Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 534 insertions, 0 deletions

diff --git a/hw/ide/pci.c b/hw/ide/pci.c
new file mode 100644
index 000000000..84ba73354
--- /dev/null
+++ b/hw/ide/pci.c
@@ -0,0 +1,534 @@
+/*
+ * QEMU IDE Emulation: PCI Bus support.
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2006 Openedhand Ltd.
+ *
+ * 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 "qemu/osdep.h"
+#include "hw/pci/pci.h"
+#include "migration/vmstate.h"
+#include "sysemu/dma.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "hw/ide/pci.h"
+#include "trace.h"
+
+#define BMDMA_PAGE_SIZE 4096
+
+#define BM_MIGRATION_COMPAT_STATUS_BITS \
+        (IDE_RETRY_DMA | IDE_RETRY_PIO | \
+        IDE_RETRY_READ | IDE_RETRY_FLUSH)
+
+static uint64_t pci_ide_status_read(void *opaque, hwaddr addr, unsigned size)
+{
+    IDEBus *bus = opaque;
+
+    if (addr != 2 || size != 1) {
+        return ((uint64_t)1 << (size * 8)) - 1;
+    }
+    return ide_status_read(bus, addr + 2);
+}
+
+static void pci_ide_ctrl_write(void *opaque, hwaddr addr,
+                               uint64_t data, unsigned size)
+{
+    IDEBus *bus = opaque;
+
+    if (addr != 2 || size != 1) {
+        return;
+    }
+    ide_ctrl_write(bus, addr + 2, data);
+}
+
+const MemoryRegionOps pci_ide_cmd_le_ops = {
+    .read = pci_ide_status_read,
+    .write = pci_ide_ctrl_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static uint64_t pci_ide_data_read(void *opaque, hwaddr addr, unsigned size)
+{
+    IDEBus *bus = opaque;
+
+    if (size == 1) {
+        return ide_ioport_read(bus, addr);
+    } else if (addr == 0) {
+        if (size == 2) {
+            return ide_data_readw(bus, addr);
+        } else {
+            return ide_data_readl(bus, addr);
+        }
+    }
+    return ((uint64_t)1 << (size * 8)) - 1;
+}
+
+static void pci_ide_data_write(void *opaque, hwaddr addr,
+                               uint64_t data, unsigned size)
+{
+    IDEBus *bus = opaque;
+
+    if (size == 1) {
+        ide_ioport_write(bus, addr, data);
+    } else if (addr == 0) {
+        if (size == 2) {
+            ide_data_writew(bus, addr, data);
+        } else {
+            ide_data_writel(bus, addr, data);
+        }
+    }
+}
+
+const MemoryRegionOps pci_ide_data_le_ops = {
+    .read = pci_ide_data_read,
+    .write = pci_ide_data_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void bmdma_start_dma(const IDEDMA *dma, IDEState *s,
+                            BlockCompletionFunc *dma_cb)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    bm->dma_cb = dma_cb;
+    bm->cur_prd_last = 0;
+    bm->cur_prd_addr = 0;
+    bm->cur_prd_len = 0;
+
+    if (bm->status & BM_STATUS_DMAING) {
+        bm->dma_cb(bmdma_active_if(bm), 0);
+    }
+}
+
+/**
+ * Prepare an sglist based on available PRDs.
+ * @limit: How many bytes to prepare total.
+ *
+ * Returns the number of bytes prepared, -1 on error.
+ * IDEState.io_buffer_size will contain the number of bytes described
+ * by the PRDs, whether or not we added them to the sglist.
+ */
+static int32_t bmdma_prepare_buf(const IDEDMA *dma, int32_t limit)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+    IDEState *s = bmdma_active_if(bm);
+    PCIDevice *pci_dev = PCI_DEVICE(bm->pci_dev);
+    struct {
+        uint32_t addr;
+        uint32_t size;
+    } prd;
+    int l, len;
+
+    pci_dma_sglist_init(&s->sg, pci_dev,
+                        s->nsector / (BMDMA_PAGE_SIZE / BDRV_SECTOR_SIZE) + 1);
+    s->io_buffer_size = 0;
+    for(;;) {
+        if (bm->cur_prd_len == 0) {
+            /* end of table (with a fail safe of one page) */
+            if (bm->cur_prd_last ||
+                (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE) {
+                return s->sg.size;
+            }
+            pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
+            bm->cur_addr += 8;
+            prd.addr = le32_to_cpu(prd.addr);
+            prd.size = le32_to_cpu(prd.size);
+            len = prd.size & 0xfffe;
+            if (len == 0)
+                len = 0x10000;
+            bm->cur_prd_len = len;
+            bm->cur_prd_addr = prd.addr;
+            bm->cur_prd_last = (prd.size & 0x80000000);
+        }
+        l = bm->cur_prd_len;
+        if (l > 0) {
+            uint64_t sg_len;
+
+            /* Don't add extra bytes to the SGList; consume any remaining
+             * PRDs from the guest, but ignore them. */
+            sg_len = MIN(limit - s->sg.size, bm->cur_prd_len);
+            if (sg_len) {
+                qemu_sglist_add(&s->sg, bm->cur_prd_addr, sg_len);
+            }
+
+            bm->cur_prd_addr += l;
+            bm->cur_prd_len -= l;
+            s->io_buffer_size += l;
+        }
+    }
+
+    qemu_sglist_destroy(&s->sg);
+    s->io_buffer_size = 0;
+    return -1;
+}
+
+/* return 0 if buffer completed */
+static int bmdma_rw_buf(const IDEDMA *dma, bool is_write)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+    IDEState *s = bmdma_active_if(bm);
+    PCIDevice *pci_dev = PCI_DEVICE(bm->pci_dev);
+    struct {
+        uint32_t addr;
+        uint32_t size;
+    } prd;
+    int l, len;
+
+    for(;;) {
+        l = s->io_buffer_size - s->io_buffer_index;
+        if (l <= 0)
+            break;
+        if (bm->cur_prd_len == 0) {
+            /* end of table (with a fail safe of one page) */
+            if (bm->cur_prd_last ||
+                (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
+                return 0;
+            pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
+            bm->cur_addr += 8;
+            prd.addr = le32_to_cpu(prd.addr);
+            prd.size = le32_to_cpu(prd.size);
+            len = prd.size & 0xfffe;
+            if (len == 0)
+                len = 0x10000;
+            bm->cur_prd_len = len;
+            bm->cur_prd_addr = prd.addr;
+            bm->cur_prd_last = (prd.size & 0x80000000);
+        }
+        if (l > bm->cur_prd_len)
+            l = bm->cur_prd_len;
+        if (l > 0) {
+            if (is_write) {
+                pci_dma_write(pci_dev, bm->cur_prd_addr,
+                              s->io_buffer + s->io_buffer_index, l);
+            } else {
+                pci_dma_read(pci_dev, bm->cur_prd_addr,
+                             s->io_buffer + s->io_buffer_index, l);
+            }
+            bm->cur_prd_addr += l;
+            bm->cur_prd_len -= l;
+            s->io_buffer_index += l;
+        }
+    }
+    return 1;
+}
+
+static void bmdma_set_inactive(const IDEDMA *dma, bool more)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    bm->dma_cb = NULL;
+    if (more) {
+        bm->status |= BM_STATUS_DMAING;
+    } else {
+        bm->status &= ~BM_STATUS_DMAING;
+    }
+}
+
+static void bmdma_restart_dma(const IDEDMA *dma)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    bm->cur_addr = bm->addr;
+}
+
+static void bmdma_cancel(BMDMAState *bm)
+{
+    if (bm->status & BM_STATUS_DMAING) {
+        /* cancel DMA request */
+        bmdma_set_inactive(&bm->dma, false);
+    }
+}
+
+static void bmdma_reset(const IDEDMA *dma)
+{
+    BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
+
+    trace_bmdma_reset();
+    bmdma_cancel(bm);
+    bm->cmd = 0;
+    bm->status = 0;
+    bm->addr = 0;
+    bm->cur_addr = 0;
+    bm->cur_prd_last = 0;
+    bm->cur_prd_addr = 0;
+    bm->cur_prd_len = 0;
+}
+
+static void bmdma_irq(void *opaque, int n, int level)
+{
+    BMDMAState *bm = opaque;
+
+    if (!level) {
+        /* pass through lower */
+        qemu_set_irq(bm->irq, level);
+        return;
+    }
+
+    bm->status |= BM_STATUS_INT;
+
+    /* trigger the real irq */
+    qemu_set_irq(bm->irq, level);
+}
+
+void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val)
+{
+    trace_bmdma_cmd_writeb(val);
+
+    /* Ignore writes to SSBM if it keeps the old value */
+    if ((val & BM_CMD_START) != (bm->cmd & BM_CMD_START)) {
+        if (!(val & BM_CMD_START)) {
+            ide_cancel_dma_sync(idebus_active_if(bm->bus));
+            bm->status &= ~BM_STATUS_DMAING;
+        } else {
+            bm->cur_addr = bm->addr;
+            if (!(bm->status & BM_STATUS_DMAING)) {
+                bm->status |= BM_STATUS_DMAING;
+                /* start dma transfer if possible */
+                if (bm->dma_cb)
+                    bm->dma_cb(bmdma_active_if(bm), 0);
+            }
+        }
+    }
+
+    bm->cmd = val & 0x09;
+}
+
+static uint64_t bmdma_addr_read(void *opaque, hwaddr addr,
+                                unsigned width)
+{
+    BMDMAState *bm = opaque;
+    uint32_t mask = (1ULL << (width * 8)) - 1;
+    uint64_t data;
+
+    data = (bm->addr >> (addr * 8)) & mask;
+    trace_bmdma_addr_read(data);
+    return data;
+}
+
+static void bmdma_addr_write(void *opaque, hwaddr addr,
+                             uint64_t data, unsigned width)
+{
+    BMDMAState *bm = opaque;
+    int shift = addr * 8;
+    uint32_t mask = (1ULL << (width * 8)) - 1;
+
+    trace_bmdma_addr_write(data);
+    bm->addr &= ~(mask << shift);
+    bm->addr |= ((data & mask) << shift) & ~3;
+}
+
+MemoryRegionOps bmdma_addr_ioport_ops = {
+    .read = bmdma_addr_read,
+    .write = bmdma_addr_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static bool ide_bmdma_current_needed(void *opaque)
+{
+    BMDMAState *bm = opaque;
+
+    return (bm->cur_prd_len != 0);
+}
+
+static bool ide_bmdma_status_needed(void *opaque)
+{
+    BMDMAState *bm = opaque;
+
+    /* Older versions abused some bits in the status register for internal
+     * error state. If any of these bits are set, we must add a subsection to
+     * transfer the real status register */
+    uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;
+
+    return ((bm->status & abused_bits) != 0);
+}
+
+static int ide_bmdma_pre_save(void *opaque)
+{
+    BMDMAState *bm = opaque;
+    uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;
+
+    if (!(bm->status & BM_STATUS_DMAING) && bm->dma_cb) {
+        bm->bus->error_status =
+            ide_dma_cmd_to_retry(bmdma_active_if(bm)->dma_cmd);
+    }
+    bm->migration_retry_unit = bm->bus->retry_unit;
+    bm->migration_retry_sector_num = bm->bus->retry_sector_num;
+    bm->migration_retry_nsector = bm->bus->retry_nsector;
+    bm->migration_compat_status =
+        (bm->status & ~abused_bits) | (bm->bus->error_status & abused_bits);
+
+    return 0;
+}
+
+/* This function accesses bm->bus->error_status which is loaded only after
+ * BMDMA itself. This is why the function is called from ide_pci_post_load
+ * instead of being registered with VMState where it would run too early. */
+static int ide_bmdma_post_load(void *opaque, int version_id)
+{
+    BMDMAState *bm = opaque;
+    uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;
+
+    if (bm->status == 0) {
+        bm->status = bm->migration_compat_status & ~abused_bits;
+        bm->bus->error_status |= bm->migration_compat_status & abused_bits;
+    }
+    if (bm->bus->error_status) {
+        bm->bus->retry_sector_num = bm->migration_retry_sector_num;
+        bm->bus->retry_nsector = bm->migration_retry_nsector;
+        bm->bus->retry_unit = bm->migration_retry_unit;
+    }
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_bmdma_current = {
+    .name = "ide bmdma_current",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = ide_bmdma_current_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(cur_addr, BMDMAState),
+        VMSTATE_UINT32(cur_prd_last, BMDMAState),
+        VMSTATE_UINT32(cur_prd_addr, BMDMAState),
+        VMSTATE_UINT32(cur_prd_len, BMDMAState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_bmdma_status = {
+    .name ="ide bmdma/status",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = ide_bmdma_status_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(status, BMDMAState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static const VMStateDescription vmstate_bmdma = {
+    .name = "ide bmdma",
+    .version_id = 3,
+    .minimum_version_id = 0,
+    .pre_save  = ide_bmdma_pre_save,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(cmd, BMDMAState),
+        VMSTATE_UINT8(migration_compat_status, BMDMAState),
+        VMSTATE_UINT32(addr, BMDMAState),
+        VMSTATE_INT64(migration_retry_sector_num, BMDMAState),
+        VMSTATE_UINT32(migration_retry_nsector, BMDMAState),
+        VMSTATE_UINT8(migration_retry_unit, BMDMAState),
+        VMSTATE_END_OF_LIST()
+    },
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_bmdma_current,
+        &vmstate_bmdma_status,
+        NULL
+    }
+};
+
+static int ide_pci_post_load(void *opaque, int version_id)
+{
+    PCIIDEState *d = opaque;
+    int i;
+
+    for(i = 0; i < 2; i++) {
+        /* current versions always store 0/1, but older version
+           stored bigger values. We only need last bit */
+        d->bmdma[i].migration_retry_unit &= 1;
+        ide_bmdma_post_load(&d->bmdma[i], -1);
+    }
+
+    return 0;
+}
+
+const VMStateDescription vmstate_ide_pci = {
+    .name = "ide",
+    .version_id = 3,
+    .minimum_version_id = 0,
+    .post_load = ide_pci_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_PCI_DEVICE(parent_obj, PCIIDEState),
+        VMSTATE_STRUCT_ARRAY(bmdma, PCIIDEState, 2, 0,
+                             vmstate_bmdma, BMDMAState),
+        VMSTATE_IDE_BUS_ARRAY(bus, PCIIDEState, 2),
+        VMSTATE_IDE_DRIVES(bus[0].ifs, PCIIDEState),
+        VMSTATE_IDE_DRIVES(bus[1].ifs, PCIIDEState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+/* hd_table must contain 4 block drivers */
+void pci_ide_create_devs(PCIDevice *dev)
+{
+    PCIIDEState *d = PCI_IDE(dev);
+    DriveInfo *hd_table[2 * MAX_IDE_DEVS];
+    static const int bus[4]  = { 0, 0, 1, 1 };
+    static const int unit[4] = { 0, 1, 0, 1 };
+    int i;
+
+    ide_drive_get(hd_table, ARRAY_SIZE(hd_table));
+    for (i = 0; i < 4; i++) {
+        if (hd_table[i]) {
+            ide_create_drive(d->bus + bus[i], unit[i], hd_table[i]);
+        }
+    }
+}
+
+static const struct IDEDMAOps bmdma_ops = {
+    .start_dma = bmdma_start_dma,
+    .prepare_buf = bmdma_prepare_buf,
+    .rw_buf = bmdma_rw_buf,
+    .restart_dma = bmdma_restart_dma,
+    .set_inactive = bmdma_set_inactive,
+    .reset = bmdma_reset,
+};
+
+void bmdma_init(IDEBus *bus, BMDMAState *bm, PCIIDEState *d)
+{
+    if (bus->dma == &bm->dma) {
+        return;
+    }
+
+    bm->dma.ops = &bmdma_ops;
+    bus->dma = &bm->dma;
+    bm->irq = bus->irq;
+    bus->irq = qemu_allocate_irq(bmdma_irq, bm, 0);
+    bm->pci_dev = d;
+}
+
+static const TypeInfo pci_ide_type_info = {
+    .name = TYPE_PCI_IDE,
+    .parent = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PCIIDEState),
+    .abstract = true,
+    .interfaces = (InterfaceInfo[]) {
+        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { },
+    },
+};
+
+static void pci_ide_register_types(void)
+{
+    type_register_static(&pci_ide_type_info);
+}
+
+type_init(pci_ide_register_types)