From fd5dcb1ccd660e47fb9f74043a16539631f53386 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 19 Jun 2023 15:41:42 +0200 Subject: [PATCH] target/i386: Intel only supports SYSCALL/SYSRET in long mode Reviewed-by: Richard Henderson Signed-off-by: Paolo Bonzini --- target/i386/cpu.c | 4 ++++ target/i386/tcg/translate.c | 9 ++++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 695e01582b..978d24b5ec 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6238,6 +6238,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, *ecx |= 1 << 1; /* CmpLegacy bit */ } } + if (tcg_enabled() && env->cpuid_vendor1 == CPUID_VENDOR_INTEL_1 && + !(env->hflags & HF_LMA_MASK)) { + *edx &= ~CPUID_EXT2_SYSCALL; + } break; case 0x80000002: case 0x80000003: diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index b2e2dccb84..ed4016f554 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -5692,7 +5692,10 @@ static bool disas_insn(DisasContext *s, CPUState *cpu) break; #ifdef TARGET_X86_64 case 0x105: /* syscall */ - /* XXX: is it usable in real mode ? */ + /* For Intel SYSCALL is only valid in long mode */ + if (!LMA(s) && env->cpuid_vendor1 == CPUID_VENDOR_INTEL_1) { + goto illegal_op; + } gen_update_cc_op(s); gen_update_eip_cur(s); gen_helper_syscall(cpu_env, cur_insn_len_i32(s)); @@ -5702,6 +5705,10 @@ static bool disas_insn(DisasContext *s, CPUState *cpu) gen_eob_worker(s, false, true); break; case 0x107: /* sysret */ + /* For Intel SYSRET is only valid in long mode */ + if (!LMA(s) && env->cpuid_vendor1 == CPUID_VENDOR_INTEL_1) { + goto illegal_op; + } if (!PE(s)) { gen_exception_gpf(s); } else {