libvirt uses "none" machine type to test KVM availability. Before this change, QEMU used to pass 0 as machine type when calling KVM_CREATE_VM. The kernel documentation says: > On arm64, the physical address size for a VM (IPA Size limit) is > limited to 40bits by default. The limit can be configured if the host > supports the extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use > KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type > identifier, where IPA_Bits is the maximum width of any physical > address used by the VM. The IPA_Bits is encoded in bits[7-0] of the > machine type identifier. > > e.g, to configure a guest to use 48bit physical address size:: > > vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48)); > > The requested size (IPA_Bits) must be: > > == ========================================================= > 0 Implies default size, 40bits (for backward compatibility) > N Implies N bits, where N is a positive integer such that, > 32 <= N <= Host_IPA_Limit > == ========================================================= > Host_IPA_Limit is the maximum possible value for IPA_Bits on the host > and is dependent on the CPU capability and the kernel configuration. > The limit can be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the > KVM_CHECK_EXTENSION ioctl() at run-time. > > Creation of the VM will fail if the requested IPA size (whether it is > implicit or explicit) is unsupported on the host. https://docs.kernel.org/virt/kvm/api.html#kvm-create-vm So if Host_IPA_Limit < 40, such KVM_CREATE_VM will fail, and libvirt incorrectly thinks KVM is not available. This actually happened on M2 MacBook Air. Fix this by specifying 32 for IPA_Bits as any arm64 system should support the value according to the documentation. Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx> --- V1 -> V2: Introduced an arch hook include/sysemu/kvm.h | 1 + accel/kvm/kvm-all.c | 2 +- target/arm/kvm.c | 2 ++ target/i386/kvm/kvm.c | 2 ++ target/mips/kvm.c | 2 ++ target/ppc/kvm.c | 2 ++ target/riscv/kvm.c | 2 ++ target/s390x/kvm/kvm.c | 2 ++ 8 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index 115f0cca79..7cc2eb1a8c 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -347,6 +347,7 @@ bool kvm_device_supported(int vmfd, uint64_t type); /* Arch specific hooks */ +extern const int kvm_arch_default_type; extern const KVMCapabilityInfo kvm_arch_required_capabilities[]; void kvm_arch_accel_class_init(ObjectClass *oc); diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 373d876c05..914ade3ec3 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2458,7 +2458,7 @@ static int kvm_init(MachineState *ms) KVMState *s; const KVMCapabilityInfo *missing_cap; int ret; - int type = 0; + int type = kvm_arch_default_type; uint64_t dirty_log_manual_caps; qemu_mutex_init(&kml_slots_lock); diff --git a/target/arm/kvm.c b/target/arm/kvm.c index b4c7654f49..f8203b9915 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -32,6 +32,8 @@ #include "hw/irq.h" #include "qemu/log.h" +const int kvm_arch_default_type = 32; + const KVMCapabilityInfo kvm_arch_required_capabilities[] = { KVM_CAP_LAST_INFO }; diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index ebfaf3d24c..00bccffdfc 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -87,6 +87,8 @@ static void kvm_init_msrs(X86CPU *cpu); +const int kvm_arch_default_type; + const KVMCapabilityInfo kvm_arch_required_capabilities[] = { KVM_CAP_INFO(SET_TSS_ADDR), KVM_CAP_INFO(EXT_CPUID), diff --git a/target/mips/kvm.c b/target/mips/kvm.c index c14e8f550f..754366874e 100644 --- a/target/mips/kvm.c +++ b/target/mips/kvm.c @@ -33,6 +33,8 @@ static int kvm_mips_fpu_cap; static int kvm_mips_msa_cap; +const int kvm_arch_default_type; + const KVMCapabilityInfo kvm_arch_required_capabilities[] = { KVM_CAP_LAST_INFO }; diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index a8a935e267..86f8b645a5 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -54,6 +54,8 @@ #define DEBUG_RETURN_GUEST 0 #define DEBUG_RETURN_GDB 1 +const int kvm_arch_default_type; + const KVMCapabilityInfo kvm_arch_required_capabilities[] = { KVM_CAP_LAST_INFO }; diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c index 9d8a8982f9..fbe56ec3bb 100644 --- a/target/riscv/kvm.c +++ b/target/riscv/kvm.c @@ -764,6 +764,8 @@ void kvm_riscv_init_user_properties(Object *cpu_obj) kvm_riscv_destroy_scratch_vcpu(&kvmcpu); } +const int kvm_arch_default_type; + const KVMCapabilityInfo kvm_arch_required_capabilities[] = { KVM_CAP_LAST_INFO }; diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c index a9e5880349..4b9347ffc8 100644 --- a/target/s390x/kvm/kvm.c +++ b/target/s390x/kvm/kvm.c @@ -144,6 +144,8 @@ static CPUWatchpoint hw_watchpoint; static struct kvm_hw_breakpoint *hw_breakpoints; static int nb_hw_breakpoints; +const int kvm_arch_default_type; + const KVMCapabilityInfo kvm_arch_required_capabilities[] = { KVM_CAP_LAST_INFO }; -- 2.41.0
