Re: [Qemu-devel] [PATCH 4/5] backdoor: [softmmu] Add QEMU-side proxy to "libbackdoor.a"

[Blue Swirl]

2011/9/29 Lluís Vilanova <address@hidden>:
> Uses a virtual device to proxy uses of the backdoor communication channel to 
> the
> user-provided code.
>
> Signed-off-by: Lluís Vilanova <address@hidden>
> ---
>  Makefile.objs           |    1
>  backdoor/qemu/softmmu.c |  124 
> +++++++++++++++++++++++++++++++++++++++++++++++
>  hw/pci.h                |    1
>  3 files changed, 126 insertions(+), 0 deletions(-)
>  create mode 100644 backdoor/qemu/softmmu.c
>
> diff --git a/Makefile.objs b/Makefile.objs
> index d39074d..5f54d10 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -398,6 +398,7 @@ $(trace-obj-y): $(GENERATED_HEADERS)
>  # backdoor
>
>  backdoor-nested-$(CONFIG_USER_ONLY) += user.o
> +backdoor-nested-$(CONFIG_SOFTMMU) += softmmu.o
>
>  backdoor-obj-y += $(addprefix backdoor/qemu/, $(backdoor-nested-y))
>
> diff --git a/backdoor/qemu/softmmu.c b/backdoor/qemu/softmmu.c
> new file mode 100644
> index 0000000..fdd3a25
> --- /dev/null
> +++ b/backdoor/qemu/softmmu.c
> @@ -0,0 +1,124 @@
> +/*
> + * QEMU-side management of backdoor channels in softmmu emulation.
> + *
> + * Copyright (C) 2011 Lluís Vilanova <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "hw/pci.h"
> +#include "backdoor/qemu/qemu-backdoor.h"
> +
> +
> +#define PAGE_SIZE TARGET_PAGE_SIZE
> +#define CTRL_BYTES sizeof(uint64_t)
> +
> +
> +typedef struct State
> +{
> +    PCIDevice dev;
> +
> +    uint8_t pages;
> +    uint64_t size;
> +
> +    uint64_t cmd;
> +
> +    void *data_ptr;
> +    MemoryRegion data;
> +    MemoryRegion control;
> +} State;

Please use BackdoorState.

> +
> +
> +static uint64_t control_io_read(void *opaque, target_phys_addr_t addr, 
> unsigned size)
> +{
> +    State *s = opaque;
> +
> +    uint64_t res = ldq_p(&s->size);
> +    uint8_t *resb = (uint8_t*)&res;
> +    return resb[addr % CTRL_BYTES];

I don't think these lines do what you mean, but I'm also not sure what
it is supposed to mean.

> +}
> +
> +static void control_io_write(void *opaque, target_phys_addr_t addr, uint64_t 
> data, unsigned size)
> +{
> +    State *s = opaque;
> +
> +    uint8_t *cmdb = (uint8_t*)&s->cmd;
> +    cmdb[addr % CTRL_BYTES] = (uint8_t)data;
> +
> +    if ((addr + size) % CTRL_BYTES == 0) {
> +        qemu_backdoor(ldq_p(&s->cmd), s->data_ptr);
> +    }

Same here.

> +}
> +
> +static const MemoryRegionOps control_ops = {
> +    .read = control_io_read,
> +    .write = control_io_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +    .impl = {
> +        .min_access_size = 1,
> +        .max_access_size = 1,
> +    },
> +};
> +
> +
> +static int init(PCIDevice *dev)
> +{
> +    State *s = DO_UPCAST(State, dev, dev);
> +
> +    if (s->pages < 1) {
> +        fprintf(stderr, "error: backdoor: "
> +                "the data channel must have one or more pages\n");
> +        return -1;
> +    }
> +    s->size = s->pages * PAGE_SIZE;
> +
> +    pci_set_word(s->dev.config + PCI_COMMAND,
> +                 PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
> +
> +    memory_region_init_io(&s->control, &control_ops, s, "backdoor.control",
> +                          PAGE_SIZE);
> +    pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->control);
> +
> +    memory_region_init_ram(&s->data, &s->dev.qdev, "backdoor.data",
> +                           s->size);
> +    pci_register_bar(&s->dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->data);
> +    s->data_ptr = qemu_get_ram_ptr(s->data.ram_addr);
> +
> +    qemu_backdoor_init(s->size);
> +
> +    return 0;
> +}
> +
> +static int fini(PCIDevice *dev)
> +{
> +    State *s = DO_UPCAST(State, dev, dev);
> +
> +    memory_region_destroy(&s->data);
> +    memory_region_destroy(&s->control);
> +
> +    return 0;
> +}
> +
> +
> +static PCIDeviceInfo info = {
> +    .qdev.name  = "backdoor",
> +    .qdev.desc  = "Backdoor communication channel",
> +    .qdev.size  = sizeof(State),
> +    .init       = init,
> +    .exit       = fini,
> +    .vendor_id  = PCI_VENDOR_ID_REDHAT_QUMRANET,
> +    .device_id  = PCI_DEVICE_ID_BACKDOOR,
> +    .class_id   = PCI_CLASS_MEMORY_RAM,
> +    .qdev.props = (Property[]) {
> +        DEFINE_PROP_UINT8("pages", State, pages, 1),
> +        DEFINE_PROP_END_OF_LIST(),
> +    }
> +};
> +
> +static void register_device(void)
> +{
> +    pci_qdev_register(&info);
> +}
> +
> +device_init(register_device)
> diff --git a/hw/pci.h b/hw/pci.h
> index 86a81c8..4d7d161 100644
> --- a/hw/pci.h
> +++ b/hw/pci.h
> @@ -75,6 +75,7 @@
>  #define PCI_DEVICE_ID_VIRTIO_BLOCK       0x1001
>  #define PCI_DEVICE_ID_VIRTIO_BALLOON     0x1002
>  #define PCI_DEVICE_ID_VIRTIO_CONSOLE     0x1003
> +#define PCI_DEVICE_ID_BACKDOOR           0x1004
>
>  #define FMT_PCIBUS                      PRIx64
>
>
>
>