From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 86584286417 for ; Tue, 6 Oct 2026 02:25:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791253533; cv=none; b=Mree23ifhYJQff4jVtxYgs4XXoLz5lVNy9IYFyhMfQxJGxgPHfvhr3XPIOq8mBoIx/kC0nAKPp4SBIMsZzbFvQNTZACmLCKxXUZ42iSHOYCElK30hZZh9FhJdfsHnzwl0LnvNiGLWX/bEKXY8PUahxi4PEbvPooG65Rq6y7Xov0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791253533; c=relaxed/simple; bh=QWAFFhzhcemt4JkAXvKSQU+sijmwJ3F9VG6lkevDJYQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=A4xy3CAuRGCx6jdiIF9XOVa+zqQmcjEP5YAOJPA57O0MyNx+j8WvOI5Doasl5BWWQ+13ZLaoFimhvR7oxmv/KNtV1UHLUIgwqWoaqWmIO1KwLgeIqipp7nFaUp7wcTqjGbEnVVNJr447GjFuQluP0EHQiihLcZ9BViWy9Z40NMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SFuSqM0k; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=NBhZ69jN; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SFuSqM0k"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="NBhZ69jN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1791253531; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ugMxefZ1qIEDU/oRAsn8b/LDZMC+9ePrF31NK37FBF8=; b=SFuSqM0kMRocs6bRvUTeS3WzPdsf1Gp5DotSQLJkYsDFmxv8HeU3M21S1hHfdkiI9/IOyl sfEAgEWf7Xei3ojQG/pMjWUaNC7eR4EF1STdJ1AVYF4xyc2qQbF/jGHw6ZqtLfbQ55SuQq VUITBINIeeTA75W6d1yvFkGIwWxcV2A= Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-83-4PO23IiZN0OaD8_bBfl2UA-1; Mon, 05 Oct 2026 22:25:30 -0400 X-MC-Unique: 4PO23IiZN0OaD8_bBfl2UA-1 X-Mimecast-MFC-AGG-ID: 4PO23IiZN0OaD8_bBfl2UA_1791253529 Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-39de4a68f7cso1982251a91.1 for ; Mon, 05 Oct 2026 19:25:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1791253529; x=1791858329; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=ugMxefZ1qIEDU/oRAsn8b/LDZMC+9ePrF31NK37FBF8=; b=NBhZ69jNhhguozeqBY4TIXOYuFgsBFi4Ps1KTx970EiBEM1DElHXQVhw6Zicvl7uwv nRQly9XjVJ/HlSLHMlkZpQunl38/y9kFxlb7PuZXB1Q9EbtUHZ9FQmG5L7FhRDLPSHSM T1yUkKiWpd6Zc7gsMtIFjzs63v+E9i2l1+k4z5+naXv92cWbmYxQ0ylyckrXbzQXdsfn UfQtykREq3JNjMKB947OF/ivwMRA9LN6K23IZge3EBJW1xIDN4JltJSoCgrKAaTgYNFI uvnnu51DysjmGIJ1qyBWCVS0Phb7FxGl+QyBL4lfk1UIZ7R0cPJ+/kn7u9/iraRMwLUq wLjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791253529; x=1791858329; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=ugMxefZ1qIEDU/oRAsn8b/LDZMC+9ePrF31NK37FBF8=; b=CqbQdQcQPqs6F7FB2XCNE5Az969xc/mg+gd9l52MTxplIwCmueG4Au6V0eLA0H75mF eQPnF8biNiIhoxWrxowCbcVyi9enQBCY3ZtBjidY5RXHUHk1iPf1AkOJl961zLXJ+HLz VFH1qvZuaKpey4BOH04ggEgCVbiP7qENYYQwOf1JoR/7M/KrVedx8OHFHWnbWPSVQAPj LkeesIDFf97FUWwmmLfxLYMSB3vjCLto5xUUT/bQc+BFFGnqKUevEuMe2cFmO/GI7zfp 1C0JfRTAQCgt/eXGgpDbyvXV45s5Til7Olhii/Qj9FtLJL2q+Si+ToHuEz7ji6zUeY69 baag== X-Forwarded-Encrypted: i=1; AKwUvBw/DuUcFTZyHRnz5IxOkiP82Xw/nLSBVhLNCvHDWi483EZDsIoJfW3FzF83jn7iFuNEJCrKayEZKqyY1Pk=@vger.kernel.org X-Gm-Message-State: AFq9FYK7cGxOIqK9g/deXqU4SiH34zYmvcNyP6SdycecfTSwxFWfmOCg p0+mrSpF7PPSRep90P3Rob81KAUyJiN6VCGXZafGQ9KfnD2QfsBCEM0lDysGpr+WkFvO5qEHU2U 08VHIMkL3kZst8umtZX2jeCBcpFRbtMwVObgwSWwzdIpcWy6am8eGShYuRJ+KkVoSqA== X-Gm-Gg: AYBFou1jakivZZrArTqNwyTwUA+TLhEoxcy5c2wVGdKp8UVg7iT6DiqHnKTWRmX6Vge /t6BYai03bV7F/4jlXX15icAI9vsUrSLW2oH4xeXZKLfTop0ZkqsEKEBdDDTiA3Eo9TR7rAweaw 2HJncp/iwqT9V7+NXB9OuytuwWPU7CmSw8/izvQFlfRd7aKdsB11jD9LGu55stpJefpEeNc6P9G Rda2SXEnTzB7Tid6mQCr/a7cRTKyjK3KtKlyZfntQjEGxWhjj1oyR38t6h88Y60NPAR1aYE9XFq EYEaLFtHHFaTPzA09HH3homXj2/qcCxWGJvaLX1ROr3G2GNdeOA4khH4bUgkf6IjViCykG6vAUH AtuBs3OeglYTM7vkcYmBjHz+t6PvWYzGmObGI313Ndw== X-Received: by 2002:a17:90b:2812:b0:3a4:cbaf:f152 with SMTP id 98e67ed59e1d1-3a6cec2fb6emr4459083a91.33.1791253529336; Mon, 05 Oct 2026 19:25:29 -0700 (PDT) X-Received: by 2002:a17:90b:2812:b0:3a4:cbaf:f152 with SMTP id 98e67ed59e1d1-3a6cec2fb6emr4459071a91.33.1791253528874; Mon, 05 Oct 2026 19:25:28 -0700 (PDT) Received: from [192.168.68.52] (n175-34-8-244.mrk21.qld.optusnet.com.au. [175.34.8.244]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a85388c664sm2351690a91.4.2026.10.05.19.25.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 05 Oct 2026 19:25:25 -0700 (PDT) Message-ID: <32c662e1-0de9-44a7-81e5-2b1e6c824114@redhat.com> Date: Tue, 6 Oct 2026 12:25:15 +1000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v22 09/23] KVM: arm64: Prevent unsupported vcpu features for VM types To: Suzuki K Poulose , 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, sudeep.holla@arm.com, jonathan.cameron@oss.qualcomm.com References: <20261005090754.2140522-1-suzuki.poulose@arm.com> <20261005090754.2140522-10-suzuki.poulose@arm.com> Content-Language: en-US From: Gavin Shan In-Reply-To: <20261005090754.2140522-10-suzuki.poulose@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/5/26 7:07 PM, Suzuki K Poulose wrote: > Prevent unsupported VCPU features for the protected VCPUs. Realms and pVMs > not support 32bit EL1 or NV yet. pKVM doesn't rely on the host vcpu > features and it clears the unsupported features while hyp_vcpu is > initialised. Block the features early in the vcpu init if we detect > incompatible features. > > Signed-off-by: Suzuki K Poulose > --- > arch/arm64/kvm/arm.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > One nitpick below. In either way: Reviewed-by: Gavin Shan > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index f31d31fa27ad9..9c2ef7ca6a961 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -1668,11 +1668,12 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level, > return -EINVAL; > } > > -static unsigned long system_supported_vcpu_features(void) > +static unsigned long system_supported_vcpu_features(struct kvm_vcpu *vcpu) > { > unsigned long features = KVM_VCPU_VALID_FEATURES; > > - if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1)) > + if (vcpu_is_protected(vcpu) || > + !cpus_have_final_cap(ARM64_HAS_32BIT_EL1)) > clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features); > > if (!kvm_supports_guest_pmuv3()) { > @@ -1688,7 +1689,8 @@ static unsigned long system_supported_vcpu_features(void) > clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features); > } > > - if (!cpus_have_final_cap(ARM64_HAS_NESTED_VIRT)) > + if (vcpu_is_protected(vcpu) || > + !cpus_have_final_cap(ARM64_HAS_NESTED_VIRT)) > clear_bit(KVM_ARM_VCPU_HAS_EL2, &features); > > return features; > @@ -1708,7 +1710,7 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu, > return -ENOENT; > } > > - if (features & ~system_supported_vcpu_features()) > + if (features & ~system_supported_vcpu_features(vcpu)) > return -EINVAL; > The following check at the beginning of kvm_vcpu_init_check_features() is redundant to the check here. We can drop that in this patch or a preparatory patch. static int kvm_vcpu_init_check_features(...) { /* * This check can be dropped since the same check has been done * by the followup "if (features & ~system_supported_vcpu_features(vcpu))" */ if (features & ~KVM_VCPU_VALID_FEATURES) return -ENOENT; } > /* Thanks, Gavin