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[Qemu-devel] Re: [PATCHv2] Support for booting from virtio disks
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From: |
Gleb Natapov |
|
Subject: |
[Qemu-devel] Re: [PATCHv2] Support for booting from virtio disks |
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Date: |
Mon, 10 May 2010 18:54:00 +0300 |
On Mon, May 10, 2010 at 10:48:42AM -0500, Anthony Liguori wrote:
> 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<address@hidden>
>
> 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.
>
Isn't this problem unrelated to this patch? I mean if I start qemu with
two ide devices can I specify from qemu command line which one I want to
boot from?
> 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<address@hidden>
> >+//
> >+// 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<address@hidden>
> >+ *
> >+ * some parts from Linux Virtio PCI driver
> >+ *
> >+ * Copyright IBM Corp. 2007
> >+ * Authors: Anthony Liguori<address@hidden>
> >+ *
> >+ * Adopted for Seabios: Gleb Natapov<address@hidden>
> >+ *
> >+ * 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<address@hidden>
> >+ *
> >+ * some parts from Linux Virtio Ring
> >+ *
> >+ * Copyright Rusty Russell IBM Corporation 2007
> >+ *
> >+ * Adopted for Seabios: Gleb Natapov<address@hidden>
> >+ *
> >+ * 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.
> >--
> >To unsubscribe from this list: send the line "unsubscribe kvm" in
> >the body of a message to address@hidden
> >More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Gleb.
- [Qemu-devel] [PATCHv2] Support for booting from virtio disks, Gleb Natapov, 2010/05/10
- [Qemu-devel] Re: [PATCHv2] Support for booting from virtio disks, Avi Kivity, 2010/05/11
- [Qemu-devel] Re: [PATCHv2] Support for booting from virtio disks, Stefan Hajnoczi, 2010/05/11
- [Qemu-devel] Re: [PATCHv2] Support for booting from virtio disks, Gleb Natapov, 2010/05/11
- [Qemu-devel] Re: [SeaBIOS] [PATCHv2] Support for booting from virtio disks, Kevin O'Connor, 2010/05/11
- [Qemu-devel] Re: [SeaBIOS] [PATCHv2] Support for booting from virtio disks, Gleb Natapov, 2010/05/11
- [Qemu-devel] Re: [SeaBIOS] [PATCHv2] Support for booting from virtio disks, Kevin O'Connor, 2010/05/11