/* * ARM implementation of KVM hooks, 32 bit specific code. * * Copyright Christoffer Dall 2009-2010 * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #include <stdio.h> #include <sys/types.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <linux/kvm.h> #include "qemu-common.h" #include "qemu/timer.h" #include "sysemu/sysemu.h" #include "sysemu/kvm.h" #include "kvm_arm.h" #include "cpu.h" #include "internals.h" #include "hw/arm/arm.h" static inline void set_feature(uint64_t *features, int feature) { *features |= 1ULL << feature; } bool kvm_arm_get_host_cpu_features(ARMHostCPUClass *ahcc) { /* Identify the feature bits corresponding to the host CPU, and * fill out the ARMHostCPUClass fields accordingly. To do this * we have to create a scratch VM, create a single CPU inside it, * and then query that CPU for the relevant ID registers. */ int i, ret, fdarray[3]; uint32_t midr, id_pfr0, id_isar0, mvfr1; uint64_t features = 0; /* Old kernels may not know about the PREFERRED_TARGET ioctl: however * we know these will only support creating one kind of guest CPU, * which is its preferred CPU type. */ static const uint32_t cpus_to_try[] = { QEMU_KVM_ARM_TARGET_CORTEX_A15, QEMU_KVM_ARM_TARGET_NONE }; struct kvm_vcpu_init init; struct kvm_one_reg idregs[] = { { .id = KVM_REG_ARM | KVM_REG_SIZE_U32 | ENCODE_CP_REG(15, 0, 0, 0, 0, 0), .addr = (uintptr_t)&midr, }, { .id = KVM_REG_ARM | KVM_REG_SIZE_U32 | ENCODE_CP_REG(15, 0, 0, 1, 0, 0), .addr = (uintptr_t)&id_pfr0, }, { .id = KVM_REG_ARM | KVM_REG_SIZE_U32 | ENCODE_CP_REG(15, 0, 0, 2, 0, 0), .addr = (uintptr_t)&id_isar0, }, { .id = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP | KVM_REG_ARM_VFP_MVFR1, .addr = (uintptr_t)&mvfr1, }, }; if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) { return false; } ahcc->target = init.target; /* This is not strictly blessed by the device tree binding docs yet, * but in practice the kernel does not care about this string so * there is no point maintaining an KVM_ARM_TARGET_* -> string table. */ ahcc->dtb_compatible = "arm,arm-v7"; for (i = 0; i < ARRAY_SIZE(idregs); i++) { ret = ioctl(fdarray[2], KVM_GET_ONE_REG, &idregs[i]); if (ret) { break; } } kvm_arm_destroy_scratch_host_vcpu(fdarray); if (ret) { return false; } /* Now we've retrieved all the register information we can * set the feature bits based on the ID register fields. * We can assume any KVM supporting CPU is at least a v7 * with VFPv3, LPAE and the generic timers; this in turn implies * most of the other feature bits, but a few must be tested. */ set_feature(&features, ARM_FEATURE_V7); set_feature(&features, ARM_FEATURE_VFP3); set_feature(&features, ARM_FEATURE_LPAE); set_feature(&features, ARM_FEATURE_GENERIC_TIMER); switch (extract32(id_isar0, 24, 4)) { case 1: set_feature(&features, ARM_FEATURE_THUMB_DIV); break; case 2: set_feature(&features, ARM_FEATURE_ARM_DIV); set_feature(&features, ARM_FEATURE_THUMB_DIV); break; default: break; } if (extract32(id_pfr0, 12, 4) == 1) { set_feature(&features, ARM_FEATURE_THUMB2EE); } if (extract32(mvfr1, 20, 4) == 1) { set_feature(&features, ARM_FEATURE_VFP_FP16); } if (extract32(mvfr1, 12, 4) == 1) { set_feature(&features, ARM_FEATURE_NEON); } if (extract32(mvfr1, 28, 4) == 1) { /* FMAC support implies VFPv4 */ set_feature(&features, ARM_FEATURE_VFP4); } ahcc->features = features; return true; } static bool reg_syncs_via_tuple_list(uint64_t regidx) { /* Return true if the regidx is a register we should synchronize * via the cpreg_tuples array (ie is not a core reg we sync by * hand in kvm_arch_get/put_registers()) */ switch (regidx & KVM_REG_ARM_COPROC_MASK) { case KVM_REG_ARM_CORE: case KVM_REG_ARM_VFP: return false; default: return true; } } static int compare_u64(const void *a, const void *b) { if (*(uint64_t *)a > *(uint64_t *)b) { return 1; } if (*(uint64_t *)a < *(uint64_t *)b) { return -1; } return 0; } int kvm_arch_init_vcpu(CPUState *cs) { struct kvm_vcpu_init init; int i, ret, arraylen; uint64_t v; struct kvm_one_reg r; struct kvm_reg_list rl; struct kvm_reg_list *rlp; ARMCPU *cpu = ARM_CPU(cs); if (cpu->kvm_target == QEMU_KVM_ARM_TARGET_NONE) { fprintf(stderr, "KVM is not supported for this guest CPU type\n"); return -EINVAL; } init.target = cpu->kvm_target; memset(init.features, 0, sizeof(init.features)); if (cpu->start_powered_off) { init.features[0] = 1 << KVM_ARM_VCPU_POWER_OFF; } ret = kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init); if (ret) { return ret; } /* Query the kernel to make sure it supports 32 VFP * registers: QEMU's "cortex-a15" CPU is always a * VFP-D32 core. The simplest way to do this is just * to attempt to read register d31. */ r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | KVM_REG_ARM_VFP | 31; r.addr = (uintptr_t)(&v); ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r); if (ret == -ENOENT) { return -EINVAL; } /* Populate the cpreg list based on the kernel's idea * of what registers exist (and throw away the TCG-created list). */ rl.n = 0; ret = kvm_vcpu_ioctl(cs, KVM_GET_REG_LIST, &rl); if (ret != -E2BIG) { return ret; } rlp = g_malloc(sizeof(struct kvm_reg_list) + rl.n * sizeof(uint64_t)); rlp->n = rl.n; ret = kvm_vcpu_ioctl(cs, KVM_GET_REG_LIST, rlp); if (ret) { goto out; } /* Sort the list we get back from the kernel, since cpreg_tuples * must be in strictly ascending order. */ qsort(&rlp->reg, rlp->n, sizeof(rlp->reg[0]), compare_u64); for (i = 0, arraylen = 0; i < rlp->n; i++) { if (!reg_syncs_via_tuple_list(rlp->reg[i])) { continue; } switch (rlp->reg[i] & KVM_REG_SIZE_MASK) { case KVM_REG_SIZE_U32: case KVM_REG_SIZE_U64: break; default: fprintf(stderr, "Can't handle size of register in kernel list\n"); ret = -EINVAL; goto out; } arraylen++; } cpu->cpreg_indexes = g_renew(uint64_t, cpu->cpreg_indexes, arraylen); cpu->cpreg_values = g_renew(uint64_t, cpu->cpreg_values, arraylen); cpu->cpreg_vmstate_indexes = g_renew(uint64_t, cpu->cpreg_vmstate_indexes, arraylen); cpu->cpreg_vmstate_values = g_renew(uint64_t, cpu->cpreg_vmstate_values, arraylen); cpu->cpreg_array_len = arraylen; cpu->cpreg_vmstate_array_len = arraylen; for (i = 0, arraylen = 0; i < rlp->n; i++) { uint64_t regidx = rlp->reg[i]; if (!reg_syncs_via_tuple_list(regidx)) { continue; } cpu->cpreg_indexes[arraylen] = regidx; arraylen++; } assert(cpu->cpreg_array_len == arraylen); if (!write_kvmstate_to_list(cpu)) { /* Shouldn't happen unless kernel is inconsistent about * what registers exist. */ fprintf(stderr, "Initial read of kernel register state failed\n"); ret = -EINVAL; goto out; } /* Save a copy of the initial register values so that we can * feed it back to the kernel on VCPU reset. */ cpu->cpreg_reset_values = g_memdup(cpu->cpreg_values, cpu->cpreg_array_len * sizeof(cpu->cpreg_values[0])); out: g_free(rlp); return ret; } typedef struct Reg { uint64_t id; int offset; } Reg; #define COREREG(KERNELNAME, QEMUFIELD) \ { \ KVM_REG_ARM | KVM_REG_SIZE_U32 | \ KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(KERNELNAME), \ offsetof(CPUARMState, QEMUFIELD) \ } #define VFPSYSREG(R) \ { \ KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP | \ KVM_REG_ARM_VFP_##R, \ offsetof(CPUARMState, vfp.xregs[ARM_VFP_##R]) \ } /* Like COREREG, but handle fields which are in a uint64_t in CPUARMState. */ #define COREREG64(KERNELNAME, QEMUFIELD) \ { \ KVM_REG_ARM | KVM_REG_SIZE_U32 | \ KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(KERNELNAME), \ offsetoflow32(CPUARMState, QEMUFIELD) \ } static const Reg regs[] = { /* R0_usr .. R14_usr */ COREREG(usr_regs.uregs[0], regs[0]), COREREG(usr_regs.uregs[1], regs[1]), COREREG(usr_regs.uregs[2], regs[2]), COREREG(usr_regs.uregs[3], regs[3]), COREREG(usr_regs.uregs[4], regs[4]), COREREG(usr_regs.uregs[5], regs[5]), COREREG(usr_regs.uregs[6], regs[6]), COREREG(usr_regs.uregs[7], regs[7]), COREREG(usr_regs.uregs[8], usr_regs[0]), COREREG(usr_regs.uregs[9], usr_regs[1]), COREREG(usr_regs.uregs[10], usr_regs[2]), COREREG(usr_regs.uregs[11], usr_regs[3]), COREREG(usr_regs.uregs[12], usr_regs[4]), COREREG(usr_regs.uregs[13], banked_r13[0]), COREREG(usr_regs.uregs[14], banked_r14[0]), /* R13, R14, SPSR for SVC, ABT, UND, IRQ banks */ COREREG(svc_regs[0], banked_r13[1]), COREREG(svc_regs[1], banked_r14[1]), COREREG64(svc_regs[2], banked_spsr[1]), COREREG(abt_regs[0], banked_r13[2]), COREREG(abt_regs[1], banked_r14[2]), COREREG64(abt_regs[2], banked_spsr[2]), COREREG(und_regs[0], banked_r13[3]), COREREG(und_regs[1], banked_r14[3]), COREREG64(und_regs[2], banked_spsr[3]), COREREG(irq_regs[0], banked_r13[4]), COREREG(irq_regs[1], banked_r14[4]), COREREG64(irq_regs[2], banked_spsr[4]), /* R8_fiq .. R14_fiq and SPSR_fiq */ COREREG(fiq_regs[0], fiq_regs[0]), COREREG(fiq_regs[1], fiq_regs[1]), COREREG(fiq_regs[2], fiq_regs[2]), COREREG(fiq_regs[3], fiq_regs[3]), COREREG(fiq_regs[4], fiq_regs[4]), COREREG(fiq_regs[5], banked_r13[5]), COREREG(fiq_regs[6], banked_r14[5]), COREREG64(fiq_regs[7], banked_spsr[5]), /* R15 */ COREREG(usr_regs.uregs[15], regs[15]), /* VFP system registers */ VFPSYSREG(FPSID), VFPSYSREG(MVFR1), VFPSYSREG(MVFR0), VFPSYSREG(FPEXC), VFPSYSREG(FPINST), VFPSYSREG(FPINST2), }; int kvm_arch_put_registers(CPUState *cs, int level) { ARMCPU *cpu = ARM_CPU(cs); CPUARMState *env = &cpu->env; struct kvm_one_reg r; int mode, bn; int ret, i; uint32_t cpsr, fpscr; /* Make sure the banked regs are properly set */ mode = env->uncached_cpsr & CPSR_M; bn = bank_number(mode); if (mode == ARM_CPU_MODE_FIQ) { memcpy(env->fiq_regs, env->regs + 8, 5 * sizeof(uint32_t)); } else { memcpy(env->usr_regs, env->regs + 8, 5 * sizeof(uint32_t)); } env->banked_r13[bn] = env->regs[13]; env->banked_r14[bn] = env->regs[14]; env->banked_spsr[bn] = env->spsr; /* Now we can safely copy stuff down to the kernel */ for (i = 0; i < ARRAY_SIZE(regs); i++) { r.id = regs[i].id; r.addr = (uintptr_t)(env) + regs[i].offset; ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &r); if (ret) { return ret; } } /* Special cases which aren't a single CPUARMState field */ cpsr = cpsr_read(env); r.id = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(usr_regs.ARM_cpsr); r.addr = (uintptr_t)(&cpsr); ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &r); if (ret) { return ret; } /* VFP registers */ r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | KVM_REG_ARM_VFP; for (i = 0; i < 32; i++) { r.addr = (uintptr_t)(&env->vfp.regs[i]); ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &r); if (ret) { return ret; } r.id++; } r.id = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP | KVM_REG_ARM_VFP_FPSCR; fpscr = vfp_get_fpscr(env); r.addr = (uintptr_t)&fpscr; ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &r); if (ret) { return ret; } /* Note that we do not call write_cpustate_to_list() * here, so we are only writing the tuple list back to * KVM. This is safe because nothing can change the * CPUARMState cp15 fields (in particular gdb accesses cannot) * and so there are no changes to sync. In fact syncing would * be wrong at this point: for a constant register where TCG and * KVM disagree about its value, the preceding write_list_to_cpustate() * would not have had any effect on the CPUARMState value (since the * register is read-only), and a write_cpustate_to_list() here would * then try to write the TCG value back into KVM -- this would either * fail or incorrectly change the value the guest sees. * * If we ever want to allow the user to modify cp15 registers via * the gdb stub, we would need to be more clever here (for instance * tracking the set of registers kvm_arch_get_registers() successfully * managed to update the CPUARMState with, and only allowing those * to be written back up into the kernel). */ if (!write_list_to_kvmstate(cpu)) { return EINVAL; } return ret; } int kvm_arch_get_registers(CPUState *cs) { ARMCPU *cpu = ARM_CPU(cs); CPUARMState *env = &cpu->env; struct kvm_one_reg r; int mode, bn; int ret, i; uint32_t cpsr, fpscr; for (i = 0; i < ARRAY_SIZE(regs); i++) { r.id = regs[i].id; r.addr = (uintptr_t)(env) + regs[i].offset; ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r); if (ret) { return ret; } } /* Special cases which aren't a single CPUARMState field */ r.id = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(usr_regs.ARM_cpsr); r.addr = (uintptr_t)(&cpsr); ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r); if (ret) { return ret; } cpsr_write(env, cpsr, 0xffffffff); /* Make sure the current mode regs are properly set */ mode = env->uncached_cpsr & CPSR_M; bn = bank_number(mode); if (mode == ARM_CPU_MODE_FIQ) { memcpy(env->regs + 8, env->fiq_regs, 5 * sizeof(uint32_t)); } else { memcpy(env->regs + 8, env->usr_regs, 5 * sizeof(uint32_t)); } env->regs[13] = env->banked_r13[bn]; env->regs[14] = env->banked_r14[bn]; env->spsr = env->banked_spsr[bn]; /* VFP registers */ r.id = KVM_REG_ARM | KVM_REG_SIZE_U64 | KVM_REG_ARM_VFP; for (i = 0; i < 32; i++) { r.addr = (uintptr_t)(&env->vfp.regs[i]); ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r); if (ret) { return ret; } r.id++; } r.id = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP | KVM_REG_ARM_VFP_FPSCR; r.addr = (uintptr_t)&fpscr; ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r); if (ret) { return ret; } vfp_set_fpscr(env, fpscr); if (!write_kvmstate_to_list(cpu)) { return EINVAL; } /* Note that it's OK to have registers which aren't in CPUState, * so we can ignore a failure return here. */ write_list_to_cpustate(cpu); return 0; } void kvm_arm_reset_vcpu(ARMCPU *cpu) { /* Feed the kernel back its initial register state */ memmove(cpu->cpreg_values, cpu->cpreg_reset_values, cpu->cpreg_array_len * sizeof(cpu->cpreg_values[0])); if (!write_list_to_kvmstate(cpu)) { abort(); } }