From patchwork Mon Jun 29 16:25:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11632549 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1510A138C for ; Mon, 29 Jun 2020 21:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F175120720 for ; Mon, 29 Jun 2020 21:15:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593465322; bh=VdO0jQ/MssMzZwJ3Jmcy7j9yhjcRN0AurIn0itRbDB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sfmz3RipZxy1OJvYHSPbzfl/crqR8fA7BMLkIP7ReVuG1VAdCqyRpqbnWxb2eFBlW SJjMHWD1F1IqYLyoenGn9Zp3nptS3vM6yZQXGvJo/Tz1oN+Aqu86GB9ev7xIAIkrUu gix4m4c7Ca94uFxZElI01stJOCcOQsSjBqulKvNY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726912AbgF2VPJ (ORCPT ); Mon, 29 Jun 2020 17:15:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:42434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729957AbgF2SzQ (ORCPT ); Mon, 29 Jun 2020 14:55:16 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 04EFD25592; Mon, 29 Jun 2020 16:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593447934; bh=VdO0jQ/MssMzZwJ3Jmcy7j9yhjcRN0AurIn0itRbDB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zzLChNvlDrQi+ZfF4CpY+8pP5YHckGR9bXphz2iJVJrvT0xNx03guK3euKdB8ey/p Aob+xKUnA2bGpyfza4nOvV7yN1TnVuNRsxal3ipw2bh8M4iNHopEaV+ZoKBk4Z7Awq +b8vSiEbWxZMtvvLzjtsY8a2kjo2IC5scsvOfFVE= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jpwb6-007M5T-Gk; Mon, 29 Jun 2020 17:25:32 +0100 From: Marc Zyngier To: Paolo Bonzini Cc: Alexandru Elisei , Andrew Jones , James Morse , Steven Price , Zenghui Yu , Julien Thierry , Suzuki K Poulose , kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 1/4] KVM: arm64: Annotate hyp NMI-related functions as __always_inline Date: Mon, 29 Jun 2020 17:25:16 +0100 Message-Id: <20200629162519.825200-2-maz@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200629162519.825200-1-maz@kernel.org> References: <20200629162519.825200-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, drjones@redhat.com, james.morse@arm.com, steven.price@arm.com, yuzenghui@huawei.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, stable@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Alexandru Elisei The "inline" keyword is a hint for the compiler to inline a function. The functions system_uses_irq_prio_masking() and gic_write_pmr() are used by the code running at EL2 on a non-VHE system, so mark them as __always_inline to make sure they'll always be part of the .hyp.text section. This fixes the following splat when trying to run a VM: [ 47.625273] Kernel panic - not syncing: HYP panic: [ 47.625273] PS:a00003c9 PC:0000ca0b42049fc4 ESR:86000006 [ 47.625273] FAR:0000ca0b42049fc4 HPFAR:0000000010001000 PAR:0000000000000000 [ 47.625273] VCPU:0000000000000000 [ 47.647261] CPU: 1 PID: 217 Comm: kvm-vcpu-0 Not tainted 5.8.0-rc1-ARCH+ #61 [ 47.654508] Hardware name: Globalscale Marvell ESPRESSOBin Board (DT) [ 47.661139] Call trace: [ 47.663659] dump_backtrace+0x0/0x1cc [ 47.667413] show_stack+0x18/0x24 [ 47.670822] dump_stack+0xb8/0x108 [ 47.674312] panic+0x124/0x2f4 [ 47.677446] panic+0x0/0x2f4 [ 47.680407] SMP: stopping secondary CPUs [ 47.684439] Kernel Offset: disabled [ 47.688018] CPU features: 0x240402,20002008 [ 47.692318] Memory Limit: none [ 47.695465] ---[ end Kernel panic - not syncing: HYP panic: [ 47.695465] PS:a00003c9 PC:0000ca0b42049fc4 ESR:86000006 [ 47.695465] FAR:0000ca0b42049fc4 HPFAR:0000000010001000 PAR:0000000000000000 [ 47.695465] VCPU:0000000000000000 ]--- The instruction abort was caused by the code running at EL2 trying to fetch an instruction which wasn't mapped in the EL2 translation tables. Using objdump showed the two functions as separate symbols in the .text section. Fixes: 85738e05dc38 ("arm64: kvm: Unmask PMR before entering guest") Cc: stable@vger.kernel.org Signed-off-by: Alexandru Elisei Signed-off-by: Marc Zyngier Acked-by: James Morse Link: https://lore.kernel.org/r/20200618171254.1596055-1-alexandru.elisei@arm.com --- arch/arm64/include/asm/arch_gicv3.h | 2 +- arch/arm64/include/asm/cpufeature.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h index a358e97572c1..6647ae4f0231 100644 --- a/arch/arm64/include/asm/arch_gicv3.h +++ b/arch/arm64/include/asm/arch_gicv3.h @@ -109,7 +109,7 @@ static inline u32 gic_read_pmr(void) return read_sysreg_s(SYS_ICC_PMR_EL1); } -static inline void gic_write_pmr(u32 val) +static __always_inline void gic_write_pmr(u32 val) { write_sysreg_s(val, SYS_ICC_PMR_EL1); } diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 5d1f4ae42799..f7c3d1ff091d 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -675,7 +675,7 @@ static inline bool system_supports_generic_auth(void) cpus_have_const_cap(ARM64_HAS_GENERIC_AUTH); } -static inline bool system_uses_irq_prio_masking(void) +static __always_inline bool system_uses_irq_prio_masking(void) { return IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && cpus_have_const_cap(ARM64_HAS_IRQ_PRIO_MASKING); From patchwork Mon Jun 29 16:25:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11632555 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9A28E138C for ; Mon, 29 Jun 2020 21:16:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FD7520768 for ; Mon, 29 Jun 2020 21:16:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593465389; bh=Dipb/rgSszc7XJQH0kxxfAICY/VzC7ACJ2EZBikguW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nkYTiAnmr8ifXbp+WoiHavoDSlLJ6gRx7UeTSmnaKH98s93x8GC8PgLA/AcMPnrvf rQd3lNzFxQygVGKIXbc0Sq3cH6Bdf0ieYysDMAuORvBSQdKO1csWrqJVd2FD/6Bsgq h5Q+jKqPfaawxZ4cP9c99FcRZKE7QuflJPGPwuO4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390700AbgF2VQK (ORCPT ); Mon, 29 Jun 2020 17:16:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:42402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729936AbgF2SzP (ORCPT ); Mon, 29 Jun 2020 14:55:15 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9FF5225594; Mon, 29 Jun 2020 16:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593447934; bh=Dipb/rgSszc7XJQH0kxxfAICY/VzC7ACJ2EZBikguW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L3elRaJ4LdrJVuZNqKJ8HI7CvmS2H0HF2zIcgQWgTavDk1r65ChRxRpAgWOruwjHb +XWY1u8+OQXGZ7Pp/uKVJ6kNzJcKo/IdAXVXnqMEImn4u0d5okoB9fcJYt5NsbDX7l 65hCZOmbMIuiDpV+yOc26gcQfguA6dq4gf3upouU= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jpwb7-007M5T-6f; Mon, 29 Jun 2020 17:25:33 +0100 From: Marc Zyngier To: Paolo Bonzini Cc: Alexandru Elisei , Andrew Jones , James Morse , Steven Price , Zenghui Yu , Julien Thierry , Suzuki K Poulose , kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/4] KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE Date: Mon, 29 Jun 2020 17:25:17 +0100 Message-Id: <20200629162519.825200-3-maz@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200629162519.825200-1-maz@kernel.org> References: <20200629162519.825200-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, drjones@redhat.com, james.morse@arm.com, steven.price@arm.com, yuzenghui@huawei.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, stable@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Steven Price If SVE is enabled then 'ret' can be assigned the return value of kvm_vcpu_enable_sve() which may be 0 causing future "goto out" sites to erroneously return 0 on failure rather than -EINVAL as expected. Remove the initialisation of 'ret' and make setting the return value explicit to avoid this situation in the future. Fixes: 9a3cdf26e336 ("KVM: arm64/sve: Allow userspace to enable SVE for vcpus") Cc: stable@vger.kernel.org Reported-by: James Morse Signed-off-by: Steven Price Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200617105456.28245-1-steven.price@arm.com --- arch/arm64/kvm/reset.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index d3b209023727..6ed36be51b4b 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -245,7 +245,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu) */ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) { - int ret = -EINVAL; + int ret; bool loaded; u32 pstate; @@ -269,15 +269,19 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) { - if (kvm_vcpu_enable_ptrauth(vcpu)) + if (kvm_vcpu_enable_ptrauth(vcpu)) { + ret = -EINVAL; goto out; + } } switch (vcpu->arch.target) { default: if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { - if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) + if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) { + ret = -EINVAL; goto out; + } pstate = VCPU_RESET_PSTATE_SVC; } else { pstate = VCPU_RESET_PSTATE_EL1; From patchwork Mon Jun 29 16:25:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11632553 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DA9246C1 for ; Mon, 29 Jun 2020 21:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2181206A1 for ; Mon, 29 Jun 2020 21:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593465361; bh=y9/mharb+W/Wo8t1uox6jiNNY7oYrYExuo1ibLqnBrI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Bvh1AYyfm+4UA2yqpckX7B4D4hoL4giWQWtHL/P+Sp5ngEUd2BwSi3JDF5/uPFaZZ PjaaniOfUhBL00Xjyxnuit85ocEgY/J6ETy+OaKKZg9pVQyFKiK9/aHAkWLQm1IxdD X8vKQRREBbqUTWwCYv+3BNVcPvv8vXezCPReUyoc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390677AbgF2VP6 (ORCPT ); Mon, 29 Jun 2020 17:15:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:42430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729954AbgF2SzQ (ORCPT ); Mon, 29 Jun 2020 14:55:16 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5CDE125595; Mon, 29 Jun 2020 16:25:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593447935; bh=y9/mharb+W/Wo8t1uox6jiNNY7oYrYExuo1ibLqnBrI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yRxh8t3va+r0SZYY70IM+SupCD7KWJrc4Fh2FeUL/H8WeeyAbNSt6OvibEVWU1PZs 1+OLP7dQQUHaABxzN6djmfymJNXZ3571UX26nWjeTZtcBL4Orcwl9eqSMHtAmDOF3X vtqNYqlW/JjXDeNy1dRZTYHhfnPSzzUbIyNd6t0M= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jpwb7-007M5T-Uj; Mon, 29 Jun 2020 17:25:34 +0100 From: Marc Zyngier To: Paolo Bonzini Cc: Alexandru Elisei , Andrew Jones , James Morse , Steven Price , Zenghui Yu , Julien Thierry , Suzuki K Poulose , kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 3/4] KVM: arm64: pvtime: Ensure task delay accounting is enabled Date: Mon, 29 Jun 2020 17:25:18 +0100 Message-Id: <20200629162519.825200-4-maz@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200629162519.825200-1-maz@kernel.org> References: <20200629162519.825200-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, drjones@redhat.com, james.morse@arm.com, steven.price@arm.com, yuzenghui@huawei.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Andrew Jones Ensure we're actually accounting run_delay before we claim that we'll expose it to the guest. If we're not, then we just pretend like steal time isn't supported in order to avoid any confusion. Signed-off-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200622142710.18677-1-drjones@redhat.com --- arch/arm64/kvm/pvtime.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c index 1e0f4c284888..f7b52ce1557e 100644 --- a/arch/arm64/kvm/pvtime.c +++ b/arch/arm64/kvm/pvtime.c @@ -3,6 +3,7 @@ #include #include +#include #include #include @@ -73,6 +74,11 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) return base; } +static bool kvm_arm_pvtime_supported(void) +{ + return !!sched_info_on(); +} + int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) { @@ -82,7 +88,8 @@ int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, int ret = 0; int idx; - if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA) + if (!kvm_arm_pvtime_supported() || + attr->attr != KVM_ARM_VCPU_PVTIME_IPA) return -ENXIO; if (get_user(ipa, user)) @@ -110,7 +117,8 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, u64 __user *user = (u64 __user *)attr->addr; u64 ipa; - if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA) + if (!kvm_arm_pvtime_supported() || + attr->attr != KVM_ARM_VCPU_PVTIME_IPA) return -ENXIO; ipa = vcpu->arch.steal.base; @@ -125,7 +133,8 @@ int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu, { switch (attr->attr) { case KVM_ARM_VCPU_PVTIME_IPA: - return 0; + if (kvm_arm_pvtime_supported()) + return 0; } return -ENXIO; } From patchwork Mon Jun 29 16:25:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11631427 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3C113913 for ; Mon, 29 Jun 2020 18:56:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 249BD206A1 for ; Mon, 29 Jun 2020 18:56:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593456986; bh=82FEL/lqihaAkT9TFcf9PCxFsGrapDUAVvxVatgi5Vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dvmWYmOSMS1skiTzEREba3x2p3S8sWiJt/eSOia7ddk2329DDwbnupTQxVA3eG9v6 85Q/E8We9D+LHFmGm60DvqFRBofnyc4axMwLDnR1JH1qWymiWeNqjegmNp6vTgMFQ9 BokJBPnK2ewDWsEDMuJuMj1RQi2ok/OZQm/MSzxk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730019AbgF2Sz5 (ORCPT ); Mon, 29 Jun 2020 14:55:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:42470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729980AbgF2SzR (ORCPT ); Mon, 29 Jun 2020 14:55:17 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EE06E25597; Mon, 29 Jun 2020 16:25:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593447936; bh=82FEL/lqihaAkT9TFcf9PCxFsGrapDUAVvxVatgi5Vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gJxoU9hYrPT/VBynK7z5mLddD59VHlU/a18A1OaJmulhYRFOSIbHFOWk72bX96NXi We08VIiml9jpcgCOpwBUkCZ0gn/wSsloMsUZVuNB0f/EHCxeF8RLs/8uvHZ7Uoj/GI Kp5U2EKZlQqsDJUNPWXMH16HikkaudzG214zKYRQ= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jpwb8-007M5T-Hn; Mon, 29 Jun 2020 17:25:34 +0100 From: Marc Zyngier To: Paolo Bonzini Cc: Alexandru Elisei , Andrew Jones , James Morse , Steven Price , Zenghui Yu , Julien Thierry , Suzuki K Poulose , kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 4/4] KVM: arm64: vgic-v4: Plug race between non-residency and v4.1 doorbell Date: Mon, 29 Jun 2020 17:25:19 +0100 Message-Id: <20200629162519.825200-5-maz@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200629162519.825200-1-maz@kernel.org> References: <20200629162519.825200-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, drjones@redhat.com, james.morse@arm.com, steven.price@arm.com, yuzenghui@huawei.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When making a vPE non-resident because it has hit a blocking WFI, the doorbell can fire at any time after the write to the RD. Crucially, it can fire right between the write to GICR_VPENDBASER and the write to the pending_last field in the its_vpe structure. This means that we would overwrite pending_last with stale data, and potentially not wakeup until some unrelated event (such as a timer interrupt) puts the vPE back on the CPU. GICv4 isn't affected by this as we actively mask the doorbell on entering the guest, while GICv4.1 automatically manages doorbell delivery without any hypervisor-driven masking. Use the vpe_lock to synchronize such update, which solves the problem altogether. Fixes: ae699ad348cdc ("irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer") Reported-by: Zenghui Yu Signed-off-by: Marc Zyngier --- arch/arm64/kvm/vgic/vgic-v4.c | 8 ++++++++ drivers/irqchip/irq-gic-v3-its.c | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c index 27ac833e5ec7..b5fa73c9fd35 100644 --- a/arch/arm64/kvm/vgic/vgic-v4.c +++ b/arch/arm64/kvm/vgic/vgic-v4.c @@ -90,7 +90,15 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info) !irqd_irq_disabled(&irq_to_desc(irq)->irq_data)) disable_irq_nosync(irq); + /* + * The v4.1 doorbell can fire concurrently with the vPE being + * made non-resident. Ensure we only update pending_last + * *after* the non-residency sequence has completed. + */ + raw_spin_lock(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vpe_lock); vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true; + raw_spin_unlock(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vpe_lock); + kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); kvm_vcpu_kick(vcpu); diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index cd685f521c77..205f69592471 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -4054,16 +4054,24 @@ static void its_vpe_4_1_deschedule(struct its_vpe *vpe, u64 val; if (info->req_db) { + unsigned long flags; + /* * vPE is going to block: make the vPE non-resident with * PendingLast clear and DB set. The GIC guarantees that if * we read-back PendingLast clear, then a doorbell will be * delivered when an interrupt comes. + * + * Note the locking to deal with the concurrent update of + * pending_last from the doorbell interrupt handler that can + * run concurrently. */ + raw_spin_lock_irqsave(&vpe->vpe_lock, flags); val = its_clear_vpend_valid(vlpi_base, GICR_VPENDBASER_PendingLast, GICR_VPENDBASER_4_1_DB); vpe->pending_last = !!(val & GICR_VPENDBASER_PendingLast); + raw_spin_unlock_irqrestore(&vpe->vpe_lock, flags); } else { /* * We're not blocking, so just make the vPE non-resident