target/i386: Clear RF on SYSCALL instruction

Fix the SYSCALL instruction in 64-bit (long mode). The RF flag
should be cleared in R11 as well as in the RFLAGS. Intel
and AMD CPUs behave same. AMD has this documented in the
APM vol 3.

Signed-off-by: Roman Kapl <rka@sysgo.com>
Signed-off-by: Rudolf Marek <rudolf.marek@sysgo.com>
Message-Id: <20181019122449.26387-1-rka@sysgo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/seg_helper.c b/target/i386/seg_helper.c
index 33714bc..63e265c 100644 (file)
--- a/target/i386/seg_helper.c
+++ b/target/i386/seg_helper.c
@@ -991,11 +991,11 @@ void helper_syscall(CPUX86State *env, int next_eip_addend)
         int code64;
 
         env->regs[R_ECX] = env->eip + next_eip_addend;
-        env->regs[11] = cpu_compute_eflags(env);
+        env->regs[11] = cpu_compute_eflags(env) & ~RF_MASK;
 
         code64 = env->hflags & HF_CS64_MASK;
 
-        env->eflags &= ~env->fmask;
+        env->eflags &= ~(env->fmask | RF_MASK);
         cpu_load_eflags(env, env->eflags, 0);
         cpu_x86_load_seg_cache(env, R_CS, selector & 0xfffc,
                            0, 0xffffffff,