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 4EB6C3DEFE6; Fri, 20 Mar 2026 16:45:50 +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=1774025152; cv=none; b=cIYjlHkCziHvQMGXx60Gpn2ZEPiNesR+KZiXdn7jLxxP/Ius4vjkXNXE+4I/tacblXLQAq+kM5LVgf0xyZjXWj+f93feG7T8v1Do6WqDHQ6gwmOKdeFLmbu1FBPdYkG0GhrVX6QyoB5QYJHl8I1iQSH/FAHG58XK6x9cb/ey6uU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774025152; c=relaxed/simple; bh=wSTJyq7SJedh76KDbDAq/uCbLAx5ABhYEcwjfiSoOyI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NqF8K6zGdmfvqOXrSz/AuWdqdsIc3a7MLNdFuaBwWleMsAmM9A9dv6gEZPzhAWngJArhirmYe6M0i+ntYyllX5HPqQ8uhjs5jOWqbzyi0sUMkDV1zq5WOCOzyUlXVIE0XonDhM8ASv/J5GJvXMIdyRAIbgWO8XoFqWdFTKG3q+c= 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 AD5A6165C; Fri, 20 Mar 2026 09:45:43 -0700 (PDT) Received: from [10.1.29.20] (e122027.cambridge.arm.com [10.1.29.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8B9053F7BD; Fri, 20 Mar 2026 09:45:44 -0700 (PDT) Message-ID: <362fada6-2b5d-4360-9f5e-7ffadeb66d47@arm.com> Date: Fri, 20 Mar 2026 16:45:42 +0000 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v13 45/48] arm64: RMI: Provide accurate register list To: Wei-Lin Chang , 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 References: <20260318155413.793430-1-steven.price@arm.com> <20260318155413.793430-46-steven.price@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 19/03/2026 18:53, Wei-Lin Chang wrote: > On Wed, Mar 18, 2026 at 03:54:09PM +0000, Steven Price wrote: >> From: Jean-Philippe Brucker >> >> Userspace can set a few registers with KVM_SET_ONE_REG (9 GP registers >> at runtime, and 3 system registers during initialization). Update the >> register list returned by KVM_GET_REG_LIST. >> >> Signed-off-by: Jean-Philippe Brucker >> Signed-off-by: Steven Price >> --- >> Changes since v11: >> * Reworked due to upstream changes. >> Changes since v8: >> * Minor type changes following review. >> Changes since v7: >> * Reworked on upstream changes. >> --- >> arch/arm64/kvm/guest.c | 6 ++++++ >> arch/arm64/kvm/hypercalls.c | 4 ++-- >> arch/arm64/kvm/sys_regs.c | 29 +++++++++++++++++++++++------ >> 3 files changed, 31 insertions(+), 8 deletions(-) >> >> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c >> index 2c4db2d1a6ca..23fdb2ee8a61 100644 >> --- a/arch/arm64/kvm/guest.c >> +++ b/arch/arm64/kvm/guest.c >> @@ -620,6 +620,9 @@ static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu) >> if (!kvm_arm_vcpu_sve_finalized(vcpu)) >> return 1; /* KVM_REG_ARM64_SVE_VLS */ >> >> + if (kvm_is_realm(vcpu->kvm)) >> + return 1; /* KVM_REG_ARM64_SVE_VLS */ >> + >> return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */) >> + 1; /* KVM_REG_ARM64_SVE_VLS */ >> } >> @@ -647,6 +650,9 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu, >> if (!kvm_arm_vcpu_sve_finalized(vcpu)) >> return num_regs; >> >> + if (kvm_is_realm(vcpu->kvm)) >> + 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); >> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c >> index 58c5fe7d7572..70ac7971416c 100644 >> --- a/arch/arm64/kvm/hypercalls.c >> +++ b/arch/arm64/kvm/hypercalls.c >> @@ -414,14 +414,14 @@ void kvm_arm_teardown_hypercalls(struct kvm *kvm) >> >> int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu) >> { >> - return ARRAY_SIZE(kvm_arm_fw_reg_ids); >> + return kvm_is_realm(vcpu->kvm) ? 0 : ARRAY_SIZE(kvm_arm_fw_reg_ids); >> } >> >> int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) >> { >> int i; >> >> - for (i = 0; i < ARRAY_SIZE(kvm_arm_fw_reg_ids); i++) { >> + for (i = 0; i < kvm_arm_get_fw_num_regs(vcpu); i++) { >> if (put_user(kvm_arm_fw_reg_ids[i], uindices++)) >> return -EFAULT; >> } >> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c >> index ebb428b861f5..088d900b9c3a 100644 >> --- a/arch/arm64/kvm/sys_regs.c >> +++ b/arch/arm64/kvm/sys_regs.c >> @@ -5436,18 +5436,18 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg >> sys_reg_descs, ARRAY_SIZE(sys_reg_descs)); >> } >> >> -static unsigned int num_demux_regs(void) >> +static inline unsigned int num_demux_regs(struct kvm_vcpu *vcpu) >> { >> - return CSSELR_MAX; >> + return kvm_is_realm(vcpu->kvm) ? 0 : CSSELR_MAX; >> } >> >> -static int write_demux_regids(u64 __user *uindices) >> +static int write_demux_regids(struct kvm_vcpu *vcpu, u64 __user *uindices) >> { >> u64 val = KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX; >> unsigned int i; >> >> val |= KVM_REG_ARM_DEMUX_ID_CCSIDR; >> - for (i = 0; i < CSSELR_MAX; i++) { >> + for (i = 0; i < num_demux_regs(vcpu); i++) { >> if (put_user(val | i, uindices)) >> return -EFAULT; >> uindices++; >> @@ -5491,11 +5491,28 @@ static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind) >> return true; >> } >> >> +static inline bool kvm_realm_sys_reg_hidden_user(const struct kvm_vcpu *vcpu, >> + u64 reg) >> +{ >> + if (!kvm_is_realm(vcpu->kvm)) >> + return false; >> + >> + switch (reg) { >> + case SYS_ID_AA64DFR0_EL1: >> + case SYS_PMCR_EL0: >> + return false; >> + } >> + return true; >> +} >> + >> static int walk_one_sys_reg(const struct kvm_vcpu *vcpu, >> const struct sys_reg_desc *rd, >> u64 __user **uind, >> unsigned int *total) >> { >> + if (kvm_realm_sys_reg_hidden_user(vcpu, reg_to_encoding(rd))) > > Hi, > > Same as my comment for patch 39, I would suggest moving the > kvm_is_realm() check out of this function. Sure, although at least this time the functions were right next to each other ;) Thanks, Steve > Thanks, > Wei-Lin Chang > >> + return 0; >> + >> /* >> * Ignore registers we trap but don't save, >> * and for which no custom user accessor is provided. >> @@ -5533,7 +5550,7 @@ static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind) >> >> unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu) >> { >> - return num_demux_regs() >> + return num_demux_regs(vcpu) >> + walk_sys_regs(vcpu, (u64 __user *)NULL); >> } >> >> @@ -5546,7 +5563,7 @@ int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) >> return err; >> uindices += err; >> >> - return write_demux_regids(uindices); >> + return write_demux_regids(vcpu, uindices); >> } >> >> #define KVM_ARM_FEATURE_ID_RANGE_INDEX(r) \ >> -- >> 2.43.0 >>