linux/arch/x86/xen/enlighten_pvh.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/mm.h>

#include <xen/hvc-console.h>

#include <asm/bootparam.h>
#include <asm/io_apic.h>
#include <asm/hypervisor.h>
#include <asm/e820/api.h>
#include <asm/setup.h>

#include <xen/xen.h>
#include <asm/xen/interface.h>
#include <asm/xen/hypercall.h>

#include <xen/interface/memory.h>

#include "xen-ops.h"

/*
 * PVH variables.
 *
 * The variable xen_pvh needs to live in a data segment since it is used
 * after startup_{32|64} is invoked, which will clear the .bss segment.
 */
bool __ro_after_init xen_pvh;
EXPORT_SYMBOL_GPL(…);

/*
 * Reserve e820 UNUSABLE regions to inflate the memory balloon.
 *
 * On PVH dom0 the host memory map is used, RAM regions available to dom0 are
 * located as the same place as in the native memory map, but since dom0 gets
 * less memory than the total amount of host RAM the ranges that can't be
 * populated are converted from RAM -> UNUSABLE.  Use such regions (up to the
 * ratio signaled in EXTRA_MEM_RATIO) in order to inflate the balloon driver at
 * boot.  Doing so prevents the guest (even if just temporary) from using holes
 * in the memory map in order to map grants or foreign addresses, and
 * hopefully limits the risk of a clash with a device MMIO region.  Ideally the
 * hypervisor should notify us which memory ranges are suitable for creating
 * foreign mappings, but that's not yet implemented.
 */
static void __init pvh_reserve_extra_memory(void)
{ … }

static void __init pvh_arch_setup(void)
{ … }

void __init xen_pvh_init(struct boot_params *boot_params)
{ … }

void __init mem_map_via_hcall(struct boot_params *boot_params_p)
{ … }