Re: [PATCH v2] tests/functional/aarch64: add tests for FEAT_RME

[Alex Bennée]

Pierrick Bouvier <pierrick.bouvier@linaro.org> writes:

> This boot an OP-TEE environment, and launch a nested guest VM inside it
> using the Realms feature. We do it for virt and sbsa-ref platforms.
>
> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
>
<snip>
> +
> +        self.vm.add_args('-accel', 'tcg')
> +        self.vm.add_args('-cpu', 'max,x-rme=on')

With debug on the PAC function are certainly very high in the perf
report. So pauth-impdef=on seems worthwhile here.

> +        self.vm.add_args('-m', '2G')
> +        self.vm.add_args('-M', 'sbsa-ref')
> +        self.vm.add_args('-drive', f'file={pflash0},format=raw,if=pflash')
> +        self.vm.add_args('-drive', f'file={pflash1},format=raw,if=pflash')
> +        self.vm.add_args('-drive', f'file=fat:rw:{virtual},format=raw')
> +        self.vm.add_args('-drive', f'format=raw,if=none,file={drive},id=hd0')
> +        self.vm.add_args('-device', 'virtio-blk-pci,drive=hd0')
> +        self.vm.add_args('-device', 
> 'virtio-9p-pci,fsdev=shr0,mount_tag=shr0')
> +        self.vm.add_args('-fsdev', 
> f'local,security_model=none,path={rme_stack},id=shr0')
> +        self.vm.add_args('-device', 'virtio-net-pci,netdev=net0')
> +        self.vm.add_args('-netdev', 'user,id=net0')
<snip>
> +
> +        self.vm.add_args('-accel', 'tcg')
> +        self.vm.add_args('-cpu', 'max,x-rme=on')

And here.

<snip>

With that the tests both pass with --enable-debug (312s, 352s) and the
profile looks like:

   6.33%  qemu-system-aar  qemu-system-aarch64                       [.] 
arm_feature
   5.66%  qemu-system-aar  qemu-system-aarch64                       [.] 
tcg_flush_jmp_cache
   3.44%  qemu-system-aar  qemu-system-aarch64                       [.] 
rebuild_hflags_a64

This I suspect is triggered by assert_hflags_rebuild_correctly() which
is validating we've not skipped rebuilding the flags when we need to.
It's a lot easier than debugging why your execution trace looks weird.

   2.95%  qemu-system-aar  qemu-system-aarch64                       [.] 
extract64
   2.52%  qemu-system-aar  qemu-system-aarch64                       [.] 
extract64

This is usually triggered by translation code which uses extract64
heavily during instruction decode.

It might be useful to see if we can get functional tests run under TCG
to dump "info jit" at the end and ensure we are not over generating code
and exhausting the translation cache.

   2.12%  qemu-system-aar  qemu-system-aarch64                       [.] 
arm_el_is_aa64
   2.11%  qemu-system-aar  qemu-system-aarch64                       [.] 
arm_security_space_below_el3
   2.11%  qemu-system-aar  qemu-system-aarch64                       [.] 
deposit64
   1.49%  qemu-system-aar  qemu-system-aarch64                       [.] 
arm_hcr_el2_eff_secstate
   1.46%  qemu-system-aar  qemu-system-aarch64                       [.] 
arm_is_el2_enabled_secstate
   1.38%  qemu-system-aar  qemu-system-aarch64                       [.] 
extract32
   1.34%  qemu-system-aar  qemu-system-aarch64                       [.] 
extract64
   1.30%  qemu-system-aar  qemu-system-aarch64                       [.] 
get_phys_addr_lpae
   1.23%  qemu-system-aar  qemu-system-aarch64                       [.] 
aa64_va_parameters
   1.09%  qemu-system-aar  qemu-system-aarch64                       [.] rol32
   1.07%  qemu-system-aar  qemu-system-aarch64                       [.] 
probe_access_internal
   1.02%  qemu-system-aar  qemu-system-aarch64                       [.] 
deposit32


-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro