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 E1417C79FB9 for ; Thu, 10 Sep 2026 10:21:44 +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=PAtVm0nKN1t8bJ7OQtStF8q2ULpMIH6eJ6NiwCWHqPI=; b=X8dMCipcESV4uuLJALb137BPSL eXwdJjs2knHgBsXxvYzAgh8ySzNhfqGKVDvCuCUPjiBK2B5duxoN6XiiJ3lmjMZuO2DgfesKB7mIr 8OgQSFP0Bob/+YVbsHXdspU7xoU3ecjFWtguuPxCMKEGLPzJChFKCwCXtHyZz5eMhlOxrQh4lGksF sme9CzxesZyLNflUucKwBNOKDgZyge5KT0nMJ4IJf7xrFVYHNJuh6g3HqOnjeiCMs67hR+BnQNzTP XI1pBPEWUE4cXljkJMszemQh9rVZOAYPz+yU/8BIMcSNomMamEqId4oM/8uEtcxWCVAPj8RGphKYD 7tM8lBMA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4buU-0000000E2LT-0EUr; Thu, 10 Sep 2026 10:21:38 +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 1x4buS-0000000E2L3-0bz7 for linux-arm-kernel@lists.infradead.org; Thu, 10 Sep 2026 10:21:37 +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 51C7D143D; Thu, 10 Sep 2026 03:21:31 -0700 (PDT) Received: from [10.0.129.245] (unknown [10.0.129.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 899BA3F7B4; Thu, 10 Sep 2026 03:21:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789035695; bh=NdJwICU4hKphndkhJfKo4meJGdIZvN650SafLlOB/BM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=k//7Ud38dQTnvnKQxVZAcd73FhyR9Iv9bKLlrmoT04DSSuniGXJGJi8nFSmCLEuE8 fX11Ow/pTfdIBC/fgh+DTGC9ZRproSkmFOyVb9rmmwngQfXyaH/MYJCYNZcxFenoQH YnDm/TS+rtBLyZhhM83WRgOUSjTOe3zhZn+o0zjo= Message-ID: Date: Thu, 10 Sep 2026 11:21:29 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v17 04/20] KVM: arm64: Refactor the vcpu_load to allow for VM specific callbacks Content-Language: en-GB To: Gavin Shan , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: maz@kernel.org, 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, joey.gouly@arm.com, tabba@google.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 References: <20260908162223.1683432-1-suzuki.poulose@arm.com> <20260908162223.1683432-5-suzuki.poulose@arm.com> From: Suzuki K Poulose In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260910_032136_278340_FA047FD4 X-CRM114-Status: GOOD ( 19.27 ) 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 10/09/2026 05:00, Gavin Shan wrote: > Hi Suzuki, > > On 9/9/26 2:22 AM, Suzuki K Poulose wrote: >> Based on a work by Marc Zyngier >> >> To keep the VCPU load/put handling cleaner with the different kinds of >> VM types, >> we are about to introduce VM specific callbacks to do just the right >> thing. >> In preparation for that, make some refactoring to add the change easier. >> >> No functional changes intended. >> >> Signed-off-by: Suzuki K Poulose >> --- >>   arch/arm64/kvm/arm.c | 46 +++++++++++++++++++++++++++----------------- >>   1 file changed, 28 insertions(+), 18 deletions(-) >> > > Nitpicks below, none of them are introduced by this patch itself. In > either way: > > Reviewed-by: Gavin Shan Thank you ! > >> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c >> index 67f1ff9bc4fbe..51fc651267157 100644 >> --- a/arch/arm64/kvm/arm.c >> +++ b/arch/arm64/kvm/arm.c >> @@ -683,14 +683,11 @@ static bool kvm_vcpu_should_clear_twe(struct >> kvm_vcpu *vcpu) >>       return single_task_running(); >>   } >> -void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) >> +static void vcpu_prepare_mmu(struct kvm_vcpu *vcpu) >>   { >>       struct kvm_s2_mmu *mmu; >>       int *last_ran; >> -    if (is_protected_kvm_enabled()) >> -        goto nommu; >> - >>       if (vcpu_has_nv(vcpu)) >>           kvm_vcpu_load_hw_mmu(vcpu); >> @@ -720,10 +717,33 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, >> int cpu) >>           kvm_call_hyp(__kvm_flush_cpu_context, mmu); >>           *last_ran = vcpu->vcpu_idx; >>       } >> +} >> + >> +static void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu) >> +{ >> +    if (kvm_vcpu_should_clear_twe(vcpu)) >> +        vcpu->arch.hcr_el2 &= ~HCR_TWE; >> +    else >> +        vcpu->arch.hcr_el2 |= HCR_TWE; >> + >> +    if (kvm_vcpu_should_clear_twi(vcpu)) >> +        vcpu->arch.hcr_el2 &= ~HCR_TWI; >> +    else >> +        vcpu->arch.hcr_el2 |= HCR_TWI; >> +} >> + > > It seems FIELD_MODIFY() can be applied here if no visible constraints > exist: > >     FIELD_MODIFY(HCR_TWE, vcpu->arch.hcr_el2, ! > kvm_vcpu_should_clear_twe(vcpu)); >     FIELD_MODIFY(HCR_TWI, vcpu->arch.hcr_el2, ! > kvm_vcpu_should_clear_twi(vcpu)); I would leave this out for now. Can be a separate patch > >> +static void vcpu_load_pvtime(struct kvm_vcpu *vcpu) >> +{ >> +    if (kvm_arm_is_pvtime_enabled(&vcpu->arch)) >> +        kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu); >> +} >> + >> +void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) >> +{ >> +    if (!is_protected_kvm_enabled()) >> +        vcpu_prepare_mmu(vcpu); >> > > I think we probably try to depend on kvm->arch.vm_flavor instead > of !is_protected_kvm_enabled(). > >     struct kvm *kvm = vcpu->kvm; > >     if (kvm_vm_is_protected(kvm) || kvm_vm_flavor_eq(kvm, VM_PKVM)) >         vcpu_prepare_mmu(vcpu); This will be removed as part of the call back in the next patch. Cheers Suzuki