From patchwork Wed Apr 16 13:41:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 14054001 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A649F2222D7; Wed, 16 Apr 2025 13:46:16 +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=1744811181; cv=none; b=p49IgY2GjXeihQtlkd5BpLsU3y0iL18oyH/Vna420wnGZ1nmYZEfcTxsj/c+uUCFbDxgj/fZXWvz3ru8jJdY/6R5HYPqVYk8MUBHEWZn+kr7vzF7yDVIz0HSY2HfgQqnWqyGdk/XZVzmuaLHJxDFptNeVDpcldMe3t95Ubod31E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744811181; c=relaxed/simple; bh=qKtBOMjOaxPiVlrNAT7QHWcOlHLhWGUX3BlFUa6VHvM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RrqsiFx/D7IIwO4LXfuTI5O6mQFFcnpqsTW78JgKQnXSPMdp7qwn4BISN+/PJp5Z0TqCxUzo2jR+3FwQvWjkYhVKPUwN7mueGyWBjPRY3sSH2gXfN5fYHjsXtZMzncHa8ofFYX9NGjZXxMHZg5jg5zo7drE09JDPyyE5tDBSeEQ= 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 15C141E7D; Wed, 16 Apr 2025 06:46:14 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.90.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 22E983F59E; Wed, 16 Apr 2025 06:46:10 -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" , Steven Price Subject: [PATCH v8 35/43] arm64: RME: Set breakpoint parameters through SET_ONE_REG Date: Wed, 16 Apr 2025 14:41:57 +0100 Message-ID: <20250416134208.383984-36-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250416134208.383984-1-steven.price@arm.com> References: <20250416134208.383984-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jean-Philippe Brucker Allow userspace to configure the number of breakpoints and watchpoints of a Realm VM through KVM_SET_ONE_REG ID_AA64DFR0_EL1. The KVM sys_reg handler checks the user value against the maximum value given by RMM (arm64_check_features() gets it from the read_sanitised_id_aa64dfr0_el1() reset handler). Userspace discovers that it can write these fields by issuing a KVM_ARM_GET_REG_WRITABLE_MASKS ioctl. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Steven Price Reviewed-by: Gavin Shan --- arch/arm64/kvm/guest.c | 2 ++ arch/arm64/kvm/rme.c | 3 +++ arch/arm64/kvm/sys_regs.c | 17 +++++++++++------ 3 files changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index da8961a5d01a..dbd45d0a0d54 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -802,6 +802,7 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) } #define KVM_REG_ARM_PMCR_EL0 ARM64_SYS_REG(3, 3, 9, 12, 0) +#define KVM_REG_ARM_ID_AA64DFR0_EL1 ARM64_SYS_REG(3, 0, 0, 5, 0) /* * The RMI ABI only enables setting some GPRs and PC. The selection of GPRs @@ -820,6 +821,7 @@ static bool validate_realm_set_reg(struct kvm_vcpu *vcpu, } else { switch (reg->id) { case KVM_REG_ARM_PMCR_EL0: + case KVM_REG_ARM_ID_AA64DFR0_EL1: return true; } } diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c index 0c358ce0a7a1..7e5469ae8a95 100644 --- a/arch/arm64/kvm/rme.c +++ b/arch/arm64/kvm/rme.c @@ -354,6 +354,7 @@ static int realm_create_rd(struct kvm *kvm) void *rd = NULL; phys_addr_t rd_phys, params_phys; size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr); + u64 dfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1); int i, r; int rtt_num_start; @@ -390,6 +391,8 @@ static int realm_create_rd(struct kvm *kvm) params->rtt_num_start = rtt_num_start; params->rtt_base = kvm->arch.mmu.pgd_phys; params->vmid = realm->vmid; + params->num_bps = SYS_FIELD_GET(ID_AA64DFR0_EL1, BRPs, dfr0); + params->num_wps = SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, dfr0); if (kvm->arch.arm_pmu) { params->pmu_num_ctrs = kvm->arch.pmcr_n; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 36e22ed84e7e..a53a06700867 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1853,6 +1853,9 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, { u8 debugver = SYS_FIELD_GET(ID_AA64DFR0_EL1, DebugVer, val); u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val); + u8 bps = SYS_FIELD_GET(ID_AA64DFR0_EL1, BRPs, val); + u8 wps = SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, val); + u8 ctx_cmps = SYS_FIELD_GET(ID_AA64DFR0_EL1, CTX_CMPs, val); /* * Prior to commit 3d0dba5764b9 ("KVM: arm64: PMU: Move the @@ -1872,10 +1875,11 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, val &= ~ID_AA64DFR0_EL1_PMUVer_MASK; /* - * ID_AA64DFR0_EL1.DebugVer is one of those awkward fields with a - * nonzero minimum safe value. + * ID_AA64DFR0_EL1.DebugVer, BRPs and WRPs all have to be greater than + * zero. CTX_CMPs is never greater than BRPs. */ - if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP) + if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP || !bps || !wps || + ctx_cmps > bps) return -EINVAL; return set_id_reg(vcpu, rd, val); @@ -2055,10 +2059,11 @@ static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, mutex_lock(&vcpu->kvm->arch.config_lock); /* - * Once the VM has started the ID registers are immutable. Reject any - * write that does not match the final register value. + * Once the VM has started or the Realm descriptor is created, the ID + * registers are immutable. Reject any write that does not match the + * final register value. */ - if (kvm_vm_has_ran_once(vcpu->kvm)) { + if (kvm_vm_has_ran_once(vcpu->kvm) || kvm_realm_is_created(vcpu->kvm)) { if (val != read_id_reg(vcpu, rd)) ret = -EBUSY; else