diff options
Diffstat (limited to 'arch/powerpc/kernel/kvm.c')
| -rw-r--r-- | arch/powerpc/kernel/kvm.c | 596 |
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..b06bdae0406 --- /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) +{ +#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC_BOOK3S) + /* 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); |