From 30929793b0a68c1f7ef85035bc0159a835e7a0cb Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Thu, 18 Feb 2016 20:31:00 +0100 Subject: fw_cfg: unbreak migration compatibility for 2.4 and earlier machines MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When I reviewed Marc's fw_cfg DMA patches, I completely missed that the way we set dma_enabled would break migration. Gerd explained the right way (see reference below): dma_enabled should be set to true by default, and only true->false transitions should be possible: - when the user requests that with -global fw_cfg_mem.dma_enabled=off or -global fw_cfg_io.dma_enabled=off as appropriate for the platform, - when HW_COMPAT_2_4 dictates it, - when board code initializes fw_cfg without requesting DMA support. Cc: Marc Marí Cc: Gerd Hoffmann Cc: Alexandre DERUMIER Cc: qemu-stable@nongnu.org Ref: http://thread.gmane.org/gmane.comp.emulators.qemu/390272/focus=391042 Ref: https://bugs.launchpad.net/qemu/+bug/1536487 Suggested-by: Gerd Hoffmann Signed-off-by: Laszlo Ersek Message-id: 1455823860-22268-1-git-send-email-lersek@redhat.com Signed-off-by: Gerd Hoffmann (cherry picked from commit e6915b5f3a874a467a9a65f7ec1d6ef8d251a51a) Conflicts: include/hw/compat.h * remove cosmetic dep on c9c0afbb Signed-off-by: Michael Roth --- hw/nvram/fw_cfg.c | 20 ++++++++++++-------- include/hw/compat.h | 8 ++++++++ 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 117809b..5a03b5d 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -782,17 +782,19 @@ FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase, DeviceState *dev; FWCfgState *s; uint32_t version = FW_CFG_VERSION; - bool dma_enabled = dma_iobase && dma_as; + bool dma_requested = dma_iobase && dma_as; dev = qdev_create(NULL, TYPE_FW_CFG_IO); qdev_prop_set_uint32(dev, "iobase", iobase); qdev_prop_set_uint32(dev, "dma_iobase", dma_iobase); - qdev_prop_set_bit(dev, "dma_enabled", dma_enabled); + if (!dma_requested) { + qdev_prop_set_bit(dev, "dma_enabled", false); + } fw_cfg_init1(dev); s = FW_CFG(dev); - if (dma_enabled) { + if (s->dma_enabled) { /* 64 bits for the address field */ s->dma_as = dma_as; s->dma_addr = 0; @@ -818,11 +820,13 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr, SysBusDevice *sbd; FWCfgState *s; uint32_t version = FW_CFG_VERSION; - bool dma_enabled = dma_addr && dma_as; + bool dma_requested = dma_addr && dma_as; dev = qdev_create(NULL, TYPE_FW_CFG_MEM); qdev_prop_set_uint32(dev, "data_width", data_width); - qdev_prop_set_bit(dev, "dma_enabled", dma_enabled); + if (!dma_requested) { + qdev_prop_set_bit(dev, "dma_enabled", false); + } fw_cfg_init1(dev); @@ -832,7 +836,7 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr, s = FW_CFG(dev); - if (dma_enabled) { + if (s->dma_enabled) { s->dma_as = dma_as; s->dma_addr = 0; sysbus_mmio_map(sbd, 2, dma_addr); @@ -877,7 +881,7 @@ static Property fw_cfg_io_properties[] = { DEFINE_PROP_UINT32("iobase", FWCfgIoState, iobase, -1), DEFINE_PROP_UINT32("dma_iobase", FWCfgIoState, dma_iobase, -1), DEFINE_PROP_BOOL("dma_enabled", FWCfgIoState, parent_obj.dma_enabled, - false), + true), DEFINE_PROP_END_OF_LIST(), }; @@ -917,7 +921,7 @@ static const TypeInfo fw_cfg_io_info = { static Property fw_cfg_mem_properties[] = { DEFINE_PROP_UINT32("data_width", FWCfgMemState, data_width, -1), DEFINE_PROP_BOOL("dma_enabled", FWCfgMemState, parent_obj.dma_enabled, - false), + true), DEFINE_PROP_END_OF_LIST(), }; diff --git a/include/hw/compat.h b/include/hw/compat.h index d0b1c4f..b7973db 100644 --- a/include/hw/compat.h +++ b/include/hw/compat.h @@ -18,6 +18,14 @@ .driver = "virtio-pci",\ .property = "migrate-extra",\ .value = "off",\ + },{\ + .driver = "fw_cfg_mem",\ + .property = "dma_enabled",\ + .value = "off",\ + },{\ + .driver = "fw_cfg_io",\ + .property = "dma_enabled",\ + .value = "off",\ }, #define HW_COMPAT_2_3 \ -- cgit v1.1