[PATCH v1 03/40] target/i386: Implement mc->kvm_type() to get VM type

Xiaoyao Li
2022-08-02T07:48:12Z

TDX VM requires VM type KVM_X86_TDX_VM to be passed to
kvm_ioctl(KVM_CREATE_VM). Hence implement mc->kvm_type() for i386
architecture.

If tdx-guest object is specified to confidential-guest-support, like,

qemu -machine ...,confidential-guest-support=tdx0 \
-object tdx-guest,id=tdx0,...

it parses VM type as KVM_X86_TDX_VM. Otherwise, it's KVM_X86_DEFAULT_VM.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
hw/i386/x86.c | 6 ++++++
target/i386/kvm/kvm.c | 30 ++++++++++++++++++++++++++++++
target/i386/kvm/kvm_i386.h | 1 +
3 files changed, 37 insertions(+)

diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 050eedc0c8e2..a15fadeb0e68 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -1379,6 +1379,11 @@ static void machine_set_sgx_epc(Object *obj, Visitor *v, const char *name,
qapi_free_SgxEPCList(list);
}

+static int x86_kvm_type(MachineState *ms, const char *vm_type)
+{
+ return kvm_get_vm_type(ms, vm_type);
+}
+
static void x86_machine_initfn(Object *obj)
{
X86MachineState *x86ms = X86_MACHINE(obj);
@@ -1403,6 +1408,7 @@ static void x86_machine_class_init(ObjectClass *oc, void *data)
mc->cpu_index_to_instance_props = x86_cpu_index_to_props;
mc->get_default_cpu_node_id = x86_get_default_cpu_node_id;
mc->possible_cpu_arch_ids = x86_possible_cpu_arch_ids;
+ mc->kvm_type = x86_kvm_type;
x86mc->save_tsc_khz = true;
x86mc->fwcfg_dma_enabled = true;
nc->nmi_monitor_handler = x86_nmi;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f148a6d52fa4..33e0d2948f77 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -30,6 +30,7 @@
#include "sysemu/runstate.h"
#include "kvm_i386.h"
#include "sev.h"
+#include "tdx.h"
#include "hyperv.h"
#include "hyperv-proto.h"

@@ -143,6 +144,35 @@ static struct kvm_msr_list *kvm_feature_msrs;
static RateLimit bus_lock_ratelimit_ctrl;
static int kvm_get_one_msr(X86CPU *cpu, int index, uint64_t *value);

+static const char* vm_type_name[] = {
+ [KVM_X86_DEFAULT_VM] = "X86_DEFAULT_VM",
+ [KVM_X86_TDX_VM] = "X86_TDX_VM",
+};
+
+int kvm_get_vm_type(MachineState *ms, const char *vm_type)
+{
+ int kvm_type = KVM_X86_DEFAULT_VM;
+
+ if (ms->cgs && object_dynamic_cast(OBJECT(ms->cgs), TYPE_TDX_GUEST)) {
+ kvm_type = KVM_X86_TDX_VM;
+ }
+
+ /*
+ * old KVM doesn't support KVM_CAP_VM_TYPES and KVM_X86_DEFAULT_VM
+ * is always supported
+ */
+ if (kvm_type == KVM_X86_DEFAULT_VM) {
+ return kvm_type;
+ }
+
+ if (!(kvm_check_extension(KVM_STATE(ms->accelerator), KVM_CAP_VM_TYPES) & BIT(kvm_type))) {
+ error_report("vm-type %s not supported by KVM", vm_type_name[kvm_type]);
+ exit(1);
+ }
+
+ return kvm_type;
+}
+
int kvm_has_pit_state2(void)
{
return has_pit_state2;
diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
index 4124912c202e..b434feaa6b1d 100644
--- a/target/i386/kvm/kvm_i386.h
+++ b/target/i386/kvm/kvm_i386.h
@@ -37,6 +37,7 @@ bool kvm_has_adjust_clock(void);
bool kvm_has_adjust_clock_stable(void);
bool kvm_has_exception_payload(void);
void kvm_synchronize_all_tsc(void);
+int kvm_get_vm_type(MachineState *ms, const char *vm_type);
void kvm_arch_reset_vcpu(X86CPU *cs);
void kvm_arch_do_init_vcpu(X86CPU *cs);

--
2.27.0