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 B19B04DEC2B; Fri, 2 Oct 2026 15:43:00 +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=1790955782; cv=none; b=Duvh1h8mnyyEFmzMKWblPkk75Twyxku+ng9z8/lNN8lN2FR3wIO47Ss/a0mybGMVWQtfOHWOpNSyN97prZrFrP62cj2ukvCQ6db9aZxYVUlR0jnCyNiwW6sQzH3P3Dl1HFBcaycdIaVuJOmHYe0AQ8AcXRqptIIxlvC556K/oqM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790955782; c=relaxed/simple; bh=r8+UnxmyfA5EDSuksv2pnxeyK5XiuiA24DSSA+ymriQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cve9XCq0OvziDnLfxZR7J8U5hPhSizaW4GVTgyxsHjiLzVweGXQkoxTPz/lDKoYYaLTxZYWyKfdpkK+rxvaLVtekejbeubQ4D6QYuGsHz2TVUVwUy6yPGz2/f9j8SvGI1z3EoBjn6Z/O9PQatZJAVT0wEYDVhEQ6LAEXvJURIT4= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=Dzh5F1AK; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="Dzh5F1AK" 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 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: [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 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. >