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, 1323 insertions, 0 deletions

diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
new file mode 100644
index 000000000..c929a9cb5
--- /dev/null
+++ b/hw/intc/arm_gicv3_its.c
@@ -0,0 +1,1323 @@
+/*
+ * ITS emulation for a GICv3-based system
+ *
+ * Copyright Linaro.org 2021
+ *
+ * Authors:
+ *  Shashi Mallela <shashi.mallela@linaro.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at your
+ * option) any later version.  See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "hw/qdev-properties.h"
+#include "hw/intc/arm_gicv3_its_common.h"
+#include "gicv3_internal.h"
+#include "qom/object.h"
+#include "qapi/error.h"
+
+typedef struct GICv3ITSClass GICv3ITSClass;
+/* This is reusing the GICv3ITSState typedef from ARM_GICV3_ITS_COMMON */
+DECLARE_OBJ_CHECKERS(GICv3ITSState, GICv3ITSClass,
+                     ARM_GICV3_ITS, TYPE_ARM_GICV3_ITS)
+
+struct GICv3ITSClass {
+    GICv3ITSCommonClass parent_class;
+    void (*parent_reset)(DeviceState *dev);
+};
+
+/*
+ * This is an internal enum used to distinguish between LPI triggered
+ * via command queue and LPI triggered via gits_translater write.
+ */
+typedef enum ItsCmdType {
+    NONE = 0, /* internal indication for GITS_TRANSLATER write */
+    CLEAR = 1,
+    DISCARD = 2,
+    INTERRUPT = 3,
+} ItsCmdType;
+
+typedef struct {
+    uint32_t iteh;
+    uint64_t itel;
+} IteEntry;
+
+static uint64_t baser_base_addr(uint64_t value, uint32_t page_sz)
+{
+    uint64_t result = 0;
+
+    switch (page_sz) {
+    case GITS_PAGE_SIZE_4K:
+    case GITS_PAGE_SIZE_16K:
+        result = FIELD_EX64(value, GITS_BASER, PHYADDR) << 12;
+        break;
+
+    case GITS_PAGE_SIZE_64K:
+        result = FIELD_EX64(value, GITS_BASER, PHYADDRL_64K) << 16;
+        result |= FIELD_EX64(value, GITS_BASER, PHYADDRH_64K) << 48;
+        break;
+
+    default:
+        break;
+    }
+    return result;
+}
+
+static bool get_cte(GICv3ITSState *s, uint16_t icid, uint64_t *cte,
+                    MemTxResult *res)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint64_t l2t_addr;
+    uint64_t value;
+    bool valid_l2t;
+    uint32_t l2t_id;
+    uint32_t max_l2_entries;
+
+    if (s->ct.indirect) {
+        l2t_id = icid / (s->ct.page_sz / L1TABLE_ENTRY_SIZE);
+
+        value = address_space_ldq_le(as,
+                                     s->ct.base_addr +
+                                     (l2t_id * L1TABLE_ENTRY_SIZE),
+                                     MEMTXATTRS_UNSPECIFIED, res);
+
+        if (*res == MEMTX_OK) {
+            valid_l2t = (value & L2_TABLE_VALID_MASK) != 0;
+
+            if (valid_l2t) {
+                max_l2_entries = s->ct.page_sz / s->ct.entry_sz;
+
+                l2t_addr = value & ((1ULL << 51) - 1);
+
+                *cte =  address_space_ldq_le(as, l2t_addr +
+                                    ((icid % max_l2_entries) * GITS_CTE_SIZE),
+                                    MEMTXATTRS_UNSPECIFIED, res);
+           }
+       }
+    } else {
+        /* Flat level table */
+        *cte =  address_space_ldq_le(as, s->ct.base_addr +
+                                     (icid * GITS_CTE_SIZE),
+                                      MEMTXATTRS_UNSPECIFIED, res);
+    }
+
+    return (*cte & TABLE_ENTRY_VALID_MASK) != 0;
+}
+
+static bool update_ite(GICv3ITSState *s, uint32_t eventid, uint64_t dte,
+                       IteEntry ite)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint64_t itt_addr;
+    MemTxResult res = MEMTX_OK;
+
+    itt_addr = (dte & GITS_DTE_ITTADDR_MASK) >> GITS_DTE_ITTADDR_SHIFT;
+    itt_addr <<= ITTADDR_SHIFT; /* 256 byte aligned */
+
+    address_space_stq_le(as, itt_addr + (eventid * (sizeof(uint64_t) +
+                         sizeof(uint32_t))), ite.itel, MEMTXATTRS_UNSPECIFIED,
+                         &res);
+
+    if (res == MEMTX_OK) {
+        address_space_stl_le(as, itt_addr + (eventid * (sizeof(uint64_t) +
+                             sizeof(uint32_t))) + sizeof(uint32_t), ite.iteh,
+                             MEMTXATTRS_UNSPECIFIED, &res);
+    }
+    if (res != MEMTX_OK) {
+        return false;
+    } else {
+        return true;
+    }
+}
+
+static bool get_ite(GICv3ITSState *s, uint32_t eventid, uint64_t dte,
+                    uint16_t *icid, uint32_t *pIntid, MemTxResult *res)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint64_t itt_addr;
+    bool status = false;
+    IteEntry ite = {};
+
+    itt_addr = (dte & GITS_DTE_ITTADDR_MASK) >> GITS_DTE_ITTADDR_SHIFT;
+    itt_addr <<= ITTADDR_SHIFT; /* 256 byte aligned */
+
+    ite.itel = address_space_ldq_le(as, itt_addr +
+                                    (eventid * (sizeof(uint64_t) +
+                                    sizeof(uint32_t))), MEMTXATTRS_UNSPECIFIED,
+                                    res);
+
+    if (*res == MEMTX_OK) {
+        ite.iteh = address_space_ldl_le(as, itt_addr +
+                                        (eventid * (sizeof(uint64_t) +
+                                        sizeof(uint32_t))) + sizeof(uint32_t),
+                                        MEMTXATTRS_UNSPECIFIED, res);
+
+        if (*res == MEMTX_OK) {
+            if (ite.itel & TABLE_ENTRY_VALID_MASK) {
+                if ((ite.itel >> ITE_ENTRY_INTTYPE_SHIFT) &
+                    GITS_TYPE_PHYSICAL) {
+                    *pIntid = (ite.itel & ITE_ENTRY_INTID_MASK) >>
+                               ITE_ENTRY_INTID_SHIFT;
+                    *icid = ite.iteh & ITE_ENTRY_ICID_MASK;
+                    status = true;
+                }
+            }
+        }
+    }
+    return status;
+}
+
+static uint64_t get_dte(GICv3ITSState *s, uint32_t devid, MemTxResult *res)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint64_t l2t_addr;
+    uint64_t value;
+    bool valid_l2t;
+    uint32_t l2t_id;
+    uint32_t max_l2_entries;
+
+    if (s->dt.indirect) {
+        l2t_id = devid / (s->dt.page_sz / L1TABLE_ENTRY_SIZE);
+
+        value = address_space_ldq_le(as,
+                                     s->dt.base_addr +
+                                     (l2t_id * L1TABLE_ENTRY_SIZE),
+                                     MEMTXATTRS_UNSPECIFIED, res);
+
+        if (*res == MEMTX_OK) {
+            valid_l2t = (value & L2_TABLE_VALID_MASK) != 0;
+
+            if (valid_l2t) {
+                max_l2_entries = s->dt.page_sz / s->dt.entry_sz;
+
+                l2t_addr = value & ((1ULL << 51) - 1);
+
+                value =  address_space_ldq_le(as, l2t_addr +
+                                   ((devid % max_l2_entries) * GITS_DTE_SIZE),
+                                   MEMTXATTRS_UNSPECIFIED, res);
+            }
+        }
+    } else {
+        /* Flat level table */
+        value = address_space_ldq_le(as, s->dt.base_addr +
+                                     (devid * GITS_DTE_SIZE),
+                                     MEMTXATTRS_UNSPECIFIED, res);
+    }
+
+    return value;
+}
+
+/*
+ * This function handles the processing of following commands based on
+ * the ItsCmdType parameter passed:-
+ * 1. triggering of lpi interrupt translation via ITS INT command
+ * 2. triggering of lpi interrupt translation via gits_translater register
+ * 3. handling of ITS CLEAR command
+ * 4. handling of ITS DISCARD command
+ */
+static bool process_its_cmd(GICv3ITSState *s, uint64_t value, uint32_t offset,
+                            ItsCmdType cmd)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint32_t devid, eventid;
+    MemTxResult res = MEMTX_OK;
+    bool dte_valid;
+    uint64_t dte = 0;
+    uint32_t max_eventid;
+    uint16_t icid = 0;
+    uint32_t pIntid = 0;
+    bool ite_valid = false;
+    uint64_t cte = 0;
+    bool cte_valid = false;
+    bool result = false;
+    uint64_t rdbase;
+
+    if (cmd == NONE) {
+        devid = offset;
+    } else {
+        devid = ((value & DEVID_MASK) >> DEVID_SHIFT);
+
+        offset += NUM_BYTES_IN_DW;
+        value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                     MEMTXATTRS_UNSPECIFIED, &res);
+    }
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+
+    eventid = (value & EVENTID_MASK);
+
+    dte = get_dte(s, devid, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+    dte_valid = dte & TABLE_ENTRY_VALID_MASK;
+
+    if (dte_valid) {
+        max_eventid = (1UL << (((dte >> 1U) & SIZE_MASK) + 1));
+
+        ite_valid = get_ite(s, eventid, dte, &icid, &pIntid, &res);
+
+        if (res != MEMTX_OK) {
+            return result;
+        }
+
+        if (ite_valid) {
+            cte_valid = get_cte(s, icid, &cte, &res);
+        }
+
+        if (res != MEMTX_OK) {
+            return result;
+        }
+    }
+
+    if ((devid > s->dt.maxids.max_devids) || !dte_valid || !ite_valid ||
+            !cte_valid || (eventid > max_eventid)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes "
+                      "devid %d or eventid %d or invalid dte %d or"
+                      "invalid cte %d or invalid ite %d\n",
+                      __func__, devid, eventid, dte_valid, cte_valid,
+                      ite_valid);
+        /*
+         * in this implementation, in case of error
+         * we ignore this command and move onto the next
+         * command in the queue
+         */
+    } else {
+        /*
+         * Current implementation only supports rdbase == procnum
+         * Hence rdbase physical address is ignored
+         */
+        rdbase = (cte & GITS_CTE_RDBASE_PROCNUM_MASK) >> 1U;
+
+        if (rdbase > s->gicv3->num_cpu) {
+            return result;
+        }
+
+        if ((cmd == CLEAR) || (cmd == DISCARD)) {
+            gicv3_redist_process_lpi(&s->gicv3->cpu[rdbase], pIntid, 0);
+        } else {
+            gicv3_redist_process_lpi(&s->gicv3->cpu[rdbase], pIntid, 1);
+        }
+
+        if (cmd == DISCARD) {
+            IteEntry ite = {};
+            /* remove mapping from interrupt translation table */
+            result = update_ite(s, eventid, dte, ite);
+        }
+    }
+
+    return result;
+}
+
+static bool process_mapti(GICv3ITSState *s, uint64_t value, uint32_t offset,
+                          bool ignore_pInt)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint32_t devid, eventid;
+    uint32_t pIntid = 0;
+    uint32_t max_eventid, max_Intid;
+    bool dte_valid;
+    MemTxResult res = MEMTX_OK;
+    uint16_t icid = 0;
+    uint64_t dte = 0;
+    IteEntry ite;
+    uint32_t int_spurious = INTID_SPURIOUS;
+    bool result = false;
+
+    devid = ((value & DEVID_MASK) >> DEVID_SHIFT);
+    offset += NUM_BYTES_IN_DW;
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+
+    eventid = (value & EVENTID_MASK);
+
+    if (!ignore_pInt) {
+        pIntid = ((value & pINTID_MASK) >> pINTID_SHIFT);
+    }
+
+    offset += NUM_BYTES_IN_DW;
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+
+    icid = value & ICID_MASK;
+
+    dte = get_dte(s, devid, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+    dte_valid = dte & TABLE_ENTRY_VALID_MASK;
+
+    max_eventid = (1UL << (((dte >> 1U) & SIZE_MASK) + 1));
+
+    if (!ignore_pInt) {
+        max_Intid = (1ULL << (GICD_TYPER_IDBITS + 1)) - 1;
+    }
+
+    if ((devid > s->dt.maxids.max_devids) || (icid > s->ct.maxids.max_collids)
+            || !dte_valid || (eventid > max_eventid) ||
+            (!ignore_pInt && (((pIntid < GICV3_LPI_INTID_START) ||
+            (pIntid > max_Intid)) && (pIntid != INTID_SPURIOUS)))) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes "
+                      "devid %d or icid %d or eventid %d or pIntid %d or"
+                      "unmapped dte %d\n", __func__, devid, icid, eventid,
+                      pIntid, dte_valid);
+        /*
+         * in this implementation, in case of error
+         * we ignore this command and move onto the next
+         * command in the queue
+         */
+    } else {
+        /* add ite entry to interrupt translation table */
+        ite.itel = (dte_valid & TABLE_ENTRY_VALID_MASK) |
+                    (GITS_TYPE_PHYSICAL << ITE_ENTRY_INTTYPE_SHIFT);
+
+        if (ignore_pInt) {
+            ite.itel |= (eventid << ITE_ENTRY_INTID_SHIFT);
+        } else {
+            ite.itel |= (pIntid << ITE_ENTRY_INTID_SHIFT);
+        }
+        ite.itel |= (int_spurious << ITE_ENTRY_INTSP_SHIFT);
+        ite.iteh = icid;
+
+        result = update_ite(s, eventid, dte, ite);
+    }
+
+    return result;
+}
+
+static bool update_cte(GICv3ITSState *s, uint16_t icid, bool valid,
+                       uint64_t rdbase)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint64_t value;
+    uint64_t l2t_addr;
+    bool valid_l2t;
+    uint32_t l2t_id;
+    uint32_t max_l2_entries;
+    uint64_t cte = 0;
+    MemTxResult res = MEMTX_OK;
+
+    if (!s->ct.valid) {
+        return true;
+    }
+
+    if (valid) {
+        /* add mapping entry to collection table */
+        cte = (valid & TABLE_ENTRY_VALID_MASK) | (rdbase << 1ULL);
+    }
+
+    /*
+     * The specification defines the format of level 1 entries of a
+     * 2-level table, but the format of level 2 entries and the format
+     * of flat-mapped tables is IMPDEF.
+     */
+    if (s->ct.indirect) {
+        l2t_id = icid / (s->ct.page_sz / L1TABLE_ENTRY_SIZE);
+
+        value = address_space_ldq_le(as,
+                                     s->ct.base_addr +
+                                     (l2t_id * L1TABLE_ENTRY_SIZE),
+                                     MEMTXATTRS_UNSPECIFIED, &res);
+
+        if (res != MEMTX_OK) {
+            return false;
+        }
+
+        valid_l2t = (value & L2_TABLE_VALID_MASK) != 0;
+
+        if (valid_l2t) {
+            max_l2_entries = s->ct.page_sz / s->ct.entry_sz;
+
+            l2t_addr = value & ((1ULL << 51) - 1);
+
+            address_space_stq_le(as, l2t_addr +
+                                 ((icid % max_l2_entries) * GITS_CTE_SIZE),
+                                 cte, MEMTXATTRS_UNSPECIFIED, &res);
+        }
+    } else {
+        /* Flat level table */
+        address_space_stq_le(as, s->ct.base_addr + (icid * GITS_CTE_SIZE),
+                             cte, MEMTXATTRS_UNSPECIFIED, &res);
+    }
+    if (res != MEMTX_OK) {
+        return false;
+    } else {
+        return true;
+    }
+}
+
+static bool process_mapc(GICv3ITSState *s, uint32_t offset)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint16_t icid;
+    uint64_t rdbase;
+    bool valid;
+    MemTxResult res = MEMTX_OK;
+    bool result = false;
+    uint64_t value;
+
+    offset += NUM_BYTES_IN_DW;
+    offset += NUM_BYTES_IN_DW;
+
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+
+    icid = value & ICID_MASK;
+
+    rdbase = (value & R_MAPC_RDBASE_MASK) >> R_MAPC_RDBASE_SHIFT;
+    rdbase &= RDBASE_PROCNUM_MASK;
+
+    valid = (value & CMD_FIELD_VALID_MASK);
+
+    if ((icid > s->ct.maxids.max_collids) || (rdbase > s->gicv3->num_cpu)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "ITS MAPC: invalid collection table attributes "
+                      "icid %d rdbase %" PRIu64 "\n",  icid, rdbase);
+        /*
+         * in this implementation, in case of error
+         * we ignore this command and move onto the next
+         * command in the queue
+         */
+    } else {
+        result = update_cte(s, icid, valid, rdbase);
+    }
+
+    return result;
+}
+
+static bool update_dte(GICv3ITSState *s, uint32_t devid, bool valid,
+                       uint8_t size, uint64_t itt_addr)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint64_t value;
+    uint64_t l2t_addr;
+    bool valid_l2t;
+    uint32_t l2t_id;
+    uint32_t max_l2_entries;
+    uint64_t dte = 0;
+    MemTxResult res = MEMTX_OK;
+
+    if (s->dt.valid) {
+        if (valid) {
+            /* add mapping entry to device table */
+            dte = (valid & TABLE_ENTRY_VALID_MASK) |
+                  ((size & SIZE_MASK) << 1U) |
+                  (itt_addr << GITS_DTE_ITTADDR_SHIFT);
+        }
+    } else {
+        return true;
+    }
+
+    /*
+     * The specification defines the format of level 1 entries of a
+     * 2-level table, but the format of level 2 entries and the format
+     * of flat-mapped tables is IMPDEF.
+     */
+    if (s->dt.indirect) {
+        l2t_id = devid / (s->dt.page_sz / L1TABLE_ENTRY_SIZE);
+
+        value = address_space_ldq_le(as,
+                                     s->dt.base_addr +
+                                     (l2t_id * L1TABLE_ENTRY_SIZE),
+                                     MEMTXATTRS_UNSPECIFIED, &res);
+
+        if (res != MEMTX_OK) {
+            return false;
+        }
+
+        valid_l2t = (value & L2_TABLE_VALID_MASK) != 0;
+
+        if (valid_l2t) {
+            max_l2_entries = s->dt.page_sz / s->dt.entry_sz;
+
+            l2t_addr = value & ((1ULL << 51) - 1);
+
+            address_space_stq_le(as, l2t_addr +
+                                 ((devid % max_l2_entries) * GITS_DTE_SIZE),
+                                 dte, MEMTXATTRS_UNSPECIFIED, &res);
+        }
+    } else {
+        /* Flat level table */
+        address_space_stq_le(as, s->dt.base_addr + (devid * GITS_DTE_SIZE),
+                             dte, MEMTXATTRS_UNSPECIFIED, &res);
+    }
+    if (res != MEMTX_OK) {
+        return false;
+    } else {
+        return true;
+    }
+}
+
+static bool process_mapd(GICv3ITSState *s, uint64_t value, uint32_t offset)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    uint32_t devid;
+    uint8_t size;
+    uint64_t itt_addr;
+    bool valid;
+    MemTxResult res = MEMTX_OK;
+    bool result = false;
+
+    devid = ((value & DEVID_MASK) >> DEVID_SHIFT);
+
+    offset += NUM_BYTES_IN_DW;
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+
+    size = (value & SIZE_MASK);
+
+    offset += NUM_BYTES_IN_DW;
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+
+    if (res != MEMTX_OK) {
+        return result;
+    }
+
+    itt_addr = (value & ITTADDR_MASK) >> ITTADDR_SHIFT;
+
+    valid = (value & CMD_FIELD_VALID_MASK);
+
+    if ((devid > s->dt.maxids.max_devids) ||
+        (size > FIELD_EX64(s->typer, GITS_TYPER, IDBITS))) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "ITS MAPD: invalid device table attributes "
+                      "devid %d or size %d\n", devid, size);
+        /*
+         * in this implementation, in case of error
+         * we ignore this command and move onto the next
+         * command in the queue
+         */
+    } else {
+        result = update_dte(s, devid, valid, size, itt_addr);
+    }
+
+    return result;
+}
+
+/*
+ * Current implementation blocks until all
+ * commands are processed
+ */
+static void process_cmdq(GICv3ITSState *s)
+{
+    uint32_t wr_offset = 0;
+    uint32_t rd_offset = 0;
+    uint32_t cq_offset = 0;
+    uint64_t data;
+    AddressSpace *as = &s->gicv3->dma_as;
+    MemTxResult res = MEMTX_OK;
+    bool result = true;
+    uint8_t cmd;
+    int i;
+
+    if (!(s->ctlr & ITS_CTLR_ENABLED)) {
+        return;
+    }
+
+    wr_offset = FIELD_EX64(s->cwriter, GITS_CWRITER, OFFSET);
+
+    if (wr_offset > s->cq.max_entries) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid write offset "
+                      "%d\n", __func__, wr_offset);
+        return;
+    }
+
+    rd_offset = FIELD_EX64(s->creadr, GITS_CREADR, OFFSET);
+
+    if (rd_offset > s->cq.max_entries) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid read offset "
+                      "%d\n", __func__, rd_offset);
+        return;
+    }
+
+    while (wr_offset != rd_offset) {
+        cq_offset = (rd_offset * GITS_CMDQ_ENTRY_SIZE);
+        data = address_space_ldq_le(as, s->cq.base_addr + cq_offset,
+                                    MEMTXATTRS_UNSPECIFIED, &res);
+        if (res != MEMTX_OK) {
+            result = false;
+        }
+        cmd = (data & CMD_MASK);
+
+        switch (cmd) {
+        case GITS_CMD_INT:
+            res = process_its_cmd(s, data, cq_offset, INTERRUPT);
+            break;
+        case GITS_CMD_CLEAR:
+            res = process_its_cmd(s, data, cq_offset, CLEAR);
+            break;
+        case GITS_CMD_SYNC:
+            /*
+             * Current implementation makes a blocking synchronous call
+             * for every command issued earlier, hence the internal state
+             * is already consistent by the time SYNC command is executed.
+             * Hence no further processing is required for SYNC command.
+             */
+            break;
+        case GITS_CMD_MAPD:
+            result = process_mapd(s, data, cq_offset);
+            break;
+        case GITS_CMD_MAPC:
+            result = process_mapc(s, cq_offset);
+            break;
+        case GITS_CMD_MAPTI:
+            result = process_mapti(s, data, cq_offset, false);
+            break;
+        case GITS_CMD_MAPI:
+            result = process_mapti(s, data, cq_offset, true);
+            break;
+        case GITS_CMD_DISCARD:
+            result = process_its_cmd(s, data, cq_offset, DISCARD);
+            break;
+        case GITS_CMD_INV:
+        case GITS_CMD_INVALL:
+            /*
+             * Current implementation doesn't cache any ITS tables,
+             * but the calculated lpi priority information. We only
+             * need to trigger lpi priority re-calculation to be in
+             * sync with LPI config table or pending table changes.
+             */
+            for (i = 0; i < s->gicv3->num_cpu; i++) {
+                gicv3_redist_update_lpi(&s->gicv3->cpu[i]);
+            }
+            break;
+        default:
+            break;
+        }
+        if (result) {
+            rd_offset++;
+            rd_offset %= s->cq.max_entries;
+            s->creadr = FIELD_DP64(s->creadr, GITS_CREADR, OFFSET, rd_offset);
+        } else {
+            /*
+             * in this implementation, in case of dma read/write error
+             * we stall the command processing
+             */
+            s->creadr = FIELD_DP64(s->creadr, GITS_CREADR, STALLED, 1);
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: %x cmd processing failed\n", __func__, cmd);
+            break;
+        }
+    }
+}
+
+/*
+ * This function extracts the ITS Device and Collection table specific
+ * parameters (like base_addr, size etc) from GITS_BASER register.
+ * It is called during ITS enable and also during post_load migration
+ */
+static void extract_table_params(GICv3ITSState *s)
+{
+    uint16_t num_pages = 0;
+    uint8_t  page_sz_type;
+    uint8_t type;
+    uint32_t page_sz = 0;
+    uint64_t value;
+
+    for (int i = 0; i < 8; i++) {
+        value = s->baser[i];
+
+        if (!value) {
+            continue;
+        }
+
+        page_sz_type = FIELD_EX64(value, GITS_BASER, PAGESIZE);
+
+        switch (page_sz_type) {
+        case 0:
+            page_sz = GITS_PAGE_SIZE_4K;
+            break;
+
+        case 1:
+            page_sz = GITS_PAGE_SIZE_16K;
+            break;
+
+        case 2:
+        case 3:
+            page_sz = GITS_PAGE_SIZE_64K;
+            break;
+
+        default:
+            g_assert_not_reached();
+        }
+
+        num_pages = FIELD_EX64(value, GITS_BASER, SIZE) + 1;
+
+        type = FIELD_EX64(value, GITS_BASER, TYPE);
+
+        switch (type) {
+
+        case GITS_BASER_TYPE_DEVICE:
+            memset(&s->dt, 0 , sizeof(s->dt));
+            s->dt.valid = FIELD_EX64(value, GITS_BASER, VALID);
+
+            if (!s->dt.valid) {
+                return;
+            }
+
+            s->dt.page_sz = page_sz;
+            s->dt.indirect = FIELD_EX64(value, GITS_BASER, INDIRECT);
+            s->dt.entry_sz = FIELD_EX64(value, GITS_BASER, ENTRYSIZE);
+
+            if (!s->dt.indirect) {
+                s->dt.max_entries = (num_pages * page_sz) / s->dt.entry_sz;
+            } else {
+                s->dt.max_entries = (((num_pages * page_sz) /
+                                     L1TABLE_ENTRY_SIZE) *
+                                     (page_sz / s->dt.entry_sz));
+            }
+
+            s->dt.maxids.max_devids = (1UL << (FIELD_EX64(s->typer, GITS_TYPER,
+                                       DEVBITS) + 1));
+
+            s->dt.base_addr = baser_base_addr(value, page_sz);
+
+            break;
+
+        case GITS_BASER_TYPE_COLLECTION:
+            memset(&s->ct, 0 , sizeof(s->ct));
+            s->ct.valid = FIELD_EX64(value, GITS_BASER, VALID);
+
+            /*
+             * GITS_TYPER.HCC is 0 for this implementation
+             * hence writes are discarded if ct.valid is 0
+             */
+            if (!s->ct.valid) {
+                return;
+            }
+
+            s->ct.page_sz = page_sz;
+            s->ct.indirect = FIELD_EX64(value, GITS_BASER, INDIRECT);
+            s->ct.entry_sz = FIELD_EX64(value, GITS_BASER, ENTRYSIZE);
+
+            if (!s->ct.indirect) {
+                s->ct.max_entries = (num_pages * page_sz) / s->ct.entry_sz;
+            } else {
+                s->ct.max_entries = (((num_pages * page_sz) /
+                                     L1TABLE_ENTRY_SIZE) *
+                                     (page_sz / s->ct.entry_sz));
+            }
+
+            if (FIELD_EX64(s->typer, GITS_TYPER, CIL)) {
+                s->ct.maxids.max_collids = (1UL << (FIELD_EX64(s->typer,
+                                            GITS_TYPER, CIDBITS) + 1));
+            } else {
+                /* 16-bit CollectionId supported when CIL == 0 */
+                s->ct.maxids.max_collids = (1UL << 16);
+            }
+
+            s->ct.base_addr = baser_base_addr(value, page_sz);
+
+            break;
+
+        default:
+            break;
+        }
+    }
+}
+
+static void extract_cmdq_params(GICv3ITSState *s)
+{
+    uint16_t num_pages = 0;
+    uint64_t value = s->cbaser;
+
+    num_pages = FIELD_EX64(value, GITS_CBASER, SIZE) + 1;
+
+    memset(&s->cq, 0 , sizeof(s->cq));
+    s->cq.valid = FIELD_EX64(value, GITS_CBASER, VALID);
+
+    if (s->cq.valid) {
+        s->cq.max_entries = (num_pages * GITS_PAGE_SIZE_4K) /
+                             GITS_CMDQ_ENTRY_SIZE;
+        s->cq.base_addr = FIELD_EX64(value, GITS_CBASER, PHYADDR);
+        s->cq.base_addr <<= R_GITS_CBASER_PHYADDR_SHIFT;
+    }
+}
+
+static MemTxResult gicv3_its_translation_write(void *opaque, hwaddr offset,
+                                               uint64_t data, unsigned size,
+                                               MemTxAttrs attrs)
+{
+    GICv3ITSState *s = (GICv3ITSState *)opaque;
+    bool result = true;
+    uint32_t devid = 0;
+
+    switch (offset) {
+    case GITS_TRANSLATER:
+        if (s->ctlr & ITS_CTLR_ENABLED) {
+            devid = attrs.requester_id;
+            result = process_its_cmd(s, data, devid, NONE);
+        }
+        break;
+    default:
+        break;
+    }
+
+    if (result) {
+        return MEMTX_OK;
+    } else {
+        return MEMTX_ERROR;
+    }
+}
+
+static bool its_writel(GICv3ITSState *s, hwaddr offset,
+                              uint64_t value, MemTxAttrs attrs)
+{
+    bool result = true;
+    int index;
+
+    switch (offset) {
+    case GITS_CTLR:
+        if (value & R_GITS_CTLR_ENABLED_MASK) {
+            s->ctlr |= ITS_CTLR_ENABLED;
+            extract_table_params(s);
+            extract_cmdq_params(s);
+            s->creadr = 0;
+            process_cmdq(s);
+        } else {
+            s->ctlr &= ~ITS_CTLR_ENABLED;
+        }
+        break;
+    case GITS_CBASER:
+        /*
+         * IMPDEF choice:- GITS_CBASER register becomes RO if ITS is
+         *                 already enabled
+         */
+        if (!(s->ctlr & ITS_CTLR_ENABLED)) {
+            s->cbaser = deposit64(s->cbaser, 0, 32, value);
+            s->creadr = 0;
+            s->cwriter = s->creadr;
+        }
+        break;
+    case GITS_CBASER + 4:
+        /*
+         * IMPDEF choice:- GITS_CBASER register becomes RO if ITS is
+         *                 already enabled
+         */
+        if (!(s->ctlr & ITS_CTLR_ENABLED)) {
+            s->cbaser = deposit64(s->cbaser, 32, 32, value);
+            s->creadr = 0;
+            s->cwriter = s->creadr;
+        }
+        break;
+    case GITS_CWRITER:
+        s->cwriter = deposit64(s->cwriter, 0, 32,
+                               (value & ~R_GITS_CWRITER_RETRY_MASK));
+        if (s->cwriter != s->creadr) {
+            process_cmdq(s);
+        }
+        break;
+    case GITS_CWRITER + 4:
+        s->cwriter = deposit64(s->cwriter, 32, 32, value);
+        break;
+    case GITS_CREADR:
+        if (s->gicv3->gicd_ctlr & GICD_CTLR_DS) {
+            s->creadr = deposit64(s->creadr, 0, 32,
+                                  (value & ~R_GITS_CREADR_STALLED_MASK));
+        } else {
+            /* RO register, ignore the write */
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: invalid guest write to RO register at offset "
+                          TARGET_FMT_plx "\n", __func__, offset);
+        }
+        break;
+    case GITS_CREADR + 4:
+        if (s->gicv3->gicd_ctlr & GICD_CTLR_DS) {
+            s->creadr = deposit64(s->creadr, 32, 32, value);
+        } else {
+            /* RO register, ignore the write */
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: invalid guest write to RO register at offset "
+                          TARGET_FMT_plx "\n", __func__, offset);
+        }
+        break;
+    case GITS_BASER ... GITS_BASER + 0x3f:
+        /*
+         * IMPDEF choice:- GITS_BASERn register becomes RO if ITS is
+         *                 already enabled
+         */
+        if (!(s->ctlr & ITS_CTLR_ENABLED)) {
+            index = (offset - GITS_BASER) / 8;
+
+            if (offset & 7) {
+                value <<= 32;
+                value &= ~GITS_BASER_RO_MASK;
+                s->baser[index] &= GITS_BASER_RO_MASK | MAKE_64BIT_MASK(0, 32);
+                s->baser[index] |= value;
+            } else {
+                value &= ~GITS_BASER_RO_MASK;
+                s->baser[index] &= GITS_BASER_RO_MASK | MAKE_64BIT_MASK(32, 32);
+                s->baser[index] |= value;
+            }
+        }
+        break;
+    case GITS_IIDR:
+    case GITS_IDREGS ... GITS_IDREGS + 0x2f:
+        /* RO registers, ignore the write */
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid guest write to RO register at offset "
+                      TARGET_FMT_plx "\n", __func__, offset);
+        break;
+    default:
+        result = false;
+        break;
+    }
+    return result;
+}
+
+static bool its_readl(GICv3ITSState *s, hwaddr offset,
+                             uint64_t *data, MemTxAttrs attrs)
+{
+    bool result = true;
+    int index;
+
+    switch (offset) {
+    case GITS_CTLR:
+        *data = s->ctlr;
+        break;
+    case GITS_IIDR:
+        *data = gicv3_iidr();
+        break;
+    case GITS_IDREGS ... GITS_IDREGS + 0x2f:
+        /* ID registers */
+        *data = gicv3_idreg(offset - GITS_IDREGS);
+        break;
+    case GITS_TYPER:
+        *data = extract64(s->typer, 0, 32);
+        break;
+    case GITS_TYPER + 4:
+        *data = extract64(s->typer, 32, 32);
+        break;
+    case GITS_CBASER:
+        *data = extract64(s->cbaser, 0, 32);
+        break;
+    case GITS_CBASER + 4:
+        *data = extract64(s->cbaser, 32, 32);
+        break;
+    case GITS_CREADR:
+        *data = extract64(s->creadr, 0, 32);
+        break;
+    case GITS_CREADR + 4:
+        *data = extract64(s->creadr, 32, 32);
+        break;
+    case GITS_CWRITER:
+        *data = extract64(s->cwriter, 0, 32);
+        break;
+    case GITS_CWRITER + 4:
+        *data = extract64(s->cwriter, 32, 32);
+        break;
+    case GITS_BASER ... GITS_BASER + 0x3f:
+        index = (offset - GITS_BASER) / 8;
+        if (offset & 7) {
+            *data = extract64(s->baser[index], 32, 32);
+        } else {
+            *data = extract64(s->baser[index], 0, 32);
+        }
+        break;
+    default:
+        result = false;
+        break;
+    }
+    return result;
+}
+
+static bool its_writell(GICv3ITSState *s, hwaddr offset,
+                               uint64_t value, MemTxAttrs attrs)
+{
+    bool result = true;
+    int index;
+
+    switch (offset) {
+    case GITS_BASER ... GITS_BASER + 0x3f:
+        /*
+         * IMPDEF choice:- GITS_BASERn register becomes RO if ITS is
+         *                 already enabled
+         */
+        if (!(s->ctlr & ITS_CTLR_ENABLED)) {
+            index = (offset - GITS_BASER) / 8;
+            s->baser[index] &= GITS_BASER_RO_MASK;
+            s->baser[index] |= (value & ~GITS_BASER_RO_MASK);
+        }
+        break;
+    case GITS_CBASER:
+        /*
+         * IMPDEF choice:- GITS_CBASER register becomes RO if ITS is
+         *                 already enabled
+         */
+        if (!(s->ctlr & ITS_CTLR_ENABLED)) {
+            s->cbaser = value;
+            s->creadr = 0;
+            s->cwriter = s->creadr;
+        }
+        break;
+    case GITS_CWRITER:
+        s->cwriter = value & ~R_GITS_CWRITER_RETRY_MASK;
+        if (s->cwriter != s->creadr) {
+            process_cmdq(s);
+        }
+        break;
+    case GITS_CREADR:
+        if (s->gicv3->gicd_ctlr & GICD_CTLR_DS) {
+            s->creadr = value & ~R_GITS_CREADR_STALLED_MASK;
+        } else {
+            /* RO register, ignore the write */
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: invalid guest write to RO register at offset "
+                          TARGET_FMT_plx "\n", __func__, offset);
+        }
+        break;
+    case GITS_TYPER:
+        /* RO registers, ignore the write */
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid guest write to RO register at offset "
+                      TARGET_FMT_plx "\n", __func__, offset);
+        break;
+    default:
+        result = false;
+        break;
+    }
+    return result;
+}
+
+static bool its_readll(GICv3ITSState *s, hwaddr offset,
+                              uint64_t *data, MemTxAttrs attrs)
+{
+    bool result = true;
+    int index;
+
+    switch (offset) {
+    case GITS_TYPER:
+        *data = s->typer;
+        break;
+    case GITS_BASER ... GITS_BASER + 0x3f:
+        index = (offset - GITS_BASER) / 8;
+        *data = s->baser[index];
+        break;
+    case GITS_CBASER:
+        *data = s->cbaser;
+        break;
+    case GITS_CREADR:
+        *data = s->creadr;
+        break;
+    case GITS_CWRITER:
+        *data = s->cwriter;
+        break;
+    default:
+        result = false;
+        break;
+    }
+    return result;
+}
+
+static MemTxResult gicv3_its_read(void *opaque, hwaddr offset, uint64_t *data,
+                                  unsigned size, MemTxAttrs attrs)
+{
+    GICv3ITSState *s = (GICv3ITSState *)opaque;
+    bool result;
+
+    switch (size) {
+    case 4:
+        result = its_readl(s, offset, data, attrs);
+        break;
+    case 8:
+        result = its_readll(s, offset, data, attrs);
+        break;
+    default:
+        result = false;
+        break;
+    }
+
+    if (!result) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid guest read at offset " TARGET_FMT_plx
+                      "size %u\n", __func__, offset, size);
+        /*
+         * The spec requires that reserved registers are RAZ/WI;
+         * so use false returns from leaf functions as a way to
+         * trigger the guest-error logging but don't return it to
+         * the caller, or we'll cause a spurious guest data abort.
+         */
+        *data = 0;
+    }
+    return MEMTX_OK;
+}
+
+static MemTxResult gicv3_its_write(void *opaque, hwaddr offset, uint64_t data,
+                                   unsigned size, MemTxAttrs attrs)
+{
+    GICv3ITSState *s = (GICv3ITSState *)opaque;
+    bool result;
+
+    switch (size) {
+    case 4:
+        result = its_writel(s, offset, data, attrs);
+        break;
+    case 8:
+        result = its_writell(s, offset, data, attrs);
+        break;
+    default:
+        result = false;
+        break;
+    }
+
+    if (!result) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid guest write at offset " TARGET_FMT_plx
+                      "size %u\n", __func__, offset, size);
+        /*
+         * The spec requires that reserved registers are RAZ/WI;
+         * so use false returns from leaf functions as a way to
+         * trigger the guest-error logging but don't return it to
+         * the caller, or we'll cause a spurious guest data abort.
+         */
+    }
+    return MEMTX_OK;
+}
+
+static const MemoryRegionOps gicv3_its_control_ops = {
+    .read_with_attrs = gicv3_its_read,
+    .write_with_attrs = gicv3_its_write,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 8,
+    .impl.min_access_size = 4,
+    .impl.max_access_size = 8,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const MemoryRegionOps gicv3_its_translation_ops = {
+    .write_with_attrs = gicv3_its_translation_write,
+    .valid.min_access_size = 2,
+    .valid.max_access_size = 4,
+    .impl.min_access_size = 2,
+    .impl.max_access_size = 4,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void gicv3_arm_its_realize(DeviceState *dev, Error **errp)
+{
+    GICv3ITSState *s = ARM_GICV3_ITS_COMMON(dev);
+    int i;
+
+    for (i = 0; i < s->gicv3->num_cpu; i++) {
+        if (!(s->gicv3->cpu[i].gicr_typer & GICR_TYPER_PLPIS)) {
+            error_setg(errp, "Physical LPI not supported by CPU %d", i);
+            return;
+        }
+    }
+
+    gicv3_its_init_mmio(s, &gicv3_its_control_ops, &gicv3_its_translation_ops);
+
+    address_space_init(&s->gicv3->dma_as, s->gicv3->dma,
+                       "gicv3-its-sysmem");
+
+    /* set the ITS default features supported */
+    s->typer = FIELD_DP64(s->typer, GITS_TYPER, PHYSICAL,
+                          GITS_TYPE_PHYSICAL);
+    s->typer = FIELD_DP64(s->typer, GITS_TYPER, ITT_ENTRY_SIZE,
+                          ITS_ITT_ENTRY_SIZE - 1);
+    s->typer = FIELD_DP64(s->typer, GITS_TYPER, IDBITS, ITS_IDBITS);
+    s->typer = FIELD_DP64(s->typer, GITS_TYPER, DEVBITS, ITS_DEVBITS);
+    s->typer = FIELD_DP64(s->typer, GITS_TYPER, CIL, 1);
+    s->typer = FIELD_DP64(s->typer, GITS_TYPER, CIDBITS, ITS_CIDBITS);
+}
+
+static void gicv3_its_reset(DeviceState *dev)
+{
+    GICv3ITSState *s = ARM_GICV3_ITS_COMMON(dev);
+    GICv3ITSClass *c = ARM_GICV3_ITS_GET_CLASS(s);
+
+    c->parent_reset(dev);
+
+    /* Quiescent bit reset to 1 */
+    s->ctlr = FIELD_DP32(s->ctlr, GITS_CTLR, QUIESCENT, 1);
+
+    /*
+     * setting GITS_BASER0.Type = 0b001 (Device)
+     *         GITS_BASER1.Type = 0b100 (Collection Table)
+     *         GITS_BASER<n>.Type,where n = 3 to 7 are 0b00 (Unimplemented)
+     *         GITS_BASER<0,1>.Page_Size = 64KB
+     * and default translation table entry size to 16 bytes
+     */
+    s->baser[0] = FIELD_DP64(s->baser[0], GITS_BASER, TYPE,
+                             GITS_BASER_TYPE_DEVICE);
+    s->baser[0] = FIELD_DP64(s->baser[0], GITS_BASER, PAGESIZE,
+                             GITS_BASER_PAGESIZE_64K);
+    s->baser[0] = FIELD_DP64(s->baser[0], GITS_BASER, ENTRYSIZE,
+                             GITS_DTE_SIZE - 1);
+
+    s->baser[1] = FIELD_DP64(s->baser[1], GITS_BASER, TYPE,
+                             GITS_BASER_TYPE_COLLECTION);
+    s->baser[1] = FIELD_DP64(s->baser[1], GITS_BASER, PAGESIZE,
+                             GITS_BASER_PAGESIZE_64K);
+    s->baser[1] = FIELD_DP64(s->baser[1], GITS_BASER, ENTRYSIZE,
+                             GITS_CTE_SIZE - 1);
+}
+
+static void gicv3_its_post_load(GICv3ITSState *s)
+{
+    if (s->ctlr & ITS_CTLR_ENABLED) {
+        extract_table_params(s);
+        extract_cmdq_params(s);
+    }
+}
+
+static Property gicv3_its_props[] = {
+    DEFINE_PROP_LINK("parent-gicv3", GICv3ITSState, gicv3, "arm-gicv3",
+                     GICv3State *),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void gicv3_its_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    GICv3ITSClass *ic = ARM_GICV3_ITS_CLASS(klass);
+    GICv3ITSCommonClass *icc = ARM_GICV3_ITS_COMMON_CLASS(klass);
+
+    dc->realize = gicv3_arm_its_realize;
+    device_class_set_props(dc, gicv3_its_props);
+    device_class_set_parent_reset(dc, gicv3_its_reset, &ic->parent_reset);
+    icc->post_load = gicv3_its_post_load;
+}
+
+static const TypeInfo gicv3_its_info = {
+    .name = TYPE_ARM_GICV3_ITS,
+    .parent = TYPE_ARM_GICV3_ITS_COMMON,
+    .instance_size = sizeof(GICv3ITSState),
+    .class_init = gicv3_its_class_init,
+    .class_size = sizeof(GICv3ITSClass),
+};
+
+static void gicv3_its_register_types(void)
+{
+    type_register_static(&gicv3_its_info);
+}
+
+type_init(gicv3_its_register_types)