From: Jeremy Linton <jeremy.linton@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, suzuki.poulose@arm.com, dave.martin@arm.com, shankerd@codeaurora.org, linux-kernel@vger.kernel.org, ykaukab@suse.de, julien.thierry@arm.com, mlangsdo@redhat.com, steven.price@arm.com, stefan.wahren@i2se.com, Jeremy Linton <jeremy.linton@arm.com> Subject: [PATCH v4 09/12] arm64: Use firmware to detect CPUs that are not affected by Spectre-v2 Date: Fri, 25 Jan 2019 12:07:08 -0600 [thread overview] Message-ID: <20190125180711.1970973-10-jeremy.linton@arm.com> (raw) In-Reply-To: <20190125180711.1970973-1-jeremy.linton@arm.com> From: Marc Zyngier <marc.zyngier@arm.com> The SMCCC ARCH_WORKAROUND_1 service can indicate that although the firmware knows about the Spectre-v2 mitigation, this particular CPU is not vulnerable, and it is thus not necessary to call the firmware on this CPU. Let's use this information to our benefit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> --- arch/arm64/kernel/cpu_errata.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 4d23b4d4cfa8..024c83ffff99 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -217,22 +217,36 @@ static int detect_harden_bp_fw(void) case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + switch ((int)res.a0) { + case 1: + /* Firmware says we're just fine */ + return 0; + case 0: + cb = call_hvc_arch_workaround_1; + /* This is a guest, no need to patch KVM vectors */ + smccc_start = NULL; + smccc_end = NULL; + break; + default: return -1; - cb = call_hvc_arch_workaround_1; - /* This is a guest, no need to patch KVM vectors */ - smccc_start = NULL; - smccc_end = NULL; + } break; case PSCI_CONDUIT_SMC: arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + switch ((int)res.a0) { + case 1: + /* Firmware says we're just fine */ + return 0; + case 0: + cb = call_smc_arch_workaround_1; + smccc_start = __smccc_workaround_1_smc_start; + smccc_end = __smccc_workaround_1_smc_end; + break; + default: return -1; - cb = call_smc_arch_workaround_1; - smccc_start = __smccc_workaround_1_smc_start; - smccc_end = __smccc_workaround_1_smc_end; + } break; default: -- 2.17.2
WARNING: multiple messages have this Message-ID (diff)
From: Jeremy Linton <jeremy.linton@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: stefan.wahren@i2se.com, mlangsdo@redhat.com, suzuki.poulose@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, julien.thierry@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, Jeremy Linton <jeremy.linton@arm.com>, steven.price@arm.com, ykaukab@suse.de, dave.martin@arm.com, shankerd@codeaurora.org Subject: [PATCH v4 09/12] arm64: Use firmware to detect CPUs that are not affected by Spectre-v2 Date: Fri, 25 Jan 2019 12:07:08 -0600 [thread overview] Message-ID: <20190125180711.1970973-10-jeremy.linton@arm.com> (raw) In-Reply-To: <20190125180711.1970973-1-jeremy.linton@arm.com> From: Marc Zyngier <marc.zyngier@arm.com> The SMCCC ARCH_WORKAROUND_1 service can indicate that although the firmware knows about the Spectre-v2 mitigation, this particular CPU is not vulnerable, and it is thus not necessary to call the firmware on this CPU. Let's use this information to our benefit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> --- arch/arm64/kernel/cpu_errata.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 4d23b4d4cfa8..024c83ffff99 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -217,22 +217,36 @@ static int detect_harden_bp_fw(void) case PSCI_CONDUIT_HVC: arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + switch ((int)res.a0) { + case 1: + /* Firmware says we're just fine */ + return 0; + case 0: + cb = call_hvc_arch_workaround_1; + /* This is a guest, no need to patch KVM vectors */ + smccc_start = NULL; + smccc_end = NULL; + break; + default: return -1; - cb = call_hvc_arch_workaround_1; - /* This is a guest, no need to patch KVM vectors */ - smccc_start = NULL; - smccc_end = NULL; + } break; case PSCI_CONDUIT_SMC: arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, ARM_SMCCC_ARCH_WORKAROUND_1, &res); - if ((int)res.a0 < 0) + switch ((int)res.a0) { + case 1: + /* Firmware says we're just fine */ + return 0; + case 0: + cb = call_smc_arch_workaround_1; + smccc_start = __smccc_workaround_1_smc_start; + smccc_end = __smccc_workaround_1_smc_end; + break; + default: return -1; - cb = call_smc_arch_workaround_1; - smccc_start = __smccc_workaround_1_smc_start; - smccc_end = __smccc_workaround_1_smc_end; + } break; default: -- 2.17.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-01-25 18:07 UTC|newest] Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-01-25 18:06 [PATCH v4 00/12] arm64: add system vulnerability sysfs entries Jeremy Linton 2019-01-25 18:06 ` Jeremy Linton 2019-01-25 18:07 ` [PATCH v4 01/12] Documentation: Document arm64 kpti control Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-30 18:02 ` Andre Przywara 2019-01-30 18:02 ` Andre Przywara 2019-02-06 19:24 ` Jeremy Linton 2019-02-06 19:24 ` Jeremy Linton 2019-02-06 21:06 ` André Przywara 2019-02-06 21:06 ` André Przywara 2019-01-31 17:58 ` Andre Przywara 2019-01-31 17:58 ` Andre Przywara 2019-02-07 0:25 ` Jonathan Corbet 2019-02-07 0:25 ` Jonathan Corbet 2019-01-25 18:07 ` [PATCH v4 02/12] arm64: Provide a command line to disable spectre_v2 mitigation Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-30 18:03 ` Andre Przywara 2019-01-30 18:03 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 03/12] arm64: Remove the ability to build a kernel without ssbd Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-30 18:04 ` Andre Przywara 2019-01-30 18:04 ` Andre Przywara 2019-02-15 18:20 ` Catalin Marinas 2019-02-15 18:20 ` Catalin Marinas 2019-02-15 18:20 ` Catalin Marinas 2019-02-15 18:54 ` Jeremy Linton 2019-02-15 18:54 ` Jeremy Linton 2019-01-25 18:07 ` [PATCH v4 04/12] arm64: remove the ability to build a kernel without hardened branch predictors Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-30 18:04 ` Andre Przywara 2019-01-30 18:04 ` Andre Przywara 2019-01-30 18:04 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 05/12] arm64: remove the ability to build a kernel without kpti Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-30 18:05 ` Andre Przywara 2019-01-30 18:05 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 06/12] arm64: add sysfs vulnerability show for spectre v1 Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-31 17:52 ` Andre Przywara 2019-01-31 17:52 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 07/12] arm64: add sysfs vulnerability show for meltdown Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-31 9:28 ` Julien Thierry 2019-01-31 9:28 ` Julien Thierry 2019-01-31 21:48 ` Jeremy Linton 2019-01-31 21:48 ` Jeremy Linton 2019-01-31 17:54 ` Andre Przywara 2019-01-31 17:54 ` Andre Przywara 2019-01-31 21:53 ` Jeremy Linton 2019-01-31 21:53 ` Jeremy Linton 2019-01-25 18:07 ` [PATCH v4 08/12] arm64: Advertise mitigation of Spectre-v2, or lack thereof Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-31 17:54 ` Andre Przywara 2019-01-31 17:54 ` Andre Przywara 2019-01-25 18:07 ` Jeremy Linton [this message] 2019-01-25 18:07 ` [PATCH v4 09/12] arm64: Use firmware to detect CPUs that are not affected by Spectre-v2 Jeremy Linton 2019-01-31 17:55 ` Andre Przywara 2019-01-31 17:55 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 10/12] arm64: add sysfs vulnerability show for spectre v2 Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-31 17:55 ` Andre Przywara 2019-01-31 17:55 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 11/12] arm64: add sysfs vulnerability show for speculative store bypass Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-31 17:55 ` Andre Przywara 2019-01-31 17:55 ` Andre Przywara 2019-01-25 18:07 ` [PATCH v4 12/12] arm64: enable generic CPU vulnerabilites support Jeremy Linton 2019-01-25 18:07 ` Jeremy Linton 2019-01-31 17:56 ` Andre Przywara 2019-01-31 17:56 ` Andre Przywara 2019-02-08 20:05 ` [PATCH v4 00/12] arm64: add system vulnerability sysfs entries Stefan Wahren 2019-02-08 20:05 ` Stefan Wahren
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