diff mbox series

[v8,04/10] hw/intc: GICv3 ITS Command processing

Message ID 20210812165341.40784-5-shashi.mallela@linaro.org (mailing list archive)
State New, archived
Headers show
Series GICv3 LPI and ITS feature implementation | expand

Commit Message

Shashi Mallela Aug. 12, 2021, 4:53 p.m. UTC 
Added ITS command queue handling for MAPTI,MAPI commands,handled ITS
translation which triggers an LPI via INT command as well as write
to GITS_TRANSLATER register,defined enum to differentiate between ITS
command interrupt trigger and GITS_TRANSLATER based interrupt trigger.
Each of these commands make use of other functionalities implemented to
get device table entry,collection table entry or interrupt translation
table entry required for their processing.

Signed-off-by: Shashi Mallela <shashi.mallela@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/intc/arm_gicv3_its.c            | 351 +++++++++++++++++++++++++++++
 hw/intc/gicv3_internal.h           |  12 +
 include/hw/intc/arm_gicv3_common.h |   2 +
 3 files changed, 365 insertions(+)

Comments

Neil Armstrong Aug. 13, 2021, 7:51 a.m. UTC | #1 
On 12/08/2021 18:53, Shashi Mallela wrote:
> Added ITS command queue handling for MAPTI,MAPI commands,handled ITS
> translation which triggers an LPI via INT command as well as write
> to GITS_TRANSLATER register,defined enum to differentiate between ITS
> command interrupt trigger and GITS_TRANSLATER based interrupt trigger.
> Each of these commands make use of other functionalities implemented to
> get device table entry,collection table entry or interrupt translation
> table entry required for their processing.
> 
> Signed-off-by: Shashi Mallela <shashi.mallela@linaro.org>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  hw/intc/arm_gicv3_its.c            | 351 +++++++++++++++++++++++++++++
>  hw/intc/gicv3_internal.h           |  12 +
>  include/hw/intc/arm_gicv3_common.h |   2 +
>  3 files changed, 365 insertions(+)
> 
> diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
> index 8bdbebbeca..d98b0e0f4c 100644
> --- a/hw/intc/arm_gicv3_its.c
> +++ b/hw/intc/arm_gicv3_its.c
> @@ -29,6 +29,22 @@ struct GICv3ITSClass {
>      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,
> +    INT = 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;
> @@ -50,6 +66,323 @@ static uint64_t baser_base_addr(uint64_t value, uint32_t page_sz)
>      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 MemTxResult 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);
> +    }
> +   return res;
> +}
> +
> +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 MemTxResult 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;
> +
> +    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 res;
> +    }
> +
> +    eventid = (value & EVENTID_MASK);
> +
> +    dte = get_dte(s, devid, &res);
> +
> +    if (res != MEMTX_OK) {
> +        return res;
> +    }
> +    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 res;
> +        }
> +
> +        if (ite_valid) {
> +            cte_valid = get_cte(s, icid, &cte, &res);
> +        }
> +
> +        if (res != MEMTX_OK) {
> +            return res;
> +        }
> +    }
> +
> +    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
> +         */
> +        if (cmd == DISCARD) {
> +            IteEntry ite = {};
> +            /* remove mapping from interrupt translation table */
> +            res = update_ite(s, eventid, dte, ite);
> +        }
> +    }
> +
> +    return res;
> +}
> +
> +static MemTxResult 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;
> +
> +    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 res;
> +    }
> +
> +    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 res;
> +    }
> +
> +    icid = value & ICID_MASK;
> +
> +    dte = get_dte(s, devid, &res);
> +
> +    if (res != MEMTX_OK) {
> +        return res;
> +    }
> +    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;
> +
> +        res = update_ite(s, eventid, dte, ite);
> +    }
> +
> +    return res;
> +}
> +
>  static MemTxResult update_cte(GICv3ITSState *s, uint16_t icid, bool valid,
>                                uint64_t rdbase)
>  {
> @@ -303,8 +636,10 @@ static void process_cmdq(GICv3ITSState *s)
>  
>          switch (cmd) {
>          case GITS_CMD_INT:
> +            res = process_its_cmd(s, data, cq_offset, INT);
>              break;
>          case GITS_CMD_CLEAR:
> +            res = process_its_cmd(s, data, cq_offset, CLEAR);
>              break;
>          case GITS_CMD_SYNC:
>              /*
> @@ -321,10 +656,13 @@ static void process_cmdq(GICv3ITSState *s)
>              res = process_mapc(s, cq_offset);
>              break;
>          case GITS_CMD_MAPTI:
> +            res = process_mapti(s, data, cq_offset, false);
>              break;
>          case GITS_CMD_MAPI:
> +            res = process_mapti(s, data, cq_offset, true);
>              break;
>          case GITS_CMD_DISCARD:
> +            res = process_its_cmd(s, data, cq_offset, DISCARD);
>              break;
>          case GITS_CMD_INV:
>          case GITS_CMD_INVALL:
> @@ -486,7 +824,20 @@ static MemTxResult gicv3_its_translation_write(void *opaque, hwaddr offset,
>                                                 uint64_t data, unsigned size,
>                                                 MemTxAttrs attrs)
>  {
> +    GICv3ITSState *s = (GICv3ITSState *)opaque;
>      MemTxResult result = MEMTX_OK;
> +    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;
> +    }
>  
>      return result;
>  }
> diff --git a/hw/intc/gicv3_internal.h b/hw/intc/gicv3_internal.h
> index 034fadfebe..1966444790 100644
> --- a/hw/intc/gicv3_internal.h
> +++ b/hw/intc/gicv3_internal.h
> @@ -334,6 +334,13 @@ FIELD(MAPC, RDBASE, 16, 32)
>  #define ITTADDR_MASK             MAKE_64BIT_MASK(ITTADDR_SHIFT, ITTADDR_LENGTH)
>  #define SIZE_MASK                 0x1f
>  
> +/* MAPI command fields */
> +#define EVENTID_MASK              ((1ULL << 32) - 1)
> +
> +/* MAPTI command fields */
> +#define pINTID_SHIFT                 32
> +#define pINTID_MASK               MAKE_64BIT_MASK(32, 32)
> +
>  #define DEVID_SHIFT                  32
>  #define DEVID_MASK                MAKE_64BIT_MASK(32, 32)
>  
> @@ -359,6 +366,11 @@ FIELD(MAPC, RDBASE, 16, 32)
>   *   Values:  |  vPEID    |  ICID   |
>   */
>  #define ITS_ITT_ENTRY_SIZE            0xC
> +#define ITE_ENTRY_INTTYPE_SHIFT        1
> +#define ITE_ENTRY_INTID_SHIFT          2
> +#define ITE_ENTRY_INTID_MASK         MAKE_64BIT_MASK(2, 24)
> +#define ITE_ENTRY_INTSP_SHIFT          26
> +#define ITE_ENTRY_ICID_MASK          MAKE_64BIT_MASK(0, 16)
>  
>  /* 16 bits EventId */
>  #define ITS_IDBITS                   GICD_TYPER_IDBITS
> diff --git a/include/hw/intc/arm_gicv3_common.h b/include/hw/intc/arm_gicv3_common.h
> index 1fd5cedbbd..0715b0bc2a 100644
> --- a/include/hw/intc/arm_gicv3_common.h
> +++ b/include/hw/intc/arm_gicv3_common.h
> @@ -36,6 +36,8 @@
>  #define GICV3_MAXIRQ 1020
>  #define GICV3_MAXSPI (GICV3_MAXIRQ - GIC_INTERNAL)
>  
> +#define GICV3_LPI_INTID_START 8192
> +
>  #define GICV3_REDIST_SIZE 0x20000
>  
>  /* Number of SGI target-list bits */
> 

Thanks for fixing !

Tested-by: Neil Armstrong <narmstrong@baylibre.com>
diff mbox series

Patch

diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
index 8bdbebbeca..d98b0e0f4c 100644
--- a/hw/intc/arm_gicv3_its.c
+++ b/hw/intc/arm_gicv3_its.c
@@ -29,6 +29,22 @@  struct GICv3ITSClass {
     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,
+    INT = 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;
@@ -50,6 +66,323 @@  static uint64_t baser_base_addr(uint64_t value, uint32_t page_sz)
     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 MemTxResult 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);
+    }
+   return res;
+}
+
+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 MemTxResult 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;
+
+    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 res;
+    }
+
+    eventid = (value & EVENTID_MASK);
+
+    dte = get_dte(s, devid, &res);
+
+    if (res != MEMTX_OK) {
+        return res;
+    }
+    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 res;
+        }
+
+        if (ite_valid) {
+            cte_valid = get_cte(s, icid, &cte, &res);
+        }
+
+        if (res != MEMTX_OK) {
+            return res;
+        }
+    }
+
+    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
+         */
+        if (cmd == DISCARD) {
+            IteEntry ite = {};
+            /* remove mapping from interrupt translation table */
+            res = update_ite(s, eventid, dte, ite);
+        }
+    }
+
+    return res;
+}
+
+static MemTxResult 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;
+
+    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 res;
+    }
+
+    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 res;
+    }
+
+    icid = value & ICID_MASK;
+
+    dte = get_dte(s, devid, &res);
+
+    if (res != MEMTX_OK) {
+        return res;
+    }
+    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;
+
+        res = update_ite(s, eventid, dte, ite);
+    }
+
+    return res;
+}
+
 static MemTxResult update_cte(GICv3ITSState *s, uint16_t icid, bool valid,
                               uint64_t rdbase)
 {
@@ -303,8 +636,10 @@  static void process_cmdq(GICv3ITSState *s)
 
         switch (cmd) {
         case GITS_CMD_INT:
+            res = process_its_cmd(s, data, cq_offset, INT);
             break;
         case GITS_CMD_CLEAR:
+            res = process_its_cmd(s, data, cq_offset, CLEAR);
             break;
         case GITS_CMD_SYNC:
             /*
@@ -321,10 +656,13 @@  static void process_cmdq(GICv3ITSState *s)
             res = process_mapc(s, cq_offset);
             break;
         case GITS_CMD_MAPTI:
+            res = process_mapti(s, data, cq_offset, false);
             break;
         case GITS_CMD_MAPI:
+            res = process_mapti(s, data, cq_offset, true);
             break;
         case GITS_CMD_DISCARD:
+            res = process_its_cmd(s, data, cq_offset, DISCARD);
             break;
         case GITS_CMD_INV:
         case GITS_CMD_INVALL:
@@ -486,7 +824,20 @@  static MemTxResult gicv3_its_translation_write(void *opaque, hwaddr offset,
                                                uint64_t data, unsigned size,
                                                MemTxAttrs attrs)
 {
+    GICv3ITSState *s = (GICv3ITSState *)opaque;
     MemTxResult result = MEMTX_OK;
+    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;
+    }
 
     return result;
 }
diff --git a/hw/intc/gicv3_internal.h b/hw/intc/gicv3_internal.h
index 034fadfebe..1966444790 100644
--- a/hw/intc/gicv3_internal.h
+++ b/hw/intc/gicv3_internal.h
@@ -334,6 +334,13 @@  FIELD(MAPC, RDBASE, 16, 32)
 #define ITTADDR_MASK             MAKE_64BIT_MASK(ITTADDR_SHIFT, ITTADDR_LENGTH)
 #define SIZE_MASK                 0x1f
 
+/* MAPI command fields */
+#define EVENTID_MASK              ((1ULL << 32) - 1)
+
+/* MAPTI command fields */
+#define pINTID_SHIFT                 32
+#define pINTID_MASK               MAKE_64BIT_MASK(32, 32)
+
 #define DEVID_SHIFT                  32
 #define DEVID_MASK                MAKE_64BIT_MASK(32, 32)
 
@@ -359,6 +366,11 @@  FIELD(MAPC, RDBASE, 16, 32)
  *   Values:  |  vPEID    |  ICID   |
  */
 #define ITS_ITT_ENTRY_SIZE            0xC
+#define ITE_ENTRY_INTTYPE_SHIFT        1
+#define ITE_ENTRY_INTID_SHIFT          2
+#define ITE_ENTRY_INTID_MASK         MAKE_64BIT_MASK(2, 24)
+#define ITE_ENTRY_INTSP_SHIFT          26
+#define ITE_ENTRY_ICID_MASK          MAKE_64BIT_MASK(0, 16)
 
 /* 16 bits EventId */
 #define ITS_IDBITS                   GICD_TYPER_IDBITS
diff --git a/include/hw/intc/arm_gicv3_common.h b/include/hw/intc/arm_gicv3_common.h
index 1fd5cedbbd..0715b0bc2a 100644
--- a/include/hw/intc/arm_gicv3_common.h
+++ b/include/hw/intc/arm_gicv3_common.h
@@ -36,6 +36,8 @@ 
 #define GICV3_MAXIRQ 1020
 #define GICV3_MAXSPI (GICV3_MAXIRQ - GIC_INTERNAL)
 
+#define GICV3_LPI_INTID_START 8192
+
 #define GICV3_REDIST_SIZE 0x20000
 
 /* Number of SGI target-list bits */