hw/intc/arm_gicv3_its: Implement MOVI

Implement the ITS MOVI command. This command specifies a (physical) LPI
by DeviceID and EventID and provides a new ICID for it. The ITS must
find the interrupt translation table entry for the LPI, which will
tell it the old ICID. It then moves the pending state of the LPI from
the old redistributor to the new one and updates the ICID field in
the translation table entry.

This is another GICv3 ITS command that we forgot to implement.  Linux
does use this one, but only if the guest powers off one of its CPUs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220122182444.724087-15-peter.maydell@linaro.org

3 files changed, 215 insertions, 0 deletions

diff --git a/hw/intc/arm_gicv3_its.c b/hw/intc/arm_gicv3_its.c
index ebc0403..51d9be4 100644
--- a/hw/intc/arm_gicv3_its.c
+++ b/hw/intc/arm_gicv3_its.c
@@ -634,6 +634,149 @@ static ItsCmdResult process_movall(GICv3ITSState *s, uint64_t value,
     return CMD_CONTINUE;
 }
 
+static ItsCmdResult process_movi(GICv3ITSState *s, uint64_t value,
+                                 uint32_t offset)
+{
+    AddressSpace *as = &s->gicv3->dma_as;
+    MemTxResult res = MEMTX_OK;
+    uint32_t devid, eventid, intid;
+    uint16_t old_icid, new_icid;
+    uint64_t old_cte, new_cte;
+    uint64_t old_rdbase, new_rdbase;
+    uint64_t dte;
+    bool dte_valid, ite_valid, cte_valid;
+    uint64_t num_eventids;
+    IteEntry ite = {};
+
+    devid = FIELD_EX64(value, MOVI_0, DEVICEID);
+
+    offset += NUM_BYTES_IN_DW;
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+    if (res != MEMTX_OK) {
+        return CMD_STALL;
+    }
+    eventid = FIELD_EX64(value, MOVI_1, EVENTID);
+
+    offset += NUM_BYTES_IN_DW;
+    value = address_space_ldq_le(as, s->cq.base_addr + offset,
+                                 MEMTXATTRS_UNSPECIFIED, &res);
+    if (res != MEMTX_OK) {
+        return CMD_STALL;
+    }
+    new_icid = FIELD_EX64(value, MOVI_2, ICID);
+
+    if (devid >= s->dt.num_entries) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: devid %d>=%d",
+                      __func__, devid, s->dt.num_entries);
+        return CMD_CONTINUE;
+    }
+    dte = get_dte(s, devid, &res);
+    if (res != MEMTX_OK) {
+        return CMD_STALL;
+    }
+
+    dte_valid = FIELD_EX64(dte, DTE, VALID);
+    if (!dte_valid) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: "
+                      "invalid dte: %"PRIx64" for %d\n",
+                      __func__, dte, devid);
+        return CMD_CONTINUE;
+    }
+
+    num_eventids = 1ULL << (FIELD_EX64(dte, DTE, SIZE) + 1);
+    if (eventid >= num_eventids) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: eventid %d >= %"
+                      PRId64 "\n",
+                      __func__, eventid, num_eventids);
+        return CMD_CONTINUE;
+    }
+
+    ite_valid = get_ite(s, eventid, dte, &old_icid, &intid, &res);
+    if (res != MEMTX_OK) {
+        return CMD_STALL;
+    }
+
+    if (!ite_valid) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: invalid ITE\n",
+                      __func__);
+        return CMD_CONTINUE;
+    }
+
+    if (old_icid >= s->ct.num_entries) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid ICID 0x%x in ITE (table corrupted?)\n",
+                      __func__, old_icid);
+        return CMD_CONTINUE;
+    }
+
+    if (new_icid >= s->ct.num_entries) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: ICID 0x%x\n",
+                      __func__, new_icid);
+        return CMD_CONTINUE;
+    }
+
+    cte_valid = get_cte(s, old_icid, &old_cte, &res);
+    if (res != MEMTX_OK) {
+        return CMD_STALL;
+    }
+    if (!cte_valid) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: "
+                      "invalid cte: %"PRIx64"\n",
+                      __func__, old_cte);
+        return CMD_CONTINUE;
+    }
+
+    cte_valid = get_cte(s, new_icid, &new_cte, &res);
+    if (res != MEMTX_OK) {
+        return CMD_STALL;
+    }
+    if (!cte_valid) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: invalid command attributes: "
+                      "invalid cte: %"PRIx64"\n",
+                      __func__, new_cte);
+        return CMD_CONTINUE;
+    }
+
+    old_rdbase = FIELD_EX64(old_cte, CTE, RDBASE);
+    if (old_rdbase >= s->gicv3->num_cpu) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: CTE has invalid rdbase 0x%"PRIx64"\n",
+                      __func__, old_rdbase);
+        return CMD_CONTINUE;
+    }
+
+    new_rdbase = FIELD_EX64(new_cte, CTE, RDBASE);
+    if (new_rdbase >= s->gicv3->num_cpu) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: CTE has invalid rdbase 0x%"PRIx64"\n",
+                      __func__, new_rdbase);
+        return CMD_CONTINUE;
+    }
+
+    if (old_rdbase != new_rdbase) {
+        /* Move the LPI from the old redistributor to the new one */
+        gicv3_redist_mov_lpi(&s->gicv3->cpu[old_rdbase],
+                             &s->gicv3->cpu[new_rdbase],
+                             intid);
+    }
+
+    /* Update the ICID field in the interrupt translation table entry */
+    ite.itel = FIELD_DP64(ite.itel, ITE_L, VALID, 1);
+    ite.itel = FIELD_DP64(ite.itel, ITE_L, INTTYPE, ITE_INTTYPE_PHYSICAL);
+    ite.itel = FIELD_DP64(ite.itel, ITE_L, INTID, intid);
+    ite.itel = FIELD_DP64(ite.itel, ITE_L, DOORBELL, INTID_SPURIOUS);
+    ite.iteh = FIELD_DP32(ite.iteh, ITE_H, ICID, new_icid);
+    return update_ite(s, eventid, dte, ite) ? CMD_CONTINUE : CMD_STALL;
+}
+
 /*
  * Current implementation blocks until all
  * commands are processed
@@ -731,6 +874,9 @@ static void process_cmdq(GICv3ITSState *s)
                 gicv3_redist_update_lpi(&s->gicv3->cpu[i]);
             }
             break;
+        case GITS_CMD_MOVI:
+            result = process_movi(s, data, cq_offset);
+            break;
         case GITS_CMD_MOVALL:
             result = process_movall(s, data, cq_offset);
             break;
diff --git a/hw/intc/arm_gicv3_redist.c b/hw/intc/arm_gicv3_redist.c
index d1645ba..412a04f 100644
--- a/hw/intc/arm_gicv3_redist.c
+++ b/hw/intc/arm_gicv3_redist.c
@@ -681,6 +681,59 @@ void gicv3_redist_process_lpi(GICv3CPUState *cs, int irq, int level)
     gicv3_redist_lpi_pending(cs, irq, level);
 }
 
+void gicv3_redist_mov_lpi(GICv3CPUState *src, GICv3CPUState *dest, int irq)
+{
+    /*
+     * Move the specified LPI's pending state from the source redistributor
+     * to the destination.
+     *
+     * If LPIs are disabled on dest this is CONSTRAINED UNPREDICTABLE:
+     * we choose to NOP. If LPIs are disabled on source there's nothing
+     * to be transferred anyway.
+     */
+    AddressSpace *as = &src->gic->dma_as;
+    uint64_t idbits;
+    uint32_t pendt_size;
+    uint64_t src_baddr;
+    uint8_t src_pend;
+
+    if (!(src->gicr_ctlr & GICR_CTLR_ENABLE_LPIS) ||
+        !(dest->gicr_ctlr & GICR_CTLR_ENABLE_LPIS)) {
+        return;
+    }
+
+    idbits = MIN(FIELD_EX64(src->gicr_propbaser, GICR_PROPBASER, IDBITS),
+                 GICD_TYPER_IDBITS);
+    idbits = MIN(FIELD_EX64(dest->gicr_propbaser, GICR_PROPBASER, IDBITS),
+                 idbits);
+
+    pendt_size = 1ULL << (idbits + 1);
+    if ((irq / 8) >= pendt_size) {
+        return;
+    }
+
+    src_baddr = src->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
+
+    address_space_read(as, src_baddr + (irq / 8),
+                       MEMTXATTRS_UNSPECIFIED, &src_pend, sizeof(src_pend));
+    if (!extract32(src_pend, irq % 8, 1)) {
+        /* Not pending on source, nothing to do */
+        return;
+    }
+    src_pend &= ~(1 << (irq % 8));
+    address_space_write(as, src_baddr + (irq / 8),
+                        MEMTXATTRS_UNSPECIFIED, &src_pend, sizeof(src_pend));
+    if (irq == src->hpplpi.irq) {
+        /*
+         * We just made this LPI not-pending so only need to update
+         * if it was previously the highest priority pending LPI
+         */
+        gicv3_redist_update_lpi(src);
+    }
+    /* Mark it pending on the destination */
+    gicv3_redist_lpi_pending(dest, irq, 1);
+}
+
 void gicv3_redist_movall_lpis(GICv3CPUState *src, GICv3CPUState *dest)
 {
     /*
diff --git a/hw/intc/gicv3_internal.h b/hw/intc/gicv3_internal.h
index da45975..b1af26d 100644
--- a/hw/intc/gicv3_internal.h
+++ b/hw/intc/gicv3_internal.h
@@ -315,6 +315,7 @@ FIELD(GITS_TYPER, CIL, 36, 1)
 #define CMD_MASK                  0xff
 
 /* ITS Commands */
+#define GITS_CMD_MOVI             0x01
 #define GITS_CMD_INT              0x03
 #define GITS_CMD_CLEAR            0x04
 #define GITS_CMD_SYNC             0x05
@@ -360,6 +361,11 @@ FIELD(MAPC, RDBASE, 16, 32)
 FIELD(MOVALL_2, RDBASE1, 16, 36)
 FIELD(MOVALL_3, RDBASE2, 16, 36)
 
+/* MOVI command fields */
+FIELD(MOVI_0, DEVICEID, 32, 32)
+FIELD(MOVI_1, EVENTID, 0, 32)
+FIELD(MOVI_2, ICID, 0, 16)
+
 /*
  * 12 bytes Interrupt translation Table Entry size
  * as per Table 5.3 in GICv3 spec
@@ -503,6 +509,16 @@ void gicv3_redist_update_lpi(GICv3CPUState *cs);
  */
 void gicv3_redist_update_lpi_only(GICv3CPUState *cs);
 /**
+ * gicv3_redist_mov_lpi:
+ * @src: source redistributor
+ * @dest: destination redistributor
+ * @irq: LPI to update
+ *
+ * Move the pending state of the specified LPI from @src to @dest,
+ * as required by the ITS MOVI command.
+ */
+void gicv3_redist_mov_lpi(GICv3CPUState *src, GICv3CPUState *dest, int irq);
+/**
  * gicv3_redist_movall_lpis:
  * @src: source redistributor
  * @dest: destination redistributor