From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 06F6E21FF24; Tue, 9 Sep 2025 13:46:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757425610; cv=none; b=gjVx4/HCvmR0LKa/Rm+/fmUP+TnwUI2Nw5d+YTcYeseQWraENxnFHogAdAfPsbn69JsFEVm0paX0X2xvnGoi74urlv6lGceAc2LFahREuMR5mU8kSfIVcevHJsdAAvHTch20xp5Quo+tYMLcB4t7ZFEcQ1V6Zd9INmeNh5dAv/o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757425610; c=relaxed/simple; bh=fzqqDDXTXgc1xKVVIHwn9vLmbH7HU5zTtM5qBx+V1ZU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BvCkzOvHw12hjEo90jHirLB+iVACfOPxYMviqHcPCzau4BlTOZlG2CRGtOwMJW43nj8iOMmVnRoTzbfGJLxSI3TTdd8sPpS7jQpt3OQIQce/+m1ZefSBfNv1Ae9/dZoDuzHN83+xUgDcBoQL3WbsQndJHH6eRwKWBDEa4bY7ZjA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=s6O+tDe2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="s6O+tDe2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5C10C4CEF4; Tue, 9 Sep 2025 13:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757425609; bh=fzqqDDXTXgc1xKVVIHwn9vLmbH7HU5zTtM5qBx+V1ZU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=s6O+tDe2nrg87Y7/S+Zk9CUrbY2AdJMilB+urbthEyUsD50w1xb2noRQ1hCfq76IO OC9sU4Hg0uJfdwkJkJOdPfYuPYJ3kLD6dm4xpaPKqMxOpRvB6YOhyKHGaoqDDtJNMk dwqSNFvk3G51DEKHhMh5plT2MAealjDxEpioHpsZDuSJmRqbkzRxgN5bRqAXaPdL4Z qecqt2l8gxUclecmElV1DM1/ODvksxyOjKEL6UsI40CQDjtXObCrGsN+vpMdcM4jU+ xFO2svDAchpW7sWBsiJrHobI4p46x7Kj0bJp+Tgv4oE94k83/EhbqFzHRLuvO3gP6j fXLkQS3/pTCCg== Date: Tue, 9 Sep 2025 14:46:42 +0100 From: Will Deacon To: Mostafa Saleh Cc: linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, robin.murphy@arm.com, jean-philippe@linaro.org, qperret@google.com, tabba@google.com, jgg@ziepe.ca, mark.rutland@arm.com, praan@google.com Subject: Re: [PATCH v4 01/28] KVM: arm64: Add a new function to donate memory with prot Message-ID: References: <20250819215156.2494305-1-smostafa@google.com> <20250819215156.2494305-2-smostafa@google.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250819215156.2494305-2-smostafa@google.com> On Tue, Aug 19, 2025 at 09:51:29PM +0000, Mostafa Saleh wrote: > Soon, IOMMU drivers running in the hypervisor might interact with > non-coherent devices, so it needs a mechanism to map memory as > non cacheable. > Add ___pkvm_host_donate_hyp() which accepts a new argument for prot, > so the driver can add KVM_PGTABLE_PROT_NORMAL_NC. > > Signed-off-by: Mostafa Saleh > --- > arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 1 + > arch/arm64/kvm/hyp/nvhe/mem_protect.c | 11 +++++++++-- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > index 5f9d56754e39..52d7ee91e18c 100644 > --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > @@ -36,6 +36,7 @@ int __pkvm_prot_finalize(void); > int __pkvm_host_share_hyp(u64 pfn); > int __pkvm_host_unshare_hyp(u64 pfn); > int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages); > +int ___pkvm_host_donate_hyp(u64 pfn, u64 nr_pages, enum kvm_pgtable_prot prot); > int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages); > int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages); > int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages); > diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > index 8957734d6183..861e448183fd 100644 > --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > @@ -769,13 +769,15 @@ int __pkvm_host_unshare_hyp(u64 pfn) > return ret; > } > > -int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages) > +int ___pkvm_host_donate_hyp(u64 pfn, u64 nr_pages, enum kvm_pgtable_prot prot) > { > u64 phys = hyp_pfn_to_phys(pfn); > u64 size = PAGE_SIZE * nr_pages; > void *virt = __hyp_va(phys); > int ret; > > + WARN_ON(prot & KVM_PGTABLE_PROT_X); Should this actually just enforce that the permissions are KVM_PGTABLE_PROT_RW: WARN_ON((prot & KVM_PGTABLE_PROT_RWX) != KVM_PGTABLE_PROT_RW); ? Since the motivation is about the memory type rather than the permissions, it would be best to preserve the current behaviour. Will