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From: Joerg Roedel <joro@8bytes.org>
To: x86@kernel.org
Subject: [PATCH v3 8/8] x86/sev-es: Replace open-coded hlt-loops with
 sev_es_terminate()
Date: Fri, 12 Mar 2021 13:38:24 +0100
Message-Id: <20210312123824.306-9-joro@8bytes.org>
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Cc: kvm@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
 Dave Hansen <dave.hansen@linux.intel.com>,
 virtualization@lists.linux-foundation.org,
 Arvind Sankar <nivedita@alum.mit.edu>, hpa@zytor.com,
 Jiri Slaby <jslaby@suse.cz>, Joerg Roedel <joro@8bytes.org>,
 David Rientjes <rientjes@google.com>, Martin Radev <martin.b.radev@gmail.com>,
 Tom Lendacky <thomas.lendacky@amd.com>, Joerg Roedel <jroedel@suse.de>,
 Kees Cook <keescook@chromium.org>, Cfir Cohen <cfir@google.com>,
 Andy Lutomirski <luto@kernel.org>, Dan Williams <dan.j.williams@intel.com>,
 Juergen Gross <jgross@suse.com>, Mike Stunes <mstunes@vmware.com>,
 Sean Christopherson <seanjc@google.com>, linux-kernel@vger.kernel.org,
 Masami Hiramatsu <mhiramat@kernel.org>, Erdem Aktas <erdemaktas@google.com>
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From: Joerg Roedel <jroedel@suse.de>

There are a few places left in the SEV-ES C code where hlt loops and/or
terminate requests are implemented. Replace them all with calls to
sev_es_terminate().

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/boot/compressed/sev-es.c | 12 +++---------
 arch/x86/kernel/sev-es-shared.c   | 10 +++-------
 2 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/x86/boot/compressed/sev-es.c b/arch/x86/boot/compressed/sev-es.c
index 27826c265aab..d904bd56b3e3 100644
--- a/arch/x86/boot/compressed/sev-es.c
+++ b/arch/x86/boot/compressed/sev-es.c
@@ -200,14 +200,8 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
 	}
 
 finish:
-	if (result == ES_OK) {
+	if (result == ES_OK)
 		vc_finish_insn(&ctxt);
-	} else if (result != ES_RETRY) {
-		/*
-		 * For now, just halt the machine. That makes debugging easier,
-		 * later we just call sev_es_terminate() here.
-		 */
-		while (true)
-			asm volatile("hlt\n");
-	}
+	else if (result != ES_RETRY)
+		sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
 }
diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c
index 387b71669818..0aa9f13efd57 100644
--- a/arch/x86/kernel/sev-es-shared.c
+++ b/arch/x86/kernel/sev-es-shared.c
@@ -24,7 +24,7 @@ static bool __init sev_es_check_cpu_features(void)
 	return true;
 }
 
-static void sev_es_terminate(unsigned int reason)
+static void __noreturn sev_es_terminate(unsigned int reason)
 {
 	u64 val = GHCB_SEV_TERMINATE;
 
@@ -206,12 +206,8 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
 	return;
 
 fail:
-	sev_es_wr_ghcb_msr(GHCB_SEV_TERMINATE);
-	VMGEXIT();
-
-	/* Shouldn't get here - if we do halt the machine */
-	while (true)
-		asm volatile("hlt\n");
+	/* Terminate the guest */
+	sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
 }
 
 static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
-- 
2.30.1

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