国内自适应网站案例,网站建设公司哪家好?,广州冼村租房,网页无法上传wordpress接前一篇文章#xff1a; 上一回讲解了virtio_pci_device_plugged函数的前两部分#xff0c;本回继续讲解virtio_pci_device_plugged函数的其余部分。为了便于理解#xff0c;再次贴出virtio_pci_device_plugged函数源码#xff0c;在hw/virtio/virtio-pci.c中#xff0c;…接前一篇文章 上一回讲解了virtio_pci_device_plugged函数的前两部分本回继续讲解virtio_pci_device_plugged函数的其余部分。为了便于理解再次贴出virtio_pci_device_plugged函数源码在hw/virtio/virtio-pci.c中如下
/* This is called by virtio-bus just after the device is plugged. */
static void virtio_pci_device_plugged(DeviceState *d, Error **errp)
{VirtIOPCIProxy *proxy VIRTIO_PCI(d);VirtioBusState *bus proxy-bus;bool legacy virtio_pci_legacy(proxy);bool modern;bool modern_pio proxy-flags VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY;uint8_t *config;uint32_t size;VirtIODevice *vdev virtio_bus_get_device(proxy-bus);/** Virtio capabilities present without* VIRTIO_F_VERSION_1 confuses guests*/if (!proxy-ignore_backend_features !virtio_has_feature(vdev-host_features, VIRTIO_F_VERSION_1)) {virtio_pci_disable_modern(proxy);if (!legacy) {error_setg(errp, Device doesnt support modern mode, and legacy mode is disabled);error_append_hint(errp, Set disable-legacy to off\n);return;}}modern virtio_pci_modern(proxy);config proxy-pci_dev.config;if (proxy-class_code) {pci_config_set_class(config, proxy-class_code);}if (legacy) {if (!virtio_legacy_allowed(vdev)) {/** To avoid migration issues, we allow legacy mode when legacy* check is disabled in the old machine types ( 5.1).*/if (virtio_legacy_check_disabled(vdev)) {warn_report(device is modern-only, but for backward compatibility legacy is allowed);} else {error_setg(errp,device is modern-only, use disable-legacyon);return;}}if (virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {error_setg(errp, VIRTIO_F_IOMMU_PLATFORM was supported by neither legacy nor transitional device);return;}/** Legacy and transitional devices use specific subsystem IDs.* Note that the subsystem vendor ID (config PCI_SUBSYSTEM_VENDOR_ID)* is set to PCI_SUBVENDOR_ID_REDHAT_QUMRANET by default.*/pci_set_word(config PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus));if (proxy-trans_devid) {pci_config_set_device_id(config, proxy-trans_devid);}} else {/* pure virtio-1.0 */pci_set_word(config PCI_VENDOR_ID,PCI_VENDOR_ID_REDHAT_QUMRANET);pci_set_word(config PCI_DEVICE_ID,PCI_DEVICE_ID_VIRTIO_10_BASE virtio_bus_get_vdev_id(bus));pci_config_set_revision(config, 1);}config[PCI_INTERRUPT_PIN] 1;if (modern) {struct virtio_pci_cap cap {.cap_len sizeof cap,};struct virtio_pci_notify_cap notify {.cap.cap_len sizeof notify,.notify_off_multiplier cpu_to_le32(virtio_pci_queue_mem_mult(proxy)),};struct virtio_pci_cfg_cap cfg {.cap.cap_len sizeof cfg,.cap.cfg_type VIRTIO_PCI_CAP_PCI_CFG,};struct virtio_pci_notify_cap notify_pio {.cap.cap_len sizeof notify,.notify_off_multiplier cpu_to_le32(0x0),};struct virtio_pci_cfg_cap *cfg_mask;virtio_pci_modern_regions_init(proxy, vdev-name);virtio_pci_modern_mem_region_map(proxy, proxy-common, cap);virtio_pci_modern_mem_region_map(proxy, proxy-isr, cap);virtio_pci_modern_mem_region_map(proxy, proxy-device, cap);virtio_pci_modern_mem_region_map(proxy, proxy-notify, notify.cap);if (modern_pio) {memory_region_init(proxy-io_bar, OBJECT(proxy),virtio-pci-io, 0x4);pci_register_bar(proxy-pci_dev, proxy-modern_io_bar_idx,PCI_BASE_ADDRESS_SPACE_IO, proxy-io_bar);virtio_pci_modern_io_region_map(proxy, proxy-notify_pio,notify_pio.cap);}pci_register_bar(proxy-pci_dev, proxy-modern_mem_bar_idx,PCI_BASE_ADDRESS_SPACE_MEMORY |PCI_BASE_ADDRESS_MEM_PREFETCH |PCI_BASE_ADDRESS_MEM_TYPE_64,proxy-modern_bar);proxy-config_cap virtio_pci_add_mem_cap(proxy, cfg.cap);cfg_mask (void *)(proxy-pci_dev.wmask proxy-config_cap);pci_set_byte(cfg_mask-cap.bar, ~0x0);pci_set_long((uint8_t *)cfg_mask-cap.offset, ~0x0);pci_set_long((uint8_t *)cfg_mask-cap.length, ~0x0);pci_set_long(cfg_mask-pci_cfg_data, ~0x0);}if (proxy-nvectors) {int err msix_init_exclusive_bar(proxy-pci_dev, proxy-nvectors,proxy-msix_bar_idx, NULL);if (err) {/* Notice when a system that supports MSIx cant initialize it */if (err ! -ENOTSUP) {warn_report(unable to init msix vectors to % PRIu32,proxy-nvectors);}proxy-nvectors 0;}}proxy-pci_dev.config_write virtio_write_config;proxy-pci_dev.config_read virtio_read_config;if (legacy) {size VIRTIO_PCI_REGION_SIZE(proxy-pci_dev) virtio_bus_get_vdev_config_len(bus);size pow2ceil(size);memory_region_init_io(proxy-bar, OBJECT(proxy),virtio_pci_config_ops,proxy, virtio-pci, size);pci_register_bar(proxy-pci_dev, proxy-legacy_io_bar_idx,PCI_BASE_ADDRESS_SPACE_IO, proxy-bar);}
}
3virtio_pci_modern_regions_init函数初始化5个MemoryRegion分别是virtio-pci-common、virtio-pci-isr、virtio-pci-device、virtio-pci-notify和virtio-pci-notify-pio。代码片段如下 virtio_pci_modern_regions_init(proxy, vdev-name);
virtio_pci_modern_regions_init函数在hw/virtio/virtio-pci.c中代码如下
static void virtio_pci_modern_regions_init(VirtIOPCIProxy *proxy,const char *vdev_name)
{static const MemoryRegionOps common_ops {.read virtio_pci_common_read,.write virtio_pci_common_write,.impl {.min_access_size 1,.max_access_size 4,},.endianness DEVICE_LITTLE_ENDIAN,};static const MemoryRegionOps isr_ops {.read virtio_pci_isr_read,.write virtio_pci_isr_write,.impl {.min_access_size 1,.max_access_size 4,},.endianness DEVICE_LITTLE_ENDIAN,};static const MemoryRegionOps device_ops {.read virtio_pci_device_read,.write virtio_pci_device_write,.impl {.min_access_size 1,.max_access_size 4,},.endianness DEVICE_LITTLE_ENDIAN,};static const MemoryRegionOps notify_ops {.read virtio_pci_notify_read,.write virtio_pci_notify_write,.impl {.min_access_size 1,.max_access_size 4,},.endianness DEVICE_LITTLE_ENDIAN,};static const MemoryRegionOps notify_pio_ops {.read virtio_pci_notify_read,.write virtio_pci_notify_write_pio,.impl {.min_access_size 1,.max_access_size 4,},.endianness DEVICE_LITTLE_ENDIAN,};g_autoptr(GString) name g_string_new(NULL);g_string_printf(name, virtio-pci-common-%s, vdev_name);memory_region_init_io(proxy-common.mr, OBJECT(proxy),common_ops,proxy,name-str,proxy-common.size);g_string_printf(name, virtio-pci-isr-%s, vdev_name);memory_region_init_io(proxy-isr.mr, OBJECT(proxy),isr_ops,proxy,name-str,proxy-isr.size);g_string_printf(name, virtio-pci-device-%s, vdev_name);memory_region_init_io(proxy-device.mr, OBJECT(proxy),device_ops,proxy,name-str,proxy-device.size);g_string_printf(name, virtio-pci-notify-%s, vdev_name);memory_region_init_io(proxy-notify.mr, OBJECT(proxy),notify_ops,proxy,name-str,proxy-notify.size);g_string_printf(name, virtio-pci-notify-pio-%s, vdev_name);memory_region_init_io(proxy-notify_pio.mr, OBJECT(proxy),notify_pio_ops,proxy,name-str,proxy-notify_pio.size);
}
VirtIOPCIProxy结构的定义在include/hw/virtio/virtio-pci.h中如下
struct VirtIOPCIProxy {PCIDevice pci_dev;MemoryRegion bar;union {struct {VirtIOPCIRegion common;VirtIOPCIRegion isr;VirtIOPCIRegion device;VirtIOPCIRegion notify;VirtIOPCIRegion notify_pio;};VirtIOPCIRegion regs[5];};MemoryRegion modern_bar;MemoryRegion io_bar;uint32_t legacy_io_bar_idx;uint32_t msix_bar_idx;uint32_t modern_io_bar_idx;uint32_t modern_mem_bar_idx;int config_cap;uint32_t flags;bool disable_modern;bool ignore_backend_features;OnOffAuto disable_legacy;/* Transitional device id */uint16_t trans_devid;uint32_t class_code;uint32_t nvectors;uint32_t dfselect;uint32_t gfselect;uint32_t guest_features[2];VirtIOPCIQueue vqs[VIRTIO_QUEUE_MAX];VirtIOIRQFD *vector_irqfd;int nvqs_with_notifiers;VirtioBusState bus;
};
virtio-pci-common、virtio-pci-isr、virtio-pci-device、virtio-pci-notify和virtio-pci-notify-pio这5个MemoryRegion的相关信息存放在VirtIOPCIProxy结构中的几个VirtIOPCIRegion成员中。
4virtio_pci_device_plugged接下来调用virtio_pci_modern_mem_region_map函。代码片段如下 virtio_pci_modern_mem_region_map(proxy, proxy-common, cap);virtio_pci_modern_mem_region_map(proxy, proxy-isr, cap);virtio_pci_modern_mem_region_map(proxy, proxy-device, cap);virtio_pci_modern_mem_region_map(proxy, proxy-notify, notify.cap);
virtio_pci_modern_mem_region_map函数在hw/virtio/virtio-pci.c中代码如下
static void virtio_pci_modern_mem_region_map(VirtIOPCIProxy *proxy,VirtIOPCIRegion *region,struct virtio_pci_cap *cap)
{virtio_pci_modern_region_map(proxy, region, cap,proxy-modern_bar, proxy-modern_mem_bar_idx);
}
virtio_pci_modern_mem_region_map函数仅仅调用了virtio_pci_modern_region_map函数。该函数也在hw/virtio/virtio-pci.c中就在上边代码如下
static void virtio_pci_modern_region_map(VirtIOPCIProxy *proxy,VirtIOPCIRegion *region,struct virtio_pci_cap *cap,MemoryRegion *mr,uint8_t bar)
{memory_region_add_subregion(mr, region-offset, region-mr);cap-cfg_type region-type;cap-bar bar;cap-offset cpu_to_le32(region-offset);cap-length cpu_to_le32(region-size);virtio_pci_add_mem_cap(proxy, cap);}virtio_pci_modern_region_map函数完成了两个功能
1将VirtIOPCIRegion的mr成员virtio-pci-***作为子MemoryRegion加入到VirtIOProxy的modern_bar成员中去。所以当在虚拟机内部写virtio PCI proxy的MMIO时会落入这几个virtio设备的MemoryRegion的回调函数。
2调用virtio_pci_add_mem_cap函数将这些寄存器信息加入到virtio PCI代理设备的pci capability上去。virtio_pci_add_mem_cap函数同样在hw/virtio/virtio-pci.c中代码如下
static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,struct virtio_pci_cap *cap)
{PCIDevice *dev proxy-pci_dev;int offset;offset pci_add_capability(dev, PCI_CAP_ID_VNDR, 0,cap-cap_len, error_abort);assert(cap-cap_len sizeof *cap);memcpy(dev-config offset PCI_CAP_FLAGS, cap-cap_len,cap-cap_len - PCI_CAP_FLAGS);return offset;
}
virtio_pci_device_plugged函数的其余部分将在下一回继续解析。
