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From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	David Brazdil <dbrazdil@google.com>,
	Will Deacon <will@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH 06/19] KVM: arm64: Simplify install_bp_hardening_cb()
Date: Fri, 18 Sep 2020 17:47:16 +0100	[thread overview]
Message-ID: <20200918164729.31994-7-will@kernel.org> (raw)
In-Reply-To: <20200918164729.31994-1-will@kernel.org>

Use is_hyp_mode_available() to detect whether or not we need to patch
the KVM vectors for branch hardening, which avoids the need to take the
vector pointers as parameters.

Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/cpu_errata.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 135bf7f92d4a..a72ca57f5630 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -126,18 +126,19 @@ static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
 	__flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K);
 }
 
-static void install_bp_hardening_cb(bp_hardening_cb_t fn,
-				    const char *hyp_vecs_start,
-				    const char *hyp_vecs_end)
+static void install_bp_hardening_cb(bp_hardening_cb_t fn)
 {
 	static DEFINE_RAW_SPINLOCK(bp_lock);
 	int cpu, slot = -1;
+	const char *hyp_vecs_start = __smccc_workaround_1_smc;
+	const char *hyp_vecs_end = __smccc_workaround_1_smc +
+				   __SMCCC_WORKAROUND_1_SMC_SZ;
 
 	/*
 	 * detect_harden_bp_fw() passes NULL for the hyp_vecs start/end if
 	 * we're a guest. Skip the hyp-vectors work.
 	 */
-	if (!hyp_vecs_start) {
+	if (!is_hyp_mode_available()) {
 		__this_cpu_write(bp_hardening_data.fn, fn);
 		return;
 	}
@@ -161,9 +162,7 @@ static void install_bp_hardening_cb(bp_hardening_cb_t fn,
 	raw_spin_unlock(&bp_lock);
 }
 #else
-static void install_bp_hardening_cb(bp_hardening_cb_t fn,
-				      const char *hyp_vecs_start,
-				      const char *hyp_vecs_end)
+static void install_bp_hardening_cb(bp_hardening_cb_t fn)
 {
 	__this_cpu_write(bp_hardening_data.fn, fn);
 }
@@ -209,7 +208,6 @@ early_param("nospectre_v2", parse_nospectre_v2);
 static int detect_harden_bp_fw(void)
 {
 	bp_hardening_cb_t cb;
-	void *smccc_start, *smccc_end;
 	struct arm_smccc_res res;
 	u32 midr = read_cpuid_id();
 
@@ -229,21 +227,10 @@ static int detect_harden_bp_fw(void)
 	switch (arm_smccc_1_1_get_conduit()) {
 	case SMCCC_CONDUIT_HVC:
 		cb = call_hvc_arch_workaround_1;
-		/* This is a guest, no need to patch KVM vectors */
-		smccc_start = NULL;
-		smccc_end = NULL;
 		break;
 
 	case SMCCC_CONDUIT_SMC:
 		cb = call_smc_arch_workaround_1;
-#if IS_ENABLED(CONFIG_KVM)
-		smccc_start = __smccc_workaround_1_smc;
-		smccc_end = __smccc_workaround_1_smc +
-			__SMCCC_WORKAROUND_1_SMC_SZ;
-#else
-		smccc_start = NULL;
-		smccc_end = NULL;
-#endif
 		break;
 
 	default:
@@ -254,7 +241,7 @@ static int detect_harden_bp_fw(void)
 	    ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1))
 		cb = qcom_link_stack_sanitization;
 
-	install_bp_hardening_cb(cb, smccc_start, smccc_end);
+	install_bp_hardening_cb(cb);
 	return 1;
 }
 
-- 
2.28.0.681.g6f77f65b4e-goog


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  parent reply	other threads:[~2020-09-18 16:51 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-18 16:47 [PATCH 00/19] Fix and rewrite arm64 spectre mitigations Will Deacon
2020-09-18 16:47 ` [PATCH 01/19] arm64: Make use of ARCH_WORKAROUND_1 even when KVM is not enabled Will Deacon
2020-09-18 16:47 ` [PATCH 02/19] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs Will Deacon
2020-09-21 12:54   ` Sasha Levin
2020-09-18 16:47 ` [PATCH 03/19] arm64: Run ARCH_WORKAROUND_2 " Will Deacon
2020-09-18 17:13   ` Suzuki K Poulose
2020-09-18 16:47 ` [PATCH 04/19] arm64: Remove Spectre-related CONFIG_* options Will Deacon
2020-09-18 16:47 ` [PATCH 05/19] KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE Will Deacon
2020-09-18 16:47 ` Will Deacon [this message]
2020-09-18 16:47 ` [PATCH 07/19] arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 Will Deacon
2020-09-18 16:47 ` [PATCH 08/19] arm64: Introduce separate file for spectre mitigations and reporting Will Deacon
2020-09-18 16:47 ` [PATCH 09/19] arm64: Rewrite Spectre-v2 mitigation code Will Deacon
2020-09-18 16:47 ` [PATCH 10/19] KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 Will Deacon
2020-09-18 16:47 ` [PATCH 11/19] arm64: Group start_thread() functions together Will Deacon
2020-09-18 16:47 ` [PATCH 12/19] arm64: Treat SSBS as a non-strict system feature Will Deacon
2020-09-18 16:47 ` [PATCH 13/19] arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4 Will Deacon
2020-09-18 16:47 ` [PATCH 14/19] arm64: Move SSBD prctl() handler alongside other spectre mitigation code Will Deacon
2020-09-18 16:47 ` [PATCH 15/19] arm64: Rewrite Spectre-v4 " Will Deacon
2020-09-18 16:47 ` [PATCH 16/19] KVM: arm64: Simplify handling of ARCH_WORKAROUND_2 Will Deacon
2020-09-18 16:47 ` [PATCH 17/19] KVM: arm64: Get rid of kvm_arm_have_ssbd() Will Deacon
2020-09-18 16:47 ` [PATCH 18/19] KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state() Will Deacon
2020-09-18 16:47 ` [PATCH 19/19] arm64: Get rid of arm64_ssbd_state Will Deacon
2020-09-18 16:59 ` [PATCH 00/19] Fix and rewrite arm64 spectre mitigations Will Deacon

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