From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C2D6236AF9; Mon, 18 Mar 2024 11:25:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710761133; cv=none; b=YOiwIQHr+4Ep96zkVWd5BMgxFNb1etaIq6elhOXqQK434cS47KDNaYoRJl4KFigdXhL1gElZpOdQ2EvSKUB8m+n8+ZLdeGF9LpZpxCry1mnzOVX1W8R0IGZy3thQfCuILoMlbLY3s9BfrollXdUnc4Y9PND7z90LbTnK8OHmGUA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710761133; c=relaxed/simple; bh=aC23jAhpl0yvzLg9qN8KuMrly14TJFysyuJEzIOBEaQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tEqybUf5H/4Awhs2pO8l87LpOZ8Bb6enRvwIiSZO67wEbWhvqWEZQcpRxZS2XLG933ipNBHz6/OSKCCOFDHEL079vn/swr0dWuEkn8b2qwWDVCyM9U1vnpVywOSWap/Ter6hiykgAW9L6jPNj6o9iq3FmJJsNiJHA1VmbTQESp0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 268A6DA7; Mon, 18 Mar 2024 04:26:06 -0700 (PDT) Received: from [10.57.12.69] (unknown [10.57.12.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1102E3F762; Mon, 18 Mar 2024 04:25:27 -0700 (PDT) Message-ID: Date: Mon, 18 Mar 2024 11:25:28 +0000 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 09/28] arm64: RME: RTT handling Content-Language: en-GB To: Ganapatrao Kulkarni , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev References: <20230127112248.136810-1-suzuki.poulose@arm.com> <20230127112932.38045-1-steven.price@arm.com> <20230127112932.38045-10-steven.price@arm.com> <84bb27a2-0649-4ba4-8f31-baff7b3a9b3a@os.amperecomputing.com> From: Steven Price In-Reply-To: <84bb27a2-0649-4ba4-8f31-baff7b3a9b3a@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 18/03/2024 11:01, Ganapatrao Kulkarni wrote: > > On 27-01-2023 04:59 pm, Steven Price wrote: >> The RMM owns the stage 2 page tables for a realm, and KVM must request >> that the RMM creates/destroys entries as necessary. The physical pages >> to store the page tables are delegated to the realm as required, and can >> be undelegated when no longer used. >> >> Signed-off-by: Steven Price >> --- >>   arch/arm64/include/asm/kvm_rme.h |  19 +++++ >>   arch/arm64/kvm/mmu.c             |   7 +- >>   arch/arm64/kvm/rme.c             | 139 +++++++++++++++++++++++++++++++ >>   3 files changed, 162 insertions(+), 3 deletions(-) >> >> diff --git a/arch/arm64/include/asm/kvm_rme.h >> b/arch/arm64/include/asm/kvm_rme.h >> index a6318af3ed11..eea5118dfa8a 100644 >> --- a/arch/arm64/include/asm/kvm_rme.h >> +++ b/arch/arm64/include/asm/kvm_rme.h >> @@ -35,5 +35,24 @@ u32 kvm_realm_ipa_limit(void); >>   int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap); >>   int kvm_init_realm_vm(struct kvm *kvm); >>   void kvm_destroy_realm(struct kvm *kvm); >> +void kvm_realm_destroy_rtts(struct realm *realm, u32 ia_bits, u32 >> start_level); >> + >> +#define RME_RTT_BLOCK_LEVEL    2 >> +#define RME_RTT_MAX_LEVEL    3 >> + >> +#define RME_PAGE_SHIFT        12 >> +#define RME_PAGE_SIZE        BIT(RME_PAGE_SHIFT) > > Can we use PAGE_SIZE and PAGE_SHIFT instead of redefining? > May be we can use them to define RME_PAGE_SIZE and RME_PAGE_SHIFT. At the moment the code only supports the host page size matching the RMM's. But I want to leave open the possibility for the host size being larger than the RMM's. In this case PAGE_SHIFT/PAGE_SIZE will not equal RME_PAGE_SIZE and RME_PAGE_SHIFT. The host will have to create multiple RMM RTTs for each host page. >> +/* See ARM64_HW_PGTABLE_LEVEL_SHIFT() */ >> +#define RME_RTT_LEVEL_SHIFT(l)    \ >> +    ((RME_PAGE_SHIFT - 3) * (4 - (l)) + 3) > > Instead of defining again, can we define to > ARM64_HW_PGTABLE_LEVEL_SHIFT? Same as above - ARM64_HW_PGTABLE_LEVEL_SHIFT uses PAGE_SHIFT, but we want the same calculation using RME_PAGE_SHIFT which might be different. Thanks, Steve