[SeaBIOS] [PATCHv2] Support for booting from virtio disks
Anthony Liguori
anthony at codemonkey.ws
Mon May 10 17:48:42 CEST 2010
On 05/10/2010 03:11 AM, Gleb Natapov wrote:
> This patch adds native support for booting from virtio disks to Seabios.
>
> Signed-off-by: Gleb Natapov<gleb at redhat.com>
>
A related problem that I think we need to think about how we solve is
indicating to Seabios which device we want to boot from
With your patch, a user can select a virtio device explicitly or if they
use only one virtio device, it will Just Work.
However, if a user uses IDE and virtio, or a user has multiple disks,
they cannot select a device via -boot.
Is this something we need to address? I don't think we'd break libvirt
if we didn't.
Regards,
Anthony Liguori
> ---
>
> Changelog:
> v1->v2:
> - free memory in case of vq initialization error.
> - change license of virtio ring/pci to LGPLv3 with permission
> of Laurent Vivier (aka the author).
>
> diff --git a/Makefile b/Makefile
> index 327a1bf..d0b8881 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -14,7 +14,8 @@ OUT=out/
> SRCBOTH=misc.c pmm.c stacks.c output.c util.c block.c floppy.c ata.c mouse.c \
> kbd.c pci.c serial.c clock.c pic.c cdrom.c ps2port.c smp.c resume.c \
> pnpbios.c pirtable.c vgahooks.c ramdisk.c pcibios.c blockcmd.c \
> - usb.c usb-uhci.c usb-ohci.c usb-ehci.c usb-hid.c usb-msc.c
> + usb.c usb-uhci.c usb-ohci.c usb-ehci.c usb-hid.c usb-msc.c \
> + virtio-ring.c virtio-pci.c virtio-blk.c
> SRC16=$(SRCBOTH) system.c disk.c apm.c font.c
> SRC32FLAT=$(SRCBOTH) post.c shadow.c memmap.c coreboot.c boot.c \
> acpi.c smm.c mptable.c smbios.c pciinit.c optionroms.c mtrr.c \
> diff --git a/src/block.c b/src/block.c
> index ddf441f..b6b1902 100644
> --- a/src/block.c
> +++ b/src/block.c
> @@ -11,6 +11,7 @@
> #include "util.h" // dprintf
> #include "ata.h" // process_ata_op
> #include "usb-msc.h" // process_usb_op
> +#include "virtio-blk.h" // process_virtio_op
>
> struct drives_s Drives VAR16VISIBLE;
>
> @@ -289,6 +290,8 @@ process_op(struct disk_op_s *op)
> return process_cdemu_op(op);
> case DTYPE_USB:
> return process_usb_op(op);
> + case DTYPE_VIRTIO:
> + return process_virtio_op(op);
> default:
> op->count = 0;
> return DISK_RET_EPARAM;
> diff --git a/src/config.h b/src/config.h
> index b101174..ad569c6 100644
> --- a/src/config.h
> +++ b/src/config.h
> @@ -136,6 +136,9 @@
> #define CONFIG_SUBMODEL_ID 0x00
> #define CONFIG_BIOS_REVISION 0x01
>
> +// Support boot from virtio storage
> +#define CONFIG_VIRTIO_BLK 1
> +
> // Various memory addresses used by the code.
> #define BUILD_STACK_ADDR 0x7000
> #define BUILD_S3RESUME_STACK_ADDR 0x1000
> diff --git a/src/disk.h b/src/disk.h
> index 0cd1b74..9e5b083 100644
> --- a/src/disk.h
> +++ b/src/disk.h
> @@ -197,6 +197,7 @@ struct drive_s {
> #define DTYPE_RAMDISK 0x04
> #define DTYPE_CDEMU 0x05
> #define DTYPE_USB 0x06
> +#define DTYPE_VIRTIO 0x07
>
> #define MAXDESCSIZE 80
>
> diff --git a/src/pci_ids.h b/src/pci_ids.h
> index 1800f1d..e1cded2 100644
> --- a/src/pci_ids.h
> +++ b/src/pci_ids.h
> @@ -2605,3 +2605,6 @@
> #define PCI_DEVICE_ID_RME_DIGI32 0x9896
> #define PCI_DEVICE_ID_RME_DIGI32_PRO 0x9897
> #define PCI_DEVICE_ID_RME_DIGI32_8 0x9898
> +
> +#define PCI_VENDOR_ID_REDHAT_QUMRANET 0x1af4
> +#define PCI_DEVICE_ID_VIRTIO_BLK 0x1001
> diff --git a/src/post.c b/src/post.c
> index 638b0f7..25535e2 100644
> --- a/src/post.c
> +++ b/src/post.c
> @@ -23,6 +23,7 @@
> #include "smbios.h" // smbios_init
> #include "paravirt.h" // qemu_cfg_port_probe
> #include "ps2port.h" // ps2port_setup
> +#include "virtio-blk.h" // virtio_blk_setup
>
> void
> __set_irq(int vector, void *loc)
> @@ -184,6 +185,7 @@ init_hw(void)
> floppy_setup();
> ata_setup();
> ramdisk_setup();
> + virtio_blk_setup();
> }
>
> // Main setup code.
> diff --git a/src/virtio-blk.c b/src/virtio-blk.c
> new file mode 100644
> index 0000000..a41c336
> --- /dev/null
> +++ b/src/virtio-blk.c
> @@ -0,0 +1,155 @@
> +// Virtio blovl boot support.
> +//
> +// Copyright (C) 2010 Red Hat Inc.
> +//
> +// Authors:
> +// Gleb Natapov<gnatapov at redhat.com>
> +//
> +// This file may be distributed under the terms of the GNU LGPLv3 license.
> +
> +#include "util.h" // dprintf
> +#include "pci.h" // foreachpci
> +#include "config.h" // CONFIG_*
> +#include "virtio-pci.h"
> +#include "virtio-blk.h"
> +#include "disk.h"
> +
> +struct virtiodrive_s {
> + struct drive_s drive;
> + struct vring_virtqueue *vq;
> + u16 ioaddr;
> +};
> +
> +static int
> +virtio_blk_read(struct disk_op_s *op)
> +{
> + struct virtiodrive_s *vdrive_g =
> + container_of(op->drive_g, struct virtiodrive_s, drive);
> + struct vring_virtqueue *vq = GET_GLOBAL(vdrive_g->vq);
> + struct virtio_blk_outhdr hdr = {
> + .type = VIRTIO_BLK_T_IN,
> + .ioprio = 0,
> + .sector = op->lba,
> + };
> + u8 status = VIRTIO_BLK_S_UNSUPP;
> + struct vring_list sg[] = {
> + {
> + .addr = MAKE_FLATPTR(GET_SEG(SS),&hdr),
> + .length = sizeof(hdr),
> + },
> + {
> + .addr = op->buf_fl,
> + .length = GET_GLOBAL(vdrive_g->drive.blksize) * op->count,
> + },
> + {
> + .addr = MAKE_FLATPTR(GET_SEG(SS),&status),
> + .length = sizeof(status),
> + },
> + };
> +
> + /* Add to virtqueue and kick host */
> + vring_add_buf(vq, sg, 1, 2, 0, 0);
> + vring_kick(GET_GLOBAL(vdrive_g->ioaddr), vq, 1);
> +
> + /* Wait for reply */
> + while (!vring_more_used(vq))
> + udelay(5);
> +
> + /* Reclaim virtqueue element */
> + vring_get_buf(vq, NULL);
> + return status == VIRTIO_BLK_S_OK ? DISK_RET_SUCCESS : DISK_RET_EBADTRACK;
> +}
> +
> +int
> +process_virtio_op(struct disk_op_s *op)
> +{
> + switch (op->command) {
> + case CMD_READ:
> + return virtio_blk_read(op);
> + case CMD_FORMAT:
> + case CMD_WRITE:
> + return DISK_RET_EWRITEPROTECT;
> + case CMD_RESET:
> + case CMD_ISREADY:
> + case CMD_VERIFY:
> + case CMD_SEEK:
> + return DISK_RET_SUCCESS;
> + default:
> + op->count = 0;
> + return DISK_RET_EPARAM;
> + }
> +}
> +
> +void
> +virtio_blk_setup(void)
> +{
> + ASSERT32FLAT();
> + if (! CONFIG_VIRTIO_BLK)
> + return;
> +
> + dprintf(3, "init virtio-blk\n");
> +
> + int bdf, max;
> + u32 id = PCI_VENDOR_ID_REDHAT_QUMRANET | (PCI_DEVICE_ID_VIRTIO_BLK<< 16);
> + foreachpci(bdf, max) {
> + u32 v = pci_config_readl(bdf, PCI_VENDOR_ID);
> + if (v != id)
> + continue;
> + dprintf(3, "found virtio-blk at %x:%x\n", pci_bdf_to_bus(bdf),
> + pci_bdf_to_dev(bdf));
> + char *desc = malloc_tmphigh(MAXDESCSIZE);
> + struct virtiodrive_s *vdrive_g = malloc_fseg(sizeof(*vdrive_g));
> + struct vring_virtqueue *vq = malloc_low(sizeof(*vq));
> + if (!vdrive_g || !desc || !vq) {
> + warn_noalloc();
> + return;
> + }
> + memset(vdrive_g, 0, sizeof(*vdrive_g));
> + vdrive_g->drive.type = DTYPE_VIRTIO;
> + vdrive_g->drive.cntl_id = bdf;
> + vdrive_g->vq = vq;
> +
> + u16 ioaddr = pci_config_readl(bdf, PCI_BASE_ADDRESS_0)&
> + PCI_BASE_ADDRESS_IO_MASK;
> +
> + vdrive_g->ioaddr = ioaddr;
> +
> + vp_reset(ioaddr);
> + vp_set_status(ioaddr, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> + VIRTIO_CONFIG_S_DRIVER );
> +
> + if (vp_find_vq(ioaddr, 0, vdrive_g->vq)< 0 ) {
> + free(vdrive_g);
> + free(desc);
> + free(vq);
> + dprintf(1, "fail to find vq for virtio-blk %x:%x\n",
> + pci_bdf_to_bus (bdf), pci_bdf_to_dev(bdf));
> + continue;
> + }
> +
> + struct virtio_blk_config cfg;
> + vp_get(ioaddr, 0,&cfg, sizeof(cfg));
> +
> + vdrive_g->drive.blksize = cfg.blk_size;
> + vdrive_g->drive.sectors = cfg.capacity;
> + dprintf(3, "virtio-blk %x:%x blksize=%d sectors=%u\n",
> + pci_bdf_to_bus (bdf), pci_bdf_to_dev(bdf),
> + vdrive_g->drive.blksize, (u32)vdrive_g->drive.sectors);
> +
> + vdrive_g->drive.pchs.cylinders = cfg.cylinders;
> + vdrive_g->drive.pchs.heads = cfg.heads;
> + vdrive_g->drive.pchs.spt = cfg.sectors;
> +
> + setup_translation(&vdrive_g->drive);
> + add_bcv_internal(&vdrive_g->drive);
> +
> + snprintf(desc, MAXDESCSIZE, "Virtio disk PCI:%x:%x",
> + pci_bdf_to_bus(bdf), pci_bdf_to_dev(bdf));
> +
> + vdrive_g->drive.desc = desc;
> +
> + vp_set_status(ioaddr, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> + VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK);
> + }
> +}
> +
> diff --git a/src/virtio-blk.h b/src/virtio-blk.h
> new file mode 100644
> index 0000000..3369ea4
> --- /dev/null
> +++ b/src/virtio-blk.h
> @@ -0,0 +1,40 @@
> +#ifndef _VIRTIO_BLK_H
> +#define _VIRTIO_BLK_H
> +
> +struct virtio_blk_config
> +{
> + u64 capacity;
> + u32 size_max;
> + u32 seg_max;
> + u16 cylinders;
> + u8 heads;
> + u8 sectors;
> + u32 blk_size;
> + u8 physical_block_exp;
> + u8 alignment_offset;
> + u16 min_io_size;
> + u32 opt_io_size;
> +} __attribute__((packed));
> +
> +/* These two define direction. */
> +#define VIRTIO_BLK_T_IN 0
> +#define VIRTIO_BLK_T_OUT 1
> +
> +/* This is the first element of the read scatter-gather list. */
> +struct virtio_blk_outhdr {
> + /* VIRTIO_BLK_T* */
> + u32 type;
> + /* io priority. */
> + u32 ioprio;
> + /* Sector (ie. 512 byte offset) */
> + u64 sector;
> +};
> +
> +#define VIRTIO_BLK_S_OK 0
> +#define VIRTIO_BLK_S_IOERR 1
> +#define VIRTIO_BLK_S_UNSUPP 2
> +
> +int process_virtio_op(struct disk_op_s *op);
> +void virtio_blk_setup(void);
> +
> +#endif /* _VIRTIO_BLK_H */
> diff --git a/src/virtio-pci.c b/src/virtio-pci.c
> new file mode 100644
> index 0000000..e171ea3
> --- /dev/null
> +++ b/src/virtio-pci.c
> @@ -0,0 +1,67 @@
> +/* virtio-pci.c - pci interface for virtio interface
> + *
> + * (c) Copyright 2008 Bull S.A.S.
> + *
> + * Author: Laurent Vivier<Laurent.Vivier at bull.net>
> + *
> + * some parts from Linux Virtio PCI driver
> + *
> + * Copyright IBM Corp. 2007
> + * Authors: Anthony Liguori<aliguori at us.ibm.com>
> + *
> + * Adopted for Seabios: Gleb Natapov<gleb at redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPLv3
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "virtio-ring.h"
> +#include "virtio-pci.h"
> +
> +int vp_find_vq(unsigned int ioaddr, int queue_index,
> + struct vring_virtqueue *vq)
> +{
> + struct vring * vr =&vq->vring;
> + u16 num;
> +
> + ASSERT32FLAT();
> + /* select the queue */
> +
> + outw(queue_index, ioaddr + VIRTIO_PCI_QUEUE_SEL);
> +
> + /* check if the queue is available */
> +
> + num = inw(ioaddr + VIRTIO_PCI_QUEUE_NUM);
> + if (!num) {
> + dprintf(1, "ERROR: queue size is 0\n");
> + return -1;
> + }
> +
> + if (num> MAX_QUEUE_NUM) {
> + dprintf(1, "ERROR: queue size %d> %d\n", num, MAX_QUEUE_NUM);
> + return -1;
> + }
> +
> + /* check if the queue is already active */
> +
> + if (inl(ioaddr + VIRTIO_PCI_QUEUE_PFN)) {
> + dprintf(1, "ERROR: queue already active\n");
> + return -1;
> + }
> +
> + vq->queue_index = queue_index;
> +
> + /* initialize the queue */
> +
> + vring_init(vr, num, (unsigned char*)&vq->queue);
> +
> + /* activate the queue
> + *
> + * NOTE: vr->desc is initialized by vring_init()
> + */
> +
> + outl((unsigned long)virt_to_phys(vr->desc)>> PAGE_SHIFT,
> + ioaddr + VIRTIO_PCI_QUEUE_PFN);
> +
> + return num;
> +}
> diff --git a/src/virtio-pci.h b/src/virtio-pci.h
> new file mode 100644
> index 0000000..6932036
> --- /dev/null
> +++ b/src/virtio-pci.h
> @@ -0,0 +1,97 @@
> +#ifndef _VIRTIO_PCI_H
> +#define _VIRTIO_PCI_H
> +
> +/* A 32-bit r/o bitmask of the features supported by the host */
> +#define VIRTIO_PCI_HOST_FEATURES 0
> +
> +/* A 32-bit r/w bitmask of features activated by the guest */
> +#define VIRTIO_PCI_GUEST_FEATURES 4
> +
> +/* A 32-bit r/w PFN for the currently selected queue */
> +#define VIRTIO_PCI_QUEUE_PFN 8
> +
> +/* A 16-bit r/o queue size for the currently selected queue */
> +#define VIRTIO_PCI_QUEUE_NUM 12
> +
> +/* A 16-bit r/w queue selector */
> +#define VIRTIO_PCI_QUEUE_SEL 14
> +
> +/* A 16-bit r/w queue notifier */
> +#define VIRTIO_PCI_QUEUE_NOTIFY 16
> +
> +/* An 8-bit device status register. */
> +#define VIRTIO_PCI_STATUS 18
> +
> +/* An 8-bit r/o interrupt status register. Reading the value will return the
> + * current contents of the ISR and will also clear it. This is effectively
> + * a read-and-acknowledge. */
> +#define VIRTIO_PCI_ISR 19
> +
> +/* The bit of the ISR which indicates a device configuration change. */
> +#define VIRTIO_PCI_ISR_CONFIG 0x2
> +
> +/* The remaining space is defined by each driver as the per-driver
> + * configuration space */
> +#define VIRTIO_PCI_CONFIG 20
> +
> +/* Virtio ABI version, this must match exactly */
> +#define VIRTIO_PCI_ABI_VERSION 0
> +
> +static inline u32 vp_get_features(unsigned int ioaddr)
> +{
> + return inl(ioaddr + VIRTIO_PCI_HOST_FEATURES);
> +}
> +
> +static inline void vp_set_features(unsigned int ioaddr, u32 features)
> +{
> + outl(features, ioaddr + VIRTIO_PCI_GUEST_FEATURES);
> +}
> +
> +static inline void vp_get(unsigned int ioaddr, unsigned offset,
> + void *buf, unsigned len)
> +{
> + u8 *ptr = buf;
> + unsigned i;
> +
> + for (i = 0; i< len; i++)
> + ptr[i] = inb(ioaddr + VIRTIO_PCI_CONFIG + offset + i);
> +}
> +
> +static inline u8 vp_get_status(unsigned int ioaddr)
> +{
> + return inb(ioaddr + VIRTIO_PCI_STATUS);
> +}
> +
> +static inline void vp_set_status(unsigned int ioaddr, u8 status)
> +{
> + if (status == 0) /* reset */
> + return;
> + outb(status, ioaddr + VIRTIO_PCI_STATUS);
> +}
> +
> +
> +static inline void vp_reset(unsigned int ioaddr)
> +{
> + outb(0, ioaddr + VIRTIO_PCI_STATUS);
> + (void)inb(ioaddr + VIRTIO_PCI_ISR);
> +}
> +
> +static inline void vp_notify(unsigned int ioaddr, int queue_index)
> +{
> + outw(queue_index, ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
> +}
> +
> +static inline void vp_del_vq(unsigned int ioaddr, int queue_index)
> +{
> + /* select the queue */
> +
> + outw(queue_index, ioaddr + VIRTIO_PCI_QUEUE_SEL);
> +
> + /* deactivate the queue */
> +
> + outl(0, ioaddr + VIRTIO_PCI_QUEUE_PFN);
> +}
> +
> +int vp_find_vq(unsigned int ioaddr, int queue_index,
> + struct vring_virtqueue *vq);
> +#endif /* _VIRTIO_PCI_H_ */
> diff --git a/src/virtio-ring.c b/src/virtio-ring.c
> new file mode 100644
> index 0000000..f4a2efe
> --- /dev/null
> +++ b/src/virtio-ring.c
> @@ -0,0 +1,152 @@
> +/* virtio-pci.c - virtio ring management
> + *
> + * (c) Copyright 2008 Bull S.A.S.
> + *
> + * Author: Laurent Vivier<Laurent.Vivier at bull.net>
> + *
> + * some parts from Linux Virtio Ring
> + *
> + * Copyright Rusty Russell IBM Corporation 2007
> + *
> + * Adopted for Seabios: Gleb Natapov<gleb at redhat.com>
> + *
> + * This work is licensed under the terms of the GNU LGPLv3
> + * See the COPYING file in the top-level directory.
> + *
> + *
> + */
> +
> +#include "virtio-ring.h"
> +#include "virtio-pci.h"
> +
> +#define BUG() do { \
> + dprintf(1, "BUG: failure at %s:%d/%s()!\n", \
> + __FILE__, __LINE__, __FUNCTION__); \
> + while(1); \
> + } while (0)
> +#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
> +
> +/*
> + * vring_more_used
> + *
> + * is there some used buffers ?
> + *
> + */
> +
> +int vring_more_used(struct vring_virtqueue *vq)
> +{
> + struct vring_used *used = GET_FLATPTR(vq->vring.used);
> + wmb();
> + return GET_FLATPTR(vq->last_used_idx) != GET_FLATPTR(used->idx);
> +}
> +
> +/*
> + * vring_free
> + *
> + * put at the begin of the free list the current desc[head]
> + */
> +
> +void vring_detach(struct vring_virtqueue *vq, unsigned int head)
> +{
> + struct vring *vr =&vq->vring;
> + struct vring_desc *desc = GET_FLATPTR(vr->desc);
> + unsigned int i;
> +
> + /* find end of given descriptor */
> +
> + i = head;
> + while (GET_FLATPTR(desc[i].flags)& VRING_DESC_F_NEXT)
> + i = GET_FLATPTR(desc[i].next);
> +
> + /* link it with free list and point to it */
> +
> + SET_FLATPTR(desc[i].next, GET_FLATPTR(vq->free_head));
> + wmb();
> + SET_FLATPTR(vq->free_head, head);
> +}
> +
> +/*
> + * vring_get_buf
> + *
> + * get a buffer from the used list
> + *
> + */
> +
> +int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len)
> +{
> + struct vring *vr =&vq->vring;
> + struct vring_used_elem *elem;
> + struct vring_used *used = GET_FLATPTR(vq->vring.used);
> + u32 id;
> + int ret;
> +
> +// BUG_ON(!vring_more_used(vq));
> +
> + elem =&used->ring[GET_FLATPTR(vq->last_used_idx) % GET_FLATPTR(vr->num)];
> + wmb();
> + id = GET_FLATPTR(elem->id);
> + if (len != NULL)
> + *len = GET_FLATPTR(elem->len);
> +
> + ret = GET_FLATPTR(vq->vdata[id]);
> +
> + vring_detach(vq, id);
> +
> + SET_FLATPTR(vq->last_used_idx, GET_FLATPTR(vq->last_used_idx) + 1);
> +
> + return ret;
> +}
> +
> +void vring_add_buf(struct vring_virtqueue *vq,
> + struct vring_list list[],
> + unsigned int out, unsigned int in,
> + int index, int num_added)
> +{
> + struct vring *vr =&vq->vring;
> + int i, av, head, prev;
> + struct vring_desc *desc = GET_FLATPTR(vr->desc);
> + struct vring_avail *avail = GET_FLATPTR(vr->avail);
> +
> + BUG_ON(out + in == 0);
> +
> + prev = 0;
> + head = GET_FLATPTR(vq->free_head);
> + for (i = head; out; i = GET_FLATPTR(desc[i].next), out--) {
> + SET_FLATPTR(desc[i].flags, VRING_DESC_F_NEXT);
> + SET_FLATPTR(desc[i].addr, (u64)virt_to_phys(list->addr));
> + SET_FLATPTR(desc[i].len, list->length);
> + prev = i;
> + list++;
> + }
> + for ( ; in; i = GET_FLATPTR(desc[i].next), in--) {
> + SET_FLATPTR(desc[i].flags, VRING_DESC_F_NEXT|VRING_DESC_F_WRITE);
> + SET_FLATPTR(desc[i].addr, (u64)virt_to_phys(list->addr));
> + SET_FLATPTR(desc[i].len, list->length);
> + prev = i;
> + list++;
> + }
> + SET_FLATPTR(desc[prev].flags,
> + GET_FLATPTR(desc[prev].flags)& ~VRING_DESC_F_NEXT);
> +
> + SET_FLATPTR(vq->free_head, i);
> +
> + SET_FLATPTR(vq->vdata[head], index);
> +
> + av = (GET_FLATPTR(avail->idx) + num_added) % GET_FLATPTR(vr->num);
> + SET_FLATPTR(avail->ring[av], head);
> + wmb();
> +}
> +
> +void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added)
> +{
> + struct vring *vr =&vq->vring;
> + struct vring_avail *avail = GET_FLATPTR(vr->avail);
> + struct vring_used *used = GET_FLATPTR(vq->vring.used);
> +
> + wmb();
> + SET_FLATPTR(avail->idx, GET_FLATPTR(avail->idx) + num_added);
> +
> + mb();
> + if (!(GET_FLATPTR(used->flags)& VRING_USED_F_NO_NOTIFY))
> + vp_notify(ioaddr, GET_FLATPTR(vq->queue_index));
> +}
> diff --git a/src/virtio-ring.h b/src/virtio-ring.h
> new file mode 100644
> index 0000000..b97d572
> --- /dev/null
> +++ b/src/virtio-ring.h
> @@ -0,0 +1,125 @@
> +#ifndef _VIRTIO_RING_H
> +#define _VIRTIO_RING_H
> +
> +#define PAGE_SHIFT 12
> +#define PAGE_MASK (PAGE_SIZE-1)
> +
> +#define virt_to_phys(v) (unsigned long)(v)
> +#define phys_to_virt(p) (void*)(p)
> +#define wmb() barrier()
> +#define mb() barrier()
> +
> +/* Status byte for guest to report progress, and synchronize features. */
> +/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
> +#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
> +/* We have found a driver for the device. */
> +#define VIRTIO_CONFIG_S_DRIVER 2
> +/* Driver has used its parts of the config, and is happy */
> +#define VIRTIO_CONFIG_S_DRIVER_OK 4
> +/* We've given up on this device. */
> +#define VIRTIO_CONFIG_S_FAILED 0x80
> +
> +#define MAX_QUEUE_NUM (128)
> +
> +#define VRING_DESC_F_NEXT 1
> +#define VRING_DESC_F_WRITE 2
> +
> +#define VRING_AVAIL_F_NO_INTERRUPT 1
> +
> +#define VRING_USED_F_NO_NOTIFY 1
> +
> +struct vring_desc
> +{
> + u64 addr;
> + u32 len;
> + u16 flags;
> + u16 next;
> +};
> +
> +struct vring_avail
> +{
> + u16 flags;
> + u16 idx;
> + u16 ring[0];
> +};
> +
> +struct vring_used_elem
> +{
> + u32 id;
> + u32 len;
> +};
> +
> +struct vring_used
> +{
> + u16 flags;
> + u16 idx;
> + struct vring_used_elem ring[];
> +};
> +
> +struct vring {
> + unsigned int num;
> + struct vring_desc *desc;
> + struct vring_avail *avail;
> + struct vring_used *used;
> +};
> +
> +#define vring_size(num) \
> + (((((sizeof(struct vring_desc) * num) + \
> + (sizeof(struct vring_avail) + sizeof(u16) * num)) \
> + + PAGE_MASK)& ~PAGE_MASK) + \
> + (sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num))
> +
> +typedef unsigned char virtio_queue_t[PAGE_MASK + vring_size(MAX_QUEUE_NUM)];
> +
> +struct vring_virtqueue {
> + virtio_queue_t queue;
> + struct vring vring;
> + u16 free_head;
> + u16 last_used_idx;
> + u16 vdata[MAX_QUEUE_NUM];
> + /* PCI */
> + int queue_index;
> +};
> +
> +struct vring_list {
> + char *addr;
> + unsigned int length;
> +};
> +
> +static inline void vring_init(struct vring *vr,
> + unsigned int num, unsigned char *queue)
> +{
> + unsigned int i;
> + unsigned long pa;
> +
> + ASSERT32FLAT();
> + vr->num = num;
> +
> + /* physical address of desc must be page aligned */
> +
> + pa = virt_to_phys(queue);
> + pa = (pa + PAGE_MASK)& ~PAGE_MASK;
> + vr->desc = phys_to_virt(pa);
> +
> + vr->avail = (struct vring_avail *)&vr->desc[num];
> +
> + /* physical address of used must be page aligned */
> +
> + pa = virt_to_phys(&vr->avail->ring[num]);
> + pa = (pa + PAGE_MASK)& ~PAGE_MASK;
> + vr->used = phys_to_virt(pa);
> +
> + for (i = 0; i< num - 1; i++)
> + vr->desc[i].next = i + 1;
> + vr->desc[i].next = 0;
> +}
> +
> +int vring_more_used(struct vring_virtqueue *vq);
> +void vring_detach(struct vring_virtqueue *vq, unsigned int head);
> +int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len);
> +void vring_add_buf(struct vring_virtqueue *vq, struct vring_list list[],
> + unsigned int out, unsigned int in,
> + int index, int num_added);
> +void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added);
> +
> +#endif /* _VIRTIO_RING_H_ */
>
> --
> Gleb.
> --
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