Although we probe for the IPA limits imposed by KVM (and the hardware) when computing the memory map, we still use the old style '0' when creating a scratch VM in kvm_arm_create_scratch_host_vcpu().
On systems that are severely IPA challenged (such as the Apple M1), this results in a failure as KVM cannot use the default 40bit that '0' represents. Instead, probe for the extension and use the reported IPA limit if available. Cc: Andrew Jones <drjo...@redhat.com> Cc: Eric Auger <eric.au...@redhat.com> Cc: Peter Maydell <peter.mayd...@linaro.org> Signed-off-by: Marc Zyngier <m...@kernel.org> --- target/arm/kvm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/target/arm/kvm.c b/target/arm/kvm.c index d8381ba224..cc3371a99b 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -70,12 +70,17 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try, struct kvm_vcpu_init *init) { int ret = 0, kvmfd = -1, vmfd = -1, cpufd = -1; + int max_vm_pa_size; kvmfd = qemu_open_old("/dev/kvm", O_RDWR); if (kvmfd < 0) { goto err; } - vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0); + max_vm_pa_size = ioctl(kvmfd, KVM_CHECK_EXTENSION, KVM_CAP_ARM_VM_IPA_SIZE); + if (max_vm_pa_size < 0) { + max_vm_pa_size = 0; + } + vmfd = ioctl(kvmfd, KVM_CREATE_VM, max_vm_pa_size); if (vmfd < 0) { goto err; } -- 2.30.2