[RFC PATCH 3/6] i386/sev: initialize SNP context

[Brijesh Singh <brijesh.singh@xxxxxxx>]

When SEV-SNP is enabled, the KVM_SNP_INIT command is used to initialize
the platform. The command checks whether SNP is enabled in the KVM, if
enabled then it allocate a new ASID from the SNP pool and calls the
firmware to initialize the all the resources.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
 target/i386/sev.c      | 24 +++++++++++++++++++++---
 target/i386/sev_i386.h |  1 +
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/target/i386/sev.c b/target/i386/sev.c
index 6b238ef969..84ae244af0 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -583,10 +583,17 @@ sev_enabled(void)
     return !!sev_guest;
 }
 
+bool
+sev_snp_enabled(void)
+{
+    return sev_guest->snp;
+}
+
 bool
 sev_es_enabled(void)
 {
-    return sev_enabled() && (sev_guest->policy & SEV_POLICY_ES);
+    return sev_snp_enabled() ||
+           (sev_enabled() && (sev_guest->policy & SEV_POLICY_ES));
 }
 
 uint64_t
@@ -1008,6 +1015,7 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     uint32_t ebx;
     uint32_t host_cbitpos;
     struct sev_user_data_status status = {};
+    void *init_args = NULL;
 
     if (!sev) {
         return 0;
@@ -1061,7 +1069,17 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     sev->api_major = status.api_major;
     sev->api_minor = status.api_minor;
 
-    if (sev_es_enabled()) {
+    if (sev_snp_enabled()) {
+        if (!kvm_kernel_irqchip_allowed()) {
+            error_report("%s: SEV-SNP guests require in-kernel irqchip support",
+                         __func__);
+            goto err;
+        }
+
+        cmd = KVM_SEV_SNP_INIT;
+        init_args = (void *)&sev->snp_config.init;
+
+    } else if (sev_es_enabled()) {
         if (!kvm_kernel_irqchip_allowed()) {
             error_report("%s: SEV-ES guests require in-kernel irqchip support",
                          __func__);
@@ -1080,7 +1098,7 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     }
 
     trace_kvm_sev_init();
-    ret = sev_ioctl(sev->sev_fd, cmd, NULL, &fw_error);
+    ret = sev_ioctl(sev->sev_fd, cmd, init_args, &fw_error);
     if (ret) {
         error_setg(errp, "%s: failed to initialize ret=%d fw_error=%d '%s'",
                    __func__, ret, fw_error, fw_error_to_str(fw_error));
diff --git a/target/i386/sev_i386.h b/target/i386/sev_i386.h
index ae6d840478..e0e1a599be 100644
--- a/target/i386/sev_i386.h
+++ b/target/i386/sev_i386.h
@@ -29,6 +29,7 @@
 #define SEV_POLICY_SEV          0x20
 
 extern bool sev_es_enabled(void);
+extern bool sev_snp_enabled(void);
 extern uint64_t sev_get_me_mask(void);
 extern SevInfo *sev_get_info(void);
 extern uint32_t sev_get_cbit_position(void);
-- 
2.17.1