From: Xiaoyao Li <xiaoyao...@intel.com>
KVM is introducing a new API to create confidential guests, which
will be used by TDX and SEV-SNP but is also available for SEV and
SEV-ES. The API uses the VM type argument to KVM_CREATE_VM to
identify which confidential computing technology to use.
Since there are no other expected uses of VM types, delegate
mc->kvm_type() for x86 boards to the confidential-guest-support
object pointed to by ms->cgs.
For example, if a sev-guest object is specified to confidential-guest-support,
like,
qemu -machine ...,confidential-guest-support=sev0 \
-object sev-guest,id=sev0,...
it will check if a VM type KVM_X86_SEV_VM or KVM_X86_SEV_ES_VM
is supported, and if so use them together with the KVM_SEV_INIT2
function of the KVM_MEMORY_ENCRYPT_OP ioctl. If not, it will fall back to
KVM_SEV_INIT and KVM_SEV_ES_INIT.
This is a preparatory work towards TDX and SEV-SNP support, but it
will also enable support for VMSA features such as DebugSwap, which
are only available via KVM_SEV_INIT2.
Co-developed-by: Xiaoyao Li <xiaoyao...@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
target/i386/confidential-guest.h | 19 ++++++++++++++
target/i386/kvm/kvm_i386.h | 2 ++
hw/i386/x86.c | 6 +++++
target/i386/kvm/kvm.c | 44 ++++++++++++++++++++++++++++++++
4 files changed, 71 insertions(+)
diff --git a/target/i386/confidential-guest.h b/target/i386/confidential-guest.h
index ca12d5a8fba..532e172a60b 100644
--- a/target/i386/confidential-guest.h
+++ b/target/i386/confidential-guest.h
@@ -36,5 +36,24 @@ struct X86ConfidentialGuest {
struct X86ConfidentialGuestClass {
/* <private> */
ConfidentialGuestSupportClass parent;
+
+ /* <public> */
+ int (*kvm_type)(X86ConfidentialGuest *cg);
};
+
+/**
+ * x86_confidential_guest_kvm_type:
+ *
+ * Calls #X86ConfidentialGuestClass.unplug callback of @plug_handler.
+ */
+static inline int x86_confidential_guest_kvm_type(X86ConfidentialGuest *cg)
+{
+ X86ConfidentialGuestClass *klass = X86_CONFIDENTIAL_GUEST_GET_CLASS(cg);
+
+ if (klass->kvm_type) {
+ return klass->kvm_type(cg);
+ } else {
+ return 0;
+ }
+}
#endif
diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
index 30fedcffea3..02168122787 100644
--- a/target/i386/kvm/kvm_i386.h
+++ b/target/i386/kvm/kvm_i386.h
@@ -37,6 +37,7 @@ bool kvm_hv_vpindex_settable(void);
bool kvm_enable_sgx_provisioning(KVMState *s);
bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp);
+int kvm_get_vm_type(MachineState *ms, const char *vm_type);
void kvm_arch_reset_vcpu(X86CPU *cs);
void kvm_arch_after_reset_vcpu(X86CPU *cpu);
void kvm_arch_do_init_vcpu(X86CPU *cs);
@@ -49,6 +50,7 @@ void kvm_request_xsave_components(X86CPU *cpu, uint64_t mask);
#ifdef CONFIG_KVM
+bool kvm_is_vm_type_supported(int type);
bool kvm_has_adjust_clock_stable(void);
bool kvm_has_exception_payload(void);
void kvm_synchronize_all_tsc(void);
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index ffbda48917f..2d4b148cd25 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -1389,6 +1389,11 @@ 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_enabled() ? kvm_get_vm_type(ms, vm_type) : 0;
+}
+
static void x86_machine_initfn(Object *obj)
{
X86MachineState *x86ms = X86_MACHINE(obj);
@@ -1413,6 +1418,7 @@ 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 0ec69109a2b..e109648f260 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -31,6 +31,7 @@
#include "sysemu/kvm_int.h"
#include "sysemu/runstate.h"
#include "kvm_i386.h"
+#include "../confidential-guest.h"
#include "sev.h"
#include "xen-emu.h"
#include "hyperv.h"
@@ -161,6 +162,49 @@ static KVMMSRHandlers
msr_handlers[KVM_MSR_FILTER_MAX_RANGES];
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] = "default",
+};
+
+bool kvm_is_vm_type_supported(int type)
+{
+ uint32_t machine_types;
+
+ /*
+ * old KVM doesn't support KVM_CAP_VM_TYPES but KVM_X86_DEFAULT_VM
+ * is always supported
+ */
+ if (type == KVM_X86_DEFAULT_VM) {
+ return true;
+ }
+
+ machine_types =
kvm_check_extension(KVM_STATE(current_machine->accelerator),
+ KVM_CAP_VM_TYPES);
+ return !!(machine_types & BIT(type));
+}
+
+int kvm_get_vm_type(MachineState *ms, const char *vm_type)
+{
+ int kvm_type = KVM_X86_DEFAULT_VM;
+
+ if (ms->cgs) {
+ if (!object_dynamic_cast(OBJECT(ms->cgs),
TYPE_X86_CONFIDENTIAL_GUEST)) {
+ error_report("configuration type %s not supported for x86 guests",
+ object_get_typename(OBJECT(ms->cgs)));
+ exit(1);
+ }
+ kvm_type = x86_confidential_guest_kvm_type(
+ X86_CONFIDENTIAL_GUEST(ms->cgs));
+ }
+
+ if (!kvm_is_vm_type_supported(kvm_type)) {
+ error_report("vm-type %s not supported by KVM",
vm_type_name[kvm_type]);
+ exit(1);
+ }
+
+ return kvm_type;
+}
+
bool kvm_has_smm(void)
{
return kvm_vm_check_extension(kvm_state, KVM_CAP_X86_SMM);
--
2.44.0
