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// 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(xen_pvh);
/*
* 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)
{
struct boot_params *bootp = &boot_params;
unsigned int i, ram_pages = 0, extra_pages;
for (i = 0; i < bootp->e820_entries; i++) {
struct boot_e820_entry *e = &bootp->e820_table[i];
if (e->type != E820_TYPE_RAM)
continue;
ram_pages += PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr);
}
/* Max amount of extra memory. */
extra_pages = EXTRA_MEM_RATIO * ram_pages;
/*
* Convert UNUSABLE ranges to RAM and reserve them for foreign mapping
* purposes.
*/
for (i = 0; i < bootp->e820_entries && extra_pages; i++) {
struct boot_e820_entry *e = &bootp->e820_table[i];
unsigned long pages;
if (e->type != E820_TYPE_UNUSABLE)
continue;
pages = min(extra_pages,
PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr));
if (pages != (PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr))) {
struct boot_e820_entry *next;
if (bootp->e820_entries ==
ARRAY_SIZE(bootp->e820_table))
/* No space left to split - skip region. */
continue;
/* Split entry. */
next = e + 1;
memmove(next, e,
(bootp->e820_entries - i) * sizeof(*e));
bootp->e820_entries++;
next->addr = PAGE_ALIGN(e->addr) + PFN_PHYS(pages);
e->size = next->addr - e->addr;
next->size -= e->size;
}
e->type = E820_TYPE_RAM;
extra_pages -= pages;
xen_add_extra_mem(PFN_UP(e->addr), pages);
}
}
static void __init pvh_arch_setup(void)
{
pvh_reserve_extra_memory();
if (xen_initial_domain())
xen_add_preferred_consoles();
}
void __init xen_pvh_init(struct boot_params *boot_params)
{
u32 msr;
u64 pfn;
xen_pvh = 1;
xen_domain_type = XEN_HVM_DOMAIN;
xen_start_flags = pvh_start_info.flags;
msr = cpuid_ebx(xen_cpuid_base() + 2);
pfn = __pa(hypercall_page);
wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
x86_init.oem.arch_setup = pvh_arch_setup;
x86_init.oem.banner = xen_banner;
xen_efi_init(boot_params);
if (xen_initial_domain()) {
struct xen_platform_op op = {
.cmd = XENPF_get_dom0_console,
};
int ret = HYPERVISOR_platform_op(&op);
if (ret > 0)
xen_init_vga(&op.u.dom0_console,
min(ret * sizeof(char),
sizeof(op.u.dom0_console)),
&boot_params->screen_info);
}
}
void __init mem_map_via_hcall(struct boot_params *boot_params_p)
{
struct xen_memory_map memmap;
int rc;
memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
if (rc) {
xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
BUG();
}
boot_params_p->e820_entries = memmap.nr_entries;
}
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