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 9E83F572660; Tue, 8 Sep 2026 16:23:47 +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=1788884629; cv=none; b=Az0JmT4sktcpVoNjVmNNjQnj/TVQzIx7I1aNUY6oPgtkFmiFvYucT3roFExArQ3bsDJw3qW42aE5b8Zg91ZJVe/n/SL//cCLqt4NR25W+gCaArJ7jlHGc2gtCh2krS3Z7ey3T/XqpACJlR6gTIXjFzywm2HRkYFhVcVUqMNFiPk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788884629; c=relaxed/simple; bh=S77v1BDbvfQaK2gnhv9ZUvhfNvS6strceig1vPocSBw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e8pkx5vYcWHceQ01Res59sJR7A65bGZNubZgwKTeeudeioQtWo7Uac11n9SJNqpZThJv8dcu6i7+y6Mh6Gur/kYasGDXUOLRE+UXEUA4vXAghBbymyaM1/IkMbwcgLyEC793j9SxMMrOg1lB9TLWNWuOmY4cYx3zfQGNf2ZW/HA= 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=ZrgX2Fl8; 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="ZrgX2Fl8" 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 0828E1C01; Tue, 8 Sep 2026 09:23:43 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.2.197.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 491C43F7B4; Tue, 8 Sep 2026 09:23:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788884626; bh=S77v1BDbvfQaK2gnhv9ZUvhfNvS6strceig1vPocSBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZrgX2Fl8MhqU/CcGK6RgBT06B4x2UojJLSg1+Vkgu/tAthB79yuNwIXm1/DqfWxH5 fhKk9UEMmYwCf567408u6vmM4aLe2J/mJudjrcgCqqcvPRVnf4CWLNOP4PyTZV6Gyb 1hw/OQ9/PF09AoSuwAK8nzqxCa1lG7Dij9B6I+UA= From: Suzuki K Poulose To: 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, gshan@redhat.com, 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, Jean-Philippe Brucker , Suzuki K Poulose Subject: [PATCH v17 16/20] KVM: arm64: CCA: Provide register list for unfinalized RECs Date: Tue, 8 Sep 2026 17:22:19 +0100 Message-ID: <20260908162223.1683432-17-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260908162223.1683432-1-suzuki.poulose@arm.com> References: <20260908162223.1683432-1-suzuki.poulose@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jean-Philippe Brucker KVM_GET_REG_LIST should not be called before SVE is finalized. The ioctl handler currently returns -EPERM in this case. But because it uses kvm_arm_vcpu_is_finalized(), it now also rejects the call for unfinalized REC even though finalizing the REC can only be done late, after Realm descriptor creation. Move the check to copy_sve_reg_indices(). One adverse side effect of this change is that a KVM_GET_REG_LIST call that only probes for the array size will now succeed even if SVE is not finalized, but that seems harmless since the following KVM_GET_REG_LIST with the full array will fail. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Steven Price Reviewed-by: Gavin Shan Signed-off-by: Suzuki K Poulose --- arch/arm64/kvm/arm.c | 14 +++++++++++++- arch/arm64/kvm/guest.c | 10 +++++----- 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index fbb4d6651ab51..3fe5a4f77738e 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1980,6 +1980,18 @@ static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, return __kvm_arm_vcpu_set_events(vcpu, events); } +/* + * Realm VCPUs can be finalized after the Realm descriptor is created. + * Allow the register list for RECs before the VCPUs are finalized, but + * after the SVE is finalized. + */ +static bool kvm_arm_vcpu_reg_list_allowed(struct kvm_vcpu *vcpu) +{ + if (kvm_arm_vcpu_is_finalized(vcpu)) + return true; + return vcpu_is_rec(vcpu); +} + long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -2035,7 +2047,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, break; r = -EPERM; - if (!kvm_arm_vcpu_is_finalized(vcpu)) + if (!kvm_arm_vcpu_reg_list_allowed(vcpu)) break; r = -EFAULT; diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index b01d6622b8720..c3ca369882273 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -598,8 +598,8 @@ static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu) if (!vcpu_has_sve(vcpu)) return 0; - /* Policed by KVM_GET_REG_LIST: */ - WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu)); + if (!kvm_arm_vcpu_sve_finalized(vcpu)) + return 1; /* KVM_REG_ARM64_SVE_VLS */ return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */) + 1; /* KVM_REG_ARM64_SVE_VLS */ @@ -616,9 +616,6 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu, if (!vcpu_has_sve(vcpu)) return 0; - /* Policed by KVM_GET_REG_LIST: */ - WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu)); - /* * Enumerate this first, so that userspace can save/restore in * the order reported by KVM_GET_REG_LIST: @@ -628,6 +625,9 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu, return -EFAULT; ++num_regs; + if (!kvm_arm_vcpu_sve_finalized(vcpu)) + return num_regs; + for (i = 0; i < slices; i++) { for (n = 0; n < SVE_NUM_ZREGS; n++) { reg = KVM_REG_ARM64_SVE_ZREG(n, i); -- 2.43.0