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 013B6CA5FC4 for ; Fri, 2 Oct 2026 15:43:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=axC4LDVOJsVlW/fdoP4BPdGRq/gYDshEFRg+pfkCn2A=; b=3g8KZtXVO0BVnD9R9/9ttA1mj9 F5WIf38hjdVqjzkPIelRtVXc81ikn4BszmX303PLb3nuQk8+rkYoTjdiA3pjgBFeP3vIzCIiUAb56 7M4TyLq4XF02DcQfNb+GqA43V5lbQVKM9kqyePceVdLTd8KUxJW6y1juZk89ao5C+uEaQPm3rt4Wv KH7mhA/xF/jZyL+ODfMhraNVOJ7c4OVIdv9y1jFqO6g9FGF3wWL7V/XgseCkc4IFWH8bWtFmIEO+z heCo7v800jI6rsP9/qY++2ja2a31WaWWTc+xxDQgY+o3KQl0mTgS/jq8fsD2v9kFg0Sy8zi9UzOHI tKf4iJCg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCfPe-0000000By6i-1lZ2; Fri, 02 Oct 2026 15:43:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCfPY-0000000By4a-2HMk for linux-arm-kernel@lists.infradead.org; Fri, 02 Oct 2026 15:43:02 +0000 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 8AFC2169C; Fri, 2 Oct 2026 08:42:56 -0700 (PDT) Received: from [10.57.8.170] (unknown [10.57.8.170]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 288203F882; Fri, 2 Oct 2026 08:42:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790955779; bh=r8+UnxmyfA5EDSuksv2pnxeyK5XiuiA24DSSA+ymriQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Dzh5F1AKrpbHWa673YlUnb+QaPBv+ryTwN2qA0v7GExcq5nJEtJAKOdiFHBJNPEFP pFwajcDOxIV5F67JsKcpzvdtetsme/gidZj8IvCCmDJwCBdfv+qHhDNUFcqS9aqjss UiKs9r9V+zuQQ5J1dugVGegGFqHZdLdg0ZgZZMCw= Message-ID: <87659487-6a77-4b04-907a-859e1738395e@arm.com> Date: Fri, 2 Oct 2026 16:42:52 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v21 05/23] KVM: arm64: Track the type of VM in kvm_arch Content-Language: en-GB To: Marc Zyngier Cc: Fuad Tabba , kvm@vger.kernel.org, kvmarm@lists.linux.dev, will@kernel.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, steven.price@arm.com, aneesh.kumar@kernel.org, oupton@kernel.org, gshan@redhat.com, joey.gouly@arm.com, yuzenghui@huawei.com, linux-coco@lists.linux.dev, gankulkarni@os.amperecomputing.com, sdonthineni@nvidia.com, alpergun@google.com, fj0570is@fujitsu.com, WeiLin.Chang@arm.com, lpieralisi@kernel.org, enju.kohei@fujitsu.com, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com References: <20261001210703.1597150-1-suzuki.poulose@arm.com> <20261001210703.1597150-6-suzuki.poulose@arm.com> <86se2o2rbs.wl-maz@kernel.org> <86pkxs2npx.wl-maz@kernel.org> <10563362-5964-4ef7-b5d7-fe1d67ce4adb@arm.com> <86mrsw2jrn.wl-maz@kernel.org> From: Suzuki K Poulose In-Reply-To: <86mrsw2jrn.wl-maz@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261002_084300_670080_7728F7C3 X-CRM114-Status: GOOD ( 16.47 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 02/10/2026 16:40, Marc Zyngier wrote: > On Fri, 02 Oct 2026 16:15:07 +0100, > Suzuki K Poulose wrote: >> >>> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c >>> index 0f4e8b71fa85d..9ba86450fe4af 100644 >>> --- a/arch/arm64/kvm/mmu.c >>> +++ b/arch/arm64/kvm/mmu.c >>> @@ -2624,7 +2624,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, >>> hva_t hva, reg_end; >>> int ret = 0; >>> - if (kvm_vm_is_protected_pkvm(kvm)) { >>> + if (kvm_vm_is_protected(kvm)) { >> >> We have slightly different handling for Realms. The final code for this >> looks like : >> >> if (kvm_vm_is_protected(kvm)) { >> if (new && >> new->flags & (KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY)) { >> return -EPERM; >> } >> } >> >> if (kvm_vm_is_protected_pkvm(kvm)) { >> /* Cannot modify memslots once a pVM has run. */ >> if (pkvm_hyp_vm_is_created(kvm) && >> (change == KVM_MR_DELETE || change == KVM_MR_MOVE)) { >> return -EPERM; >> } >> } else if (kvm_realm_is_created(kvm)) { >> /* >> * Once the Realm is created, we cannot modify any slots that >> * could be providing private memory. i.e., guest_memfd backed >> * slots. >> * TODO: Handle trusted device private memory slots >> */ >> if (kvm_slot_has_gmem(old) || kvm_slot_has_gmem(new)) >> return -EPERM; >> } >> >> >> Of course we could invert the checks to detect vm_is_protected_pkvm() > > This is how I expect this stuff to be written. > > if (kvm_vm_is_protected(kvm) && new && > new->flags & (KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY)) > return -EPERM; > > switch (kvm->vm_flavor) { > case VM_PROTECTED_PKVM: > /* Cannot modify memslots once a pVM has run. */ > if (pkvm_hyp_vm_is_created(kvm) && > (change == KVM_MR_DELETE || change == KVM_MR_MOVE)) { > return -EPERM; > break; > case VM_CCA: > /* > * Once the Realm is created, we cannot modify any slots that > * could be providing private memory. i.e., guest_memfd backed > * slots. > * TODO: Handle trusted device private memory slots > */ > if (kvm_realm_is_created(kvm) && > (kvm_slot_has_gmem(old) || kvm_slot_has_gmem(new))) > return -EPERM; > break; > default: > break; > } > Yep, we can do that. Cheers Suzuki > We have an enumeration. Make use of it. And the whole "is_created" > crap needs to be sorted one way or another. > > M. >