diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 0c23c22..e64c662 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1631,6 +1631,64 @@ static void build_piix4_pci0_int(Aml *table)
     aml_append(table, sb_scope);
 }
 
+static void append_q35_prt_entry(Aml *ctx, uint32_t nr, const char *name)
+{
+    int i;
+    int head;
+    Aml *pkg;
+    char base = name[3] < 'E' ? 'A' : 'E';
+    char *s = g_strdup(name);
+    Aml *a_nr = aml_int((nr << 16) | 0xffff);
+
+    assert(strlen(s) == 4);
+
+    head = name[3] - base;
+    for (i = 0; i < 4; i++) {
+        if (head + i > 3) {
+            head = i * -1;
+        }
+        s[3] = base + head + i;
+        pkg = aml_package(4);
+        aml_append(pkg, a_nr);
+        aml_append(pkg, aml_int(i));
+        aml_append(pkg, aml_name("%s", s));
+        aml_append(pkg, aml_int(0));
+        aml_append(ctx, pkg);
+    }
+    g_free(s);
+}
+
+static Aml *build_q35_routing_table(const char *str)
+{
+    int i;
+    Aml *pkg;
+    char *name = g_strdup_printf("%s ", str);
+
+    pkg = aml_package(128);
+    for (i = 0; i < 0x18; i++) {
+            name[3] = 'E' + (i & 0x3);
+            append_q35_prt_entry(pkg, i, name);
+    }
+
+    name[3] = 'E';
+    append_q35_prt_entry(pkg, 0x18, name);
+
+    /* INTA -> PIRQA for slot 25 - 31, see the default value of D<N>IR */
+    for (i = 0x0019; i < 0x1e; i++) {
+        name[3] = 'A';
+        append_q35_prt_entry(pkg, i, name);
+    }
+
+    /* PCIe->PCI bridge. use PIRQ[E-H] */
+    name[3] = 'E';
+    append_q35_prt_entry(pkg, 0x1e, name);
+    name[3] = 'A';
+    append_q35_prt_entry(pkg, 0x1f, name);
+
+    g_free(name);
+    return pkg;
+}
+
 static void build_q35_pci0_int(Aml *table)
 {
     Aml *field;
@@ -1638,6 +1696,9 @@ static void build_q35_pci0_int(Aml *table)
     Aml *sb_scope = aml_scope("_SB");
     Aml *pci0_scope = aml_scope("PCI0");
 
+    aml_append(pci0_scope,
+        aml_name_decl("PRTA", build_q35_routing_table("GSI")));
+
     method = aml_method("_PRT", 0, AML_NOTSERIALIZED);
     {
         Aml *if_ctx;
diff --git a/hw/i386/q35-acpi-dsdt.dsl b/hw/i386/q35-acpi-dsdt.dsl
index f265583..a3073ad 100644
--- a/hw/i386/q35-acpi-dsdt.dsl
+++ b/hw/i386/q35-acpi-dsdt.dsl
@@ -181,63 +181,6 @@ DefinitionBlock (
 
                 prt_slot_lnkA(0x001f)
             })
-
-#define prt_slot_gsi(nr, gsi0, gsi1, gsi2, gsi3)  \
-    Package() { nr##ffff, 0, gsi0, 0 },           \
-    Package() { nr##ffff, 1, gsi1, 0 },           \
-    Package() { nr##ffff, 2, gsi2, 0 },           \
-    Package() { nr##ffff, 3, gsi3, 0 }
-
-#define prt_slot_gsiA(nr) prt_slot_gsi(nr, GSIA, GSIB, GSIC, GSID)
-#define prt_slot_gsiB(nr) prt_slot_gsi(nr, GSIB, GSIC, GSID, GSIA)
-#define prt_slot_gsiC(nr) prt_slot_gsi(nr, GSIC, GSID, GSIA, GSIB)
-#define prt_slot_gsiD(nr) prt_slot_gsi(nr, GSID, GSIA, GSIB, GSIC)
-
-#define prt_slot_gsiE(nr) prt_slot_gsi(nr, GSIE, GSIF, GSIG, GSIH)
-#define prt_slot_gsiF(nr) prt_slot_gsi(nr, GSIF, GSIG, GSIH, GSIE)
-#define prt_slot_gsiG(nr) prt_slot_gsi(nr, GSIG, GSIH, GSIE, GSIF)
-#define prt_slot_gsiH(nr) prt_slot_gsi(nr, GSIH, GSIE, GSIF, GSIG)
-
-            Name(PRTA, package() {
-                prt_slot_gsiE(0x0000),
-                prt_slot_gsiF(0x0001),
-                prt_slot_gsiG(0x0002),
-                prt_slot_gsiH(0x0003),
-                prt_slot_gsiE(0x0004),
-                prt_slot_gsiF(0x0005),
-                prt_slot_gsiG(0x0006),
-                prt_slot_gsiH(0x0007),
-                prt_slot_gsiE(0x0008),
-                prt_slot_gsiF(0x0009),
-                prt_slot_gsiG(0x000a),
-                prt_slot_gsiH(0x000b),
-                prt_slot_gsiE(0x000c),
-                prt_slot_gsiF(0x000d),
-                prt_slot_gsiG(0x000e),
-                prt_slot_gsiH(0x000f),
-                prt_slot_gsiE(0x0010),
-                prt_slot_gsiF(0x0011),
-                prt_slot_gsiG(0x0012),
-                prt_slot_gsiH(0x0013),
-                prt_slot_gsiE(0x0014),
-                prt_slot_gsiF(0x0015),
-                prt_slot_gsiG(0x0016),
-                prt_slot_gsiH(0x0017),
-                prt_slot_gsiE(0x0018),
-
-                /* INTA -> PIRQA for slot 25 - 31, but 30
-                   see the default value of D<N>IR */
-                prt_slot_gsiA(0x0019),
-                prt_slot_gsiA(0x001a),
-                prt_slot_gsiA(0x001b),
-                prt_slot_gsiA(0x001c),
-                prt_slot_gsiA(0x001d),
-
-                /* PCIe->PCI bridge. use PIRQ[E-H] */
-                prt_slot_gsiE(0x001e),
-
-                prt_slot_gsiA(0x001f)
-            })
         }
 
         External(LNKA, DeviceObj)
