enlighten_pvh.c

  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/acpi.h>
  3#include <linux/cpufreq.h>
  4#include <linux/cpuidle.h>
  5#include <linux/export.h>
  6#include <linux/mm.h>
  7
  8#include <xen/hvc-console.h>
  9#include <xen/acpi.h>
 10
 11#include <asm/bootparam.h>
 12#include <asm/io_apic.h>
 13#include <asm/hypervisor.h>
 14#include <asm/e820/api.h>
 15#include <asm/setup.h>
 16
 17#include <xen/xen.h>
 18#include <asm/xen/interface.h>
 19#include <asm/xen/hypercall.h>
 20
 21#include <xen/interface/memory.h>
 22
 23#include "xen-ops.h"
 24
 25/*
 26 * PVH variables.
 27 *
 28 * The variable xen_pvh needs to live in a data segment since it is used
 29 * after startup_{32|64} is invoked, which will clear the .bss segment.
 30 */
 31bool __ro_after_init xen_pvh;
 32EXPORT_SYMBOL_GPL(xen_pvh);
 33
 34#ifdef CONFIG_XEN_DOM0
 35int xen_pvh_setup_gsi(int gsi, int trigger, int polarity)
 36{
 37	int ret;
 38	struct physdev_setup_gsi setup_gsi;
 39
 40	setup_gsi.gsi = gsi;
 41	setup_gsi.triggering = (trigger == ACPI_EDGE_SENSITIVE ? 0 : 1);
 42	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
 43
 44	ret = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
 45	if (ret == -EEXIST) {
 46		xen_raw_printk("Already setup the GSI :%d\n", gsi);
 47		ret = 0;
 48	} else if (ret)
 49		xen_raw_printk("Fail to setup GSI (%d)!\n", gsi);
 50
 51	return ret;
 52}
 53EXPORT_SYMBOL_GPL(xen_pvh_setup_gsi);
 54#endif
 55
 56/*
 57 * Reserve e820 UNUSABLE regions to inflate the memory balloon.
 58 *
 59 * On PVH dom0 the host memory map is used, RAM regions available to dom0 are
 60 * located as the same place as in the native memory map, but since dom0 gets
 61 * less memory than the total amount of host RAM the ranges that can't be
 62 * populated are converted from RAM -> UNUSABLE.  Use such regions (up to the
 63 * ratio signaled in EXTRA_MEM_RATIO) in order to inflate the balloon driver at
 64 * boot.  Doing so prevents the guest (even if just temporary) from using holes
 65 * in the memory map in order to map grants or foreign addresses, and
 66 * hopefully limits the risk of a clash with a device MMIO region.  Ideally the
 67 * hypervisor should notify us which memory ranges are suitable for creating
 68 * foreign mappings, but that's not yet implemented.
 69 */
 70static void __init pvh_reserve_extra_memory(void)
 71{
 72	struct boot_params *bootp = &boot_params;
 73	unsigned int i, ram_pages = 0, extra_pages;
 74
 75	for (i = 0; i < bootp->e820_entries; i++) {
 76		struct boot_e820_entry *e = &bootp->e820_table[i];
 77
 78		if (e->type != E820_TYPE_RAM)
 79			continue;
 80		ram_pages += PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr);
 81	}
 82
 83	/* Max amount of extra memory. */
 84	extra_pages = EXTRA_MEM_RATIO * ram_pages;
 85
 86	/*
 87	 * Convert UNUSABLE ranges to RAM and reserve them for foreign mapping
 88	 * purposes.
 89	 */
 90	for (i = 0; i < bootp->e820_entries && extra_pages; i++) {
 91		struct boot_e820_entry *e = &bootp->e820_table[i];
 92		unsigned long pages;
 93
 94		if (e->type != E820_TYPE_UNUSABLE)
 95			continue;
 96
 97		pages = min(extra_pages,
 98			PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr));
 99
100		if (pages != (PFN_DOWN(e->addr + e->size) - PFN_UP(e->addr))) {
101			struct boot_e820_entry *next;
102
103			if (bootp->e820_entries ==
104			    ARRAY_SIZE(bootp->e820_table))
105				/* No space left to split - skip region. */
106				continue;
107
108			/* Split entry. */
109			next = e + 1;
110			memmove(next, e,
111				(bootp->e820_entries - i) * sizeof(*e));
112			bootp->e820_entries++;
113			next->addr = PAGE_ALIGN(e->addr) + PFN_PHYS(pages);
114			e->size = next->addr - e->addr;
115			next->size -= e->size;
116		}
117		e->type = E820_TYPE_RAM;
118		extra_pages -= pages;
119
120		xen_add_extra_mem(PFN_UP(e->addr), pages);
121	}
122}
123
124static void __init pvh_arch_setup(void)
125{
126	pvh_reserve_extra_memory();
127
128	if (xen_initial_domain()) {
129		xen_add_preferred_consoles();
130
131		/*
132		 * Disable usage of CPU idle and frequency drivers: when
133		 * running as hardware domain the exposed native ACPI tables
134		 * causes idle and/or frequency drivers to attach and
135		 * malfunction.  It's Xen the entity that controls the idle and
136		 * frequency states.
137		 *
138		 * For unprivileged domains the exposed ACPI tables are
139		 * fabricated and don't contain such data.
140		 */
141		disable_cpuidle();
142		disable_cpufreq();
143		WARN_ON(xen_set_default_idle());
144	}
145}
146
147void __init xen_pvh_init(struct boot_params *boot_params)
148{
149	xen_pvh = 1;
150	xen_domain_type = XEN_HVM_DOMAIN;
151	xen_start_flags = pvh_start_info.flags;
152
153	x86_init.oem.arch_setup = pvh_arch_setup;
154	x86_init.oem.banner = xen_banner;
155
156	xen_efi_init(boot_params);
157
158	if (xen_initial_domain()) {
159		struct xen_platform_op op = {
160			.cmd = XENPF_get_dom0_console,
161		};
162		int ret = HYPERVISOR_platform_op(&op);
163
164		if (ret > 0)
165			xen_init_vga(&op.u.dom0_console,
166				     min(ret * sizeof(char),
167					 sizeof(op.u.dom0_console)),
168				     &boot_params->screen_info);
169	}
170}
171
172void __init mem_map_via_hcall(struct boot_params *boot_params_p)
173{
174	struct xen_memory_map memmap;
175	int rc;
176
177	memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
178	set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
179	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
180	if (rc) {
181		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
182		BUG();
183	}
184	boot_params_p->e820_entries = memmap.nr_entries;
185}