2
#define PTNETMAP_PTCTL_IFNEW 3
#define PTNETMAP_PTCTL_IFDELETE 4
#define PTNETMAP_PTCTL_RINGSCREATE 5
#define PTNETMAP_PTCTL_RINGSDELETE 6
#define PTNETMAP_PTCTL_DEREF 7
#define PTNETMAP_PTCTL_TXSYNC 8
#define PTNETMAP_PTCTL_RXSYNC 9
#define PTNETMAP_PTCTL_REGIF 10
#define PTNETMAP_PTCTL_UNREGIF 11
#define PTNETMAP_PTCTL_HOSTMEMID 12
/* I/O registers for the ptnet device. */
#define PTNET_IO_PTFEAT 0
#define PTNET_IO_PTCTL 4
#define PTNET_IO_PTSTS 8
/* hole */
#define PTNET_IO_MAC_LO 16
#define PTNET_IO_MAC_HI 20
#define PTNET_IO_CSBBAH 24
#define PTNET_IO_CSBBAL 28
#define PTNET_IO_NIFP_OFS 32
#define PTNET_IO_NUM_TX_RINGS 36
#define PTNET_IO_NUM_RX_RINGS 40
#define PTNET_IO_NUM_TX_SLOTS 44
#define PTNET_IO_NUM_RX_SLOTS 48
#define PTNET_IO_VNET_HDR_LEN 52
#define PTNET_IO_END 56
#define PTNET_IO_KICK_BASE 128
#define PTNET_IO_MASK 0xff
/* If defined, CSB is allocated by the guest, not by the host. */
#define PTNET_CSB_ALLOC
/* ptnetmap ring fields shared between guest and host */
struct ptnet_ring {
/* XXX revise the layout to minimize cache bounces. */
uint32_t head; /* GW+ HR+ the head of the guest netmap_ring */
uint32_t cur; /* GW+ HR+ the cur of the guest netmap_ring */
uint32_t guest_need_kick; /* GW+ HR+ host-->guest notification enable */
char pad[4];
uint32_t hwcur; /* GR+ HW+ the hwcur of the host netmap_kring */
uint32_t hwtail; /* GR+ HW+ the hwtail of the host netmap_kring */
uint32_t host_need_kick; /* GR+ HW+ guest-->host notification enable */
uint32_t sync_flags; /* GW+ HR+ the flags of the guest [tx|rx]sync() */
};
/* CSB for the ptnet device. */
struct ptnet_csb {
struct ptnet_ring rings[NETMAP_VIRT_CSB_SIZE/sizeof(struct ptnet_ring)];
};
#if defined (WITH_PTNETMAP_HOST) || defined (WITH_PTNETMAP_GUEST)
/* return l_elem - r_elem with wraparound */
static inline uint32_t
ptn_sub(uint32_t l_elem, uint32_t r_elem, uint32_t num_slots)
{
int64_t res;
res = (int64_t)(l_elem) - r_elem;
return (res < 0) ? res + num_slots : res;
}
#endif /* WITH_PTNETMAP_HOST || WITH_PTNETMAP_GUEST */
#ifdef WITH_PTNETMAP_HOST
/*
* ptnetmap kernel thread routines
* */
/* Functions to read and write CSB fields in the host */
#if defined (linux)
#define CSB_READ(csb, field, r) (get_user(r, &csb->field))
#define CSB_WRITE(csb, field, v) (put_user(v, &csb->field))
#else /* ! linux */
#define CSB_READ(csb, field, r) (r = fuword32(&csb->field))
#define CSB_WRITE(csb, field, v) (suword32(&csb->field, v))
#endif /* ! linux */
/*
* HOST read/write kring pointers from/in CSB
*/
/* Host: Read kring pointers (head, cur, sync_flags) from CSB */
static inline void
ptnetmap_host_read_kring_csb(struct ptnet_ring __user *ptr,
struct netmap_ring *g_ring,
uint32_t num_slots)
{
uint32_t old_head = g_ring->head, old_cur = g_ring->cur;
uint32_t d, inc_h, inc_c;
//mb(); /* Force memory complete before read CSB */
/*
* We must first read head and then cur with a barrier in the
* middle, because cur can exceed head, but not vice versa.
* The guest must first write cur and then head with a barrier.
*
* head <= cur
*
* guest host
*
* STORE(cur) LOAD(head)
* mb() ----------- mb()
* STORE(head) LOAD(cur)
*
* This approach ensures that every head that we read is
* associated with the correct cur. In this way head can not exceed cur.
*/
CSB_READ(ptr, head, g_ring->head);
mb();
CSB_READ(ptr, cur, g_ring->cur);
CSB_READ(ptr, sync_flags, g_ring->flags);
/*
* Even with the previous barrier, it is still possible that we read an
* updated cur and an old head.
* To detect this situation, we can check if the new cur overtakes
* the (apparently) new head.
*/
d = ptn_sub(old_cur, old_head, num_slots); /* previous distance */
inc_c = ptn_sub(g_ring->cur, old_cur, num_slots); /* increase of cur */
inc_h = ptn_sub(g_ring->head, old_head, num_slots); /* increase of head */
if (unlikely(inc_c > num_slots - d + inc_h)) { /* cur overtakes head */
ND(1,"ERROR cur overtakes head - old_cur: %u cur: %u old_head: %u head: %u",
old_cur, g_ring->cur, old_head, g_ring->head);
g_ring->cur = nm_prev(g_ring->head, num_slots - 1);
//*g_cur = *g_head;
}
}
/* Host: Write kring pointers (hwcur, hwtail) into the CSB */
static inline void
ptnetmap_host_write_kring_csb(struct ptnet_ring __user *ptr, uint32_t hwcur,
uint32_t hwtail)
{
/* We must write hwtail before hwcur (see below). */
CSB_WRITE(ptr, hwtail, hwtail);
mb();
CSB_WRITE(ptr, hwcur, hwcur);
//mb(); /* Force memory complete before send notification */
}
#endif /* WITH_PTNETMAP_HOST */
#ifdef WITH_PTNETMAP_GUEST
/*
* GUEST read/write kring pointers from/in CSB.
* To use into device driver.
*/
/* Guest: Write kring pointers (cur, head) into the CSB */
static inline void
ptnetmap_guest_write_kring_csb(struct ptnet_ring *ptr, uint32_t cur,
uint32_t head)
{
/* We must write cur before head for sync reason (see above) */
ptr->cur = cur;
mb();
ptr->head = head;
//mb(); /* Force memory complete before send notification */
}
/* Guest: Read kring pointers (hwcur, hwtail) from CSB */
static inline void
ptnetmap_guest_read_kring_csb(struct ptnet_ring *ptr, struct netmap_kring *kring)
{
uint32_t old_hwcur = kring->nr_hwcur, old_hwtail = kring->nr_hwtail;
uint32_t num_slots = kring->nkr_num_slots;
uint32_t d, inc_hc, inc_ht;
//mb(); /* Force memory complete before read CSB */
/*
* We must first read hwcur and then hwtail with a barrier in the
* middle, because hwtail can exceed hwcur, but not vice versa.
* The host must first write hwtail and then hwcur with a barrier.
*
* hwcur <= hwtail
*
* host guest
*
* STORE(hwtail) LOAD(hwcur)
* mb() --------- mb()
* STORE(hwcur) LOAD(hwtail)
*
* This approach ensures that every hwcur that the guest reads is
* associated with the correct hwtail. In this way hwcur can not exceed
* hwtail.
*/
kring->nr_hwcur = ptr->hwcur;
mb();
kring->nr_hwtail = ptr->hwtail;
/*
* Even with the previous barrier, it is still possible that we read an
* updated hwtail and an old hwcur.
* To detect this situation, we can check if the new hwtail overtakes
* the (apparently) new hwcur.
*/
d = ptn_sub(old_hwtail, old_hwcur, num_slots); /* previous distance */
inc_ht = ptn_sub(kring->nr_hwtail, old_hwtail, num_slots); /* increase of hwtail */
inc_hc = ptn_sub(kring->nr_hwcur, old_hwcur, num_slots); /* increase of hwcur */
if (unlikely(inc_ht > num_slots - d + inc_hc)) {
ND(1, "ERROR hwtail overtakes hwcur - old_hwtail: %u hwtail: %u old_hwcur: %u hwcur: %u",
old_hwtail, kring->nr_hwtail, old_hwcur, kring->nr_hwcur);
kring->nr_hwtail = nm_prev(kring->nr_hwcur, num_slots - 1);
//kring->nr_hwtail = kring->nr_hwcur;
}
}
/* ptnetmap_memdev routines used to talk with ptnetmap_memdev device driver */
struct ptnetmap_memdev;
int nm_os_pt_memdev_iomap(struct ptnetmap_memdev *, vm_paddr_t *, void **);
void nm_os_pt_memdev_iounmap(struct ptnetmap_memdev *);
#endif /* WITH_PTNETMAP_GUEST */
#endif /* NETMAP_VIRT_H */