From patchwork Mon Feb 26 11:30:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Clark X-Patchwork-Id: 13572026 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 B7707C54E49 for ; Mon, 26 Feb 2024 11:34:48 +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=P/HtolCzkV99VM6ng7c2DKgPeEWvvyFV4bDBO6aPIpY=; b=O7hJgqvZmOL41R kB5rlq2Q7eC1WYAEsapwrk23XU3GTu36D5rM5TXvODp34sreObKXFCF5U2JbPxSWQkk5Idufielf7 knCT+Ful8lAc4+Zt/j2qKlnlToMmnIUJMqQoWUjdEFK85Ox3bT7QsKm7lm93W/WkJsl4b0SzFF6eD CMWaDzOYZXB38uKl1lka6YPL8Ewc3Bbljl7LVyJgfox/VMSo2l3mZcYBcEfKPodkM+bXnAwVuoH9L yskht+tcSR786xnKHDVAEFpKAT4UhjGu+LzIQ0HQ5nqraYRWAtkSJVgTa/l72Xeu1clmy6KOrOkzm kDM1SdJ68e2+yrDgFBdg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1reZFk-00000000MFU-2CQX; Mon, 26 Feb 2024 11:34:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1reZFR-00000000M2v-1h1v for linux-arm-kernel@lists.infradead.org; Mon, 26 Feb 2024 11:34:19 +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 3E6B7DA7; Mon, 26 Feb 2024 03:34:55 -0800 (PST) Received: from e127643.broadband (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 220C53F6C4; Mon, 26 Feb 2024 03:34:13 -0800 (PST) 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, acme@kernel.org, oliver.upton@linux.dev, broonie@kernel.org Cc: James Clark , James Morse , Zenghui Yu , Catalin Marinas , Will Deacon , Mike Leach , Alexander Shishkin , Anshuman Khandual , Miguel Luis , Joey Gouly , Ard Biesheuvel , Javier Martinez Canillas , Mark Rutland , Arnd Bergmann , Andrew Walbran , Vincent Donnefort , Ryan Roberts , Fuad Tabba , Jing Zhang , linux-kernel@vger.kernel.org Subject: [PATCH v6 7/8] arm64: KVM: Write TRFCR value on guest switch with nVHE Date: Mon, 26 Feb 2024 11:30:35 +0000 Message-Id: <20240226113044.228403-8-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240226113044.228403-1-james.clark@arm.com> References: <20240226113044.228403-1-james.clark@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240226_033417_570755_07ED68E3 X-CRM114-Status: GOOD ( 19.90 ) 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 kvm_guest_trfcr. 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. In pKVM, the kvm_guest_trfcr can't be read and the host isn't trusted, so always disable trace. __debug_restore_trace() now has to restore unconditionally, because even a value of 0 needs to be written to overwrite whatever was set for the guest. Reviewed-by: Suzuki K Poulose Signed-off-by: James Clark Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/nvhe/debug-sr.c | 53 +++++++++++++++++------------- 1 file changed, 31 insertions(+), 22 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c index 4558c02eb352..3adac2e01908 100644 --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -51,30 +51,39 @@ static void __debug_restore_spe(u64 pmscr_el1) write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1); } -static void __debug_save_trace(u64 *trfcr_el1) +static void __debug_save_trace(struct kvm_vcpu *vcpu) { - *trfcr_el1 = 0; - - /* 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. - */ - *trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1); - write_sysreg_s(0, SYS_TRFCR_EL1); - isb(); - /* Drain the trace buffer to memory */ - tsb_csync(); + u64 host_trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1); + u64 guest_trfcr_el1; + + vcpu->arch.host_debug_state.trfcr_el1 = host_trfcr_el1; + + /* Check if the TRBE buffer or pKVM is enabled */ + if (is_protected_kvm_enabled() || + (vcpu_get_flag(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. + */ + write_sysreg_s(0, SYS_TRFCR_EL1); + isb(); + /* Drain the trace buffer to memory */ + tsb_csync(); + } else { + /* + * Tracing is allowed, apply the filters provided by the + * Coresight driver. + */ + guest_trfcr_el1 = kvm_guest_trfcr[vcpu->cpu]; + if (host_trfcr_el1 != guest_trfcr_el1) + write_sysreg_s(guest_trfcr_el1, SYS_TRFCR_EL1); + } } static void __debug_restore_trace(u64 trfcr_el1) { - if (!trfcr_el1) - return; - /* Restore trace filter controls */ write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1); } @@ -85,8 +94,8 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); /* Disable and flush Self-Hosted Trace generation */ - if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); + if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRFCR)) + __debug_save_trace(vcpu); } void __debug_switch_to_guest(struct kvm_vcpu *vcpu) @@ -98,7 +107,7 @@ void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) { if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); - if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) + if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRFCR)) __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); }