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 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 433C1C61D99 for ; Wed, 22 Nov 2023 15:15:33 +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: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0bZu4nYZa7XC9vAsLNTSiiNmfF3CIjbBYYK8xv5GDdU=; b=KejmV5iO0Y8Bgq UUfKvVQ/a0Q2EvaMKS0gBArYIOl4qi+1leL/f06nPLmzFj5wQhNqIpmCCznj5Jkr8o2wyxozIMaTp D8+j+BWmSb+sTvULw3rai/qc3JmXXqPXUFcQPGHVc8r+bXtN2swf1xtf8VnV8HVOzVNwyCiTgwPqM vMrNY7pBWzMBXG/gifqYjLZjROMhFZdWe5K4krkuKyE/7vB9OVYHEho5C34WyypGhIhiXCiQ71jSG 0kHnF71klkXydzlan9Ut3gbeHBhn1pRZxGmBo+0cBU+4wy0BOtc66dwLNhX9rUE3vvg+tfN9xKnjN pE0FR/FBqN4jrVObMsVA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r5owR-002DW7-1O; Wed, 22 Nov 2023 15:15:03 +0000 Received: from sin.source.kernel.org ([145.40.73.55]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r5owO-002DTC-0T for linux-arm-kernel@lists.infradead.org; Wed, 22 Nov 2023 15:15:02 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 72665CE210A; Wed, 22 Nov 2023 15:14:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A806BC433C9; Wed, 22 Nov 2023 15:14:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700666095; bh=1r6Oa1B7LlMPEDY9HdH5ICBzcBxUISrfcAdDre8IFaU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Hz2Znz9MhITBH/JVOlAHvoyVIwigfC5SIN29pfYeCYUwwz4oWAUqZKUQbcI36JL0A SOnhvTAvSWS3aZTJPO1owQ2PWxcAW09hsRO4GsiVV0RRISnDray2a6ljuFLdgQjR4s m8gzzZ1+Z7ZeYvRQ+QkWqFiIl1UUk/GjE9CSHOaGwCyvNgayETnq1Ys/jCaEViDxmB 9/Qed1SNbGSHOUtfLRfHnSqM5R8QV7w01ZCzQGN7UMhikflrREfe/o/uSFje6Ou6UJ HaqWUdw9WF8YTIHUGYJvFtvgSpKQoVYfH/84bbyElrHSdfkExl9npEE04PWJ8ce2Eg BVfyxq1IMh32g== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1r5owH-00FT5Q-6E; Wed, 22 Nov 2023 15:14:53 +0000 Date: Wed, 22 Nov 2023 15:14:52 +0000 Message-ID: <86h6ldzuoj.wl-maz@kernel.org> From: Marc Zyngier To: Ryan Roberts Cc: Catalin Marinas , Will Deacon , Oliver Upton , Suzuki K Poulose , James Morse , Zenghui Yu , Ard Biesheuvel , Anshuman Khandual , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: Re: [PATCH v5 04/12] arm64: Add ARM64_HAS_LPA2 CPU capability In-Reply-To: <20231116142931.1675485-5-ryan.roberts@arm.com> References: <20231116142931.1675485-1-ryan.roberts@arm.com> <20231116142931.1675485-5-ryan.roberts@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: ryan.roberts@arm.com, catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, suzuki.poulose@arm.com, james.morse@arm.com, yuzenghui@huawei.com, ardb@kernel.org, anshuman.khandual@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev 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-20231122_071500_685838_3C7348DD X-CRM114-Status: GOOD ( 21.73 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 16 Nov 2023 14:29:23 +0000, Ryan Roberts wrote: > > Expose FEAT_LPA2 as a capability so that we can take advantage of > alternatives patching in the hypervisor. > > Although FEAT_LPA2 presence is advertised separately for stage1 and > stage2, the expectation is that in practice both stages will either > support or not support it. Therefore, we combine both into a single > capability, allowing us to simplify the implementation. KVM requires > support in both stages in order to use LPA2 since the same library is > used for hyp stage 1 and guest stage 2 pgtables. > > Signed-off-by: Ryan Roberts > --- > arch/arm64/include/asm/cpufeature.h | 5 ++++ > arch/arm64/kernel/cpufeature.c | 39 +++++++++++++++++++++++++++++ > arch/arm64/tools/cpucaps | 1 + > 3 files changed, 45 insertions(+) > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index f6d416fe49b0..acf109581ac0 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -819,6 +819,11 @@ static inline bool system_supports_tlb_range(void) > return alternative_has_cap_unlikely(ARM64_HAS_TLB_RANGE); > } > > +static inline bool system_supports_lpa2(void) > +{ > + return cpus_have_final_cap(ARM64_HAS_LPA2); > +} > + > int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt); > bool try_emulate_mrs(struct pt_regs *regs, u32 isn); > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 0e7d0c2bab36..38dfdaff8176 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -1768,6 +1768,39 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, > return !meltdown_safe; > } > > +#if defined(CONFIG_ARM64_4K_PAGES) || defined(CONFIG_ARM64_16K_PAGES) nit: if you move patch #5 before this one, this can be gated by the actual definition of ID_AA64MMFR0_EL1_TGRAN_{,2_}LPA2 instead of the page size indirection. I personally would find it slightly more readable. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel