From patchwork Thu Jun 11 09:09:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11599571 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F14DF60D for ; Thu, 11 Jun 2020 09:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D484F20842 for ; Thu, 11 Jun 2020 09:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591866614; bh=yOm45AD9t0v2jikTpfEmX/BTUdf7/lOJLGc3lka2zE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eaMJRKvDHllUqXoIOenVKSgk5JRiUIbMJ374diGH9QLwvCSlqw3PaDEhuFdjd+9ad q55/bmpfVv+8z4MDxgrno0cMAw+DPnHwZ/SvvaA9+1nJDk54bfyOKsJ0ZZ4E4jsDV/ swAWNJpUBZnmXyK6RwD5e+sm+WVEjZivxxvCY9S4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727010AbgFKJKN (ORCPT ); Thu, 11 Jun 2020 05:10:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:49764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726988AbgFKJKL (ORCPT ); Thu, 11 Jun 2020 05:10:11 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2041520835; Thu, 11 Jun 2020 09:10:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591866611; bh=yOm45AD9t0v2jikTpfEmX/BTUdf7/lOJLGc3lka2zE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w6dqOHtIIKA2gHtH04eKiOqlfR6ESJ+c79VJUglnFaf3w2scE1BB6IbDiTI6cJN71 aKCCcBsNmSa+Ho/eV+3DmDmS/YRGTnZY2GEvmZpyNRvtV1zLNXASV3+KTHaQ5r4GeH +xRa4KPDBUoZSMCHob1h1eQjKLOufH4lqGpeYUfo= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jjJDt-0022ZT-M6; Thu, 11 Jun 2020 10:10:09 +0100 From: Marc Zyngier To: Paolo Bonzini Cc: Alexandru Elisei , Andrew Scull , James Morse , Mark Rutland , Julien Thierry , Suzuki K Poulose , kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: [PATCH 04/11] KVM: arm64: Stop save/restoring ACTLR_EL1 Date: Thu, 11 Jun 2020 10:09:49 +0100 Message-Id: <20200611090956.1537104-5-maz@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200611090956.1537104-1-maz@kernel.org> References: <20200611090956.1537104-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, ascull@google.com, james.morse@arm.com, mark.rutland@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: James Morse KVM sets HCR_EL2.TACR via HCR_GUEST_FLAGS. This means ACTLR* accesses from the guest are always trapped, and always return the value in the sys_regs array. The guest can't change the value of these registers, so we are save restoring the reset value, which came from the host. Stop save/restoring this register. Keep the storage for this register in sys_regs[] as this is how the value is exposed to user-space, removing it would break migration. Signed-off-by: James Morse Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200529150656.7339-4-james.morse@arm.com --- arch/arm64/kvm/hyp/sysreg-sr.c | 2 -- arch/arm64/kvm/sys_regs.c | 2 -- 2 files changed, 4 deletions(-) diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 6d2df9fe0b5d..0d60e6ee96b2 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -39,7 +39,6 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) { ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1); ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(SYS_SCTLR); - ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(SYS_CPACR); ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(SYS_TTBR0); ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(SYS_TTBR1); @@ -122,7 +121,6 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) isb(); } - write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1); write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], SYS_CPACR); write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], SYS_TTBR0); write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], SYS_TTBR1); diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 12f8d57a3cb8..dfb966f3863a 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -78,7 +78,6 @@ static bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val) switch (reg) { case CSSELR_EL1: *val = read_sysreg_s(SYS_CSSELR_EL1); break; case SCTLR_EL1: *val = read_sysreg_s(SYS_SCTLR_EL12); break; - case ACTLR_EL1: *val = read_sysreg_s(SYS_ACTLR_EL1); break; case CPACR_EL1: *val = read_sysreg_s(SYS_CPACR_EL12); break; case TTBR0_EL1: *val = read_sysreg_s(SYS_TTBR0_EL12); break; case TTBR1_EL1: *val = read_sysreg_s(SYS_TTBR1_EL12); break; @@ -118,7 +117,6 @@ static bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) switch (reg) { case CSSELR_EL1: write_sysreg_s(val, SYS_CSSELR_EL1); break; case SCTLR_EL1: write_sysreg_s(val, SYS_SCTLR_EL12); break; - case ACTLR_EL1: write_sysreg_s(val, SYS_ACTLR_EL1); break; case CPACR_EL1: write_sysreg_s(val, SYS_CPACR_EL12); break; case TTBR0_EL1: write_sysreg_s(val, SYS_TTBR0_EL12); break; case TTBR1_EL1: write_sysreg_s(val, SYS_TTBR1_EL12); break;