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[Qemu-devel] [PATCH v2 7/7] i440fx: add an iommu
From: |
Avi Kivity |
Subject: |
[Qemu-devel] [PATCH v2 7/7] i440fx: add an iommu |
Date: |
Tue, 30 Oct 2012 13:47:50 +0200 |
This iommu encrypts addresses on the device bus to avoid divuling information
to hackers equipped with bus analyzers. Following 3DES, addresses are encrypted
multiple times. A XOR cypher is employed for efficiency.
Signed-off-by: Avi Kivity <address@hidden>
---
hw/piix_pci.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)
diff --git a/hw/piix_pci.c b/hw/piix_pci.c
index 9af5847..99601f4 100644
--- a/hw/piix_pci.c
+++ b/hw/piix_pci.c
@@ -30,6 +30,7 @@
#include "sysbus.h"
#include "range.h"
#include "xen.h"
+#include "exec-memory.h"
/*
* I440FX chipset data sheet.
@@ -248,6 +249,81 @@ static int i440fx_initfn(PCIDevice *dev)
return 0;
}
+typedef struct SillyIOMMU SillyIOMMU;
+
+struct SillyIOMMU {
+ MemoryRegion fault;
+ MemoryRegion l1;
+ MemoryRegion l2;
+ hwaddr mask;
+ hwaddr secret;
+};
+
+static IOMMUTLBEntry silly_l1_translate(MemoryRegion *l1, hwaddr addr)
+{
+ SillyIOMMU *s = container_of(l1, SillyIOMMU, l1);
+ hwaddr xlat = addr ^ s->secret;
+
+ printf("l1: %" HWADDR_PRIx " -> %" HWADDR_PRIx "\n", addr, xlat);
+
+ return (IOMMUTLBEntry) {
+ .device_addr = addr & ~s->mask,
+ .translated_addr = xlat & ~s->mask,
+ .addr_mask = s->mask,
+ .perm = { true, true },
+ };
+}
+
+static MemoryRegionIOMMUOps silly_l1_iommu_ops = {
+ .translate = silly_l1_translate,
+};
+
+static IOMMUTLBEntry silly_l2_translate(MemoryRegion *l2, hwaddr addr)
+{
+ SillyIOMMU *s = container_of(l2, SillyIOMMU, l2);
+ hwaddr xlat = addr ^ s->secret;
+
+ printf("l2: %" HWADDR_PRIx " -> %" HWADDR_PRIx "\n", addr, xlat);
+
+ return (IOMMUTLBEntry) {
+ .device_addr = addr & ~s->mask,
+ .translated_addr = xlat & ~s->mask,
+ .addr_mask = s->mask,
+ .perm = { true, true },
+ };
+}
+
+static MemoryRegionIOMMUOps silly_l2_iommu_ops = {
+ .translate = silly_l2_translate,
+};
+
+static MemoryRegion *silly_iommu_new(PCIBus *bus, void *opaque, int devfn)
+{
+ SillyIOMMU *s = g_new(SillyIOMMU, 1);
+ MemoryRegion *sysmem = get_system_memory();
+
+ s->mask = (0x1000 << (devfn >> 3)) - 1;
+ s->secret = ((devfn << 24) | 0x00aabbccdd) & ~s->mask;
+ memory_region_init(&s->fault, "silly-fault", INT64_MAX);
+ memory_region_init_iommu(&s->l2, &silly_l2_iommu_ops, sysmem, &s->fault,
+ "silly-l2", INT64_MAX);
+ memory_region_init_iommu(&s->l1, &silly_l1_iommu_ops, &s->l2, &s->fault,
+ "silly-l1", INT64_MAX);
+ return &s->l1;
+}
+
+static void silly_iommu_del(MemoryRegion *l1)
+{
+ SillyIOMMU *s = container_of(l1, SillyIOMMU, l1);
+
+ memory_region_del_subregion(&s->l2, get_system_memory());
+ memory_region_del_subregion(&s->l1, &s->l2);
+ memory_region_destroy(&s->l2);
+ memory_region_destroy(&s->l1);
+ memory_region_destroy(&s->fault);
+ g_free(s);
+}
+
static PCIBus *i440fx_common_init(const char *device_name,
PCII440FXState **pi440fx_state,
int *piix3_devfn,
@@ -275,6 +351,7 @@ static PCIBus *i440fx_common_init(const char *device_name,
s->address_space = address_space_mem;
b = pci_bus_new(dev, NULL, pci_address_space,
address_space_io, 0);
+ pci_setup_iommu(b, silly_iommu_new, silly_iommu_del, NULL);
s->bus = b;
object_property_add_child(qdev_get_machine(), "i440fx", OBJECT(dev), NULL);
qdev_init_nofail(dev);
--
1.7.12