powerpc/pseries: Set or clear security feature flags

commit f636c14790ead6cc22cf62279b1f8d7e11a67116 upstream.

Now that we have feature flags for security related things, set or
clear them based on what we receive from the hypercall.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 483aa7a70d0a..a65515abe25f 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -66,6 +66,7 @@
 #include <asm/reg.h>
 #include <asm/plpar_wrappers.h>
 #include <asm/kexec.h>
+#include <asm/security_features.h>
 
 #include "pseries.h"
 
@@ -450,6 +451,40 @@ static void __init find_and_init_phbs(void)
 	of_pci_check_probe_only();
 }
 
+static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
+{
+	if (result->character & H_CPU_CHAR_SPEC_BAR_ORI31)
+		security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
+
+	if (result->character & H_CPU_CHAR_BCCTRL_SERIALISED)
+		security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
+
+	if (result->character & H_CPU_CHAR_L1D_FLUSH_ORI30)
+		security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
+
+	if (result->character & H_CPU_CHAR_L1D_FLUSH_TRIG2)
+		security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
+
+	if (result->character & H_CPU_CHAR_L1D_THREAD_PRIV)
+		security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
+
+	if (result->character & H_CPU_CHAR_COUNT_CACHE_DISABLED)
+		security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
+
+	/*
+	 * The features below are enabled by default, so we instead look to see
+	 * if firmware has *disabled* them, and clear them if so.
+	 */
+	if (!(result->character & H_CPU_BEHAV_FAVOUR_SECURITY))
+		security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
+
+	if (!(result->character & H_CPU_BEHAV_L1D_FLUSH_PR))
+		security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
+
+	if (!(result->character & H_CPU_BEHAV_BNDS_CHK_SPEC_BAR))
+		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
+}
+
 void pseries_setup_rfi_flush(void)
 {
 	struct h_cpu_char_result result;
@@ -463,6 +498,8 @@ void pseries_setup_rfi_flush(void)
 
 	rc = plpar_get_cpu_characteristics(&result);
 	if (rc == H_SUCCESS) {
+		init_cpu_char_feature_flags(&result);
+
 		if (result.character & H_CPU_CHAR_L1D_FLUSH_TRIG2)
 			types |= L1D_FLUSH_MTTRIG;
 		if (result.character & H_CPU_CHAR_L1D_FLUSH_ORI30)
@@ -473,6 +510,12 @@ void pseries_setup_rfi_flush(void)
 			enable = false;
 	}
 
+	/*
+	 * We're the guest so this doesn't apply to us, clear it to simplify
+	 * handling of it elsewhere.
+	 */
+	security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
+
 	setup_rfi_flush(types, enable);
 }