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 D00C0D65528 for ; Wed, 17 Dec 2025 10:13:50 +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=0vgehLfKuOaUaDSTV0Xa/FhqidrQttcDucSmSlBzZ9Y=; b=Yod5qTy+Aw1CrSUlXETxV5r6X2 hcR78E0G2bSft8bndj3EuYfX9gZ7mXqel1hNorxcP7LGSVGjFBgfHogV7SL0vAp9GPWTfdCLPFct4 j0gH6Va5UhgiNksDiwjsgH+HSpHggjrYTW691B2N6C63EvYm9ji4peHTDHH46+8ehWuS2JLhcQu02 sgmii1/10ZNxHIvJaoIb/UOagyutGMCRWtZpYf60HRyffySkE6EEy8bKbbbDJBFnUy3aCr8I5eCLf 5+ASgyaN/ZB27On03zYEqcWeO7ATrFofxl3KBoCrTm+t28Pht43uNGh3ht619eoU88NKsgCb/5T2f R2hA4R4Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vVoXS-00000006XW3-3KC3; Wed, 17 Dec 2025 10:13:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vVoXL-00000006XNM-02ao for linux-arm-kernel@lists.infradead.org; Wed, 17 Dec 2025 10:13:43 +0000 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 4EDAA1517; Wed, 17 Dec 2025 02:13:31 -0800 (PST) Received: from e122027.arm.com (unknown [10.57.45.201]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CFB1D3F73B; Wed, 17 Dec 2025 02:13:33 -0800 (PST) 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 Subject: [PATCH v12 23/46] arm64: RMI: Add a VMID allocator for realms Date: Wed, 17 Dec 2025 10:11:00 +0000 Message-ID: <20251217101125.91098-24-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251217101125.91098-1-steven.price@arm.com> References: <20251217101125.91098-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251217_021339_222584_3CA51469 X-CRM114-Status: GOOD ( 12.67 ) 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 The RMM v1.0 spec requires that the host manage the VMIDs of realm guests. Add a basic allocator and assign a unique VMID to the guest when creating the realm descriptor. Signed-off-by: Steven Price --- New patch for v12. NOTE: RMM v2.0 will remove the requirement for the host to manage VMIDs --- arch/arm64/kvm/rmi.c | 48 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index 18edc7eeb5fa..ede6c250bcfb 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -600,6 +600,42 @@ static int realm_create_rd(struct kvm *kvm) return r; } +/* Protects access to rmi_vmid_bitmap */ +static DEFINE_SPINLOCK(rmi_vmid_lock); +static unsigned long *rmi_vmid_bitmap; + +static int rmi_vmid_init(void) +{ + unsigned int vmid_count = 1 << kvm_get_vmid_bits(); + + rmi_vmid_bitmap = bitmap_zalloc(vmid_count, GFP_KERNEL); + if (!rmi_vmid_bitmap) { + kvm_err("%s: Couldn't allocate rmi vmid bitmap\n", __func__); + return -ENOMEM; + } + + return 0; +} + +static int rmi_vmid_reserve(void) +{ + int ret; + unsigned int vmid_count = 1 << kvm_get_vmid_bits(); + + spin_lock(&rmi_vmid_lock); + ret = bitmap_find_free_region(rmi_vmid_bitmap, vmid_count, 0); + spin_unlock(&rmi_vmid_lock); + + return ret; +} + +static void rmi_vmid_release(unsigned int vmid) +{ + spin_lock(&rmi_vmid_lock); + bitmap_release_region(rmi_vmid_bitmap, vmid, 0); + spin_unlock(&rmi_vmid_lock); +} + static int realm_unmap_private_page(struct realm *realm, unsigned long ipa, unsigned long *next_addr) @@ -903,6 +939,7 @@ static int realm_init_ipa_state(struct kvm *kvm, static int realm_ensure_created(struct kvm *kvm) { + struct realm *realm = &kvm->arch.realm; int ret; switch (kvm_realm_state(kvm)) { @@ -916,7 +953,13 @@ static int realm_ensure_created(struct kvm *kvm) return -EBUSY; } + ret = rmi_vmid_reserve(); + if (ret < 0) + return ret; + realm->vmid = ret; ret = realm_create_rd(kvm); + if (ret) + rmi_vmid_release(realm->vmid); return ret; } @@ -1307,6 +1350,8 @@ void kvm_destroy_realm(struct kvm *kvm) realm->rd = NULL; } + rmi_vmid_release(realm->vmid); + for (i = 0; i < pgd_size; i += RMM_PAGE_SIZE) { phys_addr_t pgd_phys = kvm->arch.mmu.pgd_phys + i; @@ -1342,5 +1387,8 @@ void kvm_init_rmi(void) if (WARN_ON(rmi_features(0, &rmm_feat_reg0))) return; + if (rmi_vmid_init()) + return; + /* Future patch will enable static branch kvm_rmi_is_available */ } -- 2.43.0