[PATCH 1/4] powerpc/pseries: Get entry and uaccess flush required bits from H_GET_CPU_CHARACTERISTICS
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-05-03 13:03:49
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
This allows the hypervisor / firmware to describe these workarounds to the guest. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- 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 443050906018..f962b339865c 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h@@ -393,6 +393,8 @@ #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); }
--
2.23.0