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 C9C2E423A6D; Wed, 13 May 2026 13:19:21 +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=1778678363; cv=none; b=XLewHTAzIvCdvwk5iBxRxHKFjzx8/gPAkH2Ry09byauuGanl0eNLlcZ/l5H0uL/Qt6iqbj/BP8Gt362VEmqizxhiwtNwHjE1gB70V1b04l0Tn+4I5TOPktgaV6RUbb9sm/pIwxsFPtXdGkKtmRHxtzQw/MNiY0q9JdniQZbWaqY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778678363; c=relaxed/simple; bh=ln64F1hLLRYARnpXaTByx+3uUv5w5vovu0mG8WoHuw0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bs3o5zp41yRtfWaxCUz2hm1eNpEt7surgXWQ1xjuQCVGMASNI14mjpmRve2fyEdaDBQYtfNtijqhMrmM0tQ1F21DNXoFb7VTb5qcOTNl+VEnCkOR6rroTPTvGWae8zFIzrkdLA0diNgMNA1HvxHGTEms2LnbCeSGm4K02wiv0Ak= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=mY4efkr0; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="mY4efkr0" 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 06D7A2403; Wed, 13 May 2026 06:19:16 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.68.187]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2A6333F836; Wed, 13 May 2026 06:19:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778678361; bh=ln64F1hLLRYARnpXaTByx+3uUv5w5vovu0mG8WoHuw0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mY4efkr0CH+hx/SDNBHeU1XtXYdAvX2fvkN6fWbOsZjYoBzzpcPgAlbLQy3gDbyfg NwZ3uY+CrxrnG/M0I7r0SlgfYM3qfHK2fvUpbtL0tXsiGwCCkkBTq4vVcjFCP8y8NL fDR7jEW5hlgQaQi6WLRaGNJbD7oI3uSWle51NiF4= From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , 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 , WeiLin.Chang@arm.com, Lorenzo.Pieralisi2@arm.com Subject: [PATCH v14 11/44] arm64: RMI: Check for RMI support at KVM init Date: Wed, 13 May 2026 14:17:19 +0100 Message-ID: <20260513131757.116630-12-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260513131757.116630-1-steven.price@arm.com> References: <20260513131757.116630-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Check if the RMI support is sufficient for using in KVM. Specifically we currently only support KVM in VHE mode when for creating realm VMs. Signed-off-by: Steven Price --- Changes since v13: * Most of the init has been moved out of the 'kvm' directory so this is much more basic now. Changes since v12: * Drop check for 4k page size. Changes since v11: * Reword slightly the comments on the realm states. Changes since v10: * kvm_is_realm() no longer has a NULL check. * Rename from "rme" to "rmi" when referring to the RMM interface. * Check for RME (hardware) support before probing for RMI support. Changes since v8: * No need to guard kvm_init_rme() behind 'in_hyp_mode'. Changes since v6: * Improved message for an unsupported RMI ABI version. Changes since v5: * Reword "unsupported" message from "host supports" to "we want" to clarify that 'we' are the 'host'. Changes since v2: * Drop return value from kvm_init_rme(), it was always 0. * Rely on the RMM return value to identify whether the RSI ABI is compatible. --- arch/arm64/include/asm/kvm_host.h | 4 ++++ arch/arm64/include/asm/kvm_rmi.h | 17 +++++++++++++++++ arch/arm64/include/asm/virt.h | 1 + arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/arm.c | 5 +++++ arch/arm64/kvm/rmi.c | 24 ++++++++++++++++++++++++ 6 files changed, 52 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/kvm_rmi.h create mode 100644 arch/arm64/kvm/rmi.c diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 851f6171751c..3512696ed506 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -27,6 +27,7 @@ #include #include #include +#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -424,6 +425,9 @@ struct kvm_arch { /* Nested virtualization info */ struct dentry *debugfs_nv_dentry; #endif + + bool is_realm; + struct realm realm; }; struct kvm_vcpu_fault_info { diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h new file mode 100644 index 000000000000..4936007947fd --- /dev/null +++ b/arch/arm64/include/asm/kvm_rmi.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023-2025 ARM Ltd. + */ + +#ifndef __ASM_KVM_RMI_H +#define __ASM_KVM_RMI_H + +/** + * struct realm - Additional per VM data for a Realm + */ +struct realm { +}; + +void kvm_init_rmi(void); + +#endif /* __ASM_KVM_RMI_H */ diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index b546703c3ab9..92cec42952f4 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -87,6 +87,7 @@ void __hyp_reset_vectors(void); bool is_kvm_arm_initialised(void); DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); +DECLARE_STATIC_KEY_FALSE(kvm_rmi_is_available); static inline bool is_pkvm_initialized(void) { diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 59612d2f277c..ed3cf30eb06e 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -16,7 +16,7 @@ CFLAGS_handle_exit.o += -Wno-override-init kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ inject_fault.o va_layout.o handle_exit.o config.o \ guest.o debug.o reset.o sys_regs.o stacktrace.o \ - vgic-sys-reg-v3.o fpsimd.o pkvm.o \ + vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o \ arch_timer.o trng.o vmid.o emulate-nested.o nested.o at.o \ vgic/vgic.o vgic/vgic-init.o \ vgic/vgic-irqfd.o vgic/vgic-v2.o \ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 176cbe8baad3..247e03b33035 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include @@ -109,6 +110,8 @@ long kvm_get_cap_for_kvm_ioctl(unsigned int ioctl, long *ext) return -EINVAL; } +DEFINE_STATIC_KEY_FALSE(kvm_rmi_is_available); + DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector); DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base); @@ -2975,6 +2978,8 @@ static __init int kvm_arm_init(void) in_hyp_mode = is_kernel_in_hyp_mode(); + kvm_init_rmi(); + if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) || cpus_have_final_cap(ARM64_WORKAROUND_1508412)) kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \ diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c new file mode 100644 index 000000000000..1acc972a4b92 --- /dev/null +++ b/arch/arm64/kvm/rmi.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023-2025 ARM Ltd. + */ + +#include + +#include +#include + +void kvm_init_rmi(void) +{ + /* + * TODO: Support Realm guests in nVHE mode, this will require adding + * EL2 stub(s) for REC entry and possibly other things. + */ + if (!is_kernel_in_hyp_mode()) + return; + + if (!rmi_is_available()) + return; + + /* Future patch will enable static branch kvm_rmi_is_available */ +} -- 2.43.0