1 files changed, 44 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/sev.h b/arch/x86/boot/compressed/sev.h
new file mode 100644
index 000000000000..92f79c21939c
--- /dev/null
+++ b/arch/x86/boot/compressed/sev.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AMD SEV header for early boot related functions.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#ifndef BOOT_COMPRESSED_SEV_H
+#define BOOT_COMPRESSED_SEV_H
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+
+#include "../msr.h"
+
+void snp_accept_memory(phys_addr_t start, phys_addr_t end);
+u64 sev_get_status(void);
+bool early_is_sevsnp_guest(void);
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+	struct msr m;
+
+	boot_rdmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+
+	return m.q;
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+	struct msr m;
+
+	m.q = val;
+	boot_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+}
+
+#else
+
+static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
+static inline u64 sev_get_status(void) { return 0; }
+static inline bool early_is_sevsnp_guest(void) { return false; }
+
+#endif
+
+#endif