From 0ebf32463e858c5f9cbd98e3f2fe494d0fbea259 Mon Sep 17 00:00:00 2001
From: jiangxin <jiangxin@hygon.cn>
Date: Fri, 17 Jun 2022 09:52:31 +0800
Subject: [PATCH] target/i386: csv: Add support to migrate the outgoing context
 for CSV3 guest

CSV3 needs to migrate guest cpu's context pages. Prior to migration
of the context, it should query transfer buffer length and header
data length by SEND ENCRYPT CONTEXT command. New migration flag
RAM_SAVE_ENCRYPTED_CSV3_CONTEXT is defined for CSV3.

Signed-off-by: Jiang Xin <jiangxin@hygon.cn>
Signed-off-by: hanliyang <hanliyang@hygon.cn>
---
 target/i386/csv.c        | 81 ++++++++++++++++++++++++++++++++++++++++
 target/i386/csv.h        |  1 +
 target/i386/trace-events |  1 +
 3 files changed, 83 insertions(+)

diff --git a/target/i386/csv.c b/target/i386/csv.c
index ac080b3766..cc90b57e5b 100644
--- a/target/i386/csv.c
+++ b/target/i386/csv.c
@@ -46,6 +46,7 @@ struct ConfidentialGuestMemoryEncryptionOps csv3_memory_encryption_ops = {
     .save_queued_outgoing_pages = csv3_save_queued_outgoing_pages,
     .queue_incoming_page = NULL,
     .load_queued_incoming_pages = NULL,
+    .save_outgoing_cpu_state = csv3_save_outgoing_context,
 };
 
 #define CSV3_OUTGOING_PAGE_NUM \
@@ -570,3 +571,83 @@ int csv3_load_incoming_page(QEMUFile *f, uint8_t *ptr)
 
     return csv3_receive_encrypt_data(f, ptr);
 }
+
+static int
+csv3_send_get_context_len(int *fw_err, int *context_len, int *hdr_len)
+{
+    int ret = 0;
+    struct kvm_csv3_send_encrypt_context update = { 0 };
+
+    ret = csv3_ioctl(KVM_CSV3_SEND_ENCRYPT_CONTEXT, &update, fw_err);
+    if (*fw_err != SEV_RET_INVALID_LEN) {
+        error_report("%s: failed to get context length ret=%d fw_error=%d '%s'",
+                    __func__, ret, *fw_err, fw_error_to_str(*fw_err));
+        ret = -1;
+        goto err;
+    }
+
+    if (update.trans_len <= INT_MAX && update.hdr_len <= INT_MAX) {
+        *context_len = update.trans_len;
+        *hdr_len = update.hdr_len;
+    }
+    ret = 0;
+err:
+    return ret;
+}
+
+static int
+csv3_send_encrypt_context(Csv3GuestState *s, QEMUFile *f, uint64_t *bytes_sent)
+{
+    int ret, fw_error = 0;
+    int context_len = 0;
+    int hdr_len = 0;
+    guchar *trans;
+    guchar *hdr;
+    struct kvm_csv3_send_encrypt_context update = { };
+
+    ret = csv3_send_get_context_len(&fw_error, &context_len, &hdr_len);
+    if (context_len < 1 || hdr_len < 1) {
+        error_report("%s: fail to get context length fw_error=%d '%s'",
+                     __func__, fw_error, fw_error_to_str(fw_error));
+        return 1;
+    }
+
+    /* allocate transport buffer */
+    trans = g_new(guchar, context_len);
+    hdr = g_new(guchar, hdr_len);
+
+    update.hdr_uaddr = (uintptr_t)hdr;
+    update.hdr_len = hdr_len;
+    update.trans_uaddr = (uintptr_t)trans;
+    update.trans_len = context_len;
+
+    trace_kvm_csv3_send_encrypt_context(trans, update.trans_len);
+
+    ret = csv3_ioctl(KVM_CSV3_SEND_ENCRYPT_CONTEXT, &update, &fw_error);
+    if (ret) {
+        error_report("%s: SEND_ENCRYPT_CONTEXT ret=%d fw_error=%d '%s'",
+                     __func__, ret, fw_error, fw_error_to_str(fw_error));
+        goto err;
+    }
+
+    qemu_put_be32(f, update.hdr_len);
+    qemu_put_buffer(f, (uint8_t *)update.hdr_uaddr, update.hdr_len);
+    *bytes_sent += 4 + update.hdr_len;
+
+    qemu_put_be32(f, update.trans_len);
+    qemu_put_buffer(f, (uint8_t *)update.trans_uaddr, update.trans_len);
+    *bytes_sent += 4 + update.trans_len;
+
+err:
+    g_free(trans);
+    g_free(hdr);
+    return ret;
+}
+
+int csv3_save_outgoing_context(QEMUFile *f, uint64_t *bytes_sent)
+{
+    Csv3GuestState *s = &csv3_guest;
+
+    /* send csv3 context. */
+    return csv3_send_encrypt_context(s, f, bytes_sent);
+}
diff --git a/target/i386/csv.h b/target/i386/csv.h
index afcd59180c..9f83a271fd 100644
--- a/target/i386/csv.h
+++ b/target/i386/csv.h
@@ -125,5 +125,6 @@ void csv3_shared_region_dma_unmap(uint64_t start, uint64_t end);
 int csv3_load_incoming_page(QEMUFile *f, uint8_t *ptr);
 int csv3_queue_outgoing_page(uint8_t *ptr, uint32_t sz, uint64_t addr);
 int csv3_save_queued_outgoing_pages(QEMUFile *f, uint64_t *bytes_sent);
+int csv3_save_outgoing_context(QEMUFile *f, uint64_t *bytes_sent);
 
 #endif
diff --git a/target/i386/trace-events b/target/i386/trace-events
index b3cb9aaf71..043412c569 100644
--- a/target/i386/trace-events
+++ b/target/i386/trace-events
@@ -23,4 +23,5 @@ kvm_sev_receive_update_vmsa(uint32_t cpu_id, uint32_t cpu_index, void *src, int
 # csv.c
 kvm_csv3_launch_encrypt_data(uint64_t gpa, void *addr, uint64_t len) "gpa 0x%" PRIx64 "addr %p len 0x%" PRIx64
 kvm_csv3_send_encrypt_data(void *dst, int len) "trans %p len %d"
+kvm_csv3_send_encrypt_context(void *dst, int len) "trans %p len %d"
 kvm_csv3_receive_encrypt_data(void *dst, int len, void *hdr, int hdr_len) "trans %p len %d hdr %p hdr_len %d"
-- 
2.41.0.windows.1