[PATCH v4 13/31] i386/sev: Add a class method to determine KVM VM type for SNP guests

[Pankaj Gupta <pankaj.gupta@xxxxxxx>]

SEV guests can use either KVM_X86_DEFAULT_VM, KVM_X86_SEV_VM,
or KVM_X86_SEV_ES_VM depending on the configuration and what
the host kernel supports. SNP guests on the other hand can only
ever use KVM_X86_SNP_VM, so split determination of VM type out
into a separate class method that can be set accordingly for
sev-guest vs. sev-snp-guest objects and add handling for SNP.

Signed-off-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
---
 target/i386/sev.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/target/i386/sev.c b/target/i386/sev.c
index 458ff5040d..8ca486f5d2 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -100,6 +100,9 @@ struct SevGuestState {
 
 struct SevGuestStateClass {
     SevCommonStateClass parent_class;
+
+    /* public */
+    int (*kvm_type)(X86ConfidentialGuest *cg);
 };
 
 struct SevSnpGuestState {
@@ -117,6 +120,9 @@ struct SevSnpGuestState {
 
 struct SevSnpGuestStateClass {
     SevCommonStateClass parent_class;
+
+    /* public */
+    int (*kvm_type)(X86ConfidentialGuest *cg);
 };
 
 #define DEFAULT_GUEST_POLICY    0x1 /* disable debug */
@@ -893,6 +899,11 @@ out:
     return sev_common->kvm_type;
 }
 
+static int sev_snp_kvm_type(X86ConfidentialGuest *cg)
+{
+    return KVM_X86_SNP_VM;
+}
+
 static int sev_common_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
 {
     char *devname;
@@ -902,6 +913,8 @@ static int sev_common_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     struct sev_user_data_status status = {};
     SevCommonState *sev_common = SEV_COMMON(cgs);
     SevCommonStateClass *klass = SEV_COMMON_GET_CLASS(cgs);
+    X86ConfidentialGuestClass *x86_klass =
+                               X86_CONFIDENTIAL_GUEST_GET_CLASS(cgs);
 
     sev_common->state = SEV_STATE_UNINIT;
 
@@ -972,7 +985,7 @@ static int sev_common_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     }
 
     trace_kvm_sev_init();
-    if (sev_kvm_type(X86_CONFIDENTIAL_GUEST(sev_common)) == KVM_X86_DEFAULT_VM) {
+    if (x86_klass->kvm_type(X86_CONFIDENTIAL_GUEST(sev_common)) == KVM_X86_DEFAULT_VM) {
         cmd = sev_es_enabled() ? KVM_SEV_ES_INIT : KVM_SEV_INIT;
 
         ret = sev_ioctl(sev_common->sev_fd, cmd, NULL, &fw_error);
@@ -1451,10 +1464,8 @@ static void
 sev_common_class_init(ObjectClass *oc, void *data)
 {
     ConfidentialGuestSupportClass *klass = CONFIDENTIAL_GUEST_SUPPORT_CLASS(oc);
-    X86ConfidentialGuestClass *x86_klass = X86_CONFIDENTIAL_GUEST_CLASS(oc);
 
     klass->kvm_init = sev_common_kvm_init;
-    x86_klass->kvm_type = sev_kvm_type;
 
     object_class_property_add_str(oc, "sev-device",
                                   sev_common_get_sev_device,
@@ -1539,10 +1550,12 @@ static void
 sev_guest_class_init(ObjectClass *oc, void *data)
 {
     SevCommonStateClass *klass = SEV_COMMON_CLASS(oc);
+    X86ConfidentialGuestClass *x86_klass = X86_CONFIDENTIAL_GUEST_CLASS(oc);
 
     klass->launch_start = sev_launch_start;
     klass->launch_finish = sev_launch_finish;
     klass->kvm_init = sev_kvm_init;
+    x86_klass->kvm_type = sev_kvm_type;
 
     object_class_property_add_str(oc, "dh-cert-file",
                                   sev_guest_get_dh_cert_file,
@@ -1781,8 +1794,10 @@ static void
 sev_snp_guest_class_init(ObjectClass *oc, void *data)
 {
     SevCommonStateClass *klass = SEV_COMMON_CLASS(oc);
+    X86ConfidentialGuestClass *x86_klass = X86_CONFIDENTIAL_GUEST_CLASS(oc);
 
     klass->kvm_init = sev_snp_kvm_init;
+    x86_klass->kvm_type = sev_snp_kvm_type;
 
     object_class_property_add(oc, "policy", "uint64",
                               sev_snp_guest_get_policy,
-- 
2.34.1