From 4e400056b6e3d895814d091da819ba742602581b Mon Sep 17 00:00:00 2001
From: Brijesh Singh <brijesh.singh@amd.com>
Date: Tue, 27 Jul 2021 12:10:23 +0000
Subject: [PATCH 04/29] target/i386: sev: provide callback to setup outgoing
 context

cherry-picked from https://github.com/AMDESE/qemu/commit/7521883afc0.

The user provides the target machine's Platform Diffie-Hellman key (PDH)
and certificate chain before starting the SEV guest migration. Cache the
certificate chain as we need them while creating the outgoing context.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Co-developed-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
---
 target/i386/sev.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 target/i386/sev.h |  2 ++
 2 files changed, 61 insertions(+)

diff --git a/target/i386/sev.c b/target/i386/sev.c
index 36669bbdf..5dd6c0a3f 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -76,6 +76,12 @@ struct SevGuestState {
     int sev_fd;
     SevState state;
     gchar *measurement;
+    guchar *remote_pdh;
+    size_t remote_pdh_len;
+    guchar *remote_plat_cert;
+    size_t remote_plat_cert_len;
+    guchar *amd_cert;
+    size_t amd_cert_len;
 
     uint32_t reset_cs;
     uint32_t reset_ip;
@@ -160,6 +166,12 @@ static const char *const sev_fw_errlist[] = {
 
 #define SEV_FW_MAX_ERROR      ARRAY_SIZE(sev_fw_errlist)
 
+#define SEV_FW_BLOB_MAX_SIZE            0x4000          /* 16KB */
+
+static struct ConfidentialGuestMemoryEncryptionOps sev_memory_encryption_ops = {
+    .save_setup = sev_save_setup,
+};
+
 static int
 sev_ioctl(int fd, int cmd, void *data, int *error)
 {
@@ -872,6 +884,48 @@ sev_vm_state_change(void *opaque, bool running, RunState state)
     }
 }
 
+static inline bool check_blob_length(size_t value)
+{
+    if (value > SEV_FW_BLOB_MAX_SIZE) {
+        error_report("invalid length max=%d got=%ld",
+                     SEV_FW_BLOB_MAX_SIZE, value);
+        return false;
+    }
+
+    return true;
+}
+
+int sev_save_setup(const char *pdh, const char *plat_cert,
+                   const char *amd_cert)
+{
+    SevGuestState *s = sev_guest;
+
+    s->remote_pdh = g_base64_decode(pdh, &s->remote_pdh_len);
+    if (!check_blob_length(s->remote_pdh_len)) {
+        goto error;
+    }
+
+    s->remote_plat_cert = g_base64_decode(plat_cert,
+                                          &s->remote_plat_cert_len);
+    if (!check_blob_length(s->remote_plat_cert_len)) {
+        goto error;
+    }
+
+    s->amd_cert = g_base64_decode(amd_cert, &s->amd_cert_len);
+    if (!check_blob_length(s->amd_cert_len)) {
+        goto error;
+    }
+
+    return 0;
+
+error:
+    g_free(s->remote_pdh);
+    g_free(s->remote_plat_cert);
+    g_free(s->amd_cert);
+
+    return 1;
+}
+
 int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
 {
     SevGuestState *sev
@@ -886,6 +940,9 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
         return 0;
     }
 
+    ConfidentialGuestSupportClass *cgs_class =
+        (ConfidentialGuestSupportClass *) object_get_class(OBJECT(cgs));
+
     ret = ram_block_discard_disable(true);
     if (ret) {
         error_report("%s: cannot disable RAM discard", __func__);
@@ -980,6 +1037,8 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     qemu_add_machine_init_done_notifier(&sev_machine_done_notify);
     qemu_add_vm_change_state_handler(sev_vm_state_change, sev);
 
+    cgs_class->memory_encryption_ops = &sev_memory_encryption_ops;
+
     cgs->ready = true;
 
     return 0;
diff --git a/target/i386/sev.h b/target/i386/sev.h
index 1c97bff99..14801ec44 100644
--- a/target/i386/sev.h
+++ b/target/i386/sev.h
@@ -51,6 +51,8 @@ extern uint32_t sev_get_reduced_phys_bits(void);
 extern bool sev_add_kernel_loader_hashes(SevKernelLoaderContext *ctx, Error **errp);
 
 int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp);
+int sev_save_setup(const char *pdh, const char *plat_cert,
+                   const char *amd_cert);
 int sev_inject_launch_secret(const char *hdr, const char *secret,
                              uint64_t gpa, Error **errp);
 
-- 
2.31.1