1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/acpi.h> 3 #include <linux/export.h> 4 #include <linux/mm.h> 5 6 #include <xen/hvc-console.h> 7 8 #include <asm/io_apic.h> 9 #include <asm/hypervisor.h> 10 #include <asm/e820/api.h> 11 12 #include <xen/xen.h> 13 #include <asm/xen/interface.h> 14 #include <asm/xen/hypercall.h> 15 16 #include <xen/interface/memory.h> 17 18 #include "xen-ops.h" 19 20 /* 21 * PVH variables. 22 * 23 * The variable xen_pvh needs to live in a data segment since it is used 24 * after startup_{32|64} is invoked, which will clear the .bss segment. 25 */ 26 bool __ro_after_init xen_pvh; 27 EXPORT_SYMBOL_GPL(xen_pvh); 28 29 void __init xen_pvh_init(struct boot_params *boot_params) 30 { 31 u32 msr; 32 u64 pfn; 33 34 xen_pvh = 1; 35 xen_domain_type = XEN_HVM_DOMAIN; 36 xen_start_flags = pvh_start_info.flags; 37 38 msr = cpuid_ebx(xen_cpuid_base() + 2); 39 pfn = __pa(hypercall_page); 40 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 41 42 if (xen_initial_domain()) 43 x86_init.oem.arch_setup = xen_add_preferred_consoles; 44 x86_init.oem.banner = xen_banner; 45 46 xen_efi_init(boot_params); 47 48 if (xen_initial_domain()) { 49 struct xen_platform_op op = { 50 .cmd = XENPF_get_dom0_console, 51 }; 52 int ret = HYPERVISOR_platform_op(&op); 53 54 if (ret > 0) 55 xen_init_vga(&op.u.dom0_console, 56 min(ret * sizeof(char), 57 sizeof(op.u.dom0_console)), 58 &boot_params->screen_info); 59 } 60 } 61 62 void __init mem_map_via_hcall(struct boot_params *boot_params_p) 63 { 64 struct xen_memory_map memmap; 65 int rc; 66 67 memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table); 68 set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table); 69 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap); 70 if (rc) { 71 xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc); 72 BUG(); 73 } 74 boot_params_p->e820_entries = memmap.nr_entries; 75 } 76 77 /* 78 * Reserve e820 UNUSABLE regions to inflate the memory balloon. 79 * 80 * On PVH dom0 the host memory map is used, RAM regions available to dom0 are 81 * located as the same place as in the native memory map, but since dom0 gets 82 * less memory than the total amount of host RAM the ranges that can't be 83 * populated are converted from RAM -> UNUSABLE. Use such regions (up to the 84 * ratio signaled in EXTRA_MEM_RATIO) in order to inflate the balloon driver at 85 * boot. Doing so prevents the guest (even if just temporary) from using holes 86 * in the memory map in order to map grants or foreign addresses, and 87 * hopefully limits the risk of a clash with a device MMIO region. Ideally the 88 * hypervisor should notify us which memory ranges are suitable for creating 89 * foreign mappings, but that's not yet implemented. 90 */ 91 void __init xen_reserve_extra_memory(struct boot_params *bootp) 92 { 93 unsigned int i, ram_pages = 0, extra_pages; 94 95 for (i = 0; i < bootp->e820_entries; i++) { 96 struct boot_e820_entry *e = &bootp->e820_table[i]; 97 98 if (e->type != E820_TYPE_RAM) 99 continue; 100 ram_pages += PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr); 101 } 102 103 /* Max amount of extra memory. */ 104 extra_pages = EXTRA_MEM_RATIO * ram_pages; 105 106 /* 107 * Convert UNUSABLE ranges to RAM and reserve them for foreign mapping 108 * purposes. 109 */ 110 for (i = 0; i < bootp->e820_entries && extra_pages; i++) { 111 struct boot_e820_entry *e = &bootp->e820_table[i]; 112 unsigned long pages; 113 114 if (e->type != E820_TYPE_UNUSABLE) 115 continue; 116 117 pages = min(extra_pages, 118 PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr)); 119 120 if (pages != (PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr))) { 121 struct boot_e820_entry *next; 122 123 if (bootp->e820_entries == 124 ARRAY_SIZE(bootp->e820_table)) 125 /* No space left to split - skip region. */ 126 continue; 127 128 /* Split entry. */ 129 next = e + 1; 130 memmove(next, e, 131 (bootp->e820_entries - i) * sizeof(*e)); 132 bootp->e820_entries++; 133 next->addr = PAGE_ALIGN(e->addr) + PFN_PHYS(pages); 134 e->size = next->addr - e->addr; 135 next->size -= e->size; 136 } 137 e->type = E820_TYPE_RAM; 138 extra_pages -= pages; 139 140 xen_add_extra_mem(PFN_UP(e->addr), pages); 141 } 142 } 143