From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yx2-f22.google.com (mail-yx2-f22.google.com [74.125.224.150]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BC1C471CEB for ; Sun, 20 Sep 2026 19:37:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.224.150 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789933030; cv=none; b=I6qZXNbcb6rBvcJMRJnxQZzMpB/aVsfV2qLnZIZM2slGF9Gvg7C3itgPcIl03upULj5F9mCsllkWntzim2rghvXy/5e0h7XBLxZ2Mmq51dajMioJbVv2SsrimrIBw1fM/wkk9Snol/Ngn7vDLLmLRd1q1YgzJDQBQG8JnlmBFdg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789933030; c=relaxed/simple; bh=wQ3ou0OMG8Kvrev6k20Um/PDy/0+0e9DtH56kTKSrbo=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RKJE8KK6IZp6gTi07jnKms5WiTwNOuQtZArUfIC5KuYMcN8xShIs/YUg2NftYh8W+z3E/6W0iu5q91BTsZqusgNZBjZ6i4e3hU/1C5ZskpCId5WF42sud0BFcIJ3AOLxFdcYJdJTwi8ubZkXSper1kW8ZpEPRaJa/LfOF2adGJo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=soleen.com; spf=pass smtp.mailfrom=soleen.com; dkim=pass (2048-bit key) header.d=soleen.com header.i=@soleen.com header.b=QAtDUqnm; arc=none smtp.client-ip=74.125.224.150 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=soleen.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=soleen.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=soleen.com header.i=@soleen.com header.b="QAtDUqnm" Received: by mail-yx2-f22.google.com with SMTP id 00721157ae682-85d4ddd1d91so15238087b3.1 for ; Sun, 20 Sep 2026 12:37:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; t=1789933027; x=1790537827; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to:content-type; bh=wVwJQFyVies0sN36ZwALD03xlxJgg7HjR5Oz9PMtlp0=; b=QAtDUqnm1pdUpy0LvuTn7ixIxtXtoZSUO9RJdHF/Wu2wm+XYY+PwunsSpuz2RFWMlk ZWA1l46JZBsV2Hy4a+iYd+Mb1yFmwOjYR5dMmzjDk0QjH+eoMYL4ZSpAOXjoYqKCnKTo oHB+hpxwVtBu4J3oXU7JLd9Rw8Xl9x7TW9+fEyHCfBCiXLQrOAAXWposAEJF5fdE3sXS GmkNx/yp1GJefQbF1vBDrNCd8IE/+L47FkiRL1nYjWE71OErHUbpet8Bs1OBuTTxdzHn 1o1HiShtVlApI9bUFovfd5GKK1oLBpw3h8AD07SY9q2VFzUJYOf4Sp5e+p3RFBBko2L4 zSvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789933027; x=1790537827; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to:content-type; bh=wVwJQFyVies0sN36ZwALD03xlxJgg7HjR5Oz9PMtlp0=; b=Uh0Wj8Zven9xYKboqLyap8c0+LxttQ1usbNLYBglE+7NA+JiFdImyQ2m3CrTYaeN6H GJzDlpphckV6VEkFvJmR0/ca5zf+11hG8XQXHUKgau66XBL9MqGiA2WZIpkVSY8wTtzq 2OMo5c/JEoeTs7Sm3rwXfecP36De0elTXJRtE2fyARhNhx8nJHhU1RHngOhP3Q7ObBve GMEu3YRAcZwKN9GvEYe535bQeBJqwREe/EC3zv8nQo3iTAaXDAwQe876Wx+va6T2rp5k B4oJ0vLVM8GGwQh/KeMFVSQnSPVnH5c+FHcDv8ftQgFjODT9r6cHXbB1g/xEkh2S6MRH iGNg== X-Forwarded-Encrypted: i=1; AKwUvBy8nkajOKf3JEDlFUEYl72D9Gq8LTO6UTq0BTPyL7eRGao2JvUZUm04AYabNaulPpBKw9p0RgcUsGI=@vger.kernel.org X-Gm-Message-State: AFuF++lfl1B7nTDy3ehjVvm2Cribg6tEVdr0aU5lwRwzAkz4reYp9hlR kkYBT5aCvNw/I8K695I3F4NcELHeBt+4lRq6a60QX6lNqrzKTsoXfF0Gl65X6xg4Km8= X-Gm-Gg: AYBFou1/EIXUwSg6pLMHRUuUwTKUVGEw5PUtLz3SBmWm8FNo+fhR7EPVpQynADEvrL5 0l7cTLrX5H7Y9rqHks4oWvco+LU7cihbLxyQacebiARaLGj18Vsq4Q7DIcmU29SlvDK4bj6UusK oRA5O8uSzVXvP5dksQW8xXQPh/envve9I3IgaR0xdJQEw1pWu6jZY1IGTBLiPTKbBur9NoKfZWA RAwqHFL2G0jnBUtDGh8vZS8EYBSB1xzfRNcHXC4jVlHRVbdseYJ/xVX1WcbWbVS5AZyfCdSFRMj O1qmOTmXnzPUghEt6/dX7tEhBLOSpJi7WixbHrdcyHjfSMIG4mCeXD8qzZtETvli9IgXuczRRBd 6AEqATrZUPbsnvgyjGXfNiGmJvk0x3GG3dT02zc+TakcNciZ0lwUTbTrVmud5YC+l3KBHsqHxGU 8NXem/GBobo/LP2+uQwuPr5OftQ23nV9yMnZuM5MkAXgqwAcm7xEwve20oUOzxzq9R9nEOf9jxa IzLGKWutct7UTsr1cMLn5WSybu2aAToQxBD+KmltF9bRbJUd7uD4+7j2mheOTV+DxiSB5jWwA5+ 2indAbMIPmZimeV53Ok= X-Received: by 2002:a05:690c:89:b0:89a:63da:cbe1 with SMTP id 00721157ae682-89a63dacc8fmr20430637b3.39.1789933027324; Sun, 20 Sep 2026 12:37:07 -0700 (PDT) Received: from soleen.c.googlers.com.com (16.49.199.35.bc.googleusercontent.com. [35.199.49.16]) by smtp.gmail.com with ESMTPSA id 00721157ae682-89a47139db2sm18450487b3.26.2026.09.20.12.37.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 20 Sep 2026 12:37:06 -0700 (PDT) From: Pasha Tatashin To: linux-kselftest@vger.kernel.org, legion@kernel.org, kees@kernel.org, will@kernel.org, ruanjinjie@huawei.com, atomlin@atomlin.com, rppt@kernel.org, jani.nikula@intel.com, hamzamahfooz@linux.microsoft.com, joey.gouly@arm.com, tglx@kernel.org, nsc@kernel.org, alexandre.chartre@oracle.com, james.morse@arm.com, dianders@chromium.org, bp@alien8.de, jpoimboe@kernel.org, shuah@kernel.org, catalin.marinas@arm.com, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, kvmarm@lists.linux.dev, jaredwhite@microsoft.com, johan@kernel.org, pbonzini@redhat.com, mingo@redhat.com, linux-mm@kvack.org, seanjc@google.com, mark.rutland@arm.com, vdonnefort@google.com, tarunsahu@google.com, gshan@redhat.com, skhan@linuxfoundation.org, linux-doc@vger.kernel.org, xur@google.com, djbw@kernel.org, oupton@kernel.org, nogikh@google.com, sumitg@nvidia.com, linux-kernel@vger.kernel.org, zengheng4@huawei.com, peterz@infradead.org, corbet@lwn.net, suzuki.poulose@arm.com, luto@kernel.org, hpa@zytor.com, zhangpengjie2@huawei.com, x86@kernel.org, yuzenghui@huawei.com, jic23@kernel.org, ardb@kernel.org, pasha.tatashin@soleen.com, petr.pavlu@suse.com, ryan.roberts@arm.com, kexec@lists.infradead.org, pratyush@kernel.org, dave.hansen@linux.intel.com, rdunlap@infradead.org, kvm@vger.kernel.org, fuad.tabba@linux.dev, maz@kernel.org, mbenes@suse.cz, jgross@suse.com, seiden@linux.ibm.com, pierre.gondois@arm.com, song@kernel.org, nathan@kernel.org, pmladek@suse.com, graf@amazon.com, chao.gao@intel.com, zhenglifeng1@huawei.com, arnd@arndb.de, sidnayyar@google.com, linux-arm-kernel@lists.infradead.org, vladimir.murzin@arm.com, kas@kernel.org Subject: [RFC PATCH 02/46] KVM: arm64: Split demux_c15_{get,set}_val from userspace accessors Date: Sun, 20 Sep 2026 15:36:06 -0400 Message-ID: <20260920193650.3373435-3-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog In-Reply-To: <20260920193650.3373435-1-pasha.tatashin@soleen.com> References: <20260920193650.3373435-1-pasha.tatashin@soleen.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Factor demux_c15_get_val() and demux_c15_set_val() out of demux_c15_get() and demux_c15_set() so kernel callers can read and write demultiplexed coprocessor registers without going through userspace pointers. Signed-off-by: Pasha Tatashin --- arch/arm64/kvm/sys_regs.c | 48 +++++++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 14 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 44aae52c473d..b873ccf1ab14 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -5496,10 +5496,9 @@ id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id, return r; } -static int demux_c15_get(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) +static int demux_c15_get_val(struct kvm_vcpu *vcpu, u64 id, u32 *val) { - u32 val; - u32 __user *uval = uaddr; + u32 idx; /* Fail if we have unknown bits set. */ if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK @@ -5510,21 +5509,34 @@ static int demux_c15_get(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) case KVM_REG_ARM_DEMUX_ID_CCSIDR: if (KVM_REG_SIZE(id) != 4) return -ENOENT; - val = (id & KVM_REG_ARM_DEMUX_VAL_MASK) + idx = (id & KVM_REG_ARM_DEMUX_VAL_MASK) >> KVM_REG_ARM_DEMUX_VAL_SHIFT; - if (val >= CSSELR_MAX) + if (idx >= CSSELR_MAX) return -ENOENT; - return put_user(get_ccsidr(vcpu, val), uval); + *val = get_ccsidr(vcpu, idx); + return 0; default: return -ENOENT; } } -static int demux_c15_set(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) +static int demux_c15_get(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) { - u32 val, newval; u32 __user *uval = uaddr; + u32 val; + int ret; + + ret = demux_c15_get_val(vcpu, id, &val); + if (!ret) + ret = put_user(val, uval); + + return ret; +} + +static int demux_c15_set_val(struct kvm_vcpu *vcpu, u64 id, u32 newval) +{ + u32 idx; /* Fail if we have unknown bits set. */ if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK @@ -5535,20 +5547,28 @@ static int demux_c15_set(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) case KVM_REG_ARM_DEMUX_ID_CCSIDR: if (KVM_REG_SIZE(id) != 4) return -ENOENT; - val = (id & KVM_REG_ARM_DEMUX_VAL_MASK) + idx = (id & KVM_REG_ARM_DEMUX_VAL_MASK) >> KVM_REG_ARM_DEMUX_VAL_SHIFT; - if (val >= CSSELR_MAX) + if (idx >= CSSELR_MAX) return -ENOENT; - if (get_user(newval, uval)) - return -EFAULT; - - return set_ccsidr(vcpu, val, newval); + return set_ccsidr(vcpu, idx, newval); default: return -ENOENT; } } +static int demux_c15_set(struct kvm_vcpu *vcpu, u64 id, void __user *uaddr) +{ + u32 __user *uval = uaddr; + u32 newval; + + if (get_user(newval, uval)) + return -EFAULT; + + return demux_c15_set_val(vcpu, id, newval); +} + static u64 kvm_one_reg_to_id(const struct kvm_one_reg *reg) { switch(reg->id) { -- 2.55.0.1082.g2b9226bbc0-goog