From: Philippe Mathieu-Daudé Date: Thu, 8 Jan 2026 03:30:38 +0000 (+0800) Subject: hw/i386: Assume fw_cfg DMA is always enabled X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04ddbb137da180e684e8a1c7fafdae7d1426fd4d;p=thirdparty%2Fqemu.git hw/i386: Assume fw_cfg DMA is always enabled Now all calls of x86 machines to fw_cfg_init_io_dma() pass DMA arguments, so the FWCfgState (FWCfgIoState) created by x86 machines enables DMA by default. Although other callers of fw_cfg_init_io_dma() besides x86 also pass DMA arguments to create DMA-enabled FwCfgIoState, the "dma_enabled" property of FwCfgIoState cannot yet be removed, because Sun4u and Sun4v still create DMA-disabled FwCfgIoState (bypass fw_cfg_init_io_dma()) in sun4uv_init() (hw/sparc64/sun4u.c). Maybe reusing fw_cfg_init_io_dma() for them would be a better choice, or adding fw_cfg_init_io_nodma(). However, before that, first simplify the handling of FwCfgState in x86. Considering that FwCfgIoState in x86 enables DMA by default, remove the handling for DMA-disabled cases and replace DMA checks with assertions to ensure that the default DMA-enabled setting is not broken. Then 'linuxboot.bin' isn't used anymore, and it will be removed in the next commit. Signed-off-by: Philippe Mathieu-Daudé Signed-off-by: Zhao Liu Acked-by: Igor Mammedov Reviewed-by: Thomas Huth Link: https://lore.kernel.org/r/20260108033051.777361-15-zhao1.liu@intel.com Signed-off-by: Paolo Bonzini --- diff --git a/hw/i386/fw_cfg.c b/hw/i386/fw_cfg.c index 5c0bcd5f8a..5670e8553e 100644 --- a/hw/i386/fw_cfg.c +++ b/hw/i386/fw_cfg.c @@ -215,18 +215,18 @@ void fw_cfg_build_feature_control(MachineState *ms, FWCfgState *fw_cfg) #ifdef CONFIG_ACPI void fw_cfg_add_acpi_dsdt(Aml *scope, FWCfgState *fw_cfg) { + uint8_t io_size; + Aml *dev = aml_device("FWCF"); + Aml *crs = aml_resource_template(); + /* * when using port i/o, the 8-bit data register *always* overlaps * with half of the 16-bit control register. Hence, the total size - * of the i/o region used is FW_CFG_CTL_SIZE; when using DMA, the - * DMA control register is located at FW_CFG_DMA_IO_BASE + 4 + * of the i/o region used is FW_CFG_CTL_SIZE; And the DMA control + * register is located at FW_CFG_DMA_IO_BASE + 4 */ - Object *obj = OBJECT(fw_cfg); - uint8_t io_size = object_property_get_bool(obj, "dma_enabled", NULL) ? - ROUND_UP(FW_CFG_CTL_SIZE, 4) + sizeof(dma_addr_t) : - FW_CFG_CTL_SIZE; - Aml *dev = aml_device("FWCF"); - Aml *crs = aml_resource_template(); + assert(fw_cfg_dma_enabled(fw_cfg)); + io_size = ROUND_UP(FW_CFG_CTL_SIZE, 4) + sizeof(dma_addr_t); aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0002"))); diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c index 192e91042f..de4cd7650a 100644 --- a/hw/i386/x86-common.c +++ b/hw/i386/x86-common.c @@ -1002,10 +1002,8 @@ void x86_load_linux(X86MachineState *x86ms, } option_rom[nb_option_roms].bootindex = 0; - option_rom[nb_option_roms].name = "linuxboot.bin"; - if (fw_cfg_dma_enabled(fw_cfg)) { - option_rom[nb_option_roms].name = "linuxboot_dma.bin"; - } + assert(fw_cfg_dma_enabled(fw_cfg)); + option_rom[nb_option_roms].name = "linuxboot_dma.bin"; nb_option_roms++; }