C++ xen_initial_domain函数代码示例

/**
 * intel_gvt_init_host - Load MPT modules and detect if we're running in host
 * @gvt: intel gvt device
 *
 * This function is called at the driver loading stage. If failed to find a
 * loadable MPT module or detect currently we're running in a VM, then GVT-g
 * will be disabled
 *
 * Returns:
 * Zero on success, negative error code if failed.
 *
 */
int intel_gvt_init_host(void)
{
	if (intel_gvt_host.initialized)
		return 0;

	/* Xen DOM U */
	if (xen_domain() && !xen_initial_domain())
		return -ENODEV;

	/* Try to load MPT modules for hypervisors */
	if (xen_initial_domain()) {
		/* In Xen dom0 */
		intel_gvt_host.mpt = try_then_request_module(
				symbol_get(xengt_mpt), "xengt");
		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_XEN;
	} else {
#if IS_ENABLED(CONFIG_DRM_I915_GVT_KVMGT)
		/* not in Xen. Try KVMGT */
		intel_gvt_host.mpt = try_then_request_module(
				symbol_get(kvmgt_mpt), "kvmgt");
		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_KVM;
#endif
	}

	/* Fail to load MPT modules - bail out */
	if (!intel_gvt_host.mpt)
		return -EINVAL;

	gvt_dbg_core("Running with hypervisor %s in host mode\n",
			supported_hypervisors[intel_gvt_host.hypervisor_type]);

	intel_gvt_host.initialized = true;
	return 0;
}

static int
nexus_xen_attach(device_t dev)
{
	int error;
	device_t acpi_dev = NULL;

	nexus_init_resources();
	bus_generic_probe(dev);

	if (xen_initial_domain()) {
		/* Disable some ACPI devices that are not usable by Dom0 */
		acpi_cpu_disabled = true;
		acpi_hpet_disabled = true;
		acpi_timer_disabled = true;

		acpi_dev = BUS_ADD_CHILD(dev, 10, "acpi", 0);
		if (acpi_dev == NULL)
			panic("Unable to add ACPI bus to Xen Dom0");
	}

	error = bus_generic_attach(dev);
	if (xen_initial_domain() && (error == 0))
		acpi_install_wakeup_handler(device_get_softc(acpi_dev));

	return (error);
}

static void __init xen_filter_cpu_maps(void)
{
	int i, rc;
	unsigned int subtract = 0;

	if (!xen_initial_domain())
		return;

	num_processors = 0;
	disabled_cpus = 0;
	for (i = 0; i < nr_cpu_ids; i++) {
		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
		if (rc >= 0) {
			num_processors++;
			set_cpu_possible(i, true);
		} else {
			set_cpu_possible(i, false);
			set_cpu_present(i, false);
			subtract++;
		}
	}
#ifdef CONFIG_HOTPLUG_CPU
	if (subtract)
		nr_cpu_ids = nr_cpu_ids - subtract;
#endif

}

static void __init xen_init_cpuid_mask(void)
{
	unsigned int ax, bx, cx, dx;
	unsigned int xsave_mask;

	cpuid_leaf1_edx_mask =
		~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
		  (1 << X86_FEATURE_MCA)  |  /* disable MCA */
		  (1 << X86_FEATURE_MTRR) |  /* disable MTRR */
		  (1 << X86_FEATURE_ACC));   /* thermal monitoring */

	if (!xen_initial_domain())
		cpuid_leaf1_edx_mask &=
			~((1 << X86_FEATURE_APIC) |  /* disable local APIC */
			  (1 << X86_FEATURE_ACPI));  /* disable ACPI */
	ax = 1;
	xen_cpuid(&ax, &bx, &cx, &dx);

	xsave_mask =
		(1 << (X86_FEATURE_XSAVE % 32)) |
		(1 << (X86_FEATURE_OSXSAVE % 32));

	/* Xen will set CR4.OSXSAVE if supported and not disabled by force */
	if ((cx & xsave_mask) != xsave_mask)
		cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
}

static efi_system_table_t __init *xen_efi_probe(void)
{
	struct xen_platform_op op = {
		.cmd = XENPF_firmware_info,
		.u.firmware_info = {
			.type = XEN_FW_EFI_INFO,
			.index = XEN_FW_EFI_CONFIG_TABLE
		}
	};
	union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;

	if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0)
		return NULL;

	/* Here we know that Xen runs on EFI platform. */

	efi.get_time                 = xen_efi_get_time;
	efi.set_time                 = xen_efi_set_time;
	efi.get_wakeup_time          = xen_efi_get_wakeup_time;
	efi.set_wakeup_time          = xen_efi_set_wakeup_time;
	efi.get_variable             = xen_efi_get_variable;
	efi.get_next_variable        = xen_efi_get_next_variable;
	efi.set_variable             = xen_efi_set_variable;
	efi.query_variable_info      = xen_efi_query_variable_info;
	efi.update_capsule           = xen_efi_update_capsule;
	efi.query_capsule_caps       = xen_efi_query_capsule_caps;
	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
	efi.reset_system             = xen_efi_reset_system;

	efi_systab_xen.tables = info->cfg.addr;
	efi_systab_xen.nr_tables = info->cfg.nent;

	op.cmd = XENPF_firmware_info;
	op.u.firmware_info.type = XEN_FW_EFI_INFO;
	op.u.firmware_info.index = XEN_FW_EFI_VENDOR;
	info->vendor.bufsz = sizeof(vendor);
	set_xen_guest_handle(info->vendor.name, vendor);

	if (HYPERVISOR_platform_op(&op) == 0) {
		efi_systab_xen.fw_vendor = __pa_symbol(vendor);
		efi_systab_xen.fw_revision = info->vendor.revision;
	} else
		efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN");

	op.cmd = XENPF_firmware_info;
	op.u.firmware_info.type = XEN_FW_EFI_INFO;
	op.u.firmware_info.index = XEN_FW_EFI_VERSION;

	if (HYPERVISOR_platform_op(&op) == 0)
		efi_systab_xen.hdr.revision = info->version;

	op.cmd = XENPF_firmware_info;
	op.u.firmware_info.type = XEN_FW_EFI_INFO;
	op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION;

	if (HYPERVISOR_platform_op(&op) == 0)
		efi.runtime_version = info->version;

	return &efi_systab_xen;
}

static __init void xen_init_cpuid_mask(void)
{
	unsigned int ax, bx, cx, dx;

	cpuid_leaf1_edx_mask =
		~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
		  (1 << X86_FEATURE_MCA)  |  /* disable MCA */
		  (1 << X86_FEATURE_ACC));   /* thermal monitoring */

	if (!xen_initial_domain())
		cpuid_leaf1_edx_mask &=
			~((1 << X86_FEATURE_APIC) |  /* disable local APIC */
			  (1 << X86_FEATURE_ACPI));  /* disable ACPI */

	ax = 1;
	cx = 0;
	xen_cpuid(&ax, &bx, &cx, &dx);

	/* cpuid claims we support xsave; try enabling it to see what happens */
	if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
		unsigned long cr4;

		set_in_cr4(X86_CR4_OSXSAVE);
		
		cr4 = read_cr4();

		if ((cr4 & X86_CR4_OSXSAVE) == 0)
			cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));

		clear_in_cr4(X86_CR4_OSXSAVE);
	}
}

static u32 xen_apic_read(u32 reg)
{
	struct xen_platform_op op = {
		.cmd = XENPF_get_cpuinfo,
		.interface_version = XENPF_INTERFACE_VERSION,
		.u.pcpu_info.xen_cpuid = 0,
	};
	int ret = 0;

	if (!xen_initial_domain() || smp_processor_id())
		return 0;

	if (reg == APIC_LVR)
		return 0x10;

	if (reg != APIC_ID)
		return 0;

	ret = HYPERVISOR_dom0_op(&op);
	if (ret)
		return 0;

	return op.u.pcpu_info.apic_id << 24;
}

static void xen_apic_write(u32 reg, u32 val)
{
	
	WARN_ON(1);
}

static void __init xen_filter_cpu_maps(void)
{
	int i, rc;
	unsigned int subtract = 0;

	if (!xen_initial_domain())
		return;

	num_processors = 0;
	disabled_cpus = 0;
	for (i = 0; i < nr_cpu_ids; i++) {
		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
		if (rc >= 0) {
			num_processors++;
			set_cpu_possible(i, true);
		} else {
			set_cpu_possible(i, false);
			set_cpu_present(i, false);
			subtract++;
		}
	}
#ifdef CONFIG_HOTPLUG_CPU
	/* This is akin to using 'nr_cpus' on the Linux command line.
	 * Which is OK as when we use 'dom0_max_vcpus=X' we can only
	 * have up to X, while nr_cpu_ids is greater than X. This
	 * normally is not a problem, except when CPU hotplugging
	 * is involved and then there might be more than X CPUs
	 * in the guest - which will not work as there is no
	 * hypercall to expand the max number of VCPUs an already
	 * running guest has. So cap it up to X. */
	if (subtract)
		nr_cpu_ids = nr_cpu_ids - subtract;
#endif

}

static int
xc_attach(device_t dev) 
{
	int error;

	xencons_dev = dev;
	xccons = tty_alloc(&xc_ttydevsw, NULL);
	tty_makedev(xccons, NULL, "xc%r", 0);

	callout_init(&xc_callout, 0);

	xencons_ring_init();

	cnsl_evt_reg = true;
	callout_reset(&xc_callout, XC_POLLTIME, xc_timeout, xccons);
    
	if (xen_initial_domain()) {
		error = xen_intr_bind_virq(dev, VIRQ_CONSOLE, 0, NULL,
		                           xencons_priv_interrupt, NULL,
		                           INTR_TYPE_TTY, &xen_intr_handle);
		KASSERT(error >= 0, ("can't register console interrupt"));
	}

	/* register handler to flush console on shutdown */
	if ((EVENTHANDLER_REGISTER(shutdown_post_sync, xc_shutdown,
				   NULL, SHUTDOWN_PRI_DEFAULT)) == NULL)
		printf("xencons: shutdown event registration failed!\n");
	
	return (0);
}

static u32 xen_apic_read(u32 reg)
{
	struct xen_platform_op op = {
		.cmd = XENPF_get_cpuinfo,
		.interface_version = XENPF_INTERFACE_VERSION,
		.u.pcpu_info.xen_cpuid = 0,
	};
	int ret = 0;

	/* Shouldn't need this as APIC is turned off for PV, and we only
	 * get called on the bootup processor. But just in case. */
	if (!xen_initial_domain() || smp_processor_id())
		return 0;

	if (reg == APIC_LVR)
		return 0x10;

	if (reg != APIC_ID)
		return 0;

	ret = HYPERVISOR_dom0_op(&op);
	if (ret)
		return 0;

	return op.u.pcpu_info.apic_id << 24;
}

static void xen_apic_write(u32 reg, u32 val)
{
	/* Warn to see if there's any stray references */
	WARN_ON(1);
}

static unsigned long __init xen_get_max_pages(void)
{
	unsigned long max_pages, limit;
	domid_t domid = DOMID_SELF;
	long ret;

	limit = xen_get_pages_limit();
	max_pages = limit;

	/*
	 * For the initial domain we use the maximum reservation as
	 * the maximum page.
	 *
	 * For guest domains the current maximum reservation reflects
	 * the current maximum rather than the static maximum. In this
	 * case the e820 map provided to us will cover the static
	 * maximum region.
	 */
	if (xen_initial_domain()) {
		ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
		if (ret > 0)
			max_pages = ret;
	}

	return min(max_pages, limit);
}

/*
 * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary
 *
 * This returns non-zero if we are forced to use xen_swiotlb (by the boot
 * option).
 */
int __init pci_xen_swiotlb_detect(void)
{

	if (!xen_pv_domain())
		return 0;

	/* If running as PV guest, either iommu=soft, or swiotlb=force will
	 * activate this IOMMU. If running as PV privileged, activate it
	 * irregardless.
	 */
	if ((xen_initial_domain() || swiotlb || swiotlb_force))
		xen_swiotlb = 1;

	/* If we are running under Xen, we MUST disable the native SWIOTLB.
	 * Don't worry about swiotlb_force flag activating the native, as
	 * the 'swiotlb' flag is the only one turning it on. */
	swiotlb = 0;

#ifdef CONFIG_X86_64
	/* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0
	 * (so no iommu=X command line over-writes).
	 * Considering that PV guests do not want the *native SWIOTLB* but
	 * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here.
	 */
	if (max_pfn > MAX_DMA32_PFN)
		no_iommu = 1;
#endif
	return xen_swiotlb;
}

static int __init xen_hvc_init(void)
{
	struct hvc_struct *hp;
	struct hv_ops *ops;

	if (!xen_pv_domain())
		return -ENODEV;

	if (xen_initial_domain()) {
		ops = &dom0_hvc_ops;
		xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
	} else {
		if (!xen_start_info->console.domU.evtchn)
			return -ENODEV;

		ops = &domU_hvc_ops;
		xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
	}
	if (xencons_irq < 0)
		xencons_irq = 0; /* NO_IRQ */
	else
		irq_set_noprobe(xencons_irq);

	hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256);
	if (IS_ERR(hp))
		return PTR_ERR(hp);

	hvc = hp;

	console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);

	return 0;
}

static int __init register_xen_amba_notifier(void)
{
	if (!xen_initial_domain() || acpi_disabled)
		return 0;

	return bus_register_notifier(&amba_bustype, &amba_device_nb);
}

static int __init register_xen_platform_notifier(void)
{
	if (!xen_initial_domain() || acpi_disabled)
		return 0;

	return bus_register_notifier(&platform_bus_type, &platform_device_nb);
}