/* * Machine specific setup for xen * * Jeremy Fitzhardinge , XenSource Inc, 2007 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "xen-ops.h" #include "vdso.h" /* These are code, but not functions. Defined in entry.S */ extern const char xen_hypervisor_callback[]; extern const char xen_failsafe_callback[]; extern void xen_sysenter_target(void); extern void xen_syscall_target(void); extern void xen_syscall32_target(void); static unsigned long __init xen_release_chunk(phys_addr_t start_addr, phys_addr_t end_addr) { struct xen_memory_reservation reservation = { .address_bits = 0, .extent_order = 0, .domid = DOMID_SELF }; unsigned long start, end; unsigned long len = 0; unsigned long pfn; int ret; start = PFN_UP(start_addr); end = PFN_DOWN(end_addr); if (end <= start) return 0; printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: ", start, end); for(pfn = start; pfn < end; pfn++) { unsigned long mfn = pfn_to_mfn(pfn); /* Make sure pfn exists to start with */ if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) continue; set_xen_guest_handle(reservation.extent_start, &mfn); reservation.nr_extents = 1; ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n", start, end, ret); if (ret == 1) { set_phys_to_machine(pfn, INVALID_P2M_ENTRY); len++; } } printk(KERN_CONT "%ld pages freed\n", len); return len; } static unsigned long __init xen_return_unused_memory(unsigned long max_pfn, const struct e820map *e820) { phys_addr_t max_addr = PFN_PHYS(max_pfn); phys_addr_t last_end = 0; unsigned long released = 0; int i; for (i = 0; i < e820->nr_map && last_end < max_addr; i++) { phys_addr_t end = e820->map[i].addr; end = min(max_addr, end); released += xen_release_chunk(last_end, end); last_end = e820->map[i].addr + e820->map[i].size; } if (last_end < max_addr) released += xen_release_chunk(last_end, max_addr); printk(KERN_INFO "released %ld pages of unused memory\n", released); return released; } /** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ char * __init xen_memory_setup(void) { unsigned long max_pfn = xen_start_info->nr_pages; max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); e820.nr_map = 0; e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM); /* * Even though this is normal, usable memory under Xen, reserve * ISA memory anyway because too many things think they can poke * about in there. */ e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_RESERVED); /* * Reserve Xen bits: * - mfn_list * - xen_start_info * See comment above "struct start_info" in */ reserve_early(__pa(xen_start_info->mfn_list), __pa(xen_start_info->pt_base), "XEN START INFO"); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); xen_return_unused_memory(xen_start_info->nr_pages, &e820); return "Xen"; } static void xen_idle(void) { local_irq_disable(); if (need_resched()) local_irq_enable(); else { current_thread_info()->status &= ~TS_POLLING; smp_mb__after_clear_bit(); safe_halt(); current_thread_info()->status |= TS_POLLING; } } /* * Set the bit indicating "nosegneg" library variants should be used. * We only need to bother in pure 32-bit mode; compat 32-bit processes * can have un-truncated segments, so wrapping around is allowed. */ static void __init fiddle_vdso(void) { #ifdef CONFIG_X86_32 u32 *mask; mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK); *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK); *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; #endif } static __cpuinit int register_callback(unsigned type, const void *func) { struct callback_register callback = { .type = type, .address = XEN_CALLBACK(__KERNEL_CS, func), .flags = CALLBACKF_mask_events, }; return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); } void __cpuinit xen_enable_sysenter(void) { int ret; unsigned sysenter_feature; #ifdef CONFIG_X86_32 sysenter_feature = X86_FEATURE_SEP; #else sysenter_feature = X86_FEATURE_SYSENTER32; #endif if (!boot_cpu_has(sysenter_feature)) return; ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target); if(ret != 0) setup_clear_cpu_cap(sysenter_feature); } void __cpuinit xen_enable_syscall(void) { #ifdef CONFIG_X86_64 int ret; ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target); if (ret != 0) { printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); /* Pretty fatal; 64-bit userspace has no other mechanism for syscalls. */ } if (boot_cpu_has(X86_FEATURE_SYSCALL32)) { ret = register_callback(CALLBACKTYPE_syscall32, xen_syscall32_target); if (ret != 0) setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); } #endif /* CONFIG_X86_64 */ } void __init xen_arch_setup(void) { struct physdev_set_iopl set_iopl; int rc; xen_panic_handler_init(); HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); if (!xen_feature(XENFEAT_auto_translated_physmap)) HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3); if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) || register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) BUG(); xen_enable_sysenter(); xen_enable_syscall(); set_iopl.iopl = 1; rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); if (rc != 0) printk(KERN_INFO "physdev_op failed %d\n", rc); #ifdef CONFIG_ACPI if (!(xen_start_info->flags & SIF_INITDOMAIN)) { printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); disable_acpi(); } #endif memcpy(boot_command_line, xen_start_info->cmd_line, MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); pm_idle = xen_idle; fiddle_vdso(); }