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-rw-r--r--arch/powerpc/kernel/kvm.c596
1 files changed, 596 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
new file mode 100644
index 00000000000..428d0e538ae
--- /dev/null
+++ b/arch/powerpc/kernel/kvm.c
@@ -0,0 +1,596 @@
+/*
+ * 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/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_INST_LWZ 0x80000000
+#define KVM_INST_STW 0x90000000
+#define KVM_INST_LD 0xe8000000
+#define KVM_INST_STD 0xf8000000
+#define KVM_INST_NOP 0x60000000
+#define KVM_INST_B 0x48000000
+#define KVM_INST_B_MASK 0x03ffffff
+#define KVM_INST_B_MAX 0x01ffffff
+
+#define KVM_MASK_RT 0x03e00000
+#define KVM_RT_30 0x03c00000
+#define KVM_MASK_RB 0x0000f800
+#define KVM_INST_MFMSR 0x7c0000a6
+#define KVM_INST_MFSPR_SPRG0 0x7c1042a6
+#define KVM_INST_MFSPR_SPRG1 0x7c1142a6
+#define KVM_INST_MFSPR_SPRG2 0x7c1242a6
+#define KVM_INST_MFSPR_SPRG3 0x7c1342a6
+#define KVM_INST_MFSPR_SRR0 0x7c1a02a6
+#define KVM_INST_MFSPR_SRR1 0x7c1b02a6
+#define KVM_INST_MFSPR_DAR 0x7c1302a6
+#define KVM_INST_MFSPR_DSISR 0x7c1202a6
+
+#define KVM_INST_MTSPR_SPRG0 0x7c1043a6
+#define KVM_INST_MTSPR_SPRG1 0x7c1143a6
+#define KVM_INST_MTSPR_SPRG2 0x7c1243a6
+#define KVM_INST_MTSPR_SPRG3 0x7c1343a6
+#define KVM_INST_MTSPR_SRR0 0x7c1a03a6
+#define KVM_INST_MTSPR_SRR1 0x7c1b03a6
+#define KVM_INST_MTSPR_DAR 0x7c1303a6
+#define KVM_INST_MTSPR_DSISR 0x7c1203a6
+
+#define KVM_INST_TLBSYNC 0x7c00046c
+#define KVM_INST_MTMSRD_L0 0x7c000164
+#define KVM_INST_MTMSRD_L1 0x7c010164
+#define KVM_INST_MTMSR 0x7c000124
+
+#define KVM_INST_WRTEEI_0 0x7c000146
+#define KVM_INST_WRTEEI_1 0x7c008146
+
+#define KVM_INST_MTSRIN 0x7c0001e4
+
+static bool kvm_patching_worked = true;
+static char kvm_tmp[1024 * 1024];
+static int kvm_tmp_index;
+
+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_patch_ins_ll(u32 *inst, long addr, u32 rt)
+{
+#ifdef CONFIG_64BIT
+ kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
+#else
+ kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000fffc));
+#endif
+}
+
+static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
+{
+#ifdef CONFIG_64BIT
+ kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
+#else
+ kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
+#endif
+}
+
+static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
+{
+ kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
+}
+
+static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
+{
+#ifdef CONFIG_64BIT
+ kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
+#else
+ kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
+#endif
+}
+
+static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
+{
+ kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
+}
+
+static void kvm_patch_ins_nop(u32 *inst)
+{
+ kvm_patch_ins(inst, KVM_INST_NOP);
+}
+
+static void kvm_patch_ins_b(u32 *inst, int addr)
+{
+#ifdef CONFIG_RELOCATABLE
+ /* On relocatable kernels interrupts handlers and our code
+ can be in different regions, so we don't patch them */
+
+ extern u32 __end_interrupts;
+ if ((ulong)inst < (ulong)&__end_interrupts)
+ return;
+#endif
+
+ kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
+}
+
+static u32 *kvm_alloc(int len)
+{
+ u32 *p;
+
+ if ((kvm_tmp_index + len) > ARRAY_SIZE(kvm_tmp)) {
+ printk(KERN_ERR "KVM: No more space (%d + %d)\n",
+ kvm_tmp_index, len);
+ kvm_patching_worked = false;
+ return NULL;
+ }
+
+ p = (void*)&kvm_tmp[kvm_tmp_index];
+ kvm_tmp_index += len;
+
+ return p;
+}
+
+extern u32 kvm_emulate_mtmsrd_branch_offs;
+extern u32 kvm_emulate_mtmsrd_reg_offs;
+extern u32 kvm_emulate_mtmsrd_orig_ins_offs;
+extern u32 kvm_emulate_mtmsrd_len;
+extern u32 kvm_emulate_mtmsrd[];
+
+static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
+{
+ u32 *p;
+ int distance_start;
+ int distance_end;
+ ulong next_inst;
+
+ p = kvm_alloc(kvm_emulate_mtmsrd_len * 4);
+ if (!p)
+ return;
+
+ /* Find out where we are and put everything there */
+ distance_start = (ulong)p - (ulong)inst;
+ next_inst = ((ulong)inst + 4);
+ distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsrd_branch_offs];
+
+ /* Make sure we only write valid b instructions */
+ if (distance_start > KVM_INST_B_MAX) {
+ kvm_patching_worked = false;
+ return;
+ }
+
+ /* Modify the chunk to fit the invocation */
+ memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);
+ p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;
+ switch (get_rt(rt)) {
+ case 30:
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
+ magic_var(scratch2), KVM_RT_30);
+ break;
+ case 31:
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
+ magic_var(scratch1), KVM_RT_30);
+ break;
+ default:
+ p[kvm_emulate_mtmsrd_reg_offs] |= rt;
+ break;
+ }
+
+ p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;
+ flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);
+
+ /* Patch the invocation */
+ kvm_patch_ins_b(inst, distance_start);
+}
+
+extern u32 kvm_emulate_mtmsr_branch_offs;
+extern u32 kvm_emulate_mtmsr_reg1_offs;
+extern u32 kvm_emulate_mtmsr_reg2_offs;
+extern u32 kvm_emulate_mtmsr_orig_ins_offs;
+extern u32 kvm_emulate_mtmsr_len;
+extern u32 kvm_emulate_mtmsr[];
+
+static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
+{
+ u32 *p;
+ int distance_start;
+ int distance_end;
+ ulong next_inst;
+
+ p = kvm_alloc(kvm_emulate_mtmsr_len * 4);
+ if (!p)
+ return;
+
+ /* Find out where we are and put everything there */
+ distance_start = (ulong)p - (ulong)inst;
+ next_inst = ((ulong)inst + 4);
+ distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsr_branch_offs];
+
+ /* Make sure we only write valid b instructions */
+ if (distance_start > KVM_INST_B_MAX) {
+ kvm_patching_worked = false;
+ return;
+ }
+
+ /* Modify the chunk to fit the invocation */
+ memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
+ p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;
+
+ /* Make clobbered registers work too */
+ switch (get_rt(rt)) {
+ case 30:
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
+ magic_var(scratch2), KVM_RT_30);
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
+ magic_var(scratch2), KVM_RT_30);
+ break;
+ case 31:
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
+ magic_var(scratch1), KVM_RT_30);
+ kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
+ magic_var(scratch1), KVM_RT_30);
+ break;
+ default:
+ p[kvm_emulate_mtmsr_reg1_offs] |= rt;
+ p[kvm_emulate_mtmsr_reg2_offs] |= rt;
+ break;
+ }
+
+ p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
+ flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);
+
+ /* Patch the invocation */
+ kvm_patch_ins_b(inst, distance_start);
+}
+
+#ifdef CONFIG_BOOKE
+
+extern u32 kvm_emulate_wrteei_branch_offs;
+extern u32 kvm_emulate_wrteei_ee_offs;
+extern u32 kvm_emulate_wrteei_len;
+extern u32 kvm_emulate_wrteei[];
+
+static void kvm_patch_ins_wrteei(u32 *inst)
+{
+ u32 *p;
+ int distance_start;
+ int distance_end;
+ ulong next_inst;
+
+ p = kvm_alloc(kvm_emulate_wrteei_len * 4);
+ if (!p)
+ return;
+
+ /* Find out where we are and put everything there */
+ distance_start = (ulong)p - (ulong)inst;
+ next_inst = ((ulong)inst + 4);
+ distance_end = next_inst - (ulong)&p[kvm_emulate_wrteei_branch_offs];
+
+ /* Make sure we only write valid b instructions */
+ if (distance_start > KVM_INST_B_MAX) {
+ kvm_patching_worked = false;
+ return;
+ }
+
+ /* Modify the chunk to fit the invocation */
+ memcpy(p, kvm_emulate_wrteei, kvm_emulate_wrteei_len * 4);
+ p[kvm_emulate_wrteei_branch_offs] |= distance_end & KVM_INST_B_MASK;
+ p[kvm_emulate_wrteei_ee_offs] |= (*inst & MSR_EE);
+ flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrteei_len * 4);
+
+ /* Patch the invocation */
+ kvm_patch_ins_b(inst, distance_start);
+}
+
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S_32
+
+extern u32 kvm_emulate_mtsrin_branch_offs;
+extern u32 kvm_emulate_mtsrin_reg1_offs;
+extern u32 kvm_emulate_mtsrin_reg2_offs;
+extern u32 kvm_emulate_mtsrin_orig_ins_offs;
+extern u32 kvm_emulate_mtsrin_len;
+extern u32 kvm_emulate_mtsrin[];
+
+static void kvm_patch_ins_mtsrin(u32 *inst, u32 rt, u32 rb)
+{
+ u32 *p;
+ int distance_start;
+ int distance_end;
+ ulong next_inst;
+
+ p = kvm_alloc(kvm_emulate_mtsrin_len * 4);
+ if (!p)
+ return;
+
+ /* Find out where we are and put everything there */
+ distance_start = (ulong)p - (ulong)inst;
+ next_inst = ((ulong)inst + 4);
+ distance_end = next_inst - (ulong)&p[kvm_emulate_mtsrin_branch_offs];
+
+ /* Make sure we only write valid b instructions */
+ if (distance_start > KVM_INST_B_MAX) {
+ kvm_patching_worked = false;
+ return;
+ }
+
+ /* Modify the chunk to fit the invocation */
+ memcpy(p, kvm_emulate_mtsrin, kvm_emulate_mtsrin_len * 4);
+ p[kvm_emulate_mtsrin_branch_offs] |= distance_end & KVM_INST_B_MASK;
+ p[kvm_emulate_mtsrin_reg1_offs] |= (rb << 10);
+ p[kvm_emulate_mtsrin_reg2_offs] |= rt;
+ p[kvm_emulate_mtsrin_orig_ins_offs] = *inst;
+ flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtsrin_len * 4);
+
+ /* Patch the invocation */
+ kvm_patch_ins_b(inst, distance_start);
+}
+
+#endif
+
+static void kvm_map_magic_page(void *data)
+{
+ u32 *features = data;
+
+ ulong in[8];
+ ulong out[8];
+
+ in[0] = KVM_MAGIC_PAGE;
+ in[1] = KVM_MAGIC_PAGE;
+
+ kvm_hypercall(in, out, HC_VENDOR_KVM | KVM_HC_PPC_MAP_MAGIC_PAGE);
+
+ *features = out[0];
+}
+
+static void kvm_check_ins(u32 *inst, u32 features)
+{
+ u32 _inst = *inst;
+ u32 inst_no_rt = _inst & ~KVM_MASK_RT;
+ u32 inst_rt = _inst & KVM_MASK_RT;
+
+ switch (inst_no_rt) {
+ /* Loads */
+ case KVM_INST_MFMSR:
+ kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
+ break;
+ case KVM_INST_MFSPR_SPRG0:
+ kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
+ break;
+ case KVM_INST_MFSPR_SPRG1:
+ kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
+ break;
+ case KVM_INST_MFSPR_SPRG2:
+ kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
+ break;
+ case KVM_INST_MFSPR_SPRG3:
+ kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
+ break;
+ case KVM_INST_MFSPR_SRR0:
+ kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
+ break;
+ case KVM_INST_MFSPR_SRR1:
+ kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
+ break;
+ case KVM_INST_MFSPR_DAR:
+ kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
+ break;
+ case KVM_INST_MFSPR_DSISR:
+ kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
+ break;
+
+ /* Stores */
+ case KVM_INST_MTSPR_SPRG0:
+ kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
+ break;
+ case KVM_INST_MTSPR_SPRG1:
+ kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
+ break;
+ case KVM_INST_MTSPR_SPRG2:
+ kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
+ break;
+ case KVM_INST_MTSPR_SPRG3:
+ kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
+ break;
+ case KVM_INST_MTSPR_SRR0:
+ kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
+ break;
+ case KVM_INST_MTSPR_SRR1:
+ kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
+ break;
+ case KVM_INST_MTSPR_DAR:
+ kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
+ break;
+ case KVM_INST_MTSPR_DSISR:
+ kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
+ break;
+
+ /* Nops */
+ case KVM_INST_TLBSYNC:
+ kvm_patch_ins_nop(inst);
+ break;
+
+ /* Rewrites */
+ case KVM_INST_MTMSRD_L1:
+ kvm_patch_ins_mtmsrd(inst, inst_rt);
+ break;
+ case KVM_INST_MTMSR:
+ case KVM_INST_MTMSRD_L0:
+ kvm_patch_ins_mtmsr(inst, inst_rt);
+ break;
+ }
+
+ switch (inst_no_rt & ~KVM_MASK_RB) {
+#ifdef CONFIG_PPC_BOOK3S_32
+ case KVM_INST_MTSRIN:
+ if (features & KVM_MAGIC_FEAT_SR) {
+ u32 inst_rb = _inst & KVM_MASK_RB;
+ kvm_patch_ins_mtsrin(inst, inst_rt, inst_rb);
+ }
+ break;
+ break;
+#endif
+ }
+
+ switch (_inst) {
+#ifdef CONFIG_BOOKE
+ case KVM_INST_WRTEEI_0:
+ case KVM_INST_WRTEEI_1:
+ kvm_patch_ins_wrteei(inst);
+ break;
+#endif
+ }
+}
+
+static void kvm_use_magic_page(void)
+{
+ u32 *p;
+ u32 *start, *end;
+ u32 tmp;
+ u32 features;
+
+ /* Tell the host to map the magic page to -4096 on all CPUs */
+ on_each_cpu(kvm_map_magic_page, &features, 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, features);
+
+ 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 __init void kvm_free_tmp(void)
+{
+ unsigned long start, end;
+
+ start = (ulong)&kvm_tmp[kvm_tmp_index + (PAGE_SIZE - 1)] & PAGE_MASK;
+ end = (ulong)&kvm_tmp[ARRAY_SIZE(kvm_tmp)] & PAGE_MASK;
+
+ /* Free the tmp space we don't need */
+ for (; start < end; start += PAGE_SIZE) {
+ ClearPageReserved(virt_to_page(start));
+ init_page_count(virt_to_page(start));
+ free_page(start);
+ totalram_pages++;
+ }
+}
+
+static int __init kvm_guest_init(void)
+{
+ if (!kvm_para_available())
+ goto free_tmp;
+
+ if (kvm_para_setup())
+ goto free_tmp;
+
+ if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
+ kvm_use_magic_page();
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ /* Enable napping */
+ powersave_nap = 1;
+#endif
+
+free_tmp:
+ kvm_free_tmp();
+
+ return 0;
+}
+
+postcore_initcall(kvm_guest_init);