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 C0E87C79F9E for ; Mon, 5 Jan 2026 15:50:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Ax3xWwdioWWyk4zWjqt5+6StydPy5id4jpQsfzSGAC8=; b=MlsjxpAS+YvhdvHhghVyiicZF/ 0wOZUaJkj11QKaUC67bYYpGGmduDDiuieaA8CnCSgGX9SeFEus9W3qn0ZDLI3Z+56sgtxsWu3yTaU rb4Wgx1DoVDsOTgKtr3tquXVPhCOpsRNbNRYpf8TjzxXU1KhT9e+niL/4l2Gx27f+NQjcQTCe2ozD FY+BXYF1qnHGU9W7RsbB9xgu7RdfS87jexGvxRxH4l6fror/Fq2tD9AvgYrJaTlKxrvuOhEQRQrzf OpKFhbh1ETxuZZNSrxtWcCKKWEchXFq6AUJs+A9+kevaz+2aeRkcVsCsQP0jAwK6Ni3XOsMLeg6uL dYRphVmA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vcmqe-0000000Bdpm-1M6G; Mon, 05 Jan 2026 15:50:24 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vcmqb-0000000Bdn8-2YL2 for linux-arm-kernel@lists.infradead.org; Mon, 05 Jan 2026 15:50:22 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 4F3D6435EC; Mon, 5 Jan 2026 15:50:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AB16C2BC86; Mon, 5 Jan 2026 15:50:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767628221; bh=GsmMPvHZ1/z4RRLQzI7ehnlvPi8mY9i1ReA/tcen41c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hLb0dl6+voqDY2qUTNJpJ0s8eHRJ16ROjx2CobMPOfYcPhx16h+UiJCGtWyMFthQ1 vbS4lLJHv2shja/svyd4iqmzsbeMeptZOFNHAfPohggjuJ654socjpRo/V3uvelu8L Qz4PeV5sP18+u/A+2QV0+Obmfp0MU0l6m3Mq+GTJSIn4JojYDkeY2mxlNEdBvJPk5Y h+IYkgcoGxO+imTa6TR6SKTrmFhshk111bB/9+1U6+EPPVvOs4Dtq4gYF13JmFcMqE lnWAObv5+xxIV2O57ByXjRqVNWlV/f30rL/UF4zki4DB/e1IC6gLzlB44bDIht+igm bzVQ0NnALexsA== From: Will Deacon To: kvmarm@lists.linux.dev Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Quentin Perret , Fuad Tabba , Vincent Donnefort , Mostafa Saleh Subject: [PATCH 10/30] KVM: arm64: Introduce __pkvm_host_donate_guest() Date: Mon, 5 Jan 2026 15:49:18 +0000 Message-ID: <20260105154939.11041-11-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260105154939.11041-1-will@kernel.org> References: <20260105154939.11041-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260105_075021_690310_CB609C7F X-CRM114-Status: GOOD ( 14.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In preparation for supporting protected VMs, whose memory pages are isolated from the host, introduce a new pKVM hypercall to allow the donation of pages to a guest. Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_pgtable.h | 2 +- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 21 +++++++++++++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 30 +++++++++++++++++++ 5 files changed, 55 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index d7fb23d39956..cad3ba5e1c5a 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -64,6 +64,7 @@ enum __kvm_host_smccc_func { /* Hypercalls available after pKVM finalisation */ __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp, __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp, + __KVM_HOST_SMCCC_FUNC___pkvm_host_donate_guest, __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest, __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest, __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest, diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 8b78d573fbcf..9ce55442b621 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -98,7 +98,7 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_HI_S2_XN) #define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -#define KVM_MAX_OWNER_ID 1 +#define KVM_MAX_OWNER_ID 3 /* * Used to indicate a pte for which a 'break-before-make' sequence is in diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 5f9d56754e39..9c0cc53d1dc9 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -28,6 +28,7 @@ enum pkvm_component_id { PKVM_ID_HOST, PKVM_ID_HYP, PKVM_ID_FFA, + PKVM_ID_GUEST, }; extern unsigned long hyp_nr_cpus; @@ -39,6 +40,7 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages); int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages); int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages); int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages); +int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu); int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot); int __pkvm_host_unshare_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *hyp_vm); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index e88b57eac25c..a5ee1103ce1f 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -238,6 +238,26 @@ static int pkvm_refill_memcache(struct pkvm_hyp_vcpu *hyp_vcpu) &host_vcpu->arch.pkvm_memcache); } +static void handle___pkvm_host_donate_guest(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(u64, pfn, host_ctxt, 1); + DECLARE_REG(u64, gfn, host_ctxt, 2); + struct pkvm_hyp_vcpu *hyp_vcpu; + int ret = -EINVAL; + + hyp_vcpu = pkvm_get_loaded_hyp_vcpu(); + if (!hyp_vcpu) + goto out; + + ret = pkvm_refill_memcache(hyp_vcpu); + if (ret) + goto out; + + ret = __pkvm_host_donate_guest(pfn, gfn, hyp_vcpu); +out: + cpu_reg(host_ctxt, 1) = ret; +} + static void handle___pkvm_host_share_guest(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(u64, pfn, host_ctxt, 1); @@ -580,6 +600,7 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__pkvm_host_share_hyp), HANDLE_FUNC(__pkvm_host_unshare_hyp), + HANDLE_FUNC(__pkvm_host_donate_guest), HANDLE_FUNC(__pkvm_host_share_guest), HANDLE_FUNC(__pkvm_host_unshare_guest), HANDLE_FUNC(__pkvm_host_relax_perms_guest), diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 49db32f3ddf7..ae126ab9febf 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -958,6 +958,36 @@ static int __guest_check_transition_size(u64 phys, u64 ipa, u64 nr_pages, u64 *s return 0; } +int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu) +{ + struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu); + u64 phys = hyp_pfn_to_phys(pfn); + u64 ipa = hyp_pfn_to_phys(gfn); + int ret; + + host_lock_component(); + guest_lock_component(vm); + + ret = __host_check_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_OWNED); + if (ret) + goto unlock; + + ret = __guest_check_page_state_range(vm, ipa, PAGE_SIZE, PKVM_NOPAGE); + if (ret) + goto unlock; + + WARN_ON(host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_GUEST)); + WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys, + pkvm_mkstate(KVM_PGTABLE_PROT_RWX, PKVM_PAGE_OWNED), + &vcpu->vcpu.arch.pkvm_memcache, 0)); + +unlock: + guest_unlock_component(vm); + host_unlock_component(); + + return ret; +} + int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot) { -- 2.52.0.351.gbe84eed79e-goog