From: Alexander Graf <g...@amazon.com>
The VMApple machine exposes AUX and ROOT block devices (as well as USB OTG
emulation) via virtio-pci as well as a special, simple backdoor platform
device.
This patch implements this backdoor platform device to the best of my
understanding. I left out any USB OTG parts; they're only needed for
guest recovery and I don't understand the protocol yet.
Signed-off-by: Alexander Graf <g...@amazon.com>
Signed-off-by: Phil Dennis-Jordan <p...@philjordan.eu>
---
hw/vmapple/Kconfig | 3 +
hw/vmapple/bdif.c | 245 ++++++++++++++++++++++++++++++++++++++
hw/vmapple/meson.build | 1 +
hw/vmapple/trace-events | 5 +
include/hw/vmapple/bdif.h | 31 +++++
5 files changed, 285 insertions(+)
create mode 100644 hw/vmapple/bdif.c
create mode 100644 include/hw/vmapple/bdif.h
diff --git a/hw/vmapple/Kconfig b/hw/vmapple/Kconfig
index a73504d5999..68f88876eb9 100644
--- a/hw/vmapple/Kconfig
+++ b/hw/vmapple/Kconfig
@@ -1,3 +1,6 @@
config VMAPPLE_AES
bool
+config VMAPPLE_BDIF
+ bool
+
diff --git a/hw/vmapple/bdif.c b/hw/vmapple/bdif.c
new file mode 100644
index 00000000000..36b5915ff30
--- /dev/null
+++ b/hw/vmapple/bdif.c
@@ -0,0 +1,245 @@
+/*
+ * VMApple Backdoor Interface
+ *
+ * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/vmapple/bdif.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qapi/error.h"
+#include "trace.h"
+#include "hw/block/block.h"
+#include "sysemu/block-backend.h"
+
+#define REG_DEVID_MASK 0xffff0000
+#define DEVID_ROOT 0x00000000
+#define DEVID_AUX 0x00010000
+#define DEVID_USB 0x00100000
+
+#define REG_STATUS 0x0
+#define REG_STATUS_ACTIVE BIT(0)
+#define REG_CFG 0x4
+#define REG_CFG_ACTIVE BIT(1)
+#define REG_UNK1 0x8
+#define REG_BUSY 0x10
+#define REG_BUSY_READY BIT(0)
+#define REG_UNK2 0x400
+#define REG_CMD 0x408
+#define REG_NEXT_DEVICE 0x420
+#define REG_UNK3 0x434
+
+typedef struct vblk_sector {
+ uint32_t pad;
+ uint32_t pad2;
+ uint32_t sector;
+ uint32_t pad3;
+} VblkSector;
+
+typedef struct vblk_req_cmd {
+ uint64_t addr;
+ uint32_t len;
+ uint32_t flags;
+} VblkReqCmd;
+
+typedef struct vblk_req {
+ VblkReqCmd sector;
+ VblkReqCmd data;
+ VblkReqCmd retval;
+} VblkReq;
+
+#define VBLK_DATA_FLAGS_READ 0x00030001
+#define VBLK_DATA_FLAGS_WRITE 0x00010001
+
+#define VBLK_RET_SUCCESS 0
+#define VBLK_RET_FAILED 1
+
+static uint64_t bdif_read(void *opaque, hwaddr offset, unsigned size)
+{
+ uint64_t ret = -1;
+ uint64_t devid = (offset & REG_DEVID_MASK);
+
+ switch (offset & ~REG_DEVID_MASK) {
+ case REG_STATUS:
+ ret = REG_STATUS_ACTIVE;
+ break;
+ case REG_CFG:
+ ret = REG_CFG_ACTIVE;
+ break;
+ case REG_UNK1:
+ ret = 0x420;
+ break;
+ case REG_BUSY:
+ ret = REG_BUSY_READY;
+ break;
+ case REG_UNK2:
+ ret = 0x1;
+ break;
+ case REG_UNK3:
+ ret = 0x0;
+ break;
+ case REG_NEXT_DEVICE:
+ switch (devid) {
+ case DEVID_ROOT:
+ ret = 0x8000000;
+ break;
+ case DEVID_AUX:
+ ret = 0x10000;
+ break;
+ }
+ break;
+ }
+
+ trace_bdif_read(offset, size, ret);
+ return ret;
+}
+
+static void le2cpu_sector(VblkSector *sector)
+{
+ sector->sector = le32_to_cpu(sector->sector);
+}
+
+static void le2cpu_reqcmd(VblkReqCmd *cmd)
+{
+ cmd->addr = le64_to_cpu(cmd->addr);
+ cmd->len = le32_to_cpu(cmd->len);
+ cmd->flags = le32_to_cpu(cmd->flags);
+}
+
+static void le2cpu_req(VblkReq *req)
+{
+ le2cpu_reqcmd(&req->sector);
+ le2cpu_reqcmd(&req->data);
+ le2cpu_reqcmd(&req->retval);
+}
+
+static void vblk_cmd(uint64_t devid, BlockBackend *blk, uint64_t value,
+ uint64_t static_off)
+{
+ VblkReq req;
+ VblkSector sector;
+ uint64_t off = 0;
+ char *buf = NULL;
+ uint8_t ret = VBLK_RET_FAILED;
+ int r;
+
+ cpu_physical_memory_read(value, &req, sizeof(req));
+ le2cpu_req(&req);
+
+ if (req.sector.len != sizeof(sector)) {
+ ret = VBLK_RET_FAILED;
+ goto out;
+ }
+
+ /* Read the vblk command */
+ cpu_physical_memory_read(req.sector.addr, §or, sizeof(sector));
+ le2cpu_sector(§or);
+
+ off = sector.sector * 512ULL + static_off;
+
+ /* Sanity check that we're not allocating bogus sizes */
+ if (req.data.len > (128 * 1024 * 1024)) {
+ goto out;
+ }
+
+ buf = g_malloc0(req.data.len);
+ switch (req.data.flags) {
+ case VBLK_DATA_FLAGS_READ:
+ r = blk_pread(blk, off, req.data.len, buf, 0);
+ trace_bdif_vblk_read(devid == DEVID_AUX ? "aux" : "root",
+ req.data.addr, off, req.data.len, r);
+ if (r < 0) {
+ goto out;
+ }
+ cpu_physical_memory_write(req.data.addr, buf, req.data.len);
+ ret = VBLK_RET_SUCCESS;
+ break;
+ case VBLK_DATA_FLAGS_WRITE:
+ /* Not needed, iBoot only reads */
+ break;
+ default:
+ break;
+ }
+
+out:
+ g_free(buf);
+ cpu_physical_memory_write(req.retval.addr, &ret, 1);
+}
+
+static void bdif_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+ VMAppleBdifState *s = opaque;
+ uint64_t devid = (offset & REG_DEVID_MASK);
+
+ trace_bdif_write(offset, size, value);
+
+ switch (offset & ~REG_DEVID_MASK) {
+ case REG_CMD:
+ switch (devid) {
+ case DEVID_ROOT:
+ vblk_cmd(devid, s->root, value, 0x0);
+ break;
+ case DEVID_AUX:
+ vblk_cmd(devid, s->aux, value, 0x0);
+ break;
+ }
+ break;
+ }
+}
+
+static const MemoryRegionOps bdif_ops = {
+ .read = bdif_read,
+ .write = bdif_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+ .valid = {
+ .min_access_size = 1,
+ .max_access_size = 8,
+ },
+ .impl = {
+ .min_access_size = 1,
+ .max_access_size = 8,
+ },
+};
+
+static void bdif_init(Object *obj)
+{
+ VMAppleBdifState *s = VMAPPLE_BDIF(obj);
+
+ memory_region_init_io(&s->mmio, obj, &bdif_ops, obj,
+ "VMApple Backdoor Interface", VMAPPLE_BDIF_SIZE);
+ sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static Property bdif_properties[] = {
+ DEFINE_PROP_DRIVE("aux", VMAppleBdifState, aux),
+ DEFINE_PROP_DRIVE("root", VMAppleBdifState, root),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void bdif_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->desc = "VMApple Backdoor Interface";
+ device_class_set_props(dc, bdif_properties);
+}
+
+static const TypeInfo bdif_info = {
+ .name = TYPE_VMAPPLE_BDIF,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(VMAppleBdifState),
+ .instance_init = bdif_init,
+ .class_init = bdif_class_init,
+};
+
+static void bdif_register_types(void)
+{
+ type_register_static(&bdif_info);
+}
+
+type_init(bdif_register_types)
diff --git a/hw/vmapple/meson.build b/hw/vmapple/meson.build
index bcd4dcb28d2..d4624713deb 100644
--- a/hw/vmapple/meson.build
+++ b/hw/vmapple/meson.build
@@ -1 +1,2 @@
system_ss.add(when: 'CONFIG_VMAPPLE_AES', if_true: files('aes.c'))
+system_ss.add(when: 'CONFIG_VMAPPLE_BDIF', if_true: files('bdif.c'))
diff --git a/hw/vmapple/trace-events b/hw/vmapple/trace-events
index 1c9a3326eb4..fc8e9cc5897 100644
--- a/hw/vmapple/trace-events
+++ b/hw/vmapple/trace-events
@@ -19,3 +19,8 @@ aes_2_write_unknown(uint64_t offset) "offset=0x%"PRIx64
aes_2_write(uint64_t offset, uint64_t val) "offset=0x%"PRIx64" val=0x%"PRIx64
aes_dump_data(const char *desc, const char *hex) "%s%s"
+# bdif.c
+bdif_read(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64"
size=0x%x value=0x%"PRIx64
+bdif_write(uint64_t offset, uint32_t size, uint64_t value) "offset=0x%"PRIx64"
size=0x%x value=0x%"PRIx64
+bdif_vblk_read(const char *dev, uint64_t addr, uint64_t offset, uint32_t len,
int r) "dev=%s addr=0x%"PRIx64" off=0x%"PRIx64" size=0x%x r=%d"
+
diff --git a/include/hw/vmapple/bdif.h b/include/hw/vmapple/bdif.h
new file mode 100644
index 00000000000..65ee43457b9
--- /dev/null
+++ b/include/hw/vmapple/bdif.h
@@ -0,0 +1,31 @@
+/*
+ * VMApple Backdoor Interface
+ *
+ * Copyright © 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_VMAPPLE_BDIF_H
+#define HW_VMAPPLE_BDIF_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_VMAPPLE_BDIF "vmapple-bdif"
+OBJECT_DECLARE_SIMPLE_TYPE(VMAppleBdifState, VMAPPLE_BDIF)
+
+struct VMAppleBdifState {
+ /* <private> */
+ SysBusDevice parent_obj;
+
+ /* <public> */
+ BlockBackend *aux;
+ BlockBackend *root;
+ MemoryRegion mmio;
+};
+
+#define VMAPPLE_BDIF_SIZE 0x00200000
+
+#endif /* HW_VMAPPLE_BDIF_H */
--
2.39.3 (Apple Git-145)
