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/*
* Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
*
* Authors:
* Alexander Graf <agraf@suse.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/kvm_host.h>
#include <linux/init.h>
#include <linux/kvm_para.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <asm/reg.h>
#include <asm/kvm_ppc.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <asm/disassemble.h>
#define KVM_MAGIC_PAGE (-4096L)
#define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
#define KVM_MASK_RT 0x03e00000
static bool kvm_patching_worked = true;
static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
{
*inst = new_inst;
flush_icache_range((ulong)inst, (ulong)inst + 4);
}
static void kvm_map_magic_page(void *data)
{
kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
KVM_MAGIC_PAGE, /* Physical Address */
KVM_MAGIC_PAGE); /* Effective Address */
}
static void kvm_check_ins(u32 *inst)
{
u32 _inst = *inst;
u32 inst_no_rt = _inst & ~KVM_MASK_RT;
u32 inst_rt = _inst & KVM_MASK_RT;
switch (inst_no_rt) {
}
switch (_inst) {
}
}
static void kvm_use_magic_page(void)
{
u32 *p;
u32 *start, *end;
u32 tmp;
/* Tell the host to map the magic page to -4096 on all CPUs */
on_each_cpu(kvm_map_magic_page, NULL, 1);
/* Quick self-test to see if the mapping works */
if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
kvm_patching_worked = false;
return;
}
/* Now loop through all code and find instructions */
start = (void*)_stext;
end = (void*)_etext;
for (p = start; p < end; p++)
kvm_check_ins(p);
printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
kvm_patching_worked ? "worked" : "failed");
}
unsigned long kvm_hypercall(unsigned long *in,
unsigned long *out,
unsigned long nr)
{
unsigned long register r0 asm("r0");
unsigned long register r3 asm("r3") = in[0];
unsigned long register r4 asm("r4") = in[1];
unsigned long register r5 asm("r5") = in[2];
unsigned long register r6 asm("r6") = in[3];
unsigned long register r7 asm("r7") = in[4];
unsigned long register r8 asm("r8") = in[5];
unsigned long register r9 asm("r9") = in[6];
unsigned long register r10 asm("r10") = in[7];
unsigned long register r11 asm("r11") = nr;
unsigned long register r12 asm("r12");
asm volatile("bl kvm_hypercall_start"
: "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
"=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
"=r"(r12)
: "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
"r"(r9), "r"(r10), "r"(r11)
: "memory", "cc", "xer", "ctr", "lr");
out[0] = r4;
out[1] = r5;
out[2] = r6;
out[3] = r7;
out[4] = r8;
out[5] = r9;
out[6] = r10;
out[7] = r11;
return r3;
}
EXPORT_SYMBOL_GPL(kvm_hypercall);
static int kvm_para_setup(void)
{
extern u32 kvm_hypercall_start;
struct device_node *hyper_node;
u32 *insts;
int len, i;
hyper_node = of_find_node_by_path("/hypervisor");
if (!hyper_node)
return -1;
insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
if (len % 4)
return -1;
if (len > (4 * 4))
return -1;
for (i = 0; i < (len / 4); i++)
kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);
return 0;
}
static int __init kvm_guest_init(void)
{
if (!kvm_para_available())
return 0;
if (kvm_para_setup())
return 0;
if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
kvm_use_magic_page();
return 0;
}
postcore_initcall(kvm_guest_init);
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