On 15/6/23 00:56, Alexander Graf wrote:
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 <graf@amazon.com>
---
hw/vmapple/Kconfig | 2 +
hw/vmapple/bdif.c | 245 ++++++++++++++++++++++++++++++++++++++
hw/vmapple/meson.build | 1 +
hw/vmapple/trace-events | 5 +
include/hw/vmapple/bdif.h | 31 +++++
Please enable scripts/git.orderfile if possible.
+#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
+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 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,
IIUC your implementation is using (min, max) = (4, 4):
i.e. if the guest emits a 64-bit read at offset 0, we want to return
both REG_STATUS/REG_CFG registers.