[PATCH v11 10/19] multi-process: introduce proxy object

[Jagannathan Raman <jag.raman@oracle.com>]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Defines a PCI Device proxy object as a child of TYPE_PCI_DEVICE.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
---
 MAINTAINERS            |  2 ++
 hw/pci/meson.build     |  1 +
 hw/pci/proxy.c         | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/pci/proxy.h | 36 +++++++++++++++++++
 4 files changed, 137 insertions(+)
 create mode 100644 hw/pci/proxy.c
 create mode 100644 include/hw/pci/proxy.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 4aa00ec..202db86 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3111,6 +3111,8 @@ F: include/hw/i386/remote-obj.h
 F: hw/i386/remote-obj.c
 F: include/hw/i386/remote-memory.h
 F: hw/i386/remote-memory.c
+F: hw/pci/proxy.c
+F: include/hw/pci/proxy.h
 
 Build and test automation
 -------------------------
diff --git a/hw/pci/meson.build b/hw/pci/meson.build
index 5c4bbac..0df3017 100644
--- a/hw/pci/meson.build
+++ b/hw/pci/meson.build
@@ -12,6 +12,7 @@ pci_ss.add(files(
 # allow plugging PCIe devices into PCI buses, include them even if
 # CONFIG_PCI_EXPRESS=n.
 pci_ss.add(files('pcie.c', 'pcie_aer.c'))
+pci_ss.add(when: 'CONFIG_MPQEMU', if_true: files('proxy.c'))
 softmmu_ss.add(when: 'CONFIG_PCI_EXPRESS', if_true: files('pcie_port.c', 'pcie_host.c'))
 softmmu_ss.add_all(when: 'CONFIG_PCI', if_true: pci_ss)
 
diff --git a/hw/pci/proxy.c b/hw/pci/proxy.c
new file mode 100644
index 0000000..7a12f23
--- /dev/null
+++ b/hw/pci/proxy.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright © 2018, 2020 Oracle and/or its affiliates.
+ *
+ * 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 "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/pci/proxy.h"
+#include "hw/pci/pci.h"
+#include "qapi/error.h"
+#include "io/channel-util.h"
+#include "hw/qdev-properties.h"
+#include "monitor/monitor.h"
+#include "migration/blocker.h"
+
+static void proxy_set_socket(PCIProxyDev *pdev, int fd, Error **errp)
+{
+    pdev->ioc = qio_channel_new_fd(fd, errp);
+}
+
+static Property proxy_properties[] = {
+    DEFINE_PROP_STRING("fd", PCIProxyDev, fd),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
+{
+    PCIProxyDev *dev = PCI_PROXY_DEV(device);
+    int fd;
+
+    if (dev->fd) {
+        fd = monitor_fd_param(monitor_cur(), dev->fd, errp);
+        if (fd == -1) {
+            error_prepend(errp, "proxy: unable to parse fd: ");
+            return;
+        }
+        proxy_set_socket(dev, fd, errp);
+    } else {
+        error_setg(errp, "fd parameter not specified for %s",
+                   DEVICE(device)->id);
+        return;
+    }
+
+    error_setg(&dev->migration_blocker, "%s does not support migration",
+               TYPE_PCI_PROXY_DEV);
+    if (migrate_add_blocker(dev->migration_blocker, errp)) {
+        error_free(dev->migration_blocker);
+        error_free(*errp);
+        dev->migration_blocker = NULL;
+        error_setg(errp, "Failed to set migration blocker");
+    }
+
+    qemu_mutex_init(&dev->io_mutex);
+    qio_channel_set_blocking(dev->ioc, true, NULL);
+}
+
+static void pci_proxy_dev_exit(PCIDevice *pdev)
+{
+    PCIProxyDev *dev = PCI_PROXY_DEV(pdev);
+
+    qio_channel_close(dev->ioc, NULL);
+
+    migrate_del_blocker(dev->migration_blocker);
+
+    error_free(dev->migration_blocker);
+}
+
+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->exit = pci_proxy_dev_exit;
+    device_class_set_props(dc, proxy_properties);
+}
+
+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_dev_register_types(void)
+{
+    type_register_static(&pci_proxy_dev_type_info);
+}
+
+type_init(pci_proxy_dev_register_types)
diff --git a/include/hw/pci/proxy.h b/include/hw/pci/proxy.h
new file mode 100644
index 0000000..923432a
--- /dev/null
+++ b/include/hw/pci/proxy.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright © 2018, 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef PROXY_H
+#define PROXY_H
+
+#include "hw/pci/pci.h"
+#include "io/channel.h"
+
+#define TYPE_PCI_PROXY_DEV "x-pci-proxy-dev"
+
+#define PCI_PROXY_DEV(obj) \
+            OBJECT_CHECK(PCIProxyDev, (obj), TYPE_PCI_PROXY_DEV)
+typedef struct PCIProxyDev PCIProxyDev;
+
+struct PCIProxyDev {
+    PCIDevice parent_dev;
+    char *fd;
+
+    /*
+     * Mutex used to protect the QIOChannel fd from
+     * the concurrent access by the VCPUs since proxy
+     * blocks while awaiting for the replies from the
+     * process remote.
+     */
+    QemuMutex io_mutex;
+    QIOChannel *ioc;
+    Error *migration_blocker;
+};
+
+#endif /* PROXY_H */
-- 
1.8.3.1