[PATCH v2 7/7] x86/sev-es: Replace open-coded hlt-loops with sev_es_terminate()

From: Joerg Roedel
Date: Wed Mar 10 2021 - 03:45:01 EST


From: Joerg Roedel <jroedel@xxxxxxx>

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@xxxxxxx>
---
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 cdc04d091242..7c34be61258e 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;

@@ -210,12 +210,8 @@ 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