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 3317526C3BD for ; Sun, 26 Jul 2026 15:34:31 +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=1785080073; cv=none; b=WZecu/xpTeOwS3SX7+CTb67hpdymEV4CQoYGJLVIg0tI4Z6Dw6mAIRoEVOPSoI1yTchM54+P3DnaAv1EYI5mR58P9w3XBBeKSLdNlRueFboMNFUhHr7p/33T7jz3tPpL1jARSltSHGXExDKJFgCPDeiEz+M3WPvSGgiAkVMoUOU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785080073; c=relaxed/simple; bh=N+LzBVKV1bVXuzLYBuSEDokqhnTySttiisWvhYLVMDk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=Cv4KCyrjjFv92YlDhJ02XBeFCnCZ+1TLNo4AdkaaQR0y/5FZa9YDtZ88FUfQ/89f68SJs3yEwgJ25PyaygGbyi+iKvpS0p11w9rQ0wzd0TcwrsSgppTr56hb/1GuVGk68UPiffOi6kiyIkIt2xcD70gtZjid3rn6e89GZmriJ5U= 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=JUAPZZKq; 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="JUAPZZKq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1785080071; 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=jMtayxS3HoI/U18jirl1z/zCFg4c0op5NxlN9HZkjXo=; b=JUAPZZKqSm2rcv7aDmLav82/ErpQrrB5i1F73gw4zA+2sQs0o6P/PlorLqMrWWYq+RReTv 1FzWK4Tz4mzG2Q29DHkzgd8OFk1RWGn9PkZj5PRRGZ08TUIvv4TpNUFZERoyBh5ozi5ynO X807s7WrpysQwiWEBdGjaRXIOyIWkI8= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-613-qXvyhtP_PXC2gwPCMzBkGA-1; Sun, 26 Jul 2026 11:34:29 -0400 X-MC-Unique: qXvyhtP_PXC2gwPCMzBkGA-1 X-Mimecast-MFC-AGG-ID: qXvyhtP_PXC2gwPCMzBkGA_1785080067 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9FE001956070; Sun, 26 Jul 2026 15:34:27 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.44.32.63]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 420801800611; Sun, 26 Jul 2026 15:34:19 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, kvmarm@lists.linux.dev, peter.maydell@linaro.org, shaju.abraham@nutanix.com, khushit.shah@nutanix.com, yangjinqian1@huawei.com, cohuck@redhat.com, richard.henderson@linaro.org, sebott@redhat.com, skolothumtho@nvidia.com, philmd@oss.qualcomm.com Cc: maz@kernel.org, oliver.upton@linux.dev, pbonzini@redhat.com, armbru@redhat.com, berrange@redhat.com, abologna@redhat.com, jdenemar@redhat.com Subject: [RFC PATCH v7 10/18] target/arm/kvm: Retrieve writable ID reg map Date: Sun, 26 Jul 2026 17:29:48 +0200 Message-ID: <20260726153221.24773-11-eric.auger@redhat.com> In-Reply-To: <20260726153221.24773-1-eric.auger@redhat.com> References: <20260726153221.24773-1-eric.auger@redhat.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-MFC-PROC-ID: FR2_mHHMbk6Hsf6HVNKSV3bidTJfgw-p0q6-WhOC9dU_1785080067 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true From: Cornelia Huck Add an helper to retrieve the writable id reg bitmask. then retrieve the writable_map array and dispatch it in the writable_map fields of arm64_id_regs[] elements. Signed-off-by: Eric Auger Signed-off-by: Cornelia Huck --- v5 -> v6 - use arm64_id_regs[].writable_map - squashed 2 commits (helper + user) - removed stub --- target/arm/kvm.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/target/arm/kvm.c b/target/arm/kvm.c index d40a6a9859..d270f9870e 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -28,6 +28,7 @@ #include "kvm_arm.h" #include "cpu.h" #include "cpu-sysregs.h" +#include "cpu-idregs.h" #include "trace.h" #include "internals.h" #include "hw/pci/pci.h" @@ -51,6 +52,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = { static bool cap_has_mp_state; static bool cap_has_inject_serror_esr; static bool cap_has_inject_ext_dabt; +static bool writable_map_dispatched; /** * ARMHostCPUFeatures: information about the host CPU (identified @@ -273,6 +275,21 @@ static uint32_t kvm_arm_sve_get_vls(int fd) return vls[0] & MAKE_64BIT_MASK(0, ARM_MAX_VQ); } +static int kvm_feature_idx_to_idregs_idx(int kidx) +{ + int op1, crm, op2; + ARMSysRegs sysreg; + + op1 = kidx / 64; + if (op1 == 2) { + op1 = 3; + } + crm = (kidx % 64) / 8; + op2 = kidx % 8; + sysreg = ENCODE_ID_REG(3, op1, 0, crm, op2); + return get_sysreg_idx(sysreg); +} + static void kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) { /* Identify the feature bits corresponding to the host CPU, and @@ -480,9 +497,53 @@ static void kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf) ahcf->features = features; } +static int kvm_arm_get_writable_id_regs(uint64_t *idregmap) +{ + int cap_writable_id_regs; + struct reg_mask_range range = { + .range = KVM_ARM_FEATURE_ID_RANGE, + .reserved = {0}, + .addr = (uint64_t)idregmap, + }; + + cap_writable_id_regs = + kvm_check_extension(kvm_state, KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES); + + if (!cap_writable_id_regs || + !(cap_writable_id_regs & (1 << KVM_ARM_FEATURE_ID_RANGE))) { + return -ENOSYS; + } + + if (kvm_vm_ioctl(kvm_state, KVM_ARM_GET_REG_WRITABLE_MASKS, &range)) { + return -errno; + } + return 0; +} + void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu) { CPUARMState *env = &cpu->env; + uint64_t *writable_map; + + writable_map = g_new(uint64_t, KVM_ARM_FEATURE_ID_RANGE_SIZE); + + if (!writable_map_dispatched && + !kvm_arm_get_writable_id_regs(writable_map)) { + for (int i = 0; i < KVM_ARM_FEATURE_ID_RANGE_SIZE; i++) { + uint64_t mask = writable_map[i]; + + if (mask) { + int idx = kvm_feature_idx_to_idregs_idx(i); + + if (idx < 0 || idx > ARRAY_SIZE(arm64_id_regs)) { + continue; + } + arm64_id_regs[idx].writable_mask = mask; + } + } + writable_map_dispatched = true; + } + g_free(writable_map); if (!arm_host_cpu_features.dtb_compatible) { kvm_arm_get_host_cpu_features(&arm_host_cpu_features); -- 2.53.0