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/bootparam.h> 9 #include <asm/io_apic.h> 10 #include <asm/hypervisor.h> 11 #include <asm/e820/api.h> 12 13 #include <xen/xen.h> 14 #include <asm/xen/interface.h> 15 #include <asm/xen/hypercall.h> 16 17 #include <xen/interface/memory.h> 18 19 #include "xen-ops.h" 20 21 /* 22 * PVH variables. 23 * 24 * The variable xen_pvh needs to live in a data segment since it is used 25 * after startup_{32|64} is invoked, which will clear the .bss segment. 26 */ 27 bool __ro_after_init xen_pvh; 28 EXPORT_SYMBOL_GPL(xen_pvh); 29 30 void __init xen_pvh_init(struct boot_params *boot_params) 31 { 32 u32 msr; 33 u64 pfn; 34 35 xen_pvh = 1; 36 xen_domain_type = XEN_HVM_DOMAIN; 37 xen_start_flags = pvh_start_info.flags; 38 39 msr = cpuid_ebx(xen_cpuid_base() + 2); 40 pfn = __pa(hypercall_page); 41 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); 42 43 if (xen_initial_domain()) 44 x86_init.oem.arch_setup = xen_add_preferred_consoles; 45 x86_init.oem.banner = xen_banner; 46 47 xen_efi_init(boot_params); 48 49 if (xen_initial_domain()) { 50 struct xen_platform_op op = { 51 .cmd = XENPF_get_dom0_console, 52 }; 53 int ret = HYPERVISOR_platform_op(&op); 54 55 if (ret > 0) 56 xen_init_vga(&op.u.dom0_console, 57 min(ret * sizeof(char), 58 sizeof(op.u.dom0_console)), 59 &boot_params->screen_info); 60 } 61 } 62 63 void __init mem_map_via_hcall(struct boot_params *boot_params_p) 64 { 65 struct xen_memory_map memmap; 66 int rc; 67 68 memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table); 69 set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table); 70 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap); 71 if (rc) { 72 xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc); 73 BUG(); 74 } 75 boot_params_p->e820_entries = memmap.nr_entries; 76 } 77 78 /* 79 * Reserve e820 UNUSABLE regions to inflate the memory balloon. 80 * 81 * On PVH dom0 the host memory map is used, RAM regions available to dom0 are 82 * located as the same place as in the native memory map, but since dom0 gets 83 * less memory than the total amount of host RAM the ranges that can't be 84 * populated are converted from RAM -> UNUSABLE. Use such regions (up to the 85 * ratio signaled in EXTRA_MEM_RATIO) in order to inflate the balloon driver at 86 * boot. Doing so prevents the guest (even if just temporary) from using holes 87 * in the memory map in order to map grants or foreign addresses, and 88 * hopefully limits the risk of a clash with a device MMIO region. Ideally the 89 * hypervisor should notify us which memory ranges are suitable for creating 90 * foreign mappings, but that's not yet implemented. 91 */ 92 void __init xen_reserve_extra_memory(struct boot_params *bootp) 93 { 94 unsigned int i, ram_pages = 0, extra_pages; 95 96 for (i = 0; i < bootp->e820_entries; i++) { 97 struct boot_e820_entry *e = &bootp->e820_table[i]; 98 99 if (e->type != E820_TYPE_RAM) 100 continue; 101 ram_pages += PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr); 102 } 103 104 /* Max amount of extra memory. */ 105 extra_pages = EXTRA_MEM_RATIO * ram_pages; 106 107 /* 108 * Convert UNUSABLE ranges to RAM and reserve them for foreign mapping 109 * purposes. 110 */ 111 for (i = 0; i < bootp->e820_entries && extra_pages; i++) { 112 struct boot_e820_entry *e = &bootp->e820_table[i]; 113 unsigned long pages; 114 115 if (e->type != E820_TYPE_UNUSABLE) 116 continue; 117 118 pages = min(extra_pages, 119 PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr)); 120 121 if (pages != (PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr))) { 122 struct boot_e820_entry *next; 123 124 if (bootp->e820_entries == 125 ARRAY_SIZE(bootp->e820_table)) 126 /* No space left to split - skip region. */ 127 continue; 128 129 /* Split entry. */ 130 next = e + 1; 131 memmove(next, e, 132 (bootp->e820_entries - i) * sizeof(*e)); 133 bootp->e820_entries++; 134 next->addr = PAGE_ALIGN(e->addr) + PFN_PHYS(pages); 135 e->size = next->addr - e->addr; 136 next->size -= e->size; 137 } 138 e->type = E820_TYPE_RAM; 139 extra_pages -= pages; 140 141 xen_add_extra_mem(PFN_UP(e->addr), pages); 142 } 143 } 144