Re: [PATCH v3 3/3] hw/arm/virt: handle hvf with unknown max IPA size

[Peter Maydell]

On Mon, 23 Dec 2024 at 09:30, Joelle van Dyne <j@getutm.app> wrote:
>
> When it is not possible to determine the max IPA bit size, the helper
> function will return 0. We do not try to set up the memmap in this case
> and instead fall back to the default in machvirt_init().
>
> Signed-off-by: Joelle van Dyne <j@getutm.app>
> ---
>  hw/arm/virt.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index f9b3380815..8c431e24b3 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -3053,6 +3053,11 @@ static int 
> virt_hvf_get_physical_address_range(MachineState *ms)
>      int default_ipa_size = hvf_arm_get_default_ipa_bit_size();
>      int max_ipa_size = hvf_arm_get_max_ipa_bit_size();
>
> +    /* Unknown max ipa size, we'll let the caller figure it out */
> +    if (max_ipa_size == 0) {
> +        return 0;
> +    }

When can this happen? There are other places where we call
hvf_arm_get_max_ipa_bit_size() and assume it's valid.
The implementation calls assert_hvf_ok(ret), so if it
returns at all then we ought to have got a valid IPA size
from macos...

thanks
-- PMM