[v3,1/2] kvm: Introduce kvm_arch_get_default_type hook

Commit Message

Akihiko Odaki July 22, 2023, 6:22 a.m. UTC

kvm_arch_get_default_type() returns the default KVM type. This hook is
particularly useful to derive a KVM type that is valid for "none"
machine model, which is used by libvirt to probe the availability of
KVM.

For MIPS, the existing mips_kvm_type() is reused. This function ensures
the availability of VZ which is mandatory to use KVM on the current
QEMU.

Signed-off-by: Akihiko Odaki <[e-mail]>
---
 include/sysemu/kvm.h     | 2 ++
 target/mips/kvm_mips.h   | 9 ---------
 accel/kvm/kvm-all.c      | 4 +++-
 hw/mips/loongson3_virt.c | 1 -
 target/arm/kvm.c         | 5 +++++
 target/i386/kvm/kvm.c    | 5 +++++
 target/mips/kvm.c        | 2 +-
 target/ppc/kvm.c         | 5 +++++
 target/riscv/kvm.c       | 5 +++++
 target/s390x/kvm/kvm.c   | 5 +++++
 10 files changed, 31 insertions(+), 12 deletions(-)

Comments

Philippe Mathieu-Daudé July 24, 2023, 10:53 a.m. UTC | #1

On 22/7/23 08:22, Akihiko Odaki wrote:
> kvm_arch_get_default_type() returns the default KVM type. This hook is
> particularly useful to derive a KVM type that is valid for "none"
> machine model, which is used by libvirt to probe the availability of
> KVM.
> 
> For MIPS, the existing mips_kvm_type() is reused. This function ensures
> the availability of VZ which is mandatory to use KVM on the current
> QEMU.

Pre-existing: mips_kvm_type() returns -1. Should we check for
'type' in kvm_init() before calling kvm_ioctl()?

> Signed-off-by: Akihiko Odaki <[e-mail]>
> ---
>   include/sysemu/kvm.h     | 2 ++
>   target/mips/kvm_mips.h   | 9 ---------
>   accel/kvm/kvm-all.c      | 4 +++-
>   hw/mips/loongson3_virt.c | 1 -
>   target/arm/kvm.c         | 5 +++++
>   target/i386/kvm/kvm.c    | 5 +++++
>   target/mips/kvm.c        | 2 +-
>   target/ppc/kvm.c         | 5 +++++
>   target/riscv/kvm.c       | 5 +++++
>   target/s390x/kvm/kvm.c   | 5 +++++
>   10 files changed, 31 insertions(+), 12 deletions(-)

Patch

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 115f0cca79..ccaf55caf7 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -369,6 +369,8 @@  int kvm_arch_get_registers(CPUState *cpu);
 
 int kvm_arch_put_registers(CPUState *cpu, int level);
 
+int kvm_arch_get_default_type(MachineState *ms);
+
 int kvm_arch_init(MachineState *ms, KVMState *s);
 
 int kvm_arch_init_vcpu(CPUState *cpu);
diff --git a/target/mips/kvm_mips.h b/target/mips/kvm_mips.h
index 171d53dbe1..c711269d0a 100644
--- a/target/mips/kvm_mips.h
+++ b/target/mips/kvm_mips.h
@@ -25,13 +25,4 @@  void kvm_mips_reset_vcpu(MIPSCPU *cpu);
 int kvm_mips_set_interrupt(MIPSCPU *cpu, int irq, int level);
 int kvm_mips_set_ipi_interrupt(MIPSCPU *cpu, int irq, int level);
 
-#ifdef CONFIG_KVM
-int mips_kvm_type(MachineState *machine, const char *vm_type);
-#else
-static inline int mips_kvm_type(MachineState *machine, const char *vm_type)
-{
-    return 0;
-}
-#endif
-
 #endif /* KVM_MIPS_H */
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 373d876c05..d591b5079c 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;
     uint64_t dirty_log_manual_caps;
 
     qemu_mutex_init(&kml_slots_lock);
@@ -2523,6 +2523,8 @@  static int kvm_init(MachineState *ms)
         type = mc->kvm_type(ms, kvm_type);
     } else if (mc->kvm_type) {
         type = mc->kvm_type(ms, NULL);
+    } else {
+        type = kvm_arch_get_default_type(ms);
     }
 
     do {
diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
index 4018b8c1d3..bf28f7ec43 100644
--- a/hw/mips/loongson3_virt.c
+++ b/hw/mips/loongson3_virt.c
@@ -612,7 +612,6 @@  static void loongson3v_machine_class_init(ObjectClass *oc, void *data)
     mc->max_cpus = LOONGSON_MAX_VCPUS;
     mc->default_ram_id = "loongson3.highram";
     mc->default_ram_size = 1600 * MiB;
-    mc->kvm_type = mips_kvm_type;
     mc->minimum_page_bits = 14;
     mc->default_nic = "virtio-net-pci";
 }
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index b4c7654f49..40f577bfd5 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -247,6 +247,11 @@  int kvm_arm_get_max_vm_ipa_size(MachineState *ms, bool *fixed_ipa)
     return ret > 0 ? ret : 40;
 }
 
+int kvm_arch_get_default_type(MachineState *ms)
+{
+    return 0;
+}
+
 int kvm_arch_init(MachineState *ms, KVMState *s)
 {
     int ret = 0;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index ebfaf3d24c..b45ce20fd8 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -2556,6 +2556,11 @@  static void register_smram_listener(Notifier *n, void *unused)
                                  &smram_address_space, 1, "kvm-smram");
 }
 
+int kvm_arch_get_default_type(MachineState *ms)
+{
+    return 0;
+}
+
 int kvm_arch_init(MachineState *ms, KVMState *s)
 {
     uint64_t identity_base = 0xfffbc000;
diff --git a/target/mips/kvm.c b/target/mips/kvm.c
index c14e8f550f..e98aad01bd 100644
--- a/target/mips/kvm.c
+++ b/target/mips/kvm.c
@@ -1266,7 +1266,7 @@  int kvm_arch_msi_data_to_gsi(uint32_t data)
     abort();
 }
 
-int mips_kvm_type(MachineState *machine, const char *vm_type)
+int kvm_arch_get_default_type(MachineState *machine)
 {
 #if defined(KVM_CAP_MIPS_VZ)
     int r;
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index a8a935e267..dc1182cd37 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -108,6 +108,11 @@  static int kvm_ppc_register_host_cpu_type(void);
 static void kvmppc_get_cpu_characteristics(KVMState *s);
 static int kvmppc_get_dec_bits(void);
 
+int kvm_arch_get_default_type(MachineState *ms)
+{
+    return 0;
+}
+
 int kvm_arch_init(MachineState *ms, KVMState *s)
 {
     cap_interrupt_unset = kvm_check_extension(s, KVM_CAP_PPC_UNSET_IRQ);
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 9d8a8982f9..4266dce092 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -907,6 +907,11 @@  int kvm_arch_add_msi_route_post(struct kvm_irq_routing_entry *route,
     return 0;
 }
 
+int kvm_arch_get_default_type(MachineState *ms)
+{
+    return 0;
+}
+
 int kvm_arch_init(MachineState *ms, KVMState *s)
 {
     return 0;
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index a9e5880349..9117fab6e8 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -340,6 +340,11 @@  static void ccw_machine_class_foreach(ObjectClass *oc, void *opaque)
     mc->default_cpu_type = S390_CPU_TYPE_NAME("host");
 }
 
+int kvm_arch_get_default_type(MachineState *ms)
+{
+    return 0;
+}
+
 int kvm_arch_init(MachineState *ms, KVMState *s)
 {
     object_class_foreach(ccw_machine_class_foreach, TYPE_S390_CCW_MACHINE,