From patchwork Fri Apr 19 10:29:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13636201 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 35256C4345F for ; Fri, 19 Apr 2024 10:30:54 +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=0E/TG5N05enxp5e0TNiywoNU4sq1pIYJxG1jWG4/YV0=; b=RoJvWalL/aA3Zs UlS/uNL3cLS/BbCaqW368XEWqWaVML5OqpKTcg6cn7sa689CD0vDkVhNZ0vqlAMFRFuTOHsIhxTTq 0z/cYZ6ZLy48pLzd9g8LGQDeeTqd/ZtmH9IlrVmePJF1tmxSLqbWuIcgcnBZymysVtghXukbdQwuh qD0HckrVGUbSC1XU4IJHAnY8cnfpbeo9FMVZq6Jmcpt/n5yFM8AqXn88OWZtqQuWMMGxz/knI3vBM 1zorfz2wbiD94YNBY2EuX7lgpuMYludND/ljW6YD+Jhh4//mMSqyeEaMxMqnpifDvpfnSDc+6wOg1 YQfB7GWS7C0fWo24L3aA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rxlVs-00000005JNd-1dc3; Fri, 19 Apr 2024 10:30:36 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rxlVE-00000005IrQ-41w1 for linux-arm-kernel@lists.infradead.org; Fri, 19 Apr 2024 10:30:00 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id C2C6261994; Fri, 19 Apr 2024 10:29:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90DE1C3277B; Fri, 19 Apr 2024 10:29:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713522593; bh=3mtQOeqT5hkTI2xaw9Qk8k1KFnpFiefVFxYHDiC8HeM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Uj1i38ds2XG5KPJghO7zrdheHgTFxnNz+F9EZBEIwPRkiTi+ZklEUR71F5mjZeILt OY92HxZR3Ll4ETYYw9up1ydb/rBHgiC5yEE83BNXCaw9Bl2QCZJqGfScIvc2BHI3oH 5GGLYsm/CyBTZkDBPh1G/5c0FXx1jis7UWJWiNRCxhkMtOV9fdOwMLd+LXnlgAzJQD 4Wk3etYvgsoRUFVoQpyVPsYZRdsLu9JqX+Xlp2c114mnQpP/GaMT9WHjie6bTwej9l RGIaDb1MAEVkqyu3lhXxKCVnexgR1nI/Q/9dvn9W0HOT8YcsK3sVJ2XhD6OF8AxE8C NM7sqEaKbQSag== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rxlV9-00636W-SZ; Fri, 19 Apr 2024 11:29:51 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Joey Gouly , Fuad Tabba , Mostafa Saleh , Will Deacon , Catalin Marinas Subject: [PATCH v4 13/15] KVM: arm64: nv: Handle ERETA[AB] instructions Date: Fri, 19 Apr 2024 11:29:33 +0100 Message-Id: <20240419102935.1935571-14-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240419102935.1935571-1-maz@kernel.org> References: <20240419102935.1935571-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, joey.gouly@arm.com, tabba@google.com, smostafa@google.com, will@kernel.org, catalin.marinas@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240419_032957_263784_88A25203 X-CRM114-Status: GOOD ( 17.39 ) 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 Now that we have some emulation in place for ERETA[AB], we can plug it into the exception handling machinery. As for a bare ERET, an "easy" ERETAx instruction is processed as a fixup, while something that requires a translation regime transition or an exception delivery is left to the slow path. Reviewed-by: Joey Gouly Signed-off-by: Marc Zyngier --- arch/arm64/kvm/emulate-nested.c | 22 ++++++++++++++++++++-- arch/arm64/kvm/handle_exit.c | 3 ++- arch/arm64/kvm/hyp/vhe/switch.c | 13 +++++++++++-- 3 files changed, 33 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index 63a74c0330f1..72d733c74a38 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -2172,7 +2172,7 @@ static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) { - u64 spsr, elr; + u64 spsr, elr, esr; /* * Forward this trap to the virtual EL2 if the virtual @@ -2181,12 +2181,30 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) if (forward_traps(vcpu, HCR_NV)) return; + /* Check for an ERETAx */ + esr = kvm_vcpu_get_esr(vcpu); + if (esr_iss_is_eretax(esr) && !kvm_auth_eretax(vcpu, &elr)) { + /* + * Oh no, ERETAx failed to authenticate. If we have + * FPACCOMBINE, deliver an exception right away. If we + * don't, then let the mangled ELR value trickle down the + * ERET handling, and the guest will have a little surprise. + */ + if (kvm_has_pauth(vcpu->kvm, FPACCOMBINE)) { + esr &= ESR_ELx_ERET_ISS_ERETA; + esr |= FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_FPAC); + kvm_inject_nested_sync(vcpu, esr); + return; + } + } + preempt_disable(); kvm_arch_vcpu_put(vcpu); spsr = __vcpu_sys_reg(vcpu, SPSR_EL2); spsr = kvm_check_illegal_exception_return(vcpu, spsr); - elr = __vcpu_sys_reg(vcpu, ELR_EL2); + if (!esr_iss_is_eretax(esr)) + elr = __vcpu_sys_reg(vcpu, ELR_EL2); trace_kvm_nested_eret(vcpu, elr, spsr); diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 1ba2f788b2c3..407bdfbb572b 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -248,7 +248,8 @@ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) static int kvm_handle_eret(struct kvm_vcpu *vcpu) { - if (esr_iss_is_eretax(kvm_vcpu_get_esr(vcpu))) + if (esr_iss_is_eretax(kvm_vcpu_get_esr(vcpu)) && + !vcpu_has_ptrauth(vcpu)) return kvm_handle_ptrauth(vcpu); /* diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 26395171621b..8e1d98b691c1 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -208,7 +208,8 @@ void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu) static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code) { - u64 spsr, mode; + u64 esr = kvm_vcpu_get_esr(vcpu); + u64 spsr, elr, mode; /* * Going through the whole put/load motions is a waste of time @@ -242,10 +243,18 @@ static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code) return false; } + /* If ERETAx fails, take the slow path */ + if (esr_iss_is_eretax(esr)) { + if (!(vcpu_has_ptrauth(vcpu) && kvm_auth_eretax(vcpu, &elr))) + return false; + } else { + elr = read_sysreg_el1(SYS_ELR); + } + spsr = (spsr & ~(PSR_MODE_MASK | PSR_MODE32_BIT)) | mode; write_sysreg_el2(spsr, SYS_SPSR); - write_sysreg_el2(read_sysreg_el1(SYS_ELR), SYS_ELR); + write_sysreg_el2(elr, SYS_ELR); return true; }