Re: [Qemu-devel] [RFC PATCH v1 7/8] multi-process QEMU: introduce proxy object

[Elena Ufimtseva]

On Fri, Oct 12, 2018 at 07:48:34PM -0400, Jagannathan Raman wrote:
> From: Elena Ufimtseva <address@hidden>
> 
> Define PCI Device proxy object as a parent of TYPE_PCI_DEVICE.
> PCI Proxy Object will register PCI BARs, MemoryRegionOps to handle
> access to the BARs and forward those to the remote device.
> PCI Proxy object intercepts config space reads and writes. In case
> of pci config write it forwards it to the remote device using
> communication channel.
> 
> TODO:
> - Handle interrupt messages from the emulation program and implement
>   DMA operations.
>
And one more to add to TODO:
  - dont use malloc/free.

Elena 
> Signed-off-by: Elena Ufimtseva <address@hidden>
> ---
>  hw/Makefile.objs        |   2 +
>  hw/qemu-proxy.c         | 215 
> ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/qemu-proxy.h |  56 +++++++++++++
>  3 files changed, 273 insertions(+)
>  create mode 100644 hw/qemu-proxy.c
>  create mode 100644 include/hw/qemu-proxy.h
> 
> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
> index 9c99c29..6bb2eb0 100644
> --- a/hw/Makefile.objs
> +++ b/hw/Makefile.objs
> @@ -44,3 +44,5 @@ scsi-dev-obj-y += scsi/
>  scsi-dev-obj-y += block/
>  scsi-dev-obj-y += pci/
>  scsi-dev-obj-y += nvram/
> +
> +common-obj-y += qemu-proxy.o
> diff --git a/hw/qemu-proxy.c b/hw/qemu-proxy.c
> new file mode 100644
> index 0000000..1712b41
> --- /dev/null
> +++ b/hw/qemu-proxy.c
> @@ -0,0 +1,215 @@
> +/*
> + * Copyright 2018, Oracle and/or its affiliates. All rights reserved.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <sys/types.h>
> +#include <sys/socket.h>
> +#include <unistd.h>
> +#include <assert.h>
> +#include <string.h>
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "io/proxy-link.h"
> +#include "exec/memory.h"
> +#include "exec/cpu-common.h"
> +#include "exec/address-spaces.h"
> +#include "qemu/int128.h"
> +#include "qemu/range.h"
> +#include "hw/pci/pci.h"
> +#include "qemu/option.h"
> +#include "qemu/config-file.h"
> +#include "qapi/qmp/qjson.h"
> +#include "qapi/qmp/qstring.h"
> +#include "sysemu/sysemu.h"
> +#include "hw/qemu-proxy.h"
> +
> +char command[] = "qemu-scsi-dev";
> +
> +static void pci_proxy_dev_realize(PCIDevice *dev, Error **errp);
> +
> +int config_op_send(PCIProxyDev *dev, uint32_t addr, uint32_t val, int l,
> +                                                        unsigned int op)
> +{
> +    ProcMsg msg;
> +    struct conf_data_msg conf_data;
> +
> +    conf_data.addr = addr;
> +    conf_data.val = val;
> +    conf_data.l = l;
> +
> +
> +    msg.data2 = (uint8_t *)malloc(sizeof(conf_data));
> +    if (!msg.data2) {
> +        printf("Failed to allocate memory for msg.data2\n");
> +        return -ENOMEM;
> +    }
> +    memcpy(msg.data2, (const uint8_t *)&conf_data, sizeof(conf_data));
> +    msg.size = sizeof(conf_data);
> +    msg.num_fds = 0;
> +    msg.cmd = op;
> +    msg.bytestream = 1;
> +
> +    proxy_proc_send(dev->proxy_dev.proxy_link, &msg);
> +    free(msg.data2);
> +
> +    return 0;
> +}
> +
> +static uint32_t pci_proxy_read_config(PCIDevice *d,
> +                                       uint32_t addr, int len)
> +{
> +    config_op_send(PCI_PROXY_DEV(d), addr, 0, 0, CONF_READ);
> +    return pci_default_read_config(d, addr, len);
> +}
> +
> +static void pci_proxy_write_config(PCIDevice *d, uint32_t addr, uint32_t val,
> +                                    int l)
> +{
> +    pci_default_write_config(d, addr, val, l);
> +    config_op_send(PCI_PROXY_DEV(d), addr, val, l, CONF_WRITE);
> +}
> +
> +
> +static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> +
> +    k->realize = pci_proxy_dev_realize;
> +    k->class_id = PCI_CLASS_SYSTEM_OTHER;
> +    k->vendor_id = PCI_VENDOR_ID_REDHAT;
> +    k->device_id = PCI_DEVICE_ID_REDHAT_TEST;
> +    k->config_read = pci_proxy_read_config;
> +    k->config_write = pci_proxy_write_config;
> +
> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +    dc->desc = "PCI Proxy Device";
> +}
> +
> +static const TypeInfo pci_proxy_dev_type_info = {
> +    .name          = TYPE_PCI_PROXY_DEV,
> +    .parent        = TYPE_PCI_DEVICE,
> +    .instance_size = sizeof(PCIProxyDev),
> +    .class_init    = pci_proxy_dev_class_init,
> +    .interfaces = (InterfaceInfo[]) {
> +        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
> +        { },
> +    }
> +};
> +
> +static void pci_proxy_mmio_write(void *opaque, hwaddr addr, uint64_t val,
> +                                    unsigned size)
> +{
> +    return;
> +}
> +
> +static uint64_t pci_proxy_mmio_read(void *opaque, hwaddr addr, unsigned size)
> +{
> +    return 0;
> +}
> +
> +static const MemoryRegionOps proxy_device_mmio_ops = {
> +    .read = pci_proxy_mmio_read,
> +    .write = pci_proxy_mmio_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +    .impl = {
> +        .min_access_size = 1,
> +    }
> +};
> +
> +static void pci_proxy_dev_register_types(void)
> +{
> +    type_register_static(&pci_proxy_dev_type_info);
> +}
> +
> +static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
> +{
> +    PCIProxyDev *dev = PCI_PROXY_DEV(device);
> +    uint8_t *pci_conf;
> +
> +    pci_conf = device->config;
> +
> +    init_emulation_process(dev, command, errp);
> +    if (*errp) {
> +        printf("Process did not start\n");
> +        error_report_err(*errp);
> +    }
> +
> +    if (!dev->proxy_dev.proxy_link) {
> +        printf("Proxy link is not set\n");
> +    }
> +
> +    pci_conf[PCI_LATENCY_TIMER] = 0xff;
> +
> +    memory_region_init_io(&dev->mmio_io, OBJECT(dev), &proxy_device_mmio_ops,
> +                          dev, "proxy-device-mmio", 0x400);
> +
> +    pci_register_bar(device, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, 
> &dev->mmio_io);
> +
> +}
> +
> +void init_emulation_process(PCIProxyDev *pdev, char *command, Error **errp)
> +{
> +    char *args[2];
> +    pid_t rpid;
> +    int fd[2];
> +
> +    if (socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
> +        error_setg(errp, "Unable to create unix socket.");
> +        return;
> +    }
> +
> +    rpid = qemu_fork(errp);
> +
> +    if (rpid == -1) {
> +        error_setg(errp, "Unable to spawn emulation program.");
> +        return;
> +    }
> +
> +    if (rpid == 0) {
> +        if (dup2(fd[1], STDIN_FILENO) != STDIN_FILENO) {
> +            perror("Failed to acquire socket.");
> +            exit(1);
> +        }
> +
> +        close(fd[0]);
> +        close(fd[1]);
> +
> +        args[0] = command;
> +        args[1] = NULL;
> +        execvp(args[0], (char *const *)args);
> +        exit(1);
> +    }
> +
> +    pdev->proxy_dev.proxy_link = proxy_link_create();
> +
> +    if (!pdev->proxy_dev.proxy_link) {
> +        return;
> +    }
> +
> +    proxy_link_set_sock(pdev->proxy_dev.proxy_link, fd[0]);
> +    close(fd[1]);
> +
> +}
> +
> +type_init(pci_proxy_dev_register_types)
> diff --git a/include/hw/qemu-proxy.h b/include/hw/qemu-proxy.h
> new file mode 100644
> index 0000000..0903626
> --- /dev/null
> +++ b/include/hw/qemu-proxy.h
> @@ -0,0 +1,56 @@
> +/*
> + * Copyright 2018, Oracle and/or its affiliates. All rights reserved.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef QEMU_PROXY_H
> +#define QEMU_PROXY_H
> +
> +#include "io/proxy-link.h"
> +
> +#define TYPE_PCI_PROXY_DEV "pci-proxy-dev"
> +#define PCI_PROXY_DEV(obj) \
> +            OBJECT_CHECK(PCIProxyDev, (obj), TYPE_PCI_PROXY_DEV)
> +
> +typedef struct proxy_device {
> +       int n_mr_sections;
> +        MemoryRegionSection *mr_sections;
> +        ProxyLinkState *proxy_link;
> +        int link_up;
> +} proxy_device;
> +
> +typedef struct PCIProxyDev {
> +        PCIDevice parent_dev;
> +        struct proxy_device proxy_dev;
> +
> +        MemoryRegion bar;
> +        MemoryRegion mmio_io;
> +        MemoryRegion ram_io;
> +
> +        void (*proxy_read_config)(void);
> +        void (*proxy_write_config) (void);
> +
> +} PCIProxyDev;
> +
> +void init_emulation_process(PCIProxyDev *pdev, char *command, Error **errp);
> +int config_op_send(PCIProxyDev *dev, uint32_t addr, uint32_t val, int l,
> +                                                       unsigned int op);
> +
> +#endif
> -- 
> 1.8.3.1
>