From patchwork Mon Feb 26 10:06:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13571806 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8F375811A; Mon, 26 Feb 2024 10:07:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708942071; cv=none; b=WGYPXyGuauvP6oDSDaotywYLxmbWWeVasIkq6kXsEji3O5uy7guGO+l42Se9mv2aI/Q3xfEGCLTWHBJ+saYK5IVRrZYEzvERnM7sdRJtzLtpQD1O+A5oC3Qt+wTUu7mEM/F4S2PwhxSuHxUdl5ASUdcGNtQ8TU+hwD7wLW3sQr8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708942071; c=relaxed/simple; bh=nex5gH5tTCMxgjNnQWHLjiNo0+HbQsY+jyRrPhCJzDg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=lEZsfnjQk0dgiw3gABLyKTbMPSOoT0q3dbDxSNsdvNeYswI3aoGlRZp29OOlhqtzRW3xfWHPIOqWB/A+bIkjv6oBoniQ35Ky5pfuykIkFeIKVpIpgt1WxtSZweCJahPsFaQPdwmFsfteowfeC7EYCSyT3vYk+3Og9HYV6nrvubo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bhi0kD2Z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Bhi0kD2Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F737C433F1; Mon, 26 Feb 2024 10:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708942070; bh=nex5gH5tTCMxgjNnQWHLjiNo0+HbQsY+jyRrPhCJzDg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bhi0kD2Zl4pcEnY1uKd3gXL+/9TlmeMFMvhR7cY2dpUr02+INp1LywrMozEXVaLiD Iimn+1bQalYURd+ZF57nhgjzRTLsO4P3lUlWNgj1RR7/Bgz+UgwN8hfgGg9TnmG/mi 7wQMVGnL4aXtXcZS7LMKD1jgv3/yTmoB0ZlT+cp48gUOag4iUVq/vjlVO1POpi4myH NtZcFRiSU4wGcu8Nv4N4xiSXYvCc+F+bbGQeTzq6ldp5x+aP/OpCPDGv2p7yF4joLL QTcg9eOkA2+fq2bJ2JJVg2X+aIriVxT+iIMsjuGO9WJKSkeWQ1YpGXHol954J0nsvE bUou7zVwMJanQ== 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 1reXti-006nQ5-Fu; Mon, 26 Feb 2024 10:07:46 +0000 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 , Will Deacon , Catalin Marinas Subject: [PATCH v2 12/13] KVM: arm64: nv: Handle ERETA[AB] instructions Date: Mon, 26 Feb 2024 10:06:00 +0000 Message-Id: <20240226100601.2379693-13-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240226100601.2379693-1-maz@kernel.org> References: <20240226100601.2379693-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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, 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 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. Signed-off-by: Marc Zyngier Reviewed-by: Joey Gouly --- 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 3ea9bdf6b555..49d36666040e 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; }