File: /usr/include/net/netmap_virt.h
/*
* 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: releng/12.0/sys/net/netmap_virt.h 332423 2018-04-12 07:20:50Z vmaffione $
*/
#ifndef NETMAP_VIRT_H
#define NETMAP_VIRT_H
/*
* 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 0x1b36 /* QEMU virtual devices */
#define PTNETMAP_PCI_DEVICE_ID 0x000c /* memory device */
#define PTNETMAP_PCI_NETIF_ID 0x000d /* 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 */
#define PTNET_MDEV_IO_MEMSIZE_LO 0 /* netmap memory size (low) */
#define PTNET_MDEV_IO_MEMSIZE_HI 4 /* netmap_memory_size (high) */
#define PTNET_MDEV_IO_MEMID 8 /* memory allocator ID in the host */
#define PTNET_MDEV_IO_IF_POOL_OFS 64
#define PTNET_MDEV_IO_IF_POOL_OBJNUM 68
#define PTNET_MDEV_IO_IF_POOL_OBJSZ 72
#define PTNET_MDEV_IO_RING_POOL_OFS 76
#define PTNET_MDEV_IO_RING_POOL_OBJNUM 80
#define PTNET_MDEV_IO_RING_POOL_OBJSZ 84
#define PTNET_MDEV_IO_BUF_POOL_OFS 88
#define PTNET_MDEV_IO_BUF_POOL_OBJNUM 92
#define PTNET_MDEV_IO_BUF_POOL_OBJSZ 96
#define PTNET_MDEV_IO_END 100
/*
* ptnetmap configuration
*
* The ptnet kthreads (running in host kernel-space) need to be configured
* in order to know how to intercept guest kicks (I/O register writes) and
* how to inject MSI-X interrupts to the guest. The configuration may vary
* depending on the hypervisor. Currently, we support QEMU/KVM on Linux and
* and bhyve on FreeBSD.
* The configuration is passed by the hypervisor to the host netmap module
* by means of an ioctl() with nr_cmd=NETMAP_PT_HOST_CREATE, and it is
* specified by the ptnetmap_cfg struct. This struct contains an header
* with general informations and an array of entries whose size depends
* on the hypervisor. The NETMAP_PT_HOST_CREATE command is issued every
* time the kthreads are started.
*/
struct ptnetmap_cfg {
#define PTNETMAP_CFGTYPE_QEMU 0x1
#define PTNETMAP_CFGTYPE_BHYVE 0x2
uint16_t cfgtype; /* how to interpret the cfg entries */
uint16_t entry_size; /* size of a config entry */
uint32_t num_rings; /* number of config entries */
void *csb_gh; /* CSB for guest --> host communication */
void *csb_hg; /* CSB for host --> guest communication */
/* Configuration entries are allocated right after the struct. */
};
/* Configuration of a ptnetmap ring for QEMU. */
struct ptnetmap_cfgentry_qemu {
uint32_t ioeventfd; /* to intercept guest register access */
uint32_t irqfd; /* to inject guest interrupts */
};
/* Configuration of a ptnetmap ring for bhyve. */
struct ptnetmap_cfgentry_bhyve {
uint64_t wchan; /* tsleep() parameter, to wake up kthread */
uint32_t ioctl_fd; /* ioctl fd */
/* ioctl parameters to send irq */
uint32_t ioctl_cmd;
/* vmm.ko MSIX parameters for IOCTL */
struct {
uint64_t msg_data;
uint64_t addr;
} ioctl_data;
};
/*
* Pass a pointer to a userspace buffer to be passed to kernelspace for write
* or read. Used by NETMAP_PT_HOST_CREATE.
* XXX deprecated
*/
static inline void
nmreq_pointer_put(struct nmreq *nmr, void *userptr)
{
uintptr_t *pp = (uintptr_t *)&nmr->nr_arg1;
*pp = (uintptr_t)userptr;
}
static inline void *
nmreq_pointer_get(const struct nmreq *nmr)
{
const uintptr_t *pp = (const uintptr_t *)&nmr->nr_arg1;
return (void *)*pp;
}
/* ptnetmap features */
#define PTNETMAP_F_VNET_HDR 1
/* I/O registers for the ptnet device. */
#define PTNET_IO_PTFEAT 0
#define PTNET_IO_PTCTL 4
#define PTNET_IO_MAC_LO 8
#define PTNET_IO_MAC_HI 12
#define PTNET_IO_CSBBAH 16 /* deprecated */
#define PTNET_IO_CSBBAL 20 /* deprecated */
#define PTNET_IO_NIFP_OFS 24
#define PTNET_IO_NUM_TX_RINGS 28
#define PTNET_IO_NUM_RX_RINGS 32
#define PTNET_IO_NUM_TX_SLOTS 36
#define PTNET_IO_NUM_RX_SLOTS 40
#define PTNET_IO_VNET_HDR_LEN 44
#define PTNET_IO_HOSTMEMID 48
#define PTNET_IO_CSB_GH_BAH 52
#define PTNET_IO_CSB_GH_BAL 56
#define PTNET_IO_CSB_HG_BAH 60
#define PTNET_IO_CSB_HG_BAL 64
#define PTNET_IO_END 68
#define PTNET_IO_KICK_BASE 128
#define PTNET_IO_MASK 0xff
/* ptnetmap control commands (values for PTCTL register) */
#define PTNETMAP_PTCTL_CREATE 1
#define PTNETMAP_PTCTL_DELETE 2
/* ptnetmap synchronization variables shared between guest and host */
struct ptnet_csb_gh {
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 */
uint32_t sync_flags; /* GW+ HR+ the flags of the guest [tx|rx]sync() */
char pad[48]; /* pad to a 64 bytes cacheline */
};
struct ptnet_csb_hg {
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 */
char pad[4+48];
};
#ifdef WITH_PTNETMAP_GUEST
/* 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 **,
uint64_t *);
void nm_os_pt_memdev_iounmap(struct ptnetmap_memdev *);
uint32_t nm_os_pt_memdev_ioread(struct ptnetmap_memdev *, unsigned int);
/* Guest driver: Write kring pointers (cur, head) to the CSB.
* This routine is coupled with ptnetmap_host_read_kring_csb(). */
static inline void
ptnetmap_guest_write_kring_csb(struct ptnet_csb_gh *ptr, uint32_t cur,
uint32_t head)
{
/*
* We need to write cur and head to the CSB but we cannot do it atomically.
* There is no way we can prevent the host from reading the updated value
* of one of the two and the old value of the other. However, if we make
* sure that the host never reads a value of head more recent than the
* value of cur we are safe. We can allow the host to read a value of cur
* more recent than the value of head, since in the netmap ring cur can be
* ahead of head and cur cannot wrap around head because it must be behind
* tail. Inverting the order of writes below could instead result into the
* host to think head went ahead of cur, which would cause the sync
* prologue to fail.
*
* The following memory barrier scheme is used to make this happen:
*
* Guest Host
*
* STORE(cur) LOAD(head)
* mb() <-----------> mb()
* STORE(head) LOAD(cur)
*/
ptr->cur = cur;
mb();
ptr->head = head;
}
/* Guest driver: Read kring pointers (hwcur, hwtail) from the CSB.
* This routine is coupled with ptnetmap_host_write_kring_csb(). */
static inline void
ptnetmap_guest_read_kring_csb(struct ptnet_csb_hg *pthg, struct netmap_kring *kring)
{
/*
* We place a memory barrier to make sure that the update of hwtail never
* overtakes the update of hwcur.
* (see explanation in ptnetmap_host_write_kring_csb).
*/
kring->nr_hwtail = pthg->hwtail;
mb();
kring->nr_hwcur = pthg->hwcur;
}
#endif /* 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 netmap: Write kring pointers (hwcur, hwtail) to the CSB.
* This routine is coupled with ptnetmap_guest_read_kring_csb(). */
static inline void
ptnetmap_host_write_kring_csb(struct ptnet_csb_hg __user *ptr, uint32_t hwcur,
uint32_t hwtail)
{
/*
* The same scheme used in ptnetmap_guest_write_kring_csb() applies here.
* We allow the guest to read a value of hwcur more recent than the value
* of hwtail, since this would anyway result in a consistent view of the
* ring state (and hwcur can never wraparound hwtail, since hwcur must be
* behind head).
*
* The following memory barrier scheme is used to make this happen:
*
* Guest Host
*
* STORE(hwcur) LOAD(hwtail)
* mb() <-------------> mb()
* STORE(hwtail) LOAD(hwcur)
*/
CSB_WRITE(ptr, hwcur, hwcur);
mb();
CSB_WRITE(ptr, hwtail, hwtail);
}
/* Host netmap: Read kring pointers (head, cur, sync_flags) from the CSB.
* This routine is coupled with ptnetmap_guest_write_kring_csb(). */
static inline void
ptnetmap_host_read_kring_csb(struct ptnet_csb_gh __user *ptr,
struct netmap_ring *shadow_ring,
uint32_t num_slots)
{
/*
* We place a memory barrier to make sure that the update of head never
* overtakes the update of cur.
* (see explanation in ptnetmap_guest_write_kring_csb).
*/
CSB_READ(ptr, head, shadow_ring->head);
mb();
CSB_READ(ptr, cur, shadow_ring->cur);
CSB_READ(ptr, sync_flags, shadow_ring->flags);
}
#endif /* WITH_PTNETMAP_HOST */
#endif /* NETMAP_VIRT_H */