From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3698C433F5 for ; Fri, 29 Oct 2021 00:32:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B40AB6112F for ; Fri, 29 Oct 2021 00:32:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231431AbhJ2AfO (ORCPT ); Thu, 28 Oct 2021 20:35:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231365AbhJ2AfM (ORCPT ); Thu, 28 Oct 2021 20:35:12 -0400 Received: from mail-oi1-x24a.google.com (mail-oi1-x24a.google.com [IPv6:2607:f8b0:4864:20::24a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAB85C061570 for ; Thu, 28 Oct 2021 17:32:43 -0700 (PDT) Received: by mail-oi1-x24a.google.com with SMTP id q65-20020aca5c44000000b0029c0a4d28a5so113477oib.5 for ; Thu, 28 Oct 2021 17:32:43 -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=8jHkcukOGs60Vh8sqIk5PEDCEkQaDcCSTeMEW1ZoThU=; b=JdhR5KgizbNUUTAjmlYRxJx0EtRpzClBjN8sNGCA4JJO4HHHb6OXPbkGWVWsexwurl kRU/OrYOvFTWusWVmdojV2LmmS3eksr37DnFEYydJYDaWiHjFtnAErqEYg97xPlTHxHn nLUvfSd9uIXXDeEqhI/d07olbwebG44JjMzSvnmAiFv9ny7vqeJmJcMZCzv9Txyee4A1 AH50A4MUa8rJlxoiWXiA/FNFIrwGua22jIX3diDsCegQ2R353dFwc0iVF1Ubi2YZ4UDY m1tQpzc7VBbKbCWLZcVd52Qs91rPh+JGCvqvxhTGc6bQlM+BZoafUHzt0/wQE/NVWNBr 1N3Q== 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=8jHkcukOGs60Vh8sqIk5PEDCEkQaDcCSTeMEW1ZoThU=; b=cm4kMnqLsKAz2CEQnA+hAq9y7ybZn9zoy/1Rr4JlO7D7CnV/TzAcxFBj+CjslCjp/I tw9YRWIn9B+aHO5CohC/T+I12VZX/tmE4kpDgycIpEl3rWjyeUAUPAC7CRajPHhKDlkm HbsB79Ncq+xxnfhtYYPWqMihP3jc/ePF+Y4SgMLOwfEYN1APKQEVdk1mFTYOSlJKMfik y0OQgYPZXML2J291DkPkWz8HZJzu+uR49pZkjnNGfMcf3NV50aSoXwhrszhD5dRB1Guq TT4/7JTxoIc6fq4mHtuLZ6QMqczNGLIM8N9J0ctJeh2KDHtUJ0qw8fxWqPzAsBKB2Al/ sBwg== X-Gm-Message-State: AOAM533frOhon5YjoEH/KcXjQvceTVti1c5nnonnTBZ070BlWTZX8W6o wmIgo6fOFjxSrfTh5gUUL0nqtExbPb0= X-Google-Smtp-Source: ABdhPJyaxDFxxmg122WEeWbg/RrVAHJJLIJnz/MlGJ2fjJIs/pCIhzGPDOjoXFCCGLJwb76Yre8ULKN1ULY= X-Received: from oupton.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:404]) (user=oupton job=sendgmr) by 2002:aca:3e86:: with SMTP id l128mr11380539oia.120.1635467563254; Thu, 28 Oct 2021 17:32:43 -0700 (PDT) Date: Fri, 29 Oct 2021 00:32:01 +0000 In-Reply-To: <20211029003202.158161-1-oupton@google.com> Message-Id: <20211029003202.158161-3-oupton@google.com> Mime-Version: 1.0 References: <20211029003202.158161-1-oupton@google.com> X-Mailer: git-send-email 2.33.1.1089.g2158813163f-goog Subject: [PATCH 2/3] KVM: arm64: Allow the guest to change the OS Lock status 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, Andrew Jones , Peter Shier , Ricardo Koller , Reiji Watanabe , Oliver Upton Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org KVM diverges from the architecture in the way it handles the OSLAR_EL1 register. While the architecture requires that the register be WO and that the OSLK bit is 1 out of reset, KVM implements the register as RAZ/WI. Align KVM with the architecture by permitting writes to OSLAR_EL1. Since the register is WO, stash the OS Lock status bit in OSLSR_EL1 and context switch the status between host/guest. Additionally, change the reset value of the OSLK bit to 1. Suggested-by: Marc Zyngier Signed-off-by: Oliver Upton --- arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 5 +++++ arch/arm64/kvm/sys_regs.c | 22 +++++++++++++++++++--- 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h index de7e14c862e6..a65dab34f85b 100644 --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h @@ -65,6 +65,8 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) ctxt_sys_reg(ctxt, SP_EL1) = read_sysreg(sp_el1); ctxt_sys_reg(ctxt, ELR_EL1) = read_sysreg_el1(SYS_ELR); ctxt_sys_reg(ctxt, SPSR_EL1) = read_sysreg_el1(SYS_SPSR); + + ctxt_sys_reg(ctxt, OSLSR_EL1) = read_sysreg(oslsr_el1); } static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt) @@ -149,6 +151,9 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) write_sysreg(ctxt_sys_reg(ctxt, SP_EL1), sp_el1); write_sysreg_el1(ctxt_sys_reg(ctxt, ELR_EL1), SYS_ELR); write_sysreg_el1(ctxt_sys_reg(ctxt, SPSR_EL1), SYS_SPSR); + + /* restore OSLSR_EL1 by writing the OSLK bit to OSLAR_EL1 */ + write_sysreg((ctxt_sys_reg(ctxt, OSLSR_EL1) >> 1) & 1, oslar_el1); } static inline void __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 0eb03e7508fe..0840ae081290 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -298,6 +298,22 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu, return true; } +static bool trap_oslar_el1(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 oslsr; + + if (!p->is_write) + return read_zero(vcpu, p); + + /* preserve all but the OSLK bit */ + oslsr = vcpu_read_sys_reg(vcpu, OSLSR_EL1) & ~0x2ull; + vcpu_write_sys_reg(vcpu, OSLSR_EL1, oslsr | ((p->regval & 1) << 1)); + return true; +} + + static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) @@ -1439,8 +1455,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { DBG_BCR_BVR_WCR_WVR_EL1(15), { SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi }, - { SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi }, - { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1, 0x00000008 }, + { SYS_DESC(SYS_OSLAR_EL1), trap_oslar_el1 }, + { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1, 0x0000000A }, { SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi }, { SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi }, { SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi }, @@ -1912,7 +1928,7 @@ static const struct sys_reg_desc cp14_regs[] = { DBGBXVR(0), /* DBGOSLAR */ - { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi }, + { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_oslar_el1 }, DBGBXVR(1), /* DBGOSLSR */ { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1, NULL, OSLSR_EL1 }, -- 2.33.0.1079.g6e70778dc9-goog