From: Marc Zyngier <marc.zyngier@xxxxxxx> [ Upstream commit 22765f30dbaf1118c6ff0fcb8b99c9f2b4d396d5 ] The very existence of __smccc_workaround_1_hvc_* is a thinko, as KVM will never use a HVC call to perform the branch prediction invalidation. Even as a nested hypervisor, it would use an SMC instruction. Let's get rid of it. Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- arch/arm64/kernel/bpi.S | 12 ++---------- arch/arm64/kernel/cpu_errata.c | 9 +++------ 2 files changed, 5 insertions(+), 16 deletions(-) diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index 0af46cfdbbf3..4cae34e5a24e 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -56,21 +56,13 @@ ENTRY(__bp_harden_hyp_vecs_start) ENTRY(__bp_harden_hyp_vecs_end) -.macro smccc_workaround_1 inst +ENTRY(__smccc_workaround_1_smc_start) sub sp, sp, #(8 * 4) stp x2, x3, [sp, #(8 * 0)] stp x0, x1, [sp, #(8 * 2)] mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1 - \inst #0 + smc #0 ldp x2, x3, [sp, #(8 * 0)] ldp x0, x1, [sp, #(8 * 2)] add sp, sp, #(8 * 4) -.endm - -ENTRY(__smccc_workaround_1_smc_start) - smccc_workaround_1 smc ENTRY(__smccc_workaround_1_smc_end) - -ENTRY(__smccc_workaround_1_hvc_start) - smccc_workaround_1 hvc -ENTRY(__smccc_workaround_1_hvc_end) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 4204b668df7a..6e565d8d4f71 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -85,8 +85,6 @@ DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); #ifdef CONFIG_KVM extern char __smccc_workaround_1_smc_start[]; extern char __smccc_workaround_1_smc_end[]; -extern char __smccc_workaround_1_hvc_start[]; -extern char __smccc_workaround_1_hvc_end[]; static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, const char *hyp_vecs_end) @@ -131,8 +129,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, #else #define __smccc_workaround_1_smc_start NULL #define __smccc_workaround_1_smc_end NULL -#define __smccc_workaround_1_hvc_start NULL -#define __smccc_workaround_1_hvc_end NULL static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, @@ -206,8 +202,9 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) if ((int)res.a0 < 0) return; cb = call_hvc_arch_workaround_1; - smccc_start = __smccc_workaround_1_hvc_start; - smccc_end = __smccc_workaround_1_hvc_end; + /* This is a guest, no need to patch KVM vectors */ + smccc_start = NULL; + smccc_end = NULL; break; case PSCI_CONDUIT_SMC: -- 2.20.1
