Re: [PATCH Part1 RFC v4 02/36] x86/sev: Save the negotiated GHCB version

From: Brijesh Singh
Date: Tue Aug 10 2021 - 09:15:58 EST




On 8/10/21 4:17 AM, Borislav Petkov wrote:
On Wed, Jul 07, 2021 at 01:14:32PM -0500, Brijesh Singh wrote:
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 114f62fe2529..19c2306ac02d 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -14,6 +14,15 @@
#define has_cpuflag(f) boot_cpu_has(f)
#endif
+/*
+ * Since feature negotiation related variables are set early in the boot
+ * process they must reside in the .data section so as not to be zeroed
+ * out when the .bss section is later cleared.
+ *
+ * GHCB protocol version negotiated with the hypervisor.
+ */
+static u16 ghcb_version __section(".data..ro_after_init");

There's a define for that section specifier: __ro_after_init


Noted.

thanks