diff options
Diffstat (limited to 'arch/x86/platform/pvh/enlighten.c')
| -rw-r--r-- | arch/x86/platform/pvh/enlighten.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/x86/platform/pvh/enlighten.c b/arch/x86/platform/pvh/enlighten.c new file mode 100644 index 000000000..ed0442e35 --- /dev/null +++ b/arch/x86/platform/pvh/enlighten.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/acpi.h> + +#include <xen/hvc-console.h> + +#include <asm/io_apic.h> +#include <asm/hypervisor.h> +#include <asm/e820/api.h> +#include <asm/x86_init.h> + +#include <asm/xen/interface.h> + +#include <xen/xen.h> +#include <xen/interface/hvm/start_info.h> + +/* + * PVH variables. + * + * pvh_bootparams and pvh_start_info need to live in a data segment since + * they are used after startup_{32|64}, which clear .bss, are invoked. + */ +struct boot_params __initdata pvh_bootparams; +struct hvm_start_info __initdata pvh_start_info; + +const unsigned int __initconst pvh_start_info_sz = sizeof(pvh_start_info); + +static u64 __init pvh_get_root_pointer(void) +{ + return pvh_start_info.rsdp_paddr; +} + +/* + * Xen guests are able to obtain the memory map from the hypervisor via the + * HYPERVISOR_memory_op hypercall. + * If we are trying to boot a Xen PVH guest, it is expected that the kernel + * will have been configured to provide an override for this routine to do + * just that. + */ +void __init __weak mem_map_via_hcall(struct boot_params *ptr __maybe_unused) +{ + xen_raw_printk("Error: Could not find memory map\n"); + BUG(); +} + +static void __init init_pvh_bootparams(bool xen_guest) +{ + if ((pvh_start_info.version > 0) && (pvh_start_info.memmap_entries)) { + struct hvm_memmap_table_entry *ep; + int i; + + ep = __va(pvh_start_info.memmap_paddr); + pvh_bootparams.e820_entries = pvh_start_info.memmap_entries; + + for (i = 0; i < pvh_bootparams.e820_entries ; i++, ep++) { + pvh_bootparams.e820_table[i].addr = ep->addr; + pvh_bootparams.e820_table[i].size = ep->size; + pvh_bootparams.e820_table[i].type = ep->type; + } + } else if (xen_guest) { + mem_map_via_hcall(&pvh_bootparams); + } else { + /* Non-xen guests are not supported by version 0 */ + BUG(); + } + + if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) { + pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr = + ISA_START_ADDRESS; + pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size = + ISA_END_ADDRESS - ISA_START_ADDRESS; + pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type = + E820_TYPE_RESERVED; + pvh_bootparams.e820_entries++; + } else + xen_raw_printk("Warning: Can fit ISA range into e820\n"); + + pvh_bootparams.hdr.cmd_line_ptr = + pvh_start_info.cmdline_paddr; + + /* The first module is always ramdisk. */ + if (pvh_start_info.nr_modules) { + struct hvm_modlist_entry *modaddr = + __va(pvh_start_info.modlist_paddr); + pvh_bootparams.hdr.ramdisk_image = modaddr->paddr; + pvh_bootparams.hdr.ramdisk_size = modaddr->size; + } + + /* + * See Documentation/x86/boot.rst. + * + * Version 2.12 supports Xen entry point but we will use default x86/PC + * environment (i.e. hardware_subarch 0). + */ + pvh_bootparams.hdr.version = (2 << 8) | 12; + pvh_bootparams.hdr.type_of_loader = ((xen_guest ? 0x9 : 0xb) << 4) | 0; + + x86_init.acpi.get_root_pointer = pvh_get_root_pointer; +} + +/* + * If we are trying to boot a Xen PVH guest, it is expected that the kernel + * will have been configured to provide the required override for this routine. + */ +void __init __weak xen_pvh_init(struct boot_params *boot_params) +{ + xen_raw_printk("Error: Missing xen PVH initialization\n"); + BUG(); +} + +static void __init hypervisor_specific_init(bool xen_guest) +{ + if (xen_guest) + xen_pvh_init(&pvh_bootparams); +} + +/* + * This routine (and those that it might call) should not use + * anything that lives in .bss since that segment will be cleared later. + */ +void __init xen_prepare_pvh(void) +{ + + u32 msr = xen_cpuid_base(); + bool xen_guest = !!msr; + + if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) { + xen_raw_printk("Error: Unexpected magic value (0x%08x)\n", + pvh_start_info.magic); + BUG(); + } + + memset(&pvh_bootparams, 0, sizeof(pvh_bootparams)); + + hypervisor_specific_init(xen_guest); + + init_pvh_bootparams(xen_guest); +} |