cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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enlighten.c (3841B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/acpi.h>
      3
      4#include <xen/hvc-console.h>
      5
      6#include <asm/io_apic.h>
      7#include <asm/hypervisor.h>
      8#include <asm/e820/api.h>
      9#include <asm/x86_init.h>
     10
     11#include <asm/xen/interface.h>
     12
     13#include <xen/xen.h>
     14#include <xen/interface/hvm/start_info.h>
     15
     16/*
     17 * PVH variables.
     18 *
     19 * pvh_bootparams and pvh_start_info need to live in a data segment since
     20 * they are used after startup_{32|64}, which clear .bss, are invoked.
     21 */
     22struct boot_params __initdata pvh_bootparams;
     23struct hvm_start_info __initdata pvh_start_info;
     24
     25const unsigned int __initconst pvh_start_info_sz = sizeof(pvh_start_info);
     26
     27static u64 __init pvh_get_root_pointer(void)
     28{
     29	return pvh_start_info.rsdp_paddr;
     30}
     31
     32/*
     33 * Xen guests are able to obtain the memory map from the hypervisor via the
     34 * HYPERVISOR_memory_op hypercall.
     35 * If we are trying to boot a Xen PVH guest, it is expected that the kernel
     36 * will have been configured to provide an override for this routine to do
     37 * just that.
     38 */
     39void __init __weak mem_map_via_hcall(struct boot_params *ptr __maybe_unused)
     40{
     41	xen_raw_printk("Error: Could not find memory map\n");
     42	BUG();
     43}
     44
     45static void __init init_pvh_bootparams(bool xen_guest)
     46{
     47	if ((pvh_start_info.version > 0) && (pvh_start_info.memmap_entries)) {
     48		struct hvm_memmap_table_entry *ep;
     49		int i;
     50
     51		ep = __va(pvh_start_info.memmap_paddr);
     52		pvh_bootparams.e820_entries = pvh_start_info.memmap_entries;
     53
     54		for (i = 0; i < pvh_bootparams.e820_entries ; i++, ep++) {
     55			pvh_bootparams.e820_table[i].addr = ep->addr;
     56			pvh_bootparams.e820_table[i].size = ep->size;
     57			pvh_bootparams.e820_table[i].type = ep->type;
     58		}
     59	} else if (xen_guest) {
     60		mem_map_via_hcall(&pvh_bootparams);
     61	} else {
     62		/* Non-xen guests are not supported by version 0 */
     63		BUG();
     64	}
     65
     66	if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {
     67		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =
     68			ISA_START_ADDRESS;
     69		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size =
     70			ISA_END_ADDRESS - ISA_START_ADDRESS;
     71		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type =
     72			E820_TYPE_RESERVED;
     73		pvh_bootparams.e820_entries++;
     74	} else
     75		xen_raw_printk("Warning: Can fit ISA range into e820\n");
     76
     77	pvh_bootparams.hdr.cmd_line_ptr =
     78		pvh_start_info.cmdline_paddr;
     79
     80	/* The first module is always ramdisk. */
     81	if (pvh_start_info.nr_modules) {
     82		struct hvm_modlist_entry *modaddr =
     83			__va(pvh_start_info.modlist_paddr);
     84		pvh_bootparams.hdr.ramdisk_image = modaddr->paddr;
     85		pvh_bootparams.hdr.ramdisk_size = modaddr->size;
     86	}
     87
     88	/*
     89	 * See Documentation/x86/boot.rst.
     90	 *
     91	 * Version 2.12 supports Xen entry point but we will use default x86/PC
     92	 * environment (i.e. hardware_subarch 0).
     93	 */
     94	pvh_bootparams.hdr.version = (2 << 8) | 12;
     95	pvh_bootparams.hdr.type_of_loader = ((xen_guest ? 0x9 : 0xb) << 4) | 0;
     96
     97	x86_init.acpi.get_root_pointer = pvh_get_root_pointer;
     98}
     99
    100/*
    101 * If we are trying to boot a Xen PVH guest, it is expected that the kernel
    102 * will have been configured to provide the required override for this routine.
    103 */
    104void __init __weak xen_pvh_init(struct boot_params *boot_params)
    105{
    106	xen_raw_printk("Error: Missing xen PVH initialization\n");
    107	BUG();
    108}
    109
    110static void __init hypervisor_specific_init(bool xen_guest)
    111{
    112	if (xen_guest)
    113		xen_pvh_init(&pvh_bootparams);
    114}
    115
    116/*
    117 * This routine (and those that it might call) should not use
    118 * anything that lives in .bss since that segment will be cleared later.
    119 */
    120void __init xen_prepare_pvh(void)
    121{
    122
    123	u32 msr = xen_cpuid_base();
    124	bool xen_guest = !!msr;
    125
    126	if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
    127		xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
    128				pvh_start_info.magic);
    129		BUG();
    130	}
    131
    132	memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
    133
    134	hypervisor_specific_init(xen_guest);
    135
    136	init_pvh_bootparams(xen_guest);
    137}