From patchwork Thu Oct 19 16:55:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Clark X-Patchwork-Id: 13429539 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0C6C1CDB465 for ; Thu, 19 Oct 2023 16:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rNEJ/H49MNMNBepX4tUYOujstUqOZYnAsMxUC3Vpg+A=; b=vybudgqmVGQo+6 zKRpUKSkhUyUTKngM2rDVeI8CEA3E8rABruxuRk9yQUAyCiTz/HO7TBhW0JFmRdS6ZK1cxkJFcu2f U7LiKMrkDxtzNp5Zmx6XYta0nLZwcyvahb+H+d0snfXvm9vIMPNXHDe4kvCTw4EWieY3AO8m+NdJo BrtTtf2DJLN5IHmSaQxUZj08uT4NQQYkiXcZIB8T/qCodzBhzfsNwhdD5l4BqVm/bKp4qjo5641aw fzzpnCL/osfy/bAmP97B4ikVWbks4zcYkbHoD7rht1fFE9DNSS8Vs/V4GrVifr1Bx9PjW6wd2xe+j HbUP+bgCvD4tOAf7osMA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qtWK2-000MOl-39; Thu, 19 Oct 2023 16:56:34 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qtWJw-000MME-1q for linux-arm-kernel@lists.infradead.org; Thu, 19 Oct 2023 16:56:30 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CDB95143D; Thu, 19 Oct 2023 09:57:07 -0700 (PDT) Received: from e127643.arm.com (unknown [10.57.67.150]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 74C1A3F5A1; Thu, 19 Oct 2023 09:56:23 -0700 (PDT) From: James Clark To: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, maz@kernel.org, suzuki.poulose@arm.com Cc: broonie@kernel.org, James Clark , Oliver Upton , James Morse , Zenghui Yu , Catalin Marinas , Will Deacon , Mike Leach , Leo Yan , Alexander Shishkin , Anshuman Khandual , Rob Herring , Jintack Lim , Fuad Tabba , Akihiko Odaki , Joey Gouly , linux-kernel@vger.kernel.org Subject: [PATCH v3 5/6] arm64: KVM: Write TRFCR value on guest switch with nVHE Date: Thu, 19 Oct 2023 17:55:03 +0100 Message-Id: <20231019165510.1966367-6-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231019165510.1966367-1-james.clark@arm.com> References: <20231019165510.1966367-1-james.clark@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231019_095628_714233_45EEDA36 X-CRM114-Status: GOOD ( 23.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The guest value for TRFCR requested by the Coresight driver is saved in sysregs[TRFCR_EL1]. On guest switch this value needs to be written to the register. Currently TRFCR is only modified when we want to disable trace completely in guests due to an issue with TRBE. Expand the __debug_save_trace() function to always write to the register if a different value for guests is required, but also keep the existing TRBE disable behavior if that's required. The TRFCR restore function remains functionally the same, except a value of 0 doesn't mean "don't restore" anymore. Now that we save both guest and host values the register is restored any time the guest and host values differ. Signed-off-by: James Clark Reviewed-by: Suzuki K Poulose --- arch/arm64/include/asm/kvm_hyp.h | 6 ++- arch/arm64/kvm/hyp/nvhe/debug-sr.c | 68 ++++++++++++++++++------------ arch/arm64/kvm/hyp/nvhe/switch.c | 4 +- 3 files changed, 48 insertions(+), 30 deletions(-) diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 52ac90d419e7..6286e580696e 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -103,8 +103,10 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu); void __debug_switch_to_host(struct kvm_vcpu *vcpu); #ifdef __KVM_NVHE_HYPERVISOR__ -void __debug_save_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt); -void __debug_restore_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt); +void __debug_save_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt, + struct kvm_cpu_context *guest_ctxt); +void __debug_restore_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt, + struct kvm_cpu_context *guest_ctxt); #endif void __fpsimd_save_state(struct user_fpsimd_state *fp_regs); diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c index f389ee59788c..6174f710948e 100644 --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -51,42 +51,57 @@ static void __debug_restore_spe(struct kvm_cpu_context *host_ctxt) write_sysreg_s(ctxt_sys_reg(host_ctxt, PMSCR_EL1), SYS_PMSCR_EL1); } -static void __debug_save_trace(struct kvm_cpu_context *host_ctxt) +/* + * Save TRFCR and disable trace completely if TRBE is being used, otherwise + * apply required guest TRFCR value. + */ +static void __debug_save_trace(struct kvm_cpu_context *host_ctxt, + struct kvm_cpu_context *guest_ctxt) { - ctxt_sys_reg(host_ctxt, TRFCR_EL1) = 0; + ctxt_sys_reg(host_ctxt, TRFCR_EL1) = read_sysreg_s(SYS_TRFCR_EL1); /* Check if the TRBE is enabled */ - if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_EL1_E)) - return; - /* - * Prohibit trace generation while we are in guest. - * Since access to TRFCR_EL1 is trapped, the guest can't - * modify the filtering set by the host. - */ - ctxt_sys_reg(host_ctxt, TRFCR_EL1) = read_sysreg_s(SYS_TRFCR_EL1); - write_sysreg_s(0, SYS_TRFCR_EL1); - isb(); - /* Drain the trace buffer to memory */ - tsb_csync(); + if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRBE) && + (read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_EL1_E)) { + /* + * Prohibit trace generation while we are in guest. Since access + * to TRFCR_EL1 is trapped, the guest can't modify the filtering + * set by the host. + */ + ctxt_sys_reg(guest_ctxt, TRFCR_EL1) = 0; + write_sysreg_s(0, SYS_TRFCR_EL1); + isb(); + /* Drain the trace buffer to memory */ + tsb_csync(); + } else { + /* + * Not using TRBE, so guest trace works. Apply the guest filters + * provided by the Coresight driver, if different. + */ + if (ctxt_sys_reg(host_ctxt, TRFCR_EL1) != + ctxt_sys_reg(guest_ctxt, TRFCR_EL1)) + write_sysreg_s(ctxt_sys_reg(guest_ctxt, TRFCR_EL1), + SYS_TRFCR_EL1); + } } -static void __debug_restore_trace(struct kvm_cpu_context *host_ctxt) +static void __debug_restore_trace(struct kvm_cpu_context *host_ctxt, + struct kvm_cpu_context *guest_ctxt) { - if (!ctxt_sys_reg(host_ctxt, TRFCR_EL1)) - return; - /* Restore trace filter controls */ - write_sysreg_s(ctxt_sys_reg(host_ctxt, TRFCR_EL1), SYS_TRFCR_EL1); + if (ctxt_sys_reg(host_ctxt, TRFCR_EL1) != ctxt_sys_reg(guest_ctxt, TRFCR_EL1)) + write_sysreg_s(ctxt_sys_reg(host_ctxt, TRFCR_EL1), SYS_TRFCR_EL1); } -void __debug_save_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt) +void __debug_save_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt, + struct kvm_cpu_context *guest_ctxt) { /* Disable and flush SPE data generation */ if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_SPE)) __debug_save_spe(host_ctxt); - /* Disable and flush Self-Hosted Trace generation */ - if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_save_trace(host_ctxt); + + if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRFCR)) + __debug_save_trace(host_ctxt, guest_ctxt); } void __debug_switch_to_guest(struct kvm_vcpu *vcpu) @@ -94,12 +109,13 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu) __debug_switch_to_guest_common(vcpu); } -void __debug_restore_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt) +void __debug_restore_host_buffers_nvhe(struct kvm_cpu_context *host_ctxt, + struct kvm_cpu_context *guest_ctxt) { if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_SPE)) __debug_restore_spe(host_ctxt); - if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_restore_trace(host_ctxt); + if (vcpu_get_flag(host_ctxt->__hyp_running_vcpu, DEBUG_STATE_SAVE_TRFCR)) + __debug_restore_trace(host_ctxt, guest_ctxt); } void __debug_switch_to_host(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index 6b4b24ae077f..c7bea5cf672d 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -278,7 +278,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) * translation regime to EL2 (via MDCR_EL2_E2PB == 0) and * before we load guest Stage1. */ - __debug_save_host_buffers_nvhe(host_ctxt); + __debug_save_host_buffers_nvhe(host_ctxt, guest_ctxt); /* * We're about to restore some new MMU state. Make sure @@ -345,7 +345,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) * This must come after restoring the host sysregs, since a non-VHE * system may enable SPE here and make use of the TTBRs. */ - __debug_restore_host_buffers_nvhe(host_ctxt); + __debug_restore_host_buffers_nvhe(host_ctxt, guest_ctxt); if (pmu_switch_needed) __pmu_switch_to_host(vcpu);