[PATCH stable v4.4 12/52] powerpc/pseries: Set or clear security feature flags

[Michael Ellerman]

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 <m...@ellerman.id.au>
---
 arch/powerpc/platforms/pseries/setup.c | 43 ++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/setup.c 
b/arch/powerpc/platforms/pseries/setup.c
index ab8c4c8b46bd..7c7c95c00252 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -67,6 +67,7 @@
 #include <asm/eeh.h>
 #include <asm/reg.h>
 #include <asm/plpar_wrappers.h>
+#include <asm/security_features.h>
 
 #include "pseries.h"
 
@@ -499,6 +500,40 @@ 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;
@@ -512,6 +547,8 @@ 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)
@@ -522,6 +559,12 @@ 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);
 }
 
-- 
2.20.1