From 48539e54dab1fcc9a4d375ecdcd3a117fd951763 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sat, 24 Feb 2018 17:27:06 -0500 Subject: [PATCH] target-i386: Move user-mode exception actions out of user-exec.c The exception_action() function in user-exec.c is just a call to cpu_loop_exit() for every target CPU except i386. Since this function is only called if the target's handle_mmu_fault() hook has indicated an MMU fault, and that hook is only called from the handle_cpu_signal() code path, we can simply move the x86-specific setup into that hook, which allows us to remove the TARGET_I386 ifdef from user-exec.c. Of the actions that were done by the call to raise_interrupt_err(): * cpu_svm_check_intercept_param() is a no-op in user mode * check_exception() is a no-op since double faults are impossible for user-mode * assignments to cs->exception_index and env->error_code are no-ops * assigning to env->exception_next_eip is unnecessary because it is not used unless env->exception_is_int is true * cpu_loop_exit_restore() is equivalent to cpu_loop_exit() since pc is 0 which leaves just setting env_>exception_is_int as the action that needs to be added to x86_cpu_handle_mmu_fault(). Backports commit 0c33682d5f29b0a4ae53bdec4c8e52e4fae37b34 from qemu --- qemu/target-i386/helper.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/qemu/target-i386/helper.c b/qemu/target-i386/helper.c index 4a30f3e1..36238d2a 100644 --- a/qemu/target-i386/helper.c +++ b/qemu/target-i386/helper.c @@ -514,6 +514,8 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, env->error_code = (is_write << PG_ERROR_W_BIT); env->error_code |= PG_ERROR_U_MASK; cs->exception_index = EXCP0E_PAGE; + env->exception_is_int = 0; + env->exception_next_eip = -1; return 1; }