[Qemu-block] [PATCH] Added iopmem device emulation

[Logan Gunthorpe]

An iopmem device is one which exposes volatile or non-volatile memory mapped
directly to a BAR region. One purpose is to provide buffers to do peer
to peer transfers on the bus. As such this device uses QEMU's drive
backing store to simulate non-volatile memory and provides through a
mapped BAR window.

This patch creates an emulated device which helps to test and debug the
kernel driver for iopmem while hardware availability is poor. A kernel
patch for a driver is being prepared simultaneously.

Signed-off-by: Logan Gunthorpe <address@hidden>
Signed-off-by: Stephen Bates <address@hidden>
---
 default-configs/pci.mak  |   1 +
 hw/block/Makefile.objs   |   1 +
 hw/block/iopmem.c        | 141 +++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/pci/pci_ids.h |   2 +
 4 files changed, 145 insertions(+)
 create mode 100644 hw/block/iopmem.c

diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index fff7ce3..aef2b35 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -39,3 +39,4 @@ CONFIG_VGA=y
 CONFIG_VGA_PCI=y
 CONFIG_IVSHMEM=$(CONFIG_EVENTFD)
 CONFIG_ROCKER=y
+CONFIG_IOPMEM_PCI=y
diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
index d4c3ab7..1c8044b 100644
--- a/hw/block/Makefile.objs
+++ b/hw/block/Makefile.objs
@@ -8,6 +8,7 @@ common-obj-$(CONFIG_XEN_BACKEND) += xen_disk.o
 common-obj-$(CONFIG_ECC) += ecc.o
 common-obj-$(CONFIG_ONENAND) += onenand.o
 common-obj-$(CONFIG_NVME_PCI) += nvme.o
+common-obj-$(CONFIG_IOPMEM_PCI) += iopmem.o
 
 obj-$(CONFIG_SH4) += tc58128.o
 
diff --git a/hw/block/iopmem.c b/hw/block/iopmem.c
new file mode 100644
index 0000000..9c2d716
--- /dev/null
+++ b/hw/block/iopmem.c
@@ -0,0 +1,141 @@
+/*
+ * QEMU iopmem Controller
+ *
+ * Copyright (c) 2016, Microsemi Corporation
+ *
+ * Written by Logan Gunthorpe <address@hidden>
+ *
+ * This code is licensed under the GNU GPL v2 or later.
+ */
+
+
+/**
+ * Usage: add options:
+ *      -drive file=<file>,if=none,id=<drive_id>
+ *      -device iopmem,drive=<drive_id>,id=<id[optional]>
+ */
+
+#include "qemu/osdep.h"
+#include "hw/pci/pci.h"
+#include "sysemu/block-backend.h"
+
+typedef struct IoPmemCtrl {
+    PCIDevice    parent_obj;
+    MemoryRegion iomem;
+    BlockBackend *blk;
+    uint64_t     size;
+} IoPmemCtrl;
+
+#define TYPE_IOPMEM "iopmem"
+#define IOPMEM(obj) \
+        OBJECT_CHECK(IoPmemCtrl, (obj), TYPE_IOPMEM)
+
+static uint64_t iopmem_bar_read(void *opaque, hwaddr addr, unsigned size)
+{
+    IoPmemCtrl *ipm = (IoPmemCtrl *)opaque;
+    uint64_t val;
+
+    blk_pread(ipm->blk, addr, &val, size);
+
+    return val;
+}
+
+static void iopmem_bar_write(void *opaque, hwaddr addr, uint64_t data,
+                           unsigned size)
+{
+    IoPmemCtrl *ipm = (IoPmemCtrl *)opaque;
+
+    if (addr & 3) {
+        return;
+    }
+
+    blk_pwrite(ipm->blk, addr, &data, size, 0);
+}
+
+static const MemoryRegionOps iopmem_bar_ops = {
+    .read = iopmem_bar_read,
+    .write = iopmem_bar_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 8,
+    },
+};
+
+static int iopmem_init(PCIDevice *pci_dev)
+{
+    IoPmemCtrl *ipm = IOPMEM(pci_dev);
+
+    if (!ipm->blk) {
+        return -1;
+    }
+
+    ipm->size = blk_getlength(ipm->blk);
+
+    pci_config_set_prog_interface(pci_dev->config, 0x2);
+    pci_config_set_class(pci_dev->config, PCI_CLASS_STORAGE_OTHER);
+    pcie_endpoint_cap_init(&ipm->parent_obj, 0x80);
+
+    memory_region_init_io(&ipm->iomem, OBJECT(ipm), &iopmem_bar_ops, ipm,
+                          "iopmem", ipm->size);
+
+    pci_register_bar(&ipm->parent_obj, 4,
+                     PCI_BASE_ADDRESS_SPACE_MEMORY |
+                     PCI_BASE_ADDRESS_MEM_PREFETCH |
+                     PCI_BASE_ADDRESS_MEM_TYPE_64,
+                     &ipm->iomem);
+
+    return 0;
+}
+
+static void iopmem_exit(PCIDevice *pci_dev)
+{
+    IoPmemCtrl *ipm = IOPMEM(pci_dev);
+
+    if (ipm->blk) {
+        blk_flush(ipm->blk);
+    }
+}
+
+static Property iopmem_props[] = {
+    DEFINE_PROP_DRIVE("drive", IoPmemCtrl, blk),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static const VMStateDescription iopmem_vmstate = {
+    .name = "iopmem",
+    .unmigratable = 1,
+};
+
+static void iopmem_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    PCIDeviceClass *pc = PCI_DEVICE_CLASS(oc);
+
+    pc->init = iopmem_init;
+    pc->exit = iopmem_exit;
+    pc->class_id = PCI_CLASS_STORAGE_OTHER;
+    pc->vendor_id = PCI_VENDOR_ID_PMC_SIERRA;
+    pc->device_id = 0xf115;
+    pc->revision = 2;
+    pc->is_express = 1;
+
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    dc->desc = "Non-Volatile IO Memory Storage";
+    dc->props = iopmem_props;
+    dc->vmsd = &iopmem_vmstate;
+}
+
+static const TypeInfo iopmem_info = {
+    .name          = "iopmem",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(IoPmemCtrl),
+    .class_init    = iopmem_class_init,
+};
+
+static void iopmem_register_types(void)
+{
+    type_register_static(&iopmem_info);
+}
+
+type_init(iopmem_register_types)
diff --git a/include/hw/pci/pci_ids.h b/include/hw/pci/pci_ids.h
index d77ca60..e7046e1 100644
--- a/include/hw/pci/pci_ids.h
+++ b/include/hw/pci/pci_ids.h
@@ -113,6 +113,8 @@
 
 #define PCI_VENDOR_ID_MARVELL            0x11ab
 
+#define PCI_VENDOR_ID_PMC_SIERRA         0x11f8
+
 #define PCI_VENDOR_ID_ENSONIQ            0x1274
 #define PCI_DEVICE_ID_ENSONIQ_ES1370     0x5000
 
-- 
2.1.4