From patchwork Fri Apr 1 01:08:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 12797827 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 6EA0EC433EF for ; Fri, 1 Apr 2022 01:10:28 +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:Cc:To:From:Subject:References: Mime-Version:Message-Id:In-Reply-To:Date:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=8phEwXt3N/qj5FUZ5OBz0fYfe+uQsU50s05D4aygaGw=; b=4ue3jQ2jFd3hMAaMhJA3YzaqmF iamyCX+8e1RrRH9DhefRBpJH57/d7+GcRMu2EQ26g+i2iB9oofiYSzcTeMYHBY2uqYAPQ9S4mQ0iO z1uMIGfcpqMXiS4YC5C4/nFXvxa7X+Z1SbJ4vXN1kmuuuLqu9PjKsXXPlSfLMGFDvkM/tFCiZHc3D IZE3Y1wbCTXnXfnkVEFyclfgy63AAiyGqgns0P7K6ezJYWegPDnJFV+2kyc8jz8/mssAuQwI9957I ZQjuub0HLtFqvKILlTc+yuBijlmBUdm6favxBi1oKfIJR66G25ciFYZRDGdAQtAdy7R2ULqLCHj9S Ghs6BhAw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1na5ms-0047fH-Go; Fri, 01 Apr 2022 01:09:14 +0000 Received: from mail-il1-x149.google.com ([2607:f8b0:4864:20::149]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1na5mN-0047X0-EQ for linux-arm-kernel@lists.infradead.org; Fri, 01 Apr 2022 01:08:45 +0000 Received: by mail-il1-x149.google.com with SMTP id s4-20020a92c5c4000000b002c7884b8608so841371ilt.21 for ; Thu, 31 Mar 2022 18:08:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=06vWdix0nphKiUgy/DH5I5wyYbLVTiSxn7JE1pEyNQk=; b=FLhwlY5XN01iVZRMrKYr/uhdah5Vk/+PRwg8u6ly+7J8I0HOyqcf+E+ggm+HGeuUeL trFUgcq1JRk2zubIBPxJvdzUPy92mnt2WDytdEC8c2A8c2OmqKItvcVEoYHA4bVN5jmQ hCJuvk+U9bOfPqjchOOwA9uWCl8ArYmtSHyu2JZawi2ekEwIoQMtxvDJKQ3kwMOHbpOo 0IBeHSWXx0DsHoCeHEC9p0AU2hesZh2XmMRKlIM1Gmu7BCpTqnKcwA6mUaTsu5GTbAUx KMptlZIF4ZDJZPmymeTAbH2Hc0aymqdbIZv7InT24VcPR0e2DQxpKruF7E9qg9jcz5yY 6x5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=06vWdix0nphKiUgy/DH5I5wyYbLVTiSxn7JE1pEyNQk=; b=iR+iIoXumrap+NlssGJeKefg0Sw+6gXxR9cdMb1nL+iU35yTeARVNnDG1Ue5QGI8Im k6I8P9YFwUIsvzocQ/jmcKz/GKVvOZdqs7apQtE4TKlmt37JDj4g9BABq7EfUT2SQpfV DdMMBTMcnAKildPsSZ+KkhCimJCJfptgrId9Efkrc0pBH18BSLksrxRZNnG/nUt0SD84 3Srt+KWsi06OBAOsvNpWF+WZ9l8dyJXAXU4UhnQW1R47ajOp4IzRcBQAc828+PFvp2He 16txpVhGGRapR3COxP/6roEF8m8keH0FxtaoXu0LsEpO78geLM1WebI02CXYC4Q/rhuh PG5Q== X-Gm-Message-State: AOAM530YzG2N9A74HcZHxdKTW0l3yMenuIVW7/WjENSA2hj4BT2NFK0t JED0jl6MASFMg13H1v9Ocags98aUx34= X-Google-Smtp-Source: ABdhPJxie27Eja2GBAYjy1wyGtshgFLEF0uMF2Yaxdt/g8WYlz3+cHfV7mgpsQgpGHu2s2wyB45MDZlErNY= X-Received: from oupton.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:404]) (user=oupton job=sendgmr) by 2002:a05:6e02:dd3:b0:2c9:cf64:6be6 with SMTP id l19-20020a056e020dd300b002c9cf646be6mr8239156ilj.68.1648775321155; Thu, 31 Mar 2022 18:08:41 -0700 (PDT) Date: Fri, 1 Apr 2022 01:08:31 +0000 In-Reply-To: <20220401010832.3425787-1-oupton@google.com> Message-Id: <20220401010832.3425787-3-oupton@google.com> Mime-Version: 1.0 References: <20220401010832.3425787-1-oupton@google.com> X-Mailer: git-send-email 2.35.1.1094.g7c7d902a7c-goog Subject: [PATCH v2 2/3] KVM: arm64: Plumb cp10 ID traps through the AArch64 sysreg handler From: Oliver Upton To: kvmarm@lists.cs.columbia.edu Cc: kvm@vger.kernel.org, Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , linux-arm-kernel@lists.infradead.org, Peter Shier , Ricardo Koller , Reiji Watanabe , Oliver Upton X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220331_180844_001798_760357EA X-CRM114-Status: GOOD ( 13.96 ) 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 In order to enable HCR_EL2.TID3 for AArch32 guests KVM needs to handle traps where ESR_EL2.EC=0x8, which corresponds to an attempted VMRS access from an ID group register. Specifically, the MVFR{0-2} registers are accessed this way from AArch32. Conveniently, these registers are architecturally mapped to MVFR{0-2}_EL1 in AArch64. Furthermore, KVM already handles reads to these aliases in AArch64. Plumb VMRS read traps through to the general AArch64 system register handler. Signed-off-by: Oliver Upton Reviewed-by: Reiji Watanabe --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/handle_exit.c | 1 + arch/arm64/kvm/sys_regs.c | 61 +++++++++++++++++++++++++++++++ 3 files changed, 63 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 0e96087885fe..7a65ac268a22 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -673,6 +673,7 @@ int kvm_handle_cp14_64(struct kvm_vcpu *vcpu); int kvm_handle_cp15_32(struct kvm_vcpu *vcpu); int kvm_handle_cp15_64(struct kvm_vcpu *vcpu); int kvm_handle_sys_reg(struct kvm_vcpu *vcpu); +int kvm_handle_cp10_id(struct kvm_vcpu *vcpu); void kvm_reset_sys_regs(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 97fe14aab1a3..5088a86ace5b 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -167,6 +167,7 @@ static exit_handle_fn arm_exit_handlers[] = { [ESR_ELx_EC_CP15_64] = kvm_handle_cp15_64, [ESR_ELx_EC_CP14_MR] = kvm_handle_cp14_32, [ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store, + [ESR_ELx_EC_CP10_ID] = kvm_handle_cp10_id, [ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64, [ESR_ELx_EC_HVC32] = handle_hvc, [ESR_ELx_EC_SMC32] = handle_smc, diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 8b791256a5b4..4863592d060d 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2341,6 +2341,67 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, static int emulate_sys_reg(struct kvm_vcpu *vcpu, struct sys_reg_params *params); +/* + * The CP10 ID registers are architecturally mapped to AArch64 feature + * registers. Abuse that fact so we can rely on the AArch64 handler for accesses + * from AArch32. + */ +static bool kvm_esr_cp10_id_to_sys64(u32 esr, struct sys_reg_params *params) +{ + params->is_write = ((esr & 1) == 0); + params->Op0 = 3; + params->Op1 = 0; + params->CRn = 0; + params->CRm = 3; + + switch ((esr >> 10) & 0xf) { + /* MVFR0 */ + case 0b0111: + params->Op2 = 0; + break; + /* MVFR1 */ + case 0b0110: + params->Op2 = 1; + break; + /* MVFR2 */ + case 0b0101: + params->Op2 = 2; + break; + default: + return false; + } + + return true; +} + +/** + * kvm_handle_cp10_id() - Handles a VMRS trap on guest access to a 'Media and + * VFP Register' from AArch32. + * @vcpu: The vCPU pointer + * + * MVFR{0-2} are architecturally mapped to the AArch64 MVFR{0-2}_EL1 registers. + * Work out the correct AArch64 system register encoding and reroute to the + * AArch64 system register emulation. + */ +int kvm_handle_cp10_id(struct kvm_vcpu *vcpu) +{ + int Rt = kvm_vcpu_sys_get_rt(vcpu); + u32 esr = kvm_vcpu_get_esr(vcpu); + struct sys_reg_params params; + int ret; + + /* UNDEF on any unhandled register or an attempted write */ + if (!kvm_esr_cp10_id_to_sys64(esr, ¶ms) || params.is_write) { + kvm_inject_undefined(vcpu); + return 1; + } + + ret = emulate_sys_reg(vcpu, ¶ms); + + vcpu_set_reg(vcpu, Rt, params.regval); + return ret; +} + /** * kvm_emulate_cp15_id_reg() - Handles an MRC trap on a guest CP15 access where * CRn=0, which corresponds to the AArch32 feature