linux/linux-5.4.31/arch/x86/platform/pvh/enlighten.c

138 lines
3.8 KiB
C

// 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 the data segment since
* they are used after startup_{32|64}, which clear .bss, are invoked.
*/
struct boot_params pvh_bootparams __attribute__((section(".data")));
struct hvm_start_info pvh_start_info __attribute__((section(".data")));
unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
static u64 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 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);
}