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 EB7CA10D14A2 for ; Mon, 30 Mar 2026 12:26:53 +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=W+S0OLV+NhC/lOPonbsRJOqngR35goWEZdbqiaOd5cs=; b=z4seu9TXh81fdO v4lnlBLpdhXoDZsTevjXNcRQGSEW/r+diwu0BXLfCtlRdbi4UpqtNRRReEkjTREm1ViSqRiD+6Txa u8qrb6CIh4Hc0R6sUXn99y/dgGt6W0zV/LAW6xt9tBajneinzAPYlAPNzDFBhzzXrOjP+fEMUCb7+ r42RZF/SEEQCGI2ozBG6rocQ8No2JKIAbl++fMe4yBiQ83thxdKGcvqJX23cnOxLQ4bXj7gcBlpEH nTVfRGNlxQwz1gcAgQtXw+pP1BOje+RoU9/NpbyiY6RU+YZ6NH3INHwALNLGeOz/apTfYPmaqXgAA whVYlo2vryoDFo/Fmu+w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w7Bhf-0000000BFp9-30B8; Mon, 30 Mar 2026 12:26:47 +0000 Received: from out30-118.freemail.mail.aliyun.com ([115.124.30.118]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w7BhY-0000000BFjj-3tPR; Mon, 30 Mar 2026 12:26:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1774873594; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=hFPV9OZsT6eJowdta/xFZt6DIyl+vW5qGVBuswXMeAQ=; b=RQ4NShaaFF6YWBT8WReqoqRHaXoEIIFRIUCxenVvXr3Eb1qmRxEtoxvqE7GCS96Xt8VQVpKomNwgwJAuTpNvkFZ+QfMyr4f/DR0VHDyPBGSCg9C9liaDbuUFLFQRrh+xuHeKamCm3MQdN4CJCclysQSy5uxx/enQDYs10Ts6tsY= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037033178;MF=fangyu.yu@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0X.zfcJd_1774873592; Received: from localhost.localdomain(mailfrom:fangyu.yu@linux.alibaba.com fp:SMTPD_---0X.zfcJd_1774873592 cluster:ay36) by smtp.aliyun-inc.com; Mon, 30 Mar 2026 20:26:33 +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, skhan@linuxfoundation.org Cc: guoren@kernel.org, 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 v6 4/4] RISC-V: KVM: add KVM_CAP_RISCV_SET_HGATP_MODE Date: Mon, 30 Mar 2026 20:26:01 +0800 Message-Id: <20260330122601.22140-5-fangyu.yu@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260330122601.22140-1-fangyu.yu@linux.alibaba.com> References: <20260330122601.22140-1-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-20260330_052641_509022_53042CBE X-CRM114-Status: GOOD ( 15.85 ) 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 Reviewed-by: Andrew Jones --- Documentation/virt/kvm/api.rst | 27 +++++++++++++++++++++++++++ arch/riscv/kvm/vm.c | 18 ++++++++++++++++-- include/uapi/linux/kvm.h | 1 + 3 files changed, 44 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 032516783e96..9d7f6958fa81 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8902,6 +8902,33 @@ 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. + +If this capability is not enabled, KVM will select the default HGATP mode +automatically. The default is the highest HGATP.MODE value supported by +hardware. + +``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. Supported-mode bitmask use HGATP.MODE +encodings as defined by the RISC-V privileged specification, such as Sv39x4 +corresponds to HGATP.MODE=8, so userspace should test bitmask & BIT(8). + 8. Other capabilities. ====================== diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c index 4d82a886102c..5e82a3ad3ad0 100644 --- a/arch/riscv/kvm/vm.c +++ b/arch/riscv/kvm/vm.c @@ -201,6 +201,9 @@ 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.pgd_levels); break; + case KVM_CAP_RISCV_SET_HGATP_MODE: + r = kvm_riscv_get_hgatp_mode_mask(); + break; default: r = 0; break; @@ -211,12 +214,23 @@ 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: + if (!kvm_riscv_hgatp_mode_is_valid(cap->args[0])) + return -EINVAL; + + if (kvm->created_vcpus || !kvm_are_all_memslots_empty(kvm)) + return -EBUSY; +#ifdef CONFIG_64BIT + kvm->arch.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 80364d4dbebb..a74a80fd4046 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -989,6 +989,7 @@ struct kvm_enable_cap { #define KVM_CAP_ARM_SEA_TO_USER 245 #define KVM_CAP_S390_USER_OPEREXEC 246 #define KVM_CAP_S390_KEYOP 247 +#define KVM_CAP_RISCV_SET_HGATP_MODE 248 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