mirror of
https://github.com/torvalds/linux.git
synced 2024-11-29 07:31:29 +00:00
ce11e48b7f
This patch adds the debug stub support on booke/bookehv. Now QEMU debug stub can use hw breakpoint, watchpoint and software breakpoint to debug guest. This is how we save/restore debug register context when switching between guest, userspace and kernel user-process: When QEMU is running -> thread->debug_reg == QEMU debug register context. -> Kernel will handle switching the debug register on context switch. -> no vcpu_load() called QEMU makes ioctls (except RUN) -> This will call vcpu_load() -> should not change context. -> Some ioctls can change vcpu debug register, context saved in vcpu->debug_regs QEMU Makes RUN ioctl -> Save thread->debug_reg on STACK -> Store thread->debug_reg == vcpu->debug_reg -> load thread->debug_reg -> RUN VCPU ( So thread points to vcpu context ) Context switch happens When VCPU running -> makes vcpu_load() should not load any context -> kernel loads the vcpu context as thread->debug_regs points to vcpu context. On heavyweight_exit -> Load the context saved on stack in thread->debug_reg Currently we do not support debug resource emulation to guest, On debug exception, always exit to user space irrespective of user space is expecting the debug exception or not. If this is unexpected exception (breakpoint/watchpoint event not set by userspace) then let us leave the action on user space. This is similar to what it was before, only thing is that now we have proper exit state available to user space. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> |
||
|---|---|---|
| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| include | ||
| kernel | ||
| kvm | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| perf | ||
| platforms | ||
| sysdev | ||
| xmon | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||
| relocs_check.pl | ||