Re: [PATCH 4/4] kvm: i386: Add classic PCI device assignment

[Blue Swirl <blauwirbel@gmail.com>]

On Mon, Aug 27, 2012 at 6:28 AM, Jan Kiszka <jan.kiszka@web.de> wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> This adds PCI device assignment for i386 targets using the classic KVM
> interfaces. This version is 100% identical to what is being maintained
> in qemu-kvm for several years and is supported by libvirt as well. It is
> expected to remain relevant for another couple of years until kernels
> without full-features and performance-wise equivalent VFIO support are
> obsolete.
>
> A refactoring to-do that should be done in-tree is to model MSI and
> MSI-X support via the generic PCI layer, similar to what VFIO is already
> doing for MSI-X. This should improve the correctness and clean up the
> code from duplicate logic.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  hw/kvm/Makefile.objs |    2 +-
>  hw/kvm/pci-assign.c  | 1929 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 1930 insertions(+), 1 deletions(-)
>  create mode 100644 hw/kvm/pci-assign.c
>
> diff --git a/hw/kvm/Makefile.objs b/hw/kvm/Makefile.objs
> index 226497a..f620d7f 100644
> --- a/hw/kvm/Makefile.objs
> +++ b/hw/kvm/Makefile.objs
> @@ -1 +1 @@
> -obj-$(CONFIG_KVM) += clock.o apic.o i8259.o ioapic.o i8254.o
> +obj-$(CONFIG_KVM) += clock.o apic.o i8259.o ioapic.o i8254.o pci-assign.o
> diff --git a/hw/kvm/pci-assign.c b/hw/kvm/pci-assign.c
> new file mode 100644
> index 0000000..9cce02c
> --- /dev/null
> +++ b/hw/kvm/pci-assign.c
> @@ -0,0 +1,1929 @@
> +/*
> + * Copyright (c) 2007, Neocleus Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + *
> + *
> + *  Assign a PCI device from the host to a guest VM.
> + *
> + *  Adapted for KVM by Qumranet.
> + *
> + *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
> + *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
> + *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
> + *  Copyright (C) 2008, Red Hat, Amit Shah (amit.shah@redhat.com)
> + *  Copyright (C) 2008, IBM, Muli Ben-Yehuda (muli@il.ibm.com)
> + */
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <sys/io.h>
> +#include <sys/mman.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include "hw/hw.h"
> +#include "hw/pc.h"
> +#include "qemu-error.h"
> +#include "console.h"
> +#include "hw/loader.h"
> +#include "monitor.h"
> +#include "range.h"
> +#include "sysemu.h"
> +#include "hw/pci.h"
> +#include "hw/msi.h"
> +#include "kvm_i386.h"
> +
> +#define MSIX_PAGE_SIZE 0x1000
> +
> +/* From linux/ioport.h */
> +#define IORESOURCE_IO       0x00000100  /* Resource type */
> +#define IORESOURCE_MEM      0x00000200
> +#define IORESOURCE_IRQ      0x00000400
> +#define IORESOURCE_DMA      0x00000800
> +#define IORESOURCE_PREFETCH 0x00002000  /* No side effects */
> +
> +/* #define DEVICE_ASSIGNMENT_DEBUG 1 */
> +
> +#ifdef DEVICE_ASSIGNMENT_DEBUG
> +#define DEBUG(fmt, ...)                                       \
> +    do {                                                      \
> +        fprintf(stderr, "%s: " fmt, __func__ , __VA_ARGS__);  \
> +    } while (0)
> +#else
> +#define DEBUG(fmt, ...)
> +#endif
> +
> +typedef struct {
> +    int type;           /* Memory or port I/O */
> +    int valid;
> +    uint32_t base_addr;
> +    uint32_t size;    /* size of the region */
> +    int resource_fd;
> +} PCIRegion;

Please don't use anonymous structs.

> +
> +typedef struct {
> +    uint8_t bus, dev, func; /* Bus inside domain, device and function */
> +    int irq;                /* IRQ number */
> +    uint16_t region_number; /* number of active regions */
> +
> +    /* Port I/O or MMIO Regions */
> +    PCIRegion regions[PCI_NUM_REGIONS - 1];
> +    int config_fd;
> +} PCIDevRegions;
> +
> +typedef struct {
> +    MemoryRegion container;
> +    MemoryRegion real_iomem;
> +    union {
> +        void *r_virtbase;    /* mmapped access address for memory regions */
> +        uint32_t r_baseport; /* the base guest port for I/O regions */
> +    } u;
> +    pcibus_t e_size;    /* emulated size of region in bytes */
> +    pcibus_t r_size;    /* real size of region in bytes */
> +    PCIRegion *region;
> +} AssignedDevRegion;
> +
> +#define ASSIGNED_DEVICE_PREFER_MSI_BIT  0
> +#define ASSIGNED_DEVICE_SHARE_INTX_BIT  1
> +
> +#define ASSIGNED_DEVICE_PREFER_MSI_MASK (1 << ASSIGNED_DEVICE_PREFER_MSI_BIT)
> +#define ASSIGNED_DEVICE_SHARE_INTX_MASK (1 << ASSIGNED_DEVICE_SHARE_INTX_BIT)
> +
> +typedef struct {
> +    uint32_t addr_lo;
> +    uint32_t addr_hi;
> +    uint32_t data;
> +    uint32_t ctrl;
> +} MSIXTableEntry;
> +
> +typedef enum AssignedIRQType {
> +    ASSIGNED_IRQ_NONE = 0,
> +    ASSIGNED_IRQ_INTX_HOST_INTX,
> +    ASSIGNED_IRQ_INTX_HOST_MSI,
> +    ASSIGNED_IRQ_MSI,
> +    ASSIGNED_IRQ_MSIX
> +} AssignedIRQType;
> +
> +typedef struct AssignedDevice {
> +    PCIDevice dev;
> +    PCIHostDeviceAddress host;
> +    uint32_t dev_id;
> +    uint32_t features;
> +    int intpin;
> +    AssignedDevRegion v_addrs[PCI_NUM_REGIONS - 1];
> +    PCIDevRegions real_device;
> +    PCIINTxRoute intx_route;
> +    AssignedIRQType assigned_irq_type;
> +    struct {
> +#define ASSIGNED_DEVICE_CAP_MSI (1 << 0)
> +#define ASSIGNED_DEVICE_CAP_MSIX (1 << 1)
> +        uint32_t available;
> +#define ASSIGNED_DEVICE_MSI_ENABLED (1 << 0)
> +#define ASSIGNED_DEVICE_MSIX_ENABLED (1 << 1)
> +#define ASSIGNED_DEVICE_MSIX_MASKED (1 << 2)
> +        uint32_t state;
> +    } cap;
> +    uint8_t emulate_config_read[PCI_CONFIG_SPACE_SIZE];
> +    uint8_t emulate_config_write[PCI_CONFIG_SPACE_SIZE];
> +    int msi_virq_nr;
> +    int *msi_virq;
> +    MSIXTableEntry *msix_table;
> +    target_phys_addr_t msix_table_addr;
> +    uint16_t msix_max;
> +    MemoryRegion mmio;
> +    char *configfd_name;

const? Not if this would mean more casts.

> +    int32_t bootindex;
> +} AssignedDevice;
> +
> +static void assigned_dev_update_irq_routing(PCIDevice *dev);
> +
> +static void assigned_dev_load_option_rom(AssignedDevice *dev);
> +
> +static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev);
> +
> +static uint64_t assigned_dev_ioport_rw(AssignedDevRegion *dev_region,
> +                                       target_phys_addr_t addr, int size,
> +                                       uint64_t *data)
> +{
> +    uint64_t val = 0;
> +    int fd = dev_region->region->resource_fd;
> +
> +    if (fd >= 0) {
> +        if (data) {
> +            DEBUG("pwrite data=%lx, size=%d, e_phys=%lx, addr=%lx\n",

PRIx64 for data, TARGET_FMT_Plx for e_phys and addr.

> +                  *data, size, addr, addr);
> +            if (pwrite(fd, data, size, addr) != size) {
> +                fprintf(stderr, "%s - pwrite failed %s\n",
> +                        __func__, strerror(errno));
> +            }
> +        } else {
> +            if (pread(fd, &val, size, addr) != size) {
> +                fprintf(stderr, "%s - pread failed %s\n",
> +                        __func__, strerror(errno));
> +                val = (1UL << (size * 8)) - 1;
> +            }
> +            DEBUG("pread val=%lx, size=%d, e_phys=%lx, addr=%lx\n",

Also here. Please fix all DEBUG statements.

> +                  val, size, addr, addr);
> +        }
> +    } else {
> +        uint32_t port = addr + dev_region->u.r_baseport;
> +
> +        if (data) {
> +            DEBUG("out data=%lx, size=%d, e_phys=%lx, host=%x\n",
> +                  *data, size, addr, port);
> +            switch (size) {
> +            case 1:
> +                outb(*data, port);
> +                break;
> +            case 2:
> +                outw(*data, port);
> +                break;
> +            case 4:
> +                outl(*data, port);
> +                break;

Maybe add case 8: and default: with abort(), also below.

> +            }
> +        } else {
> +            switch (size) {
> +            case 1:
> +                val = inb(port);
> +                break;
> +            case 2:
> +                val = inw(port);
> +                break;
> +            case 4:
> +                val = inl(port);
> +                break;
> +            }
> +            DEBUG("in data=%lx, size=%d, e_phys=%lx, host=%x\n",
> +                  val, size, addr, port);
> +        }
> +    }
> +    return val;
> +}
> +
> +static void assigned_dev_ioport_write(void *opaque, target_phys_addr_t addr,
> +                                      uint64_t data, unsigned size)
> +{
> +    assigned_dev_ioport_rw(opaque, addr, size, &data);
> +}
> +
> +static uint64_t assigned_dev_ioport_read(void *opaque,
> +                                         target_phys_addr_t addr, unsigned size)
> +{
> +    return assigned_dev_ioport_rw(opaque, addr, size, NULL);
> +}
> +
> +static uint32_t slow_bar_readb(void *opaque, target_phys_addr_t addr)
> +{
> +    AssignedDevRegion *d = opaque;
> +    uint8_t *in = d->u.r_virtbase + addr;

Don't perform arithmetic with void pointers.

> +    uint32_t r;
> +
> +    r = *in;
> +    DEBUG("slow_bar_readl addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, r);
> +
> +    return r;
> +}
> +
> +static uint32_t slow_bar_readw(void *opaque, target_phys_addr_t addr)
> +{
> +    AssignedDevRegion *d = opaque;
> +    uint16_t *in = d->u.r_virtbase + addr;
> +    uint32_t r;
> +
> +    r = *in;
> +    DEBUG("slow_bar_readl addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, r);
> +
> +    return r;
> +}
> +
> +static uint32_t slow_bar_readl(void *opaque, target_phys_addr_t addr)
> +{
> +    AssignedDevRegion *d = opaque;
> +    uint32_t *in = d->u.r_virtbase + addr;
> +    uint32_t r;
> +
> +    r = *in;
> +    DEBUG("slow_bar_readl addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, r);
> +
> +    return r;
> +}
> +
> +static void slow_bar_writeb(void *opaque, target_phys_addr_t addr, uint32_t val)
> +{
> +    AssignedDevRegion *d = opaque;
> +    uint8_t *out = d->u.r_virtbase + addr;
> +
> +    DEBUG("slow_bar_writeb addr=0x" TARGET_FMT_plx " val=0x%02x\n", addr, val);
> +    *out = val;
> +}
> +
> +static void slow_bar_writew(void *opaque, target_phys_addr_t addr, uint32_t val)
> +{
> +    AssignedDevRegion *d = opaque;
> +    uint16_t *out = d->u.r_virtbase + addr;
> +
> +    DEBUG("slow_bar_writew addr=0x" TARGET_FMT_plx " val=0x%04x\n", addr, val);
> +    *out = val;
> +}
> +
> +static void slow_bar_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
> +{
> +    AssignedDevRegion *d = opaque;
> +    uint32_t *out = d->u.r_virtbase + addr;
> +
> +    DEBUG("slow_bar_writel addr=0x" TARGET_FMT_plx " val=0x%08x\n", addr, val);
> +    *out = val;
> +}
> +
> +static const MemoryRegionOps slow_bar_ops = {
> +    .old_mmio = {
> +        .read = { slow_bar_readb, slow_bar_readw, slow_bar_readl, },
> +        .write = { slow_bar_writeb, slow_bar_writew, slow_bar_writel, },
> +    },
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static void assigned_dev_iomem_setup(PCIDevice *pci_dev, int region_num,
> +                                     pcibus_t e_size)
> +{
> +    AssignedDevice *r_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    AssignedDevRegion *region = &r_dev->v_addrs[region_num];
> +    PCIRegion *real_region = &r_dev->real_device.regions[region_num];
> +
> +    if (e_size > 0) {
> +        memory_region_init(&region->container, "assigned-dev-container",
> +                           e_size);
> +        memory_region_add_subregion(&region->container, 0, &region->real_iomem);
> +
> +        /* deal with MSI-X MMIO page */
> +        if (real_region->base_addr <= r_dev->msix_table_addr &&
> +                real_region->base_addr + real_region->size >
> +                r_dev->msix_table_addr) {
> +            int offset = r_dev->msix_table_addr - real_region->base_addr;
> +
> +            memory_region_add_subregion_overlap(&region->container,
> +                                                offset,
> +                                                &r_dev->mmio,
> +                                                1);
> +        }
> +    }
> +}
> +
> +static const MemoryRegionOps assigned_dev_ioport_ops = {
> +    .read = assigned_dev_ioport_read,
> +    .write = assigned_dev_ioport_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static void assigned_dev_ioport_setup(PCIDevice *pci_dev, int region_num,
> +                                      pcibus_t size)
> +{
> +    AssignedDevice *r_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    AssignedDevRegion *region = &r_dev->v_addrs[region_num];
> +
> +    region->e_size = size;
> +    memory_region_init(&region->container, "assigned-dev-container", size);
> +    memory_region_init_io(&region->real_iomem, &assigned_dev_ioport_ops,
> +                          r_dev->v_addrs + region_num,
> +                          "assigned-dev-iomem", size);
> +    memory_region_add_subregion(&region->container, 0, &region->real_iomem);
> +}
> +
> +static uint32_t assigned_dev_pci_read(PCIDevice *d, int pos, int len)
> +{
> +    AssignedDevice *pci_dev = DO_UPCAST(AssignedDevice, dev, d);
> +    uint32_t val;
> +    ssize_t ret;
> +    int fd = pci_dev->real_device.config_fd;
> +
> +again:
> +    ret = pread(fd, &val, len, pos);
> +    if (ret != len) {
> +        if ((ret < 0) && (errno == EINTR || errno == EAGAIN)) {
> +            goto again;
> +        }
> +
> +        hw_error("pci read failed, ret = %zd errno = %d\n", ret, errno);
> +    }
> +
> +    return val;
> +}
> +
> +static uint8_t assigned_dev_pci_read_byte(PCIDevice *d, int pos)
> +{
> +    return (uint8_t)assigned_dev_pci_read(d, pos, 1);
> +}
> +
> +static void assigned_dev_pci_write(PCIDevice *d, int pos, uint32_t val, int len)
> +{
> +    AssignedDevice *pci_dev = DO_UPCAST(AssignedDevice, dev, d);
> +    ssize_t ret;
> +    int fd = pci_dev->real_device.config_fd;
> +
> +again:
> +    ret = pwrite(fd, &val, len, pos);
> +    if (ret != len) {
> +        if ((ret < 0) && (errno == EINTR || errno == EAGAIN)) {
> +            goto again;
> +        }
> +
> +        hw_error("pci write failed, ret = %zd errno = %d\n", ret, errno);
> +    }
> +}
> +
> +static void assigned_dev_emulate_config_read(AssignedDevice *dev,
> +                                             uint32_t offset, uint32_t len)
> +{
> +    memset(dev->emulate_config_read + offset, 0xff, len);
> +}
> +
> +static void assigned_dev_direct_config_read(AssignedDevice *dev,
> +                                            uint32_t offset, uint32_t len)
> +{
> +    memset(dev->emulate_config_read + offset, 0, len);
> +}
> +
> +static void assigned_dev_direct_config_write(AssignedDevice *dev,
> +                                             uint32_t offset, uint32_t len)
> +{
> +    memset(dev->emulate_config_write + offset, 0, len);
> +}
> +
> +static uint8_t pci_find_cap_offset(PCIDevice *d, uint8_t cap, uint8_t start)
> +{
> +    int id;
> +    int max_cap = 48;
> +    int pos = start ? start : PCI_CAPABILITY_LIST;
> +    int status;
> +
> +    status = assigned_dev_pci_read_byte(d, PCI_STATUS);
> +    if ((status & PCI_STATUS_CAP_LIST) == 0) {
> +        return 0;
> +    }
> +
> +    while (max_cap--) {
> +        pos = assigned_dev_pci_read_byte(d, pos);
> +        if (pos < 0x40) {
> +            break;
> +        }
> +
> +        pos &= ~3;
> +        id = assigned_dev_pci_read_byte(d, pos + PCI_CAP_LIST_ID);
> +
> +        if (id == 0xff) {
> +            break;
> +        }
> +        if (id == cap) {
> +            return pos;
> +        }
> +
> +        pos += PCI_CAP_LIST_NEXT;
> +    }
> +    return 0;
> +}
> +
> +static int assigned_dev_register_regions(PCIRegion *io_regions,
> +                                         unsigned long regions_num,
> +                                         AssignedDevice *pci_dev)
> +{
> +    uint32_t i;
> +    PCIRegion *cur_region = io_regions;
> +
> +    for (i = 0; i < regions_num; i++, cur_region++) {
> +        if (!cur_region->valid) {
> +            continue;
> +        }
> +
> +        /* handle memory io regions */
> +        if (cur_region->type & IORESOURCE_MEM) {
> +            int t = cur_region->type & IORESOURCE_PREFETCH
> +                ? PCI_BASE_ADDRESS_MEM_PREFETCH
> +                : PCI_BASE_ADDRESS_SPACE_MEMORY;
> +
> +            /* map physical memory */
> +            pci_dev->v_addrs[i].u.r_virtbase = mmap(NULL, cur_region->size,
> +                                                    PROT_WRITE | PROT_READ,
> +                                                    MAP_SHARED,
> +                                                    cur_region->resource_fd,
> +                                                    (off_t)0);
> +
> +            if (pci_dev->v_addrs[i].u.r_virtbase == MAP_FAILED) {
> +                pci_dev->v_addrs[i].u.r_virtbase = NULL;
> +                fprintf(stderr, "%s: Error: Couldn't mmap 0x%x!"
> +                        "\n", __func__,
> +                        (uint32_t) (cur_region->base_addr));

Why truncate with cast?

> +                return -1;
> +            }
> +
> +            pci_dev->v_addrs[i].r_size = cur_region->size;
> +            pci_dev->v_addrs[i].e_size = 0;
> +
> +            /* add offset */
> +            pci_dev->v_addrs[i].u.r_virtbase +=
> +                (cur_region->base_addr & 0xFFF);
> +
> +            if (cur_region->size & 0xFFF) {
> +                fprintf(stderr, "PCI region %d at address 0x%llx "

PRIx64 ...

> +                        "has size 0x%x, which is not a multiple of 4K. "
> +                        "You might experience some performance hit "
> +                        "due to that.\n",
> +                        i, (unsigned long long)cur_region->base_addr,

... and remove cast.

> +                        cur_region->size);
> +                memory_region_init_io(&pci_dev->v_addrs[i].real_iomem,
> +                                      &slow_bar_ops, &pci_dev->v_addrs[i],
> +                                      "assigned-dev-slow-bar",
> +                                      cur_region->size);
> +            } else {
> +                void *virtbase = pci_dev->v_addrs[i].u.r_virtbase;
> +                char name[32];
> +                snprintf(name, sizeof(name), "%s.bar%d",
> +                         object_get_typename(OBJECT(pci_dev)), i);
> +                memory_region_init_ram_ptr(&pci_dev->v_addrs[i].real_iomem,
> +                                           name, cur_region->size,
> +                                           virtbase);
> +                vmstate_register_ram(&pci_dev->v_addrs[i].real_iomem,
> +                                     &pci_dev->dev.qdev);
> +            }
> +
> +            assigned_dev_iomem_setup(&pci_dev->dev, i, cur_region->size);
> +            pci_register_bar((PCIDevice *) pci_dev, i, t,
> +                             &pci_dev->v_addrs[i].container);
> +            continue;
> +        } else {
> +            /* handle port io regions */
> +            uint32_t val;
> +            int ret;
> +
> +            /* Test kernel support for ioport resource read/write.  Old
> +             * kernels return EIO.  New kernels only allow 1/2/4 byte reads
> +             * so should return EINVAL for a 3 byte read */
> +            ret = pread(pci_dev->v_addrs[i].region->resource_fd, &val, 3, 0);
> +            if (ret >= 0) {
> +                fprintf(stderr, "Unexpected return from I/O port read: %d\n",
> +                        ret);
> +                abort();
> +            } else if (errno != EINVAL) {
> +                fprintf(stderr, "Kernel doesn't support ioport resource "
> +                                "access, hiding this region.\n");
> +                close(pci_dev->v_addrs[i].region->resource_fd);
> +                cur_region->valid = 0;
> +                continue;
> +            }
> +
> +            pci_dev->v_addrs[i].u.r_baseport = cur_region->base_addr;
> +            pci_dev->v_addrs[i].r_size = cur_region->size;
> +            pci_dev->v_addrs[i].e_size = 0;
> +
> +            assigned_dev_ioport_setup(&pci_dev->dev, i, cur_region->size);
> +            pci_register_bar((PCIDevice *) pci_dev, i,
> +                             PCI_BASE_ADDRESS_SPACE_IO,
> +                             &pci_dev->v_addrs[i].container);
> +        }
> +    }
> +
> +    /* success */
> +    return 0;
> +}
> +
> +static int get_real_id(const char *devpath, const char *idname, uint16_t *val)
> +{
> +    FILE *f;
> +    char name[128];
> +    long id;
> +
> +    snprintf(name, sizeof(name), "%s%s", devpath, idname);
> +    f = fopen(name, "r");
> +    if (f == NULL) {
> +        fprintf(stderr, "%s: %s: %m\n", __func__, name);
> +        return -1;
> +    }
> +    if (fscanf(f, "%li\n", &id) == 1) {
> +        *val = id;
> +    } else {
> +        return -1;
> +    }
> +    fclose(f);
> +
> +    return 0;
> +}
> +
> +static int get_real_vendor_id(const char *devpath, uint16_t *val)
> +{
> +    return get_real_id(devpath, "vendor", val);
> +}
> +
> +static int get_real_device_id(const char *devpath, uint16_t *val)
> +{
> +    return get_real_id(devpath, "device", val);
> +}
> +
> +static int get_real_device(AssignedDevice *pci_dev, uint16_t r_seg,
> +                           uint8_t r_bus, uint8_t r_dev, uint8_t r_func)
> +{
> +    char dir[128], name[128];
> +    int fd, r = 0, v;
> +    FILE *f;
> +    unsigned long long start, end, size, flags;

uint64_t

> +    uint16_t id;
> +    PCIRegion *rp;
> +    PCIDevRegions *dev = &pci_dev->real_device;
> +
> +    dev->region_number = 0;
> +
> +    snprintf(dir, sizeof(dir), "/sys/bus/pci/devices/%04x:%02x:%02x.%x/",
> +             r_seg, r_bus, r_dev, r_func);
> +
> +    snprintf(name, sizeof(name), "%sconfig", dir);
> +
> +    if (pci_dev->configfd_name && *pci_dev->configfd_name) {
> +        if (qemu_isdigit(pci_dev->configfd_name[0])) {
> +            dev->config_fd = strtol(pci_dev->configfd_name, NULL, 0);
> +        } else {
> +            dev->config_fd = monitor_get_fd(cur_mon, pci_dev->configfd_name);
> +            if (dev->config_fd < 0) {
> +                fprintf(stderr, "%s: (%s) unkown\n", __func__,
> +                        pci_dev->configfd_name);
> +                return 1;
> +            }
> +        }
> +    } else {
> +        dev->config_fd = open(name, O_RDWR);
> +
> +        if (dev->config_fd == -1) {
> +            fprintf(stderr, "%s: %s: %m\n", __func__, name);
> +            return 1;
> +        }
> +    }
> +again:
> +    r = read(dev->config_fd, pci_dev->dev.config,
> +             pci_config_size(&pci_dev->dev));
> +    if (r < 0) {
> +        if (errno == EINTR || errno == EAGAIN) {
> +            goto again;
> +        }
> +        fprintf(stderr, "%s: read failed, errno = %d\n", __func__, errno);
> +    }
> +
> +    /* Restore or clear multifunction, this is always controlled by qemu */
> +    if (pci_dev->dev.cap_present & QEMU_PCI_CAP_MULTIFUNCTION) {
> +        pci_dev->dev.config[PCI_HEADER_TYPE] |= PCI_HEADER_TYPE_MULTI_FUNCTION;
> +    } else {
> +        pci_dev->dev.config[PCI_HEADER_TYPE] &= ~PCI_HEADER_TYPE_MULTI_FUNCTION;
> +    }
> +
> +    /* Clear host resource mapping info.  If we choose not to register a
> +     * BAR, such as might be the case with the option ROM, we can get
> +     * confusing, unwritable, residual addresses from the host here. */
> +    memset(&pci_dev->dev.config[PCI_BASE_ADDRESS_0], 0, 24);
> +    memset(&pci_dev->dev.config[PCI_ROM_ADDRESS], 0, 4);
> +
> +    snprintf(name, sizeof(name), "%sresource", dir);
> +
> +    f = fopen(name, "r");
> +    if (f == NULL) {
> +        fprintf(stderr, "%s: %s: %m\n", __func__, name);
> +        return 1;
> +    }
> +
> +    for (r = 0; r < PCI_ROM_SLOT; r++) {
> +        if (fscanf(f, "%lli %lli %lli\n", &start, &end, &flags) != 3) {

SCNi64

> +            break;
> +        }
> +
> +        rp = dev->regions + r;
> +        rp->valid = 0;
> +        rp->resource_fd = -1;
> +        size = end - start + 1;
> +        flags &= IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
> +        if (size == 0 || (flags & ~IORESOURCE_PREFETCH) == 0) {
> +            continue;
> +        }
> +        if (flags & IORESOURCE_MEM) {
> +            flags &= ~IORESOURCE_IO;
> +        } else {
> +            flags &= ~IORESOURCE_PREFETCH;
> +        }
> +        snprintf(name, sizeof(name), "%sresource%d", dir, r);
> +        fd = open(name, O_RDWR);
> +        if (fd == -1) {
> +            continue;
> +        }
> +        rp->resource_fd = fd;
> +
> +        rp->type = flags;
> +        rp->valid = 1;
> +        rp->base_addr = start;
> +        rp->size = size;
> +        pci_dev->v_addrs[r].region = rp;
> +        DEBUG("region %d size %d start 0x%llx type %d resource_fd %d\n",
> +              r, rp->size, start, rp->type, rp->resource_fd);
> +    }
> +
> +    fclose(f);
> +
> +    /* read and fill vendor ID */
> +    v = get_real_vendor_id(dir, &id);
> +    if (v) {
> +        return 1;
> +    }
> +    pci_dev->dev.config[0] = id & 0xff;
> +    pci_dev->dev.config[1] = (id & 0xff00) >> 8;
> +
> +    /* read and fill device ID */
> +    v = get_real_device_id(dir, &id);
> +    if (v) {
> +        return 1;
> +    }
> +    pci_dev->dev.config[2] = id & 0xff;
> +    pci_dev->dev.config[3] = (id & 0xff00) >> 8;
> +
> +    pci_word_test_and_clear_mask(pci_dev->emulate_config_write + PCI_COMMAND,
> +                                 PCI_COMMAND_MASTER | PCI_COMMAND_INTX_DISABLE);
> +
> +    dev->region_number = r;
> +    return 0;
> +}

Pretty long function, how about refactoring?

> +
> +static void free_msi_virqs(AssignedDevice *dev)
> +{
> +    int i;
> +
> +    for (i = 0; i < dev->msi_virq_nr; i++) {
> +        if (dev->msi_virq[i] >= 0) {
> +            kvm_irqchip_release_virq(kvm_state, dev->msi_virq[i]);
> +            dev->msi_virq[i] = -1;
> +        }
> +    }
> +    g_free(dev->msi_virq);
> +    dev->msi_virq = NULL;
> +    dev->msi_virq_nr = 0;
> +}
> +
> +static void free_assigned_device(AssignedDevice *dev)
> +{
> +    int i;
> +
> +    if (dev->cap.available & ASSIGNED_DEVICE_CAP_MSIX) {
> +        assigned_dev_unregister_msix_mmio(dev);
> +    }
> +    for (i = 0; i < dev->real_device.region_number; i++) {
> +        PCIRegion *pci_region = &dev->real_device.regions[i];
> +        AssignedDevRegion *region = &dev->v_addrs[i];
> +
> +        if (!pci_region->valid) {
> +            continue;
> +        }
> +        if (pci_region->type & IORESOURCE_IO) {
> +            if (region->u.r_baseport) {
> +                memory_region_del_subregion(&region->container,
> +                                            &region->real_iomem);
> +                memory_region_destroy(&region->real_iomem);
> +                memory_region_destroy(&region->container);
> +            }
> +        } else if (pci_region->type & IORESOURCE_MEM) {
> +            if (region->u.r_virtbase) {
> +                memory_region_del_subregion(&region->container,
> +                                            &region->real_iomem);
> +
> +                /* Remove MSI-X table subregion */
> +                if (pci_region->base_addr <= dev->msix_table_addr &&
> +                    pci_region->base_addr + pci_region->size >
> +                    dev->msix_table_addr) {
> +                    memory_region_del_subregion(&region->container,
> +                                                &dev->mmio);
> +                }
> +
> +                memory_region_destroy(&region->real_iomem);
> +                memory_region_destroy(&region->container);
> +                if (munmap(region->u.r_virtbase,
> +                           (pci_region->size + 0xFFF) & 0xFFFFF000)) {
> +                    fprintf(stderr,
> +                            "Failed to unmap assigned device region: %s\n",
> +                            strerror(errno));
> +                }
> +            }
> +        }
> +        if (pci_region->resource_fd >= 0) {
> +            close(pci_region->resource_fd);
> +        }
> +    }
> +
> +    if (dev->real_device.config_fd >= 0) {
> +        close(dev->real_device.config_fd);
> +    }
> +
> +    free_msi_virqs(dev);
> +}
> +
> +static void assign_failed_examine(AssignedDevice *dev)
> +{
> +    char name[PATH_MAX], dir[PATH_MAX], driver[PATH_MAX] = {}, *ns;
> +    uint16_t vendor_id, device_id;
> +    int r;
> +
> +    sprintf(dir, "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/",
> +            dev->host.domain, dev->host.bus, dev->host.slot,
> +            dev->host.function);

Please use snprintf(), also below.

> +
> +    sprintf(name, "%sdriver", dir);
> +
> +    r = readlink(name, driver, sizeof(driver));
> +    if ((r <= 0) || r >= sizeof(driver)) {
> +        goto fail;
> +    }
> +
> +    ns = strrchr(driver, '/');
> +    if (!ns) {
> +        goto fail;
> +    }
> +
> +    ns++;
> +
> +    if (get_real_vendor_id(dir, &vendor_id) ||
> +        get_real_device_id(dir, &device_id)) {
> +        goto fail;
> +    }
> +
> +    fprintf(stderr, "*** The driver '%s' is occupying your device "
> +                    "%04x:%02x:%02x.%x.\n",
> +            ns, dev->host.domain, dev->host.bus, dev->host.slot,
> +            dev->host.function);
> +    fprintf(stderr, "***\n");
> +    fprintf(stderr, "*** You can try the following commands to free it:\n");
> +    fprintf(stderr, "***\n");
> +    fprintf(stderr, "*** $ echo \"%04x %04x\" > /sys/bus/pci/drivers/pci-stub/"
> +                    "new_id\n", vendor_id, device_id);
> +    fprintf(stderr, "*** $ echo \"%04x:%02x:%02x.%x\" > /sys/bus/pci/drivers/"
> +                    "%s/unbind\n",
> +            dev->host.domain, dev->host.bus, dev->host.slot,
> +            dev->host.function, ns);
> +    fprintf(stderr, "*** $ echo \"%04x:%02x:%02x.%x\" > /sys/bus/pci/drivers/"
> +                    "pci-stub/bind\n",
> +            dev->host.domain, dev->host.bus, dev->host.slot,
> +            dev->host.function);
> +    fprintf(stderr, "*** $ echo \"%04x %04x\" > /sys/bus/pci/drivers/pci-stub"
> +                    "/remove_id\n", vendor_id, device_id);
> +    fprintf(stderr, "***\n");
> +
> +    return;
> +
> +fail:
> +    fprintf(stderr, "Couldn't find out why.\n");
> +}
> +
> +static int assign_device(AssignedDevice *dev)
> +{
> +    uint32_t flags = KVM_DEV_ASSIGN_ENABLE_IOMMU;
> +    int r;
> +
> +    /* Only pass non-zero PCI segment to capable module */
> +    if (!kvm_check_extension(kvm_state, KVM_CAP_PCI_SEGMENT) &&
> +        dev->host.domain) {
> +        fprintf(stderr, "Can't assign device inside non-zero PCI segment "
> +                "as this KVM module doesn't support it.\n");
> +        return -ENODEV;
> +    }
> +
> +    if (!kvm_check_extension(kvm_state, KVM_CAP_IOMMU)) {
> +        fprintf(stderr, "No IOMMU found.  Unable to assign device \"%s\"\n",
> +                dev->dev.qdev.id);
> +        return -ENODEV;
> +    }
> +
> +    if (dev->features & ASSIGNED_DEVICE_SHARE_INTX_MASK &&
> +        kvm_has_intx_set_mask()) {
> +        flags |= KVM_DEV_ASSIGN_PCI_2_3;
> +    }
> +
> +    r = kvm_device_pci_assign(kvm_state, &dev->host, flags, &dev->dev_id);
> +    if (r < 0) {
> +        fprintf(stderr, "Failed to assign device \"%s\" : %s\n",
> +                dev->dev.qdev.id, strerror(-r));
> +
> +        switch (r) {
> +        case -EBUSY:
> +            assign_failed_examine(dev);
> +            break;
> +        default:
> +            break;
> +        }
> +    }
> +    return r;
> +}
> +
> +static bool check_irqchip_in_kernel(void)
> +{
> +    if (kvm_irqchip_in_kernel()) {
> +        return true;
> +    }
> +    error_report("pci-assign: error: requires KVM with in-kernel irqchip "
> +                 "enabled");
> +    return false;
> +}
> +
> +static int assign_intx(AssignedDevice *dev)
> +{
> +    AssignedIRQType new_type;
> +    PCIINTxRoute intx_route;
> +    bool intx_host_msi;
> +    int r;
> +
> +    /* Interrupt PIN 0 means don't use INTx */
> +    if (assigned_dev_pci_read_byte(&dev->dev, PCI_INTERRUPT_PIN) == 0) {
> +        pci_device_set_intx_routing_notifier(&dev->dev, NULL);
> +        return 0;
> +    }
> +
> +    if (!check_irqchip_in_kernel()) {
> +        return -ENOTSUP;
> +    }
> +
> +    pci_device_set_intx_routing_notifier(&dev->dev,
> +                                         assigned_dev_update_irq_routing);
> +
> +    intx_route = pci_device_route_intx_to_irq(&dev->dev, 0);
> +    assert(intx_route.mode != PCI_INTX_INVERTED);
> +
> +    if (dev->intx_route.mode == intx_route.mode &&
> +        dev->intx_route.irq == intx_route.irq) {
> +        return 0;
> +    }
> +
> +    switch (dev->assigned_irq_type) {
> +    case ASSIGNED_IRQ_INTX_HOST_INTX:
> +    case ASSIGNED_IRQ_INTX_HOST_MSI:
> +        intx_host_msi = dev->assigned_irq_type == ASSIGNED_IRQ_INTX_HOST_MSI;
> +        r = kvm_device_intx_deassign(kvm_state, dev->dev_id, intx_host_msi);
> +        break;
> +    case ASSIGNED_IRQ_MSI:
> +        r = kvm_device_msi_deassign(kvm_state, dev->dev_id);
> +        break;
> +    case ASSIGNED_IRQ_MSIX:
> +        r = kvm_device_msix_deassign(kvm_state, dev->dev_id);
> +        break;
> +    default:
> +        r = 0;
> +        break;
> +    }
> +    if (r) {
> +        perror("assign_intx: deassign");

This error message is not very clear.

> +    }
> +    dev->assigned_irq_type = ASSIGNED_IRQ_NONE;
> +
> +    if (intx_route.mode == PCI_INTX_DISABLED) {
> +        dev->intx_route = intx_route;
> +        return 0;
> +    }
> +
> +retry:
> +    if (dev->features & ASSIGNED_DEVICE_PREFER_MSI_MASK &&
> +        dev->cap.available & ASSIGNED_DEVICE_CAP_MSI) {
> +        intx_host_msi = true;
> +        new_type = ASSIGNED_IRQ_INTX_HOST_MSI;
> +    } else {
> +        intx_host_msi = false;
> +        new_type = ASSIGNED_IRQ_INTX_HOST_INTX;
> +    }
> +
> +    r = kvm_device_intx_assign(kvm_state, dev->dev_id, intx_host_msi,
> +                               intx_route.irq);
> +    if (r < 0) {
> +        if (r == -EIO && !(dev->features & ASSIGNED_DEVICE_PREFER_MSI_MASK) &&
> +            dev->cap.available & ASSIGNED_DEVICE_CAP_MSI) {
> +            /* Retry with host-side MSI. There might be an IRQ conflict and
> +             * either the kernel or the device doesn't support sharing. */
> +            fprintf(stderr,
> +                    "Host-side INTx sharing not supported, "
> +                    "using MSI instead.\n"
> +                    "Some devices do not to work properly in this mode.\n");
> +            dev->features |= ASSIGNED_DEVICE_PREFER_MSI_MASK;
> +            goto retry;
> +        }
> +        fprintf(stderr, "Failed to assign irq for \"%s\": %s\n",
> +                dev->dev.qdev.id, strerror(-r));
> +        fprintf(stderr, "Perhaps you are assigning a device "
> +                "that shares an IRQ with another device?\n");
> +        return r;
> +    }
> +
> +    dev->intx_route = intx_route;
> +    dev->assigned_irq_type = new_type;
> +    return r;
> +}
> +
> +static void deassign_device(AssignedDevice *dev)
> +{
> +    int r;
> +
> +    r = kvm_device_pci_deassign(kvm_state, dev->dev_id);
> +    if (r < 0) {
> +        fprintf(stderr, "Failed to deassign device \"%s\" : %s\n",
> +                dev->dev.qdev.id, strerror(-r));
> +    }
> +}
> +
> +/* The pci config space got updated. Check if irq numbers have changed
> + * for our devices
> + */
> +static void assigned_dev_update_irq_routing(PCIDevice *dev)
> +{
> +    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, dev);
> +    Error *err = NULL;
> +    int r;
> +
> +    r = assign_intx(assigned_dev);
> +    if (r < 0) {
> +        qdev_unplug(&dev->qdev, &err);
> +        assert(!err);
> +    }
> +}
> +
> +static void assigned_dev_update_msi(PCIDevice *pci_dev)
> +{
> +    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint8_t ctrl_byte = pci_get_byte(pci_dev->config + pci_dev->msi_cap +
> +                                     PCI_MSI_FLAGS);
> +    int r;
> +
> +    /* Some guests gratuitously disable MSI even if they're not using it,
> +     * try to catch this by only deassigning irqs if the guest is using
> +     * MSI or intends to start. */
> +    if (assigned_dev->assigned_irq_type == ASSIGNED_IRQ_MSI ||
> +        (ctrl_byte & PCI_MSI_FLAGS_ENABLE)) {
> +        r = kvm_device_msi_deassign(kvm_state, assigned_dev->dev_id);
> +        /* -ENXIO means no assigned irq */
> +        if (r && r != -ENXIO) {
> +            perror("assigned_dev_update_msi: deassign irq");
> +        }
> +
> +        free_msi_virqs(assigned_dev);
> +
> +        assigned_dev->assigned_irq_type = ASSIGNED_IRQ_NONE;
> +        pci_device_set_intx_routing_notifier(pci_dev, NULL);
> +    }
> +
> +    if (ctrl_byte & PCI_MSI_FLAGS_ENABLE) {
> +        uint8_t *pos = pci_dev->config + pci_dev->msi_cap;
> +        MSIMessage msg;
> +        int virq;
> +
> +        msg.address = pci_get_long(pos + PCI_MSI_ADDRESS_LO);
> +        msg.data = pci_get_word(pos + PCI_MSI_DATA_32);
> +        virq = kvm_irqchip_add_msi_route(kvm_state, msg);
> +        if (virq < 0) {
> +            perror("assigned_dev_update_msi: kvm_irqchip_add_msi_route");
> +            return;
> +        }
> +
> +        assigned_dev->msi_virq = g_malloc(sizeof(*assigned_dev->msi_virq));

Is this ever freed?

> +        assigned_dev->msi_virq_nr = 1;
> +        assigned_dev->msi_virq[0] = virq;
> +        if (kvm_device_msi_assign(kvm_state, assigned_dev->dev_id, virq) < 0) {
> +            perror("assigned_dev_update_msi: kvm_device_msi_assign");
> +        }
> +
> +        assigned_dev->intx_route.mode = PCI_INTX_DISABLED;
> +        assigned_dev->intx_route.irq = -1;
> +        assigned_dev->assigned_irq_type = ASSIGNED_IRQ_MSI;
> +    } else {
> +        assign_intx(assigned_dev);
> +    }
> +}
> +
> +static bool msix_masked(MSIXTableEntry *entry)
> +{
> +    return (entry->ctrl & cpu_to_le32(0x1)) != 0;
> +}
> +
> +static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
> +{
> +    AssignedDevice *adev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint16_t entries_nr = 0;
> +    int i, r = 0;
> +    MSIXTableEntry *entry = adev->msix_table;
> +    MSIMessage msg;
> +
> +    /* Get the usable entry number for allocating */
> +    for (i = 0; i < adev->msix_max; i++, entry++) {
> +        if (msix_masked(entry)) {
> +            continue;
> +        }
> +        entries_nr++;
> +    }
> +
> +    DEBUG("MSI-X entries: %d\n", entries_nr);
> +
> +    /* It's valid to enable MSI-X with all entries masked */
> +    if (!entries_nr) {
> +        return 0;
> +    }
> +
> +    r = kvm_device_msix_init_vectors(kvm_state, adev->dev_id, entries_nr);
> +    if (r != 0) {
> +        fprintf(stderr, "fail to set MSI-X entry number for MSIX! %s\n",
> +                strerror(-r));
> +        return r;
> +    }
> +
> +    free_msi_virqs(adev);
> +
> +    adev->msi_virq_nr = adev->msix_max;
> +    adev->msi_virq = g_malloc(adev->msix_max * sizeof(*adev->msi_virq));
> +
> +    entry = adev->msix_table;
> +    for (i = 0; i < adev->msix_max; i++, entry++) {
> +        adev->msi_virq[i] = -1;
> +
> +        if (msix_masked(entry)) {
> +            continue;
> +        }
> +
> +        msg.address = entry->addr_lo | ((uint64_t)entry->addr_hi << 32);
> +        msg.data = entry->data;
> +        r = kvm_irqchip_add_msi_route(kvm_state, msg);
> +        if (r < 0) {
> +            return r;
> +        }
> +        adev->msi_virq[i] = r;
> +
> +        DEBUG("MSI-X vector %d, gsi %d, addr %08x_%08x, data %08x\n", i,
> +              r, entry->addr_hi, entry->addr_lo, entry->data);
> +
> +        r = kvm_device_msix_set_vector(kvm_state, adev->dev_id, i,
> +                                       adev->msi_virq[i]);
> +        if (r) {
> +            fprintf(stderr, "fail to set MSI-X entry! %s\n", strerror(-r));
> +            break;
> +        }
> +    }
> +
> +    return r;
> +}
> +
> +static void assigned_dev_update_msix(PCIDevice *pci_dev)
> +{
> +    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint16_t ctrl_word = pci_get_word(pci_dev->config + pci_dev->msix_cap +
> +                                      PCI_MSIX_FLAGS);
> +    int r;
> +
> +    /* Some guests gratuitously disable MSIX even if they're not using it,
> +     * try to catch this by only deassigning irqs if the guest is using
> +     * MSIX or intends to start. */
> +    if ((assigned_dev->assigned_irq_type == ASSIGNED_IRQ_MSIX) ||
> +        (ctrl_word & PCI_MSIX_FLAGS_ENABLE)) {
> +        r = kvm_device_msix_deassign(kvm_state, assigned_dev->dev_id);
> +        /* -ENXIO means no assigned irq */
> +        if (r && r != -ENXIO) {
> +            perror("assigned_dev_update_msix: deassign irq");
> +        }
> +
> +        free_msi_virqs(assigned_dev);
> +
> +        assigned_dev->assigned_irq_type = ASSIGNED_IRQ_NONE;
> +        pci_device_set_intx_routing_notifier(pci_dev, NULL);
> +    }
> +
> +    if (ctrl_word & PCI_MSIX_FLAGS_ENABLE) {
> +        if (assigned_dev_update_msix_mmio(pci_dev) < 0) {
> +            perror("assigned_dev_update_msix_mmio");
> +            return;
> +        }
> +
> +        if (assigned_dev->msi_virq_nr > 0) {
> +            if (kvm_device_msix_assign(kvm_state, assigned_dev->dev_id) < 0) {
> +                perror("assigned_dev_enable_msix: assign irq");
> +                return;
> +            }
> +        }
> +        assigned_dev->intx_route.mode = PCI_INTX_DISABLED;
> +        assigned_dev->intx_route.irq = -1;
> +        assigned_dev->assigned_irq_type = ASSIGNED_IRQ_MSIX;
> +    } else {
> +        assign_intx(assigned_dev);
> +    }
> +}
> +
> +static uint32_t assigned_dev_pci_read_config(PCIDevice *pci_dev,
> +                                             uint32_t address, int len)
> +{
> +    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint32_t virt_val = pci_default_read_config(pci_dev, address, len);
> +    uint32_t real_val, emulate_mask, full_emulation_mask;
> +
> +    emulate_mask = 0;
> +    memcpy(&emulate_mask, assigned_dev->emulate_config_read + address, len);
> +    emulate_mask = le32_to_cpu(emulate_mask);
> +
> +    full_emulation_mask = 0xffffffff >> (32 - len * 8);
> +
> +    if (emulate_mask != full_emulation_mask) {
> +        real_val = assigned_dev_pci_read(pci_dev, address, len);
> +        return (virt_val & emulate_mask) | (real_val & ~emulate_mask);
> +    } else {
> +        return virt_val;
> +    }
> +}
> +
> +static void assigned_dev_pci_write_config(PCIDevice *pci_dev, uint32_t address,
> +                                          uint32_t val, int len)
> +{
> +    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint16_t old_cmd = pci_get_word(pci_dev->config + PCI_COMMAND);
> +    uint32_t emulate_mask, full_emulation_mask;
> +    int ret;
> +
> +    pci_default_write_config(pci_dev, address, val, len);
> +
> +    if (kvm_has_intx_set_mask() &&
> +        range_covers_byte(address, len, PCI_COMMAND + 1)) {
> +        bool intx_masked = (pci_get_word(pci_dev->config + PCI_COMMAND) &
> +                            PCI_COMMAND_INTX_DISABLE);
> +
> +        if (intx_masked != !!(old_cmd & PCI_COMMAND_INTX_DISABLE)) {
> +            ret = kvm_device_intx_set_mask(kvm_state, assigned_dev->dev_id,
> +                                           intx_masked);
> +            if (ret) {
> +                perror("assigned_dev_pci_write_config: set intx mask");
> +            }
> +        }
> +    }
> +    if (assigned_dev->cap.available & ASSIGNED_DEVICE_CAP_MSI) {
> +        if (range_covers_byte(address, len,
> +                              pci_dev->msi_cap + PCI_MSI_FLAGS)) {
> +            assigned_dev_update_msi(pci_dev);
> +        }
> +    }
> +    if (assigned_dev->cap.available & ASSIGNED_DEVICE_CAP_MSIX) {
> +        if (range_covers_byte(address, len,
> +                              pci_dev->msix_cap + PCI_MSIX_FLAGS + 1)) {
> +            assigned_dev_update_msix(pci_dev);
> +        }
> +    }
> +
> +    emulate_mask = 0;
> +    memcpy(&emulate_mask, assigned_dev->emulate_config_write + address, len);
> +    emulate_mask = le32_to_cpu(emulate_mask);
> +
> +    full_emulation_mask = 0xffffffff >> (32 - len * 8);
> +
> +    if (emulate_mask != full_emulation_mask) {
> +        if (emulate_mask) {
> +            val &= ~emulate_mask;
> +            val |= assigned_dev_pci_read(pci_dev, address, len) & emulate_mask;
> +        }
> +        assigned_dev_pci_write(pci_dev, address, val, len);
> +    }
> +}
> +
> +static void assigned_dev_setup_cap_read(AssignedDevice *dev, uint32_t offset,
> +                                        uint32_t len)
> +{
> +    assigned_dev_direct_config_read(dev, offset, len);
> +    assigned_dev_emulate_config_read(dev, offset + PCI_CAP_LIST_NEXT, 1);
> +}
> +
> +static int assigned_device_pci_cap_init(PCIDevice *pci_dev)
> +{
> +    AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    PCIRegion *pci_region = dev->real_device.regions;
> +    int ret, pos;
> +
> +    /* Clear initial capabilities pointer and status copied from hw */
> +    pci_set_byte(pci_dev->config + PCI_CAPABILITY_LIST, 0);
> +    pci_set_word(pci_dev->config + PCI_STATUS,
> +                 pci_get_word(pci_dev->config + PCI_STATUS) &
> +                 ~PCI_STATUS_CAP_LIST);
> +
> +    /* Expose MSI capability
> +     * MSI capability is the 1st capability in capability config */
> +    pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_MSI, 0);
> +    if (pos != 0 && kvm_check_extension(kvm_state, KVM_CAP_ASSIGN_DEV_IRQ)) {
> +        if (!check_irqchip_in_kernel()) {
> +            return -ENOTSUP;
> +        }
> +        dev->cap.available |= ASSIGNED_DEVICE_CAP_MSI;
> +        /* Only 32-bit/no-mask currently supported */
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_MSI, pos, 10);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +        pci_dev->msi_cap = pos;
> +
> +        pci_set_word(pci_dev->config + pos + PCI_MSI_FLAGS,
> +                     pci_get_word(pci_dev->config + pos + PCI_MSI_FLAGS) &
> +                     PCI_MSI_FLAGS_QMASK);
> +        pci_set_long(pci_dev->config + pos + PCI_MSI_ADDRESS_LO, 0);
> +        pci_set_word(pci_dev->config + pos + PCI_MSI_DATA_32, 0);
> +
> +        /* Set writable fields */
> +        pci_set_word(pci_dev->wmask + pos + PCI_MSI_FLAGS,
> +                     PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);
> +        pci_set_long(pci_dev->wmask + pos + PCI_MSI_ADDRESS_LO, 0xfffffffc);
> +        pci_set_word(pci_dev->wmask + pos + PCI_MSI_DATA_32, 0xffff);
> +    }
> +    /* Expose MSI-X capability */
> +    pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_MSIX, 0);
> +    if (pos != 0 && kvm_device_msix_supported(kvm_state)) {
> +        int bar_nr;
> +        uint32_t msix_table_entry;
> +
> +        if (!check_irqchip_in_kernel()) {
> +            return -ENOTSUP;
> +        }
> +        dev->cap.available |= ASSIGNED_DEVICE_CAP_MSIX;
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_MSIX, pos, 12);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +        pci_dev->msix_cap = pos;
> +
> +        pci_set_word(pci_dev->config + pos + PCI_MSIX_FLAGS,
> +                     pci_get_word(pci_dev->config + pos + PCI_MSIX_FLAGS) &
> +                     PCI_MSIX_FLAGS_QSIZE);
> +
> +        /* Only enable and function mask bits are writable */
> +        pci_set_word(pci_dev->wmask + pos + PCI_MSIX_FLAGS,
> +                     PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL);
> +
> +        msix_table_entry = pci_get_long(pci_dev->config + pos + PCI_MSIX_TABLE);
> +        bar_nr = msix_table_entry & PCI_MSIX_FLAGS_BIRMASK;
> +        msix_table_entry &= ~PCI_MSIX_FLAGS_BIRMASK;
> +        dev->msix_table_addr = pci_region[bar_nr].base_addr + msix_table_entry;
> +        dev->msix_max = pci_get_word(pci_dev->config + pos + PCI_MSIX_FLAGS);
> +        dev->msix_max &= PCI_MSIX_FLAGS_QSIZE;
> +        dev->msix_max += 1;
> +    }
> +
> +    /* Minimal PM support, nothing writable, device appears to NAK changes */
> +    pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_PM, 0);
> +    if (pos) {
> +        uint16_t pmc;
> +
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_PM, pos, PCI_PM_SIZEOF);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +
> +        assigned_dev_setup_cap_read(dev, pos, PCI_PM_SIZEOF);
> +
> +        pmc = pci_get_word(pci_dev->config + pos + PCI_CAP_FLAGS);
> +        pmc &= (PCI_PM_CAP_VER_MASK | PCI_PM_CAP_DSI);
> +        pci_set_word(pci_dev->config + pos + PCI_CAP_FLAGS, pmc);
> +
> +        /* assign_device will bring the device up to D0, so we don't need
> +         * to worry about doing that ourselves here. */
> +        pci_set_word(pci_dev->config + pos + PCI_PM_CTRL,
> +                     PCI_PM_CTRL_NO_SOFT_RESET);
> +
> +        pci_set_byte(pci_dev->config + pos + PCI_PM_PPB_EXTENSIONS, 0);
> +        pci_set_byte(pci_dev->config + pos + PCI_PM_DATA_REGISTER, 0);
> +    }
> +
> +    pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_EXP, 0);
> +    if (pos) {
> +        uint8_t version, size = 0;
> +        uint16_t type, devctl, lnksta;
> +        uint32_t devcap, lnkcap;
> +
> +        version = pci_get_byte(pci_dev->config + pos + PCI_EXP_FLAGS);
> +        version &= PCI_EXP_FLAGS_VERS;
> +        if (version == 1) {
> +            size = 0x14;
> +        } else if (version == 2) {
> +            /*
> +             * Check for non-std size, accept reduced size to 0x34,
> +             * which is what bcm5761 implemented, violating the
> +             * PCIe v3.0 spec that regs should exist and be read as 0,
> +             * not optionally provided and shorten the struct size.
> +             */
> +            size = MIN(0x3c, PCI_CONFIG_SPACE_SIZE - pos);
> +            if (size < 0x34) {
> +                fprintf(stderr,
> +                        "%s: Invalid size PCIe cap-id 0x%x\n",
> +                        __func__, PCI_CAP_ID_EXP);
> +                return -EINVAL;
> +            } else if (size != 0x3c) {
> +                fprintf(stderr,
> +                        "WARNING, %s: PCIe cap-id 0x%x has "
> +                        "non-standard size 0x%x; std size should be 0x3c\n",
> +                         __func__, PCI_CAP_ID_EXP, size);
> +            }
> +        } else if (version == 0) {
> +            uint16_t vid, did;
> +            vid = pci_get_word(pci_dev->config + PCI_VENDOR_ID);
> +            did = pci_get_word(pci_dev->config + PCI_DEVICE_ID);
> +            if (vid == PCI_VENDOR_ID_INTEL && did == 0x10ed) {
> +                /*
> +                 * quirk for Intel 82599 VF with invalid PCIe capability
> +                 * version, should really be version 2 (same as PF)
> +                 */
> +                size = 0x3c;
> +            }
> +        }
> +
> +        if (size == 0) {
> +            fprintf(stderr,
> +                    "%s: Unsupported PCI express capability version %d\n",
> +                    __func__, version);
> +            return -EINVAL;
> +        }
> +
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_EXP, pos, size);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +
> +        assigned_dev_setup_cap_read(dev, pos, size);
> +
> +        type = pci_get_word(pci_dev->config + pos + PCI_EXP_FLAGS);
> +        type = (type & PCI_EXP_FLAGS_TYPE) >> 4;
> +        if (type != PCI_EXP_TYPE_ENDPOINT &&
> +            type != PCI_EXP_TYPE_LEG_END && type != PCI_EXP_TYPE_RC_END) {
> +            fprintf(stderr,
> +                    "Device assignment only supports endpoint assignment, "
> +                    "device type %d\n", type);
> +            return -EINVAL;
> +        }
> +
> +        /* capabilities, pass existing read-only copy
> +         * PCI_EXP_FLAGS_IRQ: updated by hardware, should be direct read */
> +
> +        /* device capabilities: hide FLR */
> +        devcap = pci_get_long(pci_dev->config + pos + PCI_EXP_DEVCAP);
> +        devcap &= ~PCI_EXP_DEVCAP_FLR;
> +        pci_set_long(pci_dev->config + pos + PCI_EXP_DEVCAP, devcap);
> +
> +        /* device control: clear all error reporting enable bits, leaving
> +         *                 only a few host values.  Note, these are
> +         *                 all writable, but not passed to hw.
> +         */
> +        devctl = pci_get_word(pci_dev->config + pos + PCI_EXP_DEVCTL);
> +        devctl = (devctl & (PCI_EXP_DEVCTL_READRQ | PCI_EXP_DEVCTL_PAYLOAD)) |
> +                  PCI_EXP_DEVCTL_RELAX_EN | PCI_EXP_DEVCTL_NOSNOOP_EN;
> +        pci_set_word(pci_dev->config + pos + PCI_EXP_DEVCTL, devctl);
> +        devctl = PCI_EXP_DEVCTL_BCR_FLR | PCI_EXP_DEVCTL_AUX_PME;
> +        pci_set_word(pci_dev->wmask + pos + PCI_EXP_DEVCTL, ~devctl);
> +
> +        /* Clear device status */
> +        pci_set_word(pci_dev->config + pos + PCI_EXP_DEVSTA, 0);
> +
> +        /* Link capabilities, expose links and latencues, clear reporting */
> +        lnkcap = pci_get_long(pci_dev->config + pos + PCI_EXP_LNKCAP);
> +        lnkcap &= (PCI_EXP_LNKCAP_SLS | PCI_EXP_LNKCAP_MLW |
> +                   PCI_EXP_LNKCAP_ASPMS | PCI_EXP_LNKCAP_L0SEL |
> +                   PCI_EXP_LNKCAP_L1EL);
> +        pci_set_long(pci_dev->config + pos + PCI_EXP_LNKCAP, lnkcap);
> +
> +        /* Link control, pass existing read-only copy.  Should be writable? */
> +
> +        /* Link status, only expose current speed and width */
> +        lnksta = pci_get_word(pci_dev->config + pos + PCI_EXP_LNKSTA);
> +        lnksta &= (PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
> +        pci_set_word(pci_dev->config + pos + PCI_EXP_LNKSTA, lnksta);
> +
> +        if (version >= 2) {
> +            /* Slot capabilities, control, status - not needed for endpoints */
> +            pci_set_long(pci_dev->config + pos + PCI_EXP_SLTCAP, 0);
> +            pci_set_word(pci_dev->config + pos + PCI_EXP_SLTCTL, 0);
> +            pci_set_word(pci_dev->config + pos + PCI_EXP_SLTSTA, 0);
> +
> +            /* Root control, capabilities, status - not needed for endpoints */
> +            pci_set_word(pci_dev->config + pos + PCI_EXP_RTCTL, 0);
> +            pci_set_word(pci_dev->config + pos + PCI_EXP_RTCAP, 0);
> +            pci_set_long(pci_dev->config + pos + PCI_EXP_RTSTA, 0);
> +
> +            /* Device capabilities/control 2, pass existing read-only copy */
> +            /* Link control 2, pass existing read-only copy */
> +        }
> +    }
> +
> +    pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_PCIX, 0);
> +    if (pos) {
> +        uint16_t cmd;
> +        uint32_t status;
> +
> +        /* Only expose the minimum, 8 byte capability */
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_PCIX, pos, 8);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +
> +        assigned_dev_setup_cap_read(dev, pos, 8);
> +
> +        /* Command register, clear upper bits, including extended modes */
> +        cmd = pci_get_word(pci_dev->config + pos + PCI_X_CMD);
> +        cmd &= (PCI_X_CMD_DPERR_E | PCI_X_CMD_ERO | PCI_X_CMD_MAX_READ |
> +                PCI_X_CMD_MAX_SPLIT);
> +        pci_set_word(pci_dev->config + pos + PCI_X_CMD, cmd);
> +
> +        /* Status register, update with emulated PCI bus location, clear
> +         * error bits, leave the rest. */
> +        status = pci_get_long(pci_dev->config + pos + PCI_X_STATUS);
> +        status &= ~(PCI_X_STATUS_BUS | PCI_X_STATUS_DEVFN);
> +        status |= (pci_bus_num(pci_dev->bus) << 8) | pci_dev->devfn;
> +        status &= ~(PCI_X_STATUS_SPL_DISC | PCI_X_STATUS_UNX_SPL |
> +                    PCI_X_STATUS_SPL_ERR);
> +        pci_set_long(pci_dev->config + pos + PCI_X_STATUS, status);
> +    }
> +
> +    pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_VPD, 0);
> +    if (pos) {
> +        /* Direct R/W passthrough */
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_VPD, pos, 8);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +
> +        assigned_dev_setup_cap_read(dev, pos, 8);
> +
> +        /* direct write for cap content */
> +        assigned_dev_direct_config_write(dev, pos + 2, 6);
> +    }
> +
> +    /* Devices can have multiple vendor capabilities, get them all */
> +    for (pos = 0; (pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_VNDR, pos));
> +        pos += PCI_CAP_LIST_NEXT) {
> +        uint8_t len = pci_get_byte(pci_dev->config + pos + PCI_CAP_FLAGS);
> +        /* Direct R/W passthrough */
> +        ret = pci_add_capability(pci_dev, PCI_CAP_ID_VNDR, pos, len);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +
> +        assigned_dev_setup_cap_read(dev, pos, len);
> +
> +        /* direct write for cap content */
> +        assigned_dev_direct_config_write(dev, pos + 2, len - 2);
> +    }
> +
> +    /* If real and virtual capability list status bits differ, virtualize the
> +     * access. */
> +    if ((pci_get_word(pci_dev->config + PCI_STATUS) & PCI_STATUS_CAP_LIST) !=
> +        (assigned_dev_pci_read_byte(pci_dev, PCI_STATUS) &
> +         PCI_STATUS_CAP_LIST)) {
> +        dev->emulate_config_read[PCI_STATUS] |= PCI_STATUS_CAP_LIST;
> +    }
> +
> +    return 0;
> +}

Also this function is way too long.

> +
> +static uint64_t msix_mmio_read(void *opaque, target_phys_addr_t addr,
> +                               unsigned size)
> +{
> +    AssignedDevice *adev = opaque;
> +    uint64_t val;
> +
> +    memcpy(&val, (void *)((uint8_t *)adev->msix_table + addr), size);
> +
> +    return val;
> +}
> +
> +static void msix_mmio_write(void *opaque, target_phys_addr_t addr,
> +                            uint64_t val, unsigned size)
> +{
> +    AssignedDevice *adev = opaque;
> +    PCIDevice *pdev = &adev->dev;
> +    uint16_t ctrl;
> +    MSIXTableEntry orig;
> +    int i = addr >> 4;
> +
> +    if (i >= adev->msix_max) {
> +        return; /* Drop write */
> +    }
> +
> +    ctrl = pci_get_word(pdev->config + pdev->msix_cap + PCI_MSIX_FLAGS);
> +
> +    DEBUG("write to MSI-X table offset 0x%lx, val 0x%lx\n", addr, val);
> +
> +    if (ctrl & PCI_MSIX_FLAGS_ENABLE) {
> +        orig = adev->msix_table[i];
> +    }
> +
> +    memcpy((void *)((uint8_t *)adev->msix_table + addr), &val, size);

Cast to void * shouldn't be necessary.

> +
> +    if (ctrl & PCI_MSIX_FLAGS_ENABLE) {
> +        MSIXTableEntry *entry = &adev->msix_table[i];
> +
> +        if (!msix_masked(&orig) && msix_masked(entry)) {
> +            /*
> +             * Vector masked, disable it
> +             *
> +             * XXX It's not clear if we can or should actually attempt
> +             * to mask or disable the interrupt.  KVM doesn't have
> +             * support for pending bits and kvm_assign_set_msix_entry
> +             * doesn't modify the device hardware mask.  Interrupts
> +             * while masked are simply not injected to the guest, so
> +             * are lost.  Can we get away with always injecting an
> +             * interrupt on unmask?
> +             */
> +        } else if (msix_masked(&orig) && !msix_masked(entry)) {
> +            /* Vector unmasked */
> +            if (i >= adev->msi_virq_nr || adev->msi_virq[i] < 0) {
> +                /* Previously unassigned vector, start from scratch */
> +                assigned_dev_update_msix(pdev);
> +                return;
> +            } else {
> +                /* Update an existing, previously masked vector */
> +                MSIMessage msg;
> +                int ret;
> +
> +                msg.address = entry->addr_lo |
> +                    ((uint64_t)entry->addr_hi << 32);
> +                msg.data = entry->data;
> +
> +                ret = kvm_irqchip_update_msi_route(kvm_state,
> +                                                   adev->msi_virq[i], msg);
> +                if (ret) {
> +                    fprintf(stderr,
> +                            "Error updating irq routing entry (%d)\n", ret);
> +                }
> +            }
> +        }
> +    }
> +}
> +
> +static const MemoryRegionOps msix_mmio_ops = {
> +    .read = msix_mmio_read,
> +    .write = msix_mmio_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +    .valid = {
> +        .min_access_size = 4,
> +        .max_access_size = 8,
> +    },
> +    .impl = {
> +        .min_access_size = 4,
> +        .max_access_size = 8,
> +    },
> +};
> +
> +static void msix_reset(AssignedDevice *dev)
> +{
> +    MSIXTableEntry *entry;
> +    int i;
> +
> +    if (!dev->msix_table) {
> +        return;
> +    }
> +
> +    memset(dev->msix_table, 0, MSIX_PAGE_SIZE);
> +
> +    for (i = 0, entry = dev->msix_table; i < dev->msix_max; i++, entry++) {
> +        entry->ctrl = cpu_to_le32(0x1); /* Masked */
> +    }
> +}
> +
> +static int assigned_dev_register_msix_mmio(AssignedDevice *dev)
> +{
> +    dev->msix_table = mmap(NULL, MSIX_PAGE_SIZE, PROT_READ|PROT_WRITE,
> +                           MAP_ANONYMOUS|MAP_PRIVATE, 0, 0);
> +    if (dev->msix_table == MAP_FAILED) {
> +        fprintf(stderr, "fail allocate msix_table! %s\n", strerror(errno));
> +        return -EFAULT;
> +    }
> +
> +    msix_reset(dev);
> +
> +    memory_region_init_io(&dev->mmio, &msix_mmio_ops, dev,
> +                          "assigned-dev-msix", MSIX_PAGE_SIZE);
> +    return 0;
> +}
> +
> +static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
> +{
> +    if (!dev->msix_table) {
> +        return;
> +    }
> +
> +    memory_region_destroy(&dev->mmio);
> +
> +    if (munmap(dev->msix_table, MSIX_PAGE_SIZE) == -1) {
> +        fprintf(stderr, "error unmapping msix_table! %s\n",
> +                strerror(errno));
> +    }
> +    dev->msix_table = NULL;
> +}
> +
> +static const VMStateDescription vmstate_assigned_device = {
> +    .name = "pci-assign",
> +    .unmigratable = 1,
> +};
> +
> +static void reset_assigned_device(DeviceState *dev)
> +{
> +    PCIDevice *pci_dev = DO_UPCAST(PCIDevice, qdev, dev);
> +    AssignedDevice *adev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    char reset_file[64];
> +    const char reset[] = "1";
> +    int fd, ret;
> +
> +    /*
> +     * If a guest is reset without being shutdown, MSI/MSI-X can still
> +     * be running.  We want to return the device to a known state on
> +     * reset, so disable those here.  We especially do not want MSI-X
> +     * enabled since it lives in MMIO space, which is about to get
> +     * disabled.
> +     */
> +    if (adev->assigned_irq_type == ASSIGNED_IRQ_MSIX) {
> +        uint16_t ctrl = pci_get_word(pci_dev->config +
> +                                     pci_dev->msix_cap + PCI_MSIX_FLAGS);
> +
> +        pci_set_word(pci_dev->config + pci_dev->msix_cap + PCI_MSIX_FLAGS,
> +                     ctrl & ~PCI_MSIX_FLAGS_ENABLE);
> +        assigned_dev_update_msix(pci_dev);
> +    } else if (adev->assigned_irq_type == ASSIGNED_IRQ_MSI) {
> +        uint8_t ctrl = pci_get_byte(pci_dev->config +
> +                                    pci_dev->msi_cap + PCI_MSI_FLAGS);
> +
> +        pci_set_byte(pci_dev->config + pci_dev->msi_cap + PCI_MSI_FLAGS,
> +                     ctrl & ~PCI_MSI_FLAGS_ENABLE);
> +        assigned_dev_update_msi(pci_dev);
> +    }
> +
> +    snprintf(reset_file, sizeof(reset_file),
> +             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/reset",
> +             adev->host.domain, adev->host.bus, adev->host.slot,
> +             adev->host.function);
> +
> +    /*
> +     * Issue a device reset via pci-sysfs.  Note that we use write(2) here
> +     * and ignore the return value because some kernels have a bug that
> +     * returns 0 rather than bytes written on success, sending us into an
> +     * infinite retry loop using other write mechanisms.
> +     */
> +    fd = open(reset_file, O_WRONLY);
> +    if (fd != -1) {
> +        ret = write(fd, reset, strlen(reset));
> +        (void)ret;
> +        close(fd);
> +    }
> +
> +    /*
> +     * When a 0 is written to the bus master register, the device is logically
> +     * disconnected from the PCI bus. This avoids further DMA transfers.
> +     */
> +    assigned_dev_pci_write_config(pci_dev, PCI_COMMAND, 0, 1);
> +}
> +
> +static int assigned_initfn(struct PCIDevice *pci_dev)
> +{
> +    AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint8_t e_intx;
> +    int r;
> +
> +    if (!kvm_enabled()) {
> +        error_report("pci-assign: error: requires KVM support");
> +        return -1;
> +    }
> +
> +    if (!dev->host.domain && !dev->host.bus && !dev->host.slot &&
> +        !dev->host.function) {
> +        error_report("pci-assign: error: no host device specified");
> +        return -1;
> +    }
> +
> +    /*
> +     * Set up basic config space access control. Will be further refined during
> +     * device initialization.
> +     */
> +    assigned_dev_emulate_config_read(dev, 0, PCI_CONFIG_SPACE_SIZE);
> +    assigned_dev_direct_config_read(dev, PCI_STATUS, 2);
> +    assigned_dev_direct_config_read(dev, PCI_REVISION_ID, 1);
> +    assigned_dev_direct_config_read(dev, PCI_CLASS_PROG, 3);
> +    assigned_dev_direct_config_read(dev, PCI_CACHE_LINE_SIZE, 1);
> +    assigned_dev_direct_config_read(dev, PCI_LATENCY_TIMER, 1);
> +    assigned_dev_direct_config_read(dev, PCI_BIST, 1);
> +    assigned_dev_direct_config_read(dev, PCI_CARDBUS_CIS, 4);
> +    assigned_dev_direct_config_read(dev, PCI_SUBSYSTEM_VENDOR_ID, 2);
> +    assigned_dev_direct_config_read(dev, PCI_SUBSYSTEM_ID, 2);
> +    assigned_dev_direct_config_read(dev, PCI_CAPABILITY_LIST + 1, 7);
> +    assigned_dev_direct_config_read(dev, PCI_MIN_GNT, 1);
> +    assigned_dev_direct_config_read(dev, PCI_MAX_LAT, 1);
> +    memcpy(dev->emulate_config_write, dev->emulate_config_read,
> +           sizeof(dev->emulate_config_read));
> +
> +    if (get_real_device(dev, dev->host.domain, dev->host.bus,
> +                        dev->host.slot, dev->host.function)) {
> +        error_report("pci-assign: Error: Couldn't get real device (%s)!",
> +                     dev->dev.qdev.id);
> +        goto out;
> +    }
> +
> +    if (assigned_device_pci_cap_init(pci_dev) < 0) {
> +        goto out;
> +    }
> +
> +    /* intercept MSI-X entry page in the MMIO */
> +    if (dev->cap.available & ASSIGNED_DEVICE_CAP_MSIX) {
> +        if (assigned_dev_register_msix_mmio(dev)) {
> +            goto out;
> +        }
> +    }
> +
> +    /* handle real device's MMIO/PIO BARs */
> +    if (assigned_dev_register_regions(dev->real_device.regions,
> +                                      dev->real_device.region_number,
> +                                      dev)) {
> +        goto out;
> +    }
> +
> +    /* handle interrupt routing */
> +    e_intx = dev->dev.config[0x3d] - 1;
> +    dev->intpin = e_intx;
> +    dev->intx_route.mode = PCI_INTX_DISABLED;
> +    dev->intx_route.irq = -1;
> +
> +    /* assign device to guest */
> +    r = assign_device(dev);
> +    if (r < 0) {
> +        goto out;
> +    }
> +
> +    /* assign legacy INTx to the device */
> +    r = assign_intx(dev);
> +    if (r < 0) {
> +        goto assigned_out;
> +    }
> +
> +    assigned_dev_load_option_rom(dev);
> +
> +    add_boot_device_path(dev->bootindex, &pci_dev->qdev, NULL);
> +
> +    return 0;
> +
> +assigned_out:
> +    deassign_device(dev);
> +out:
> +    free_assigned_device(dev);
> +    return -1;
> +}
> +
> +static void assigned_exitfn(struct PCIDevice *pci_dev)
> +{
> +    AssignedDevice *dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +
> +    deassign_device(dev);
> +    free_assigned_device(dev);
> +}
> +
> +static Property da_properties[] = {

const?

> +    DEFINE_PROP_PCI_HOST_DEVADDR("host", AssignedDevice, host),
> +    DEFINE_PROP_BIT("prefer_msi", AssignedDevice, features,
> +                    ASSIGNED_DEVICE_PREFER_MSI_BIT, false),
> +    DEFINE_PROP_BIT("share_intx", AssignedDevice, features,
> +                    ASSIGNED_DEVICE_SHARE_INTX_BIT, true),
> +    DEFINE_PROP_INT32("bootindex", AssignedDevice, bootindex, -1),
> +    DEFINE_PROP_STRING("configfd", AssignedDevice, configfd_name),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void assign_class_init(ObjectClass *klass, void *data)
> +{
> +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    k->init         = assigned_initfn;
> +    k->exit         = assigned_exitfn;
> +    k->config_read  = assigned_dev_pci_read_config;
> +    k->config_write = assigned_dev_pci_write_config;
> +    dc->props       = da_properties;
> +    dc->vmsd        = &vmstate_assigned_device;
> +    dc->reset       = reset_assigned_device;
> +}
> +
> +static TypeInfo assign_info = {

const?

> +    .name               = "pci-assign",
> +    .parent             = TYPE_PCI_DEVICE,
> +    .instance_size      = sizeof(AssignedDevice),
> +    .class_init         = assign_class_init,
> +};
> +
> +static void assign_register_types(void)
> +{
> +    type_register_static(&assign_info);
> +}
> +
> +type_init(assign_register_types)
> +
> +/*
> + * Scan the assigned devices for the devices that have an option ROM, and then
> + * load the corresponding ROM data to RAM. If an error occurs while loading an
> + * option ROM, we just ignore that option ROM and continue with the next one.
> + */
> +static void assigned_dev_load_option_rom(AssignedDevice *dev)
> +{
> +    char name[32], rom_file[64];
> +    FILE *fp;
> +    uint8_t val;
> +    struct stat st;
> +    void *ptr;
> +
> +    /* If loading ROM from file, pci handles it */
> +    if (dev->dev.romfile || !dev->dev.rom_bar) {
> +        return;
> +    }
> +
> +    snprintf(rom_file, sizeof(rom_file),
> +             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/rom",
> +             dev->host.domain, dev->host.bus, dev->host.slot,
> +             dev->host.function);
> +
> +    if (stat(rom_file, &st)) {
> +        return;
> +    }
> +
> +    if (access(rom_file, F_OK)) {
> +        fprintf(stderr, "pci-assign: Insufficient privileges for %s\n",
> +                rom_file);
> +        return;
> +    }
> +
> +    /* Write "1" to the ROM file to enable it */
> +    fp = fopen(rom_file, "r+");
> +    if (fp == NULL) {
> +        return;
> +    }
> +    val = 1;
> +    if (fwrite(&val, 1, 1, fp) != 1) {
> +        goto close_rom;
> +    }
> +    fseek(fp, 0, SEEK_SET);
> +
> +    snprintf(name, sizeof(name), "%s.rom",
> +            object_get_typename(OBJECT(dev)));
> +    memory_region_init_ram(&dev->dev.rom, name, st.st_size);
> +    vmstate_register_ram(&dev->dev.rom, &dev->dev.qdev);
> +    ptr = memory_region_get_ram_ptr(&dev->dev.rom);
> +    memset(ptr, 0xff, st.st_size);
> +
> +    if (!fread(ptr, 1, st.st_size, fp)) {
> +        fprintf(stderr, "pci-assign: Cannot read from host %s\n"
> +                "\tDevice option ROM contents are probably invalid "
> +                "(check dmesg).\n\tSkip option ROM probe with rombar=0, "
> +                "or load from file with romfile=\n", rom_file);
> +        memory_region_destroy(&dev->dev.rom);
> +        goto close_rom;
> +    }
> +
> +    pci_register_bar(&dev->dev, PCI_ROM_SLOT, 0, &dev->dev.rom);
> +    dev->dev.has_rom = true;
> +close_rom:
> +    /* Write "0" to disable ROM */
> +    fseek(fp, 0, SEEK_SET);
> +    val = 0;
> +    if (!fwrite(&val, 1, 1, fp)) {
> +        DEBUG("%s\n", "Failed to disable pci-sysfs rom file");
> +    }
> +    fclose(fp);
> +}
> --
> 1.7.3.4
>
>