From: Peter Maydell <peter.maydell@linaro.org>
Date: Fri, 29 May 2026 17:46:38 +0000 (+0100)
Subject: hw/nvram/fw_cfg: Remove support for I/O port fw_cfg without DMA
X-Git-Tag: v11.1.0-rc0~26^2~28
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb642dc302b9cd4e3ba1c9fb66da010ee1949923;p=thirdparty%2Fqemu.git

hw/nvram/fw_cfg: Remove support for I/O port fw_cfg without DMA

Currently fw_cfg_init_io_dma() allows the caller to pass a NULL
dma_as argument, which causes it to create a fw_cfg without
the DMA port or DMA support. None of the callers use this
capability: they all pass &address_space_memory.

We don't really want to leave the door open for some future x86
machine type which doesn't support DMA for the fw_cfg device, so
remove this, and instead make the function assert that it has a
non-NULL dma_as argument, like fw_cfg_init_mem_dma().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@mailo.com>
Message-id: 20260529174639.451353-5-peter.maydell@linaro.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index f68191553b..a9d45adb2d 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -1026,12 +1026,10 @@ FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, AddressSpace *dma_as)
     FWCfgIoState *ios;
     FWCfgState *s;
     MemoryRegion *iomem = get_system_io();
-    bool dma_requested = dma_as;
+
+    assert(dma_as);
 
     dev = qdev_new(TYPE_FW_CFG_IO);
-    if (!dma_requested) {
-        qdev_prop_set_bit(dev, "dma_enabled", false);
-    }
 
     object_property_add_child(OBJECT(qdev_get_machine()), TYPE_FW_CFG,
                               OBJECT(dev));