Re: Regarding how qemu handles write request to the Main Meormy issued by the Guest OS

[Peter Maydell]

On Wed, 4 Sept 2024 at 14:20, Samindu Cooray <samiducooray@gmail.com> wrote:
>
> Hi, I'm an undergrad pursuing a computer science degree. Currently, I'm going 
> through the Qemu code. I want to find the function that triggers in Qemu when 
> the guest os issues a write request to its main memory. At this point, I have 
> checked the address_space_write() and cpu_physical_memory_write() functions, 
> and they are not handling what I'm looking for. Can someone please help me?

There is no single function which all guest writes go through.
For the common case where we have determined that the guest
write is to something backed by host RAM, we optimize this in
the JIT so that the write happens directly from the host
code that the JIT generates, without going out to any C code
in QEMU itself.

-- PMM