[PATCH Part1 RFC v3 02/22] x86/sev: Define the Linux specific guest termination reasons

[Brijesh Singh]

GHCB specification defines the reason code for reason set 0. The reason
codes defined in the set 0 do not cover all possible causes for a guest
to request termination.

The reason set 1 to 255 is reserved for the vendor-specific codes.
Reseve the reason set 1 for the Linux guest. Define an error codes for
reason set 1.

While at it, change the sev_es_terminate() to accept the reason set
parameter.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
 arch/x86/boot/compressed/sev.c    | 6 +++---
 arch/x86/include/asm/sev-common.h | 5 +++++
 arch/x86/kernel/sev-shared.c      | 6 +++---
 arch/x86/kernel/sev.c             | 4 ++--
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 28bcf04c022e..87621f4e4703 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -122,7 +122,7 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
 static bool early_setup_sev_es(void)
 {
 	if (!sev_es_negotiate_protocol())
-		sev_es_terminate(GHCB_SEV_ES_PROT_UNSUPPORTED);
+		sev_es_terminate(0, GHCB_SEV_ES_PROT_UNSUPPORTED);
 
 	if (set_page_decrypted((unsigned long)&boot_ghcb_page))
 		return false;
@@ -175,7 +175,7 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
 	enum es_result result;
 
 	if (!boot_ghcb && !early_setup_sev_es())
-		sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
+		sev_es_terminate(0, GHCB_SEV_ES_GEN_REQ);
 
 	vc_ghcb_invalidate(boot_ghcb);
 	result = vc_init_em_ctxt(&ctxt, regs, exit_code);
@@ -202,5 +202,5 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
 	if (result == ES_OK)
 		vc_finish_insn(&ctxt);
 	else if (result != ES_RETRY)
-		sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
+		sev_es_terminate(0, GHCB_SEV_ES_GEN_REQ);
 }
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 11b7d9cea775..f1e2aacb0d61 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -59,4 +59,9 @@
 
 #define GHCB_RESP_CODE(v)		((v) & GHCB_MSR_INFO_MASK)
 
+/* Linux specific reason codes (used with reason set 1) */
+#define GHCB_TERM_REGISTER		0	/* GHCB GPA registration failure */
+#define GHCB_TERM_PSC			1	/* Page State Change failure */
+#define GHCB_TERM_PVALIDATE		2	/* Pvalidate failure */
+
 #endif
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 14198075ff8b..de0e7e6c52b8 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -24,7 +24,7 @@ static bool __init sev_es_check_cpu_features(void)
 	return true;
 }
 
-static void __noreturn sev_es_terminate(unsigned int reason)
+static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason)
 {
 	u64 val = GHCB_MSR_TERM_REQ;
 
@@ -32,7 +32,7 @@ static void __noreturn sev_es_terminate(unsigned int reason)
 	 * Tell the hypervisor what went wrong - only reason-set 0 is
 	 * currently supported.
 	 */
-	val |= GHCB_SEV_TERM_REASON(0, reason);
+	val |= GHCB_SEV_TERM_REASON(set, reason);
 
 	/* Request Guest Termination from Hypvervisor */
 	sev_es_wr_ghcb_msr(val);
@@ -207,7 +207,7 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
 
 fail:
 	/* Terminate the guest */
-	sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
+	sev_es_terminate(0, GHCB_SEV_ES_GEN_REQ);
 }
 
 static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 460717e3f72d..77a754365ba9 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -1383,7 +1383,7 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)
 		show_regs(regs);
 
 		/* Ask hypervisor to sev_es_terminate */
-		sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
+		sev_es_terminate(0, GHCB_SEV_ES_GEN_REQ);
 
 		/* If that fails and we get here - just panic */
 		panic("Returned from Terminate-Request to Hypervisor\n");
@@ -1416,7 +1416,7 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
 
 	/* Do initial setup or terminate the guest */
 	if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb()))
-		sev_es_terminate(GHCB_SEV_ES_GEN_REQ);
+		sev_es_terminate(0, GHCB_SEV_ES_GEN_REQ);
 
 	vc_ghcb_invalidate(boot_ghcb);
 
-- 
2.17.1