On Mon, 20 May 2024 at 19:48, Perry Hung <pe...@mosi.io> wrote: > > Philippe, Peter, > > Thank you for the comments. I am not even sure what the semantics of > putting a breakpoint or watchpoint > on device regions are supposed to be. I would imagine it is > architecture-specific as to whether this is even allowed. > > It appears for example, that armv8-a allows watchpoints to be set on any > type of memory. armv7-a prohibits > watchpoints on Device or Strongly-ordered memory that might be accessed > by instructions multiple times > (e.g LDM and LDC instructions). > > What is the current behavior for QEMU and what should > breakpoints/watchpoints do when placed on IO memory?
Personally I don't think it matters very much, because the user shouldn't really be doing something silly like that in the first place. If they do, they get to deal with whatever problems result. My feeling is that the neater place to put the handling of memory regions that aren't RAM/ROM is probably in address_space_write_rom_internal(). But doing that makes me nervous, because that's in the file-loading path and I bet there are dubious guest images out there that put data in some area covered by a device and currently rely on it being ignored when the image is loaded... thanks -- PMM
