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authorKevin O'Connor <kevin@koconnor.net>2015-10-08 17:02:58 +0200
committerGerd Hoffmann <kraxel@redhat.com>2015-10-19 15:26:54 +0200
commit2cc06a8843ace3d03464032eb3c74bc6e2b07579 (patch)
treea26f32b3b9cdf3aaf3080e61c561be64ee26bf4d /hw/nvram
parentc886fc4c20ff8456b2f788a1404dd321b8b59243 (diff)
downloadqemu-2cc06a8843ace3d03464032eb3c74bc6e2b07579.tar.gz
fw_cfg: Define a static signature to be returned on DMA port reads
Return a static signature ("QEMU CFG") if the guest does a read to the DMA address io register. Signed-off-by: Kevin O'Connor <kevin@koconnor.net> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/nvram')
-rw-r--r--hw/nvram/fw_cfg.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 91829d4e4b..73b0a813a7 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -53,6 +53,8 @@
#define FW_CFG_DMA_CTL_SKIP 0x04
#define FW_CFG_DMA_CTL_SELECT 0x08
+#define FW_CFG_DMA_SIGNATURE 0x51454d5520434647ULL /* "QEMU CFG" */
+
typedef struct FWCfgEntry {
uint32_t len;
uint8_t *data;
@@ -397,6 +399,13 @@ static void fw_cfg_dma_transfer(FWCfgState *s)
trace_fw_cfg_read(s, 0);
}
+static uint64_t fw_cfg_dma_mem_read(void *opaque, hwaddr addr,
+ unsigned size)
+{
+ /* Return a signature value (and handle various read sizes) */
+ return extract64(FW_CFG_DMA_SIGNATURE, (8 - addr - size) * 8, size * 8);
+}
+
static void fw_cfg_dma_mem_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
@@ -420,8 +429,8 @@ static void fw_cfg_dma_mem_write(void *opaque, hwaddr addr,
static bool fw_cfg_dma_mem_valid(void *opaque, hwaddr addr,
unsigned size, bool is_write)
{
- return is_write && ((size == 4 && (addr == 0 || addr == 4)) ||
- (size == 8 && addr == 0));
+ return !is_write || ((size == 4 && (addr == 0 || addr == 4)) ||
+ (size == 8 && addr == 0));
}
static bool fw_cfg_data_mem_valid(void *opaque, hwaddr addr,
@@ -492,6 +501,7 @@ static const MemoryRegionOps fw_cfg_comb_mem_ops = {
};
static const MemoryRegionOps fw_cfg_dma_mem_ops = {
+ .read = fw_cfg_dma_mem_read,
.write = fw_cfg_dma_mem_write,
.endianness = DEVICE_BIG_ENDIAN,
.valid.accepts = fw_cfg_dma_mem_valid,