From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 23631E7DEE3 for ; Mon, 2 Feb 2026 14:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RW1zrFlmlWu/6cUZQPtibZfPbfJzcIQM0z6uaYSjvlM=; b=yH/nhikrO5o4Sg WmCqf2YAhMNFzFh4ajkGbhMdYjWtWPD9XPig5ioXf5FsPXwHRfoTJJ+1sVah1eEqZEITNKA6HKe34 +yJq9o8X4OXBthyr2NV4/zN+XTBF0Iki8Sl2nJW+UaO7AwUyWFNLO0SOOiJ0aaRSBxW3oNXNOiXcg 9zKMl2igQaXxIDNMfZaapPpT02uvFLWhS5FawmV8BOldNuRBH1DUhLtXvNYEb57ZeVrcPI+7WMmMN xlfL5GzUrpscHW6ekGTDUVjTz+yx0NHwh4CsDYQXLBDwcL1ZD07EVscg+83Px2lTXYdeT4OOvzWAv eAMJMZOI9f8qkQEaOppQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vmujs-000000055Ig-2rpu; Mon, 02 Feb 2026 14:17:16 +0000 Received: from out199-9.us.a.mail.aliyun.com ([47.90.199.9]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vmujp-000000055Hu-2UqW; Mon, 02 Feb 2026 14:17:15 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1770041818; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=xL+lY+t7zetS6qr1sGNBiYnMdBqphOvpSAPSUtqTssc=; b=xQn77DDywFTwJiPCP/5poe5Q0Ezkq5mIbDYPcv88CXBDEzxn0dVyMzXizuJuNHRNFVFwua0jU8C7N53m9yAaGKnm7Zq7TVwTTwx/VQ1odo93rwTjk+xmxOlsT22LZjR2QkSGxaPJCDxSeoTAJRxN/9yvsOYl/ZLUaB5dpaj8/30= Received: from localhost.localdomain(mailfrom:fangyu.yu@linux.alibaba.com fp:SMTPD_---0WyO62XS_1770041255 cluster:ay36) by smtp.aliyun-inc.com; Mon, 02 Feb 2026 22:07:37 +0800 From: fangyu.yu@linux.alibaba.com To: pbonzini@redhat.com, corbet@lwn.net, anup@brainfault.org, atish.patra@linux.dev, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr Cc: guoren@kernel.org, ajones@ventanamicro.com, rkrcmar@ventanamicro.com, radim.krcmar@oss.qualcomm.com, andrew.jones@oss.qualcomm.com, linux-doc@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Fangyu Yu Subject: [PATCH v4 3/4] RISC-V: KVM: add KVM_CAP_RISCV_SET_HGATP_MODE Date: Mon, 2 Feb 2026 22:07:15 +0800 Message-Id: <20260202140716.34323-4-fangyu.yu@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260202140716.34323-1-fangyu.yu@linux.alibaba.com> References: <20260202140716.34323-1-fangyu.yu@linux.alibaba.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260202_061713_907755_E4DB44F0 X-CRM114-Status: GOOD ( 15.18 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Fangyu Yu Add a VM capability that allows userspace to select the G-stage page table format by setting HGATP.MODE on a per-VM basis. Userspace enables the capability via KVM_ENABLE_CAP, passing the requested HGATP.MODE in args[0]. The request is rejected with -EINVAL if the mode is not supported by the host, and with -EBUSY if the VM has already been committed (e.g. vCPUs have been created or any memslot is populated). KVM_CHECK_EXTENSION(KVM_CAP_RISCV_SET_HGATP_MODE) returns a bitmask of the HGATP.MODE formats supported by the host. Signed-off-by: Fangyu Yu --- Documentation/virt/kvm/api.rst | 27 +++++++++++++++++++++++++++ arch/riscv/kvm/vm.c | 20 ++++++++++++++++++-- include/uapi/linux/kvm.h | 1 + 3 files changed, 46 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 01a3abef8abb..1a0c5ddacae8 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8765,6 +8765,33 @@ helpful if user space wants to emulate instructions which are not This capability can be enabled dynamically even if VCPUs were already created and are running. +7.47 KVM_CAP_RISCV_SET_HGATP_MODE +--------------------------------- + +:Architectures: riscv +:Type: VM +:Parameters: args[0] contains the requested HGATP mode +:Returns: + - 0 on success. + - -EINVAL if args[0] is outside the range of HGATP modes supported by the + hardware. + - -EBUSY if vCPUs have already been created for the VM, if the VM has any + non-empty memslots. + +This capability allows userspace to explicitly select the HGATP mode for +the VM. The selected mode must be supported by both KVM and hardware. This +capability must be enabled before creating any vCPUs or memslots. + +``KVM_CHECK_EXTENSION(KVM_CAP_RISCV_SET_HGATP_MODE)`` returns a bitmask of +HGATP.MODE values supported by the host. A return value of 0 indicates that +the capability is not supported. + +The returned bitmask uses the following bit positions:: + + bit 0: HGATP.MODE = SV39X4 + bit 1: HGATP.MODE = SV48X4 + bit 2: HGATP.MODE = SV57X4 + 8. Other capabilities. ====================== diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c index 4b2156df40fc..3bbbcb6a17a6 100644 --- a/arch/riscv/kvm/vm.c +++ b/arch/riscv/kvm/vm.c @@ -202,6 +202,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_VM_GPA_BITS: r = kvm_riscv_gstage_gpa_bits(&kvm->arch); break; + case KVM_CAP_RISCV_SET_HGATP_MODE: + r = kvm_riscv_get_hgatp_mode_mask(); + break; default: r = 0; break; @@ -212,12 +215,25 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { + if (cap->flags) + return -EINVAL; + switch (cap->cap) { case KVM_CAP_RISCV_MP_STATE_RESET: - if (cap->flags) - return -EINVAL; kvm->arch.mp_state_reset = true; return 0; + case KVM_CAP_RISCV_SET_HGATP_MODE: +#ifdef CONFIG_64BIT + if (!kvm_riscv_hgatp_mode_is_valid(cap->args[0])) + return -EINVAL; + + if (kvm->created_vcpus || !kvm_are_all_memslots_empty(kvm)) + return -EBUSY; + + kvm->arch.kvm_riscv_gstage_pgd_levels = + 3 + cap->args[0] - HGATP_MODE_SV39X4; +#endif + return 0; default: return -EINVAL; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index dddb781b0507..00c02a880518 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -974,6 +974,7 @@ struct kvm_enable_cap { #define KVM_CAP_GUEST_MEMFD_FLAGS 244 #define KVM_CAP_ARM_SEA_TO_USER 245 #define KVM_CAP_S390_USER_OPEREXEC 246 +#define KVM_CAP_RISCV_SET_HGATP_MODE 247 struct kvm_irq_routing_irqchip { __u32 irqchip; -- 2.50.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv