On Wed, 16 Jul 2025 at 18:28, Philippe Mathieu-Daudé <phi...@linaro.org> wrote: > > Emit a warning when HVF doesn't return the IPA bit length > and return -1 as "this accelerator is not usable", allowing > QEMU to try with the next one (when using '-accel hvf:tcg'). > > Reported-by: Ivan Krasilnikov > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2981 > Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org> > --- > hw/arm/virt.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > index ef6be3660f5..062812bf252 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -3149,8 +3149,12 @@ static int > virt_hvf_get_physical_address_range(MachineState *ms) > { > VirtMachineState *vms = VIRT_MACHINE(ms); > > - int default_ipa_size = hvf_arm_get_default_ipa_bit_size(); > - int max_ipa_size = hvf_arm_get_max_ipa_bit_size(); > + uint32_t default_ipa_size = hvf_arm_get_default_ipa_bit_size(); > + uint32_t max_ipa_size = hvf_arm_get_max_ipa_bit_size(); > + if (!default_ipa_size || !max_ipa_size) { > + warn_report("HVF didn't report IPA bit length"); > + return -1; > + }
Even if we avoid blowing up in this function, won't hvf_accel_init() immediately fail in hvf_arch_vm_create() and either exit(1) or assert() depending on what error code it got back ? It's unfortunate that there's no convenient way we can check "hvf is basically going to work" in hvf_accel_init() before we get into the machine-specific hook. "HVF didn't report IPA bit length" isn't really a very good message to report for "HVF isn't going to work at all here". (More generally, I think the hvf code rather overuses assert_hvf_ok(). I don't think the KVM code uses asserts for error checking like this.) thanks -- PMM
