iommu: provide ACPI tables

The OS needs an ACPI IVRS table to discover and use the IOMMU.

Signed-off-by: Eduard - Gabriel Munteanu <>
---
 src/acpi.c |   79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/src/acpi.c b/src/acpi.c
index 18830dc..c267c54 100644
--- a/src/acpi.c
+++ b/src/acpi.c
@@ -6,6 +6,7 @@
 // This file may be distributed under the terms of the GNU LGPLv3 license.
 
 #include "acpi.h" // struct rsdp_descriptor
+#include "iommu.h"
 #include "util.h" // memcpy
 #include "pci.h" // pci_find_device
 #include "biosvar.h" // GET_EBDA
@@ -196,6 +197,36 @@ struct srat_memory_affinity
     u32    reserved3[2];
 } PACKED;
 
+/*
+ * IVRS (I/O Virtualization Reporting Structure) table.
+ *
+ * Describes the AMD IOMMU, as per:
+ * "AMD I/O Virtualization Technology (IOMMU) Specification", rev 1.26
+ */
+
+struct ivrs_ivhd
+{
+    u8    type;
+    u8    flags;
+    u16   length;
+    u16   devid;
+    u16   capab_off;
+    u32   iommu_base_low;
+    u32   iommu_base_high;
+    u16   pci_seg_group;
+    u16   iommu_info;
+    u32   reserved;
+    u8    entry[0];
+} PACKED;
+
+struct ivrs_table
+{
+    ACPI_TABLE_HEADER_DEF    /* ACPI common table header. */
+    u32                iv_info;
+    u32                reserved[2];
+    struct ivrs_ivhd   ivhd;
+} PACKED;
+
 #include "acpi-dsdt.hex"
 
 static void
@@ -586,6 +617,53 @@ static const struct pci_device_id acpi_find_tbl[] = {
     PCI_DEVICE_END,
 };
 
+#define IVRS_SIGNATURE 0x53525649 // IVRS
+#define IVRS_MAX_DEVS  32
+static void *
+build_ivrs(void)
+{
+    int iommu_bdf, bdf, max, i;
+    struct ivrs_table *ivrs;
+    struct ivrs_ivhd *ivhd;
+
+    iommu_bdf = pci_find_class(PCI_CLASS_SYSTEM_IOMMU);
+    if (iommu_bdf < 0)
+        return NULL;
+
+    ivrs = malloc_high(sizeof(struct ivrs_table) + 4 * IVRS_MAX_DEVS);
+    ivrs->iv_info = iommu_get_misc() & ~0x000F;
+
+    ivhd = &ivrs->ivhd;
+    ivhd->type              = 0x10;
+    ivhd->flags             = 0;
+    ivhd->length            = sizeof(struct ivrs_ivhd);
+    ivhd->devid             = iommu_get_bdf();
+    ivhd->capab_off         = iommu_get_cap_offset();
+    ivhd->iommu_base_low    = iommu_get_base();
+    ivhd->iommu_base_high   = 0;
+    ivhd->pci_seg_group     = 0;
+    ivhd->iommu_info        = 0;
+    ivhd->reserved          = 0;
+
+    i = 0;
+    foreachpci(bdf, max) {
+        if (bdf == ivhd->devid)
+            continue;
+        ivhd->entry[4 * i + 0] = 2;
+        ivhd->entry[4 * i + 1] = bdf & 0xFF;
+        ivhd->entry[4 * i + 2] = (bdf >> 8) & 0xFF;
+        ivhd->entry[4 * i + 3] = ~(1 << 3);
+        ivhd->length += 4;
+        if (++i >= IVRS_MAX_DEVS)
+            break;
+    }
+
+    build_header((void *) ivrs, IVRS_SIGNATURE,
+                 sizeof(struct ivrs_table) + 4 * i, 1);
+
+    return ivrs;
+}
+
 struct rsdp_descriptor *RsdpAddr;
 
 #define MAX_ACPI_TABLES 20
@@ -625,6 +703,7 @@ acpi_bios_init(void)
     ACPI_INIT_TABLE(build_madt());
     ACPI_INIT_TABLE(build_hpet());
     ACPI_INIT_TABLE(build_srat());
+    ACPI_INIT_TABLE(build_ivrs());
 
     u16 i, external_tables = qemu_cfg_acpi_additional_tables();
 
-- 
1.7.1

---

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