Re: [PATCH v14 08/10] Adding info [tb-list|tb] commands to HMP (WIP)

[Peter Maydell]

On Thu, 8 Jun 2023 at 08:44, Wu, Fei <fei2.wu@intel.com> wrote:
>
> On 6/7/2023 8:49 PM, Wu, Fei wrote:
> > On 6/1/2023 10:40 AM, Richard Henderson wrote:
> >> Did you really need something different than monitor_disas?  You almost
> >> certainly want to read physical memory and not virtual anyway.
> >>
> > Yes, it's usually okay for kernel address, but cannot re-gen the code
> > for userspace virtual address (guest kernel panic on riscv guest). I
> > tried monitor_disas() but it failed to disas too:
> >     monitor_disas(mon, mon_get_cpu(mon), tbs->phys_pc, num_inst, true);
> >
> > How to use this function correctly?
> >
> 'phys_pc' in tbs is returned by get_page_addr_code_hostp(), which is not
> guest phys address actually, but ram_addr_t instead, so it's always
> wrong for monitor_disas. After some dirty changes, tbs can record the
> guest pa. Now we can disas both kernel and user space code. But still,
> no code is regenerated, disas in 'info tb' is just a convenient way to 'xp'.
>
> Is there any existing function to convert ram_addr_t to guest pa?

Such a function would not be well-defined, because a block of RAM
as specified by a ram_addr_t could be present at (aliased to) multiple
guest physical addresses, or even currently not mapped to any guest
physical address at all. And it could be present at different physical
addresses for different vCPUs.

thanks
-- PMM