From f7a69fa6e6e21580b6e56dac87ad2ab0bf228065 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Thu, 6 Jul 2023 07:17:32 -0300 Subject: [PATCH] target/riscv/kvm.c: add multi-letter extension KVM properties Let's add KVM user properties for the multi-letter extensions that KVM currently supports: zicbom, zicboz, zihintpause, zbb, ssaia, sstc, svinval and svpbmt. As with MISA extensions, we're using the KVMCPUConfig type to hold information about the state of each extension. However, multi-letter extensions have more cases to cover than MISA extensions, so we're adding an extra 'supported' flag as well. This flag will reflect if a given extension is supported by KVM, i.e. KVM knows how to handle it. This is determined during KVM extension discovery in kvm_riscv_init_multiext_cfg(), where we test for EINVAL errors. Any other error will cause an abort. The use of the 'user_set' is similar to what we already do with MISA extensions: the flag set only if the user is changing the extension state. The 'supported' flag will be used later on to make an exception for users that are disabling multi-letter extensions that are unknown to KVM. Signed-off-by: Daniel Henrique Barboza Acked-by: Alistair Francis Reviewed-by: Andrew Jones Message-Id: <20230706101738.460804-15-dbarboza@ventanamicro.com> Signed-off-by: Alistair Francis --- target/riscv/cpu.c | 8 +++ target/riscv/kvm.c | 119 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 127 insertions(+) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 5c8832a030..31e591a938 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -1860,6 +1860,14 @@ static void riscv_cpu_add_user_properties(Object *obj) riscv_cpu_add_misa_properties(obj); for (prop = riscv_cpu_extensions; prop && prop->name; prop++) { +#ifndef CONFIG_USER_ONLY + if (kvm_enabled()) { + /* Check if KVM created the property already */ + if (object_property_find(obj, prop->name)) { + continue; + } + } +#endif qdev_property_add_static(dev, prop); } diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c index f64019e87c..bd86d8748e 100644 --- a/target/riscv/kvm.c +++ b/target/riscv/kvm.c @@ -113,6 +113,7 @@ typedef struct KVMCPUConfig { target_ulong offset; int kvm_reg_id; bool user_set; + bool supported; } KVMCPUConfig; #define KVM_MISA_CFG(_bit, _reg_id) \ @@ -197,6 +198,81 @@ static void kvm_riscv_update_cpu_misa_ext(RISCVCPU *cpu, CPUState *cs) } } +#define CPUCFG(_prop) offsetof(struct RISCVCPUConfig, _prop) + +#define KVM_EXT_CFG(_name, _prop, _reg_id) \ + {.name = _name, .offset = CPUCFG(_prop), \ + .kvm_reg_id = _reg_id} + +static KVMCPUConfig kvm_multi_ext_cfgs[] = { + KVM_EXT_CFG("zicbom", ext_icbom, KVM_RISCV_ISA_EXT_ZICBOM), + KVM_EXT_CFG("zicboz", ext_icboz, KVM_RISCV_ISA_EXT_ZICBOZ), + KVM_EXT_CFG("zihintpause", ext_zihintpause, KVM_RISCV_ISA_EXT_ZIHINTPAUSE), + KVM_EXT_CFG("zbb", ext_zbb, KVM_RISCV_ISA_EXT_ZBB), + KVM_EXT_CFG("ssaia", ext_ssaia, KVM_RISCV_ISA_EXT_SSAIA), + KVM_EXT_CFG("sstc", ext_sstc, KVM_RISCV_ISA_EXT_SSTC), + KVM_EXT_CFG("svinval", ext_svinval, KVM_RISCV_ISA_EXT_SVINVAL), + KVM_EXT_CFG("svpbmt", ext_svpbmt, KVM_RISCV_ISA_EXT_SVPBMT), +}; + +static void kvm_cpu_cfg_set(RISCVCPU *cpu, KVMCPUConfig *multi_ext, + uint32_t val) +{ + int cpu_cfg_offset = multi_ext->offset; + bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset; + + *ext_enabled = val; +} + +static uint32_t kvm_cpu_cfg_get(RISCVCPU *cpu, + KVMCPUConfig *multi_ext) +{ + int cpu_cfg_offset = multi_ext->offset; + bool *ext_enabled = (void *)&cpu->cfg + cpu_cfg_offset; + + return *ext_enabled; +} + +static void kvm_cpu_set_multi_ext_cfg(Object *obj, Visitor *v, + const char *name, + void *opaque, Error **errp) +{ + KVMCPUConfig *multi_ext_cfg = opaque; + RISCVCPU *cpu = RISCV_CPU(obj); + bool value, host_val; + + if (!visit_type_bool(v, name, &value, errp)) { + return; + } + + host_val = kvm_cpu_cfg_get(cpu, multi_ext_cfg); + + /* + * Ignore if the user is setting the same value + * as the host. + */ + if (value == host_val) { + return; + } + + if (!multi_ext_cfg->supported) { + /* + * Error out if the user is trying to enable an + * extension that KVM doesn't support. Ignore + * option otherwise. + */ + if (value) { + error_setg(errp, "KVM does not support disabling extension %s", + multi_ext_cfg->name); + } + + return; + } + + multi_ext_cfg->user_set = true; + kvm_cpu_cfg_set(cpu, multi_ext_cfg, value); +} + static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj) { int i; @@ -215,6 +291,15 @@ static void kvm_riscv_add_cpu_user_properties(Object *cpu_obj) object_property_set_description(cpu_obj, misa_cfg->name, misa_cfg->description); } + + for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) { + KVMCPUConfig *multi_cfg = &kvm_multi_ext_cfgs[i]; + + object_property_add(cpu_obj, multi_cfg->name, "bool", + NULL, + kvm_cpu_set_multi_ext_cfg, + NULL, multi_cfg); + } } static int kvm_riscv_get_regs_core(CPUState *cs) @@ -530,6 +615,39 @@ static void kvm_riscv_init_misa_ext_mask(RISCVCPU *cpu, env->misa_ext = env->misa_ext_mask; } +static void kvm_riscv_init_multiext_cfg(RISCVCPU *cpu, KVMScratchCPU *kvmcpu) +{ + CPURISCVState *env = &cpu->env; + uint64_t val; + int i, ret; + + for (i = 0; i < ARRAY_SIZE(kvm_multi_ext_cfgs); i++) { + KVMCPUConfig *multi_ext_cfg = &kvm_multi_ext_cfgs[i]; + struct kvm_one_reg reg; + + reg.id = kvm_riscv_reg_id(env, KVM_REG_RISCV_ISA_EXT, + multi_ext_cfg->kvm_reg_id); + reg.addr = (uint64_t)&val; + ret = ioctl(kvmcpu->cpufd, KVM_GET_ONE_REG, ®); + if (ret != 0) { + if (errno == EINVAL) { + /* Silently default to 'false' if KVM does not support it. */ + multi_ext_cfg->supported = false; + val = false; + } else { + error_report("Unable to read ISA_EXT KVM register %s, " + "error %d", multi_ext_cfg->name, ret); + kvm_riscv_destroy_scratch_vcpu(kvmcpu); + exit(EXIT_FAILURE); + } + } else { + multi_ext_cfg->supported = true; + } + + kvm_cpu_cfg_set(cpu, multi_ext_cfg, val); + } +} + void kvm_riscv_init_user_properties(Object *cpu_obj) { RISCVCPU *cpu = RISCV_CPU(cpu_obj); @@ -542,6 +660,7 @@ void kvm_riscv_init_user_properties(Object *cpu_obj) kvm_riscv_add_cpu_user_properties(cpu_obj); kvm_riscv_init_machine_ids(cpu, &kvmcpu); kvm_riscv_init_misa_ext_mask(cpu, &kvmcpu); + kvm_riscv_init_multiext_cfg(cpu, &kvmcpu); kvm_riscv_destroy_scratch_vcpu(&kvmcpu); }