From nobody Sat Feb 7 06:35:14 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 72F1036C249; Wed, 20 Aug 2025 15:00:18 +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=1755702019; cv=none; b=dhBjBoYCgaGaEKQnUkawA/uPOR7VxO6EJO+1ELJStJyxDuHHq0MNAjYLImi3QJVoHV+ivVhhwkG+o/RXWardGGck4tSu9b+azeLc7png1DCKkcxaCViXXuyeSoZ3hcBIfR7aVnKuQx7/eruRdB4RUWHDom9+Xcx41L0C8DwLL+g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755702019; c=relaxed/simple; bh=ngPpCOAhcdP8m+0IHAdw7Im+qwS0PIDC95b/p1sP6ow=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kH5Hxro+bedUoNqbyqo2CCfPQwG+5ap6fSgSkOJYe4P/3hhdYZEErBM/WMnz3Gp/4NYAmtaEi9Mp42sSYSegePD2nOe6+PVkvfQuBQfzoH5ajagjYJco1hJPPTWD7034uq95inO/jWFb5c9j3tPFxLia8xU81dvNXwLFSjnytEE= 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; 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 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 91ABD2C3E; Wed, 20 Aug 2025 08:00:09 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.2.58]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9373D3F738; Wed, 20 Aug 2025 08:00:13 -0700 (PDT) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Jean-Philippe Brucker , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve , Steven Price Subject: [PATCH v10 39/43] arm64: RME: Provide register list for unfinalized RME RECs Date: Wed, 20 Aug 2025 15:55:59 +0100 Message-ID: <20250820145606.180644-40-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250820145606.180644-1-steven.price@arm.com> References: <20250820145606.180644-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- arch/arm64/kvm/arm.c | 4 ---- arch/arm64/kvm/guest.c | 10 +++++----- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 23e87076330e..d90db9b9c62f 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1856,10 +1856,6 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (unlikely(!kvm_vcpu_initialized(vcpu))) break; =20 - r =3D -EPERM; - if (!kvm_arm_vcpu_is_finalized(vcpu)) - break; - r =3D -EFAULT; if (copy_from_user(®_list, user_list, sizeof(reg_list))) break; diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 5dcf3728fe25..c95a00b711c0 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -675,8 +675,8 @@ static unsigned long num_sve_regs(const struct kvm_vcpu= *vcpu) if (!vcpu_has_sve(vcpu)) return 0; =20 - /* 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 */ =20 return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */) + 1; /* KVM_REG_ARM64_SVE_VLS */ @@ -693,9 +693,6 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *= vcpu, if (!vcpu_has_sve(vcpu)) return 0; =20 - /* 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: @@ -705,6 +702,9 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *= vcpu, return -EFAULT; ++num_regs; =20 + if (!kvm_arm_vcpu_sve_finalized(vcpu)) + return num_regs; + for (i =3D 0; i < slices; i++) { for (n =3D 0; n < SVE_NUM_ZREGS; n++) { reg =3D KVM_REG_ARM64_SVE_ZREG(n, i); --=20 2.43.0