linux/arch/x86/xen/enlighten_pvh.c
Juergen Gross 418492ba40 x86/virt/xen: Use guest_late_init to detect Xen PVH guest
In case we are booted via the default boot entry by a generic loader
like grub or OVMF it is necessary to distinguish between a HVM guest
with a device model supporting legacy devices and a PVH guest without
device model.

PVH guests will always have x86_platform.legacy.no_vga set and
x86_platform.legacy.rtc cleared, while both won't be true for HVM
guests.

Test for both conditions in the guest_late_init hook and set xen_pvh
to true if they are met.

Move some of the early PVH initializations to the new hook in order
to avoid duplicated code.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-6-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-10 10:03:14 +01:00

99 lines
2.6 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/xen/interface.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/memory.h>
#include <xen/interface/hvm/start_info.h>
/*
* PVH variables.
*
* xen_pvh and pvh_bootparams need to live in data segment since they
* are used after startup_{32|64}, which clear .bss, are invoked.
*/
bool xen_pvh __attribute__((section(".data"))) = 0;
struct boot_params pvh_bootparams __attribute__((section(".data")));
struct hvm_start_info pvh_start_info;
unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
static void __init init_pvh_bootparams(void)
{
struct xen_memory_map memmap;
int rc;
memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);
set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);
rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
if (rc) {
xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
BUG();
}
pvh_bootparams.e820_entries = memmap.nr_entries;
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.txt.
*
* Version 2.12 supports Xen entry point but we will use default x86/PC
* environment (i.e. hardware_subarch 0).
*/
pvh_bootparams.hdr.version = 0x212;
pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
}
/*
* 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;
u64 pfn;
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();
}
xen_pvh = 1;
msr = cpuid_ebx(xen_cpuid_base() + 2);
pfn = __pa(hypercall_page);
wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
init_pvh_bootparams();
}