From 65c7d070850e109a8a75a431f5a7f6eb4c007b77 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
Date: Mon, 3 May 2021 23:02:40 +1000
Subject: [PATCH] powerpc/pseries: Get entry and uaccess flush required bits
from H_GET_CPU_CHARACTERISTICS
References: bsc#1188885 ltc#193722
Patch-mainline: v5.14-rc1
Git-commit: 65c7d070850e109a8a75a431f5a7f6eb4c007b77
This allows the hypervisor / firmware to describe these workarounds to
the guest.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503130243.891868-2-npiggin@gmail.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/include/asm/hvcall.h | 2 ++
arch/powerpc/platforms/pseries/setup.c | 6 ++++++
2 files changed, 8 insertions(+)
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 7c3418d1b5e9..d769ffbb04f2 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -400,6 +400,8 @@
#define H_CPU_BEHAV_FAVOUR_SECURITY_H (1ull << 60) // IBM bit 3
#define H_CPU_BEHAV_FLUSH_COUNT_CACHE (1ull << 58) // IBM bit 5
#define H_CPU_BEHAV_FLUSH_LINK_STACK (1ull << 57) // IBM bit 6
+#define H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY (1ull << 56) // IBM bit 7
+#define H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS (1ull << 55) // IBM bit 8
/* Flag values used in H_REGISTER_PROC_TBL hcall */
#define PROC_TABLE_OP_MASK 0x18
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 754e493b7c05..287f33645419 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -549,6 +549,12 @@ static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
if (!(result->behaviour & H_CPU_BEHAV_L1D_FLUSH_PR))
security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
+ if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY)
+ security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
+
+ if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS)
+ security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
+
if (!(result->behaviour & H_CPU_BEHAV_BNDS_CHK_SPEC_BAR))
security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
}
--
2.26.2