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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AC27C433F5 for ; Tue, 19 Oct 2021 12:13:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55EF761260 for ; Tue, 19 Oct 2021 12:13:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235734AbhJSMQC (ORCPT ); Tue, 19 Oct 2021 08:16:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235664AbhJSMPs (ORCPT ); Tue, 19 Oct 2021 08:15:48 -0400 Received: from mail-wm1-x34a.google.com (mail-wm1-x34a.google.com [IPv6:2a00:1450:4864:20::34a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E7CDC061749 for ; Tue, 19 Oct 2021 05:13:36 -0700 (PDT) Received: by mail-wm1-x34a.google.com with SMTP id l39-20020a05600c1d2700b0030dba1dc6eeso1068476wms.7 for ; Tue, 19 Oct 2021 05:13:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Ck8KqbWWMae7AkcYUcDJVvLhTKwYixox75Gde7aqwnI=; b=N1X0+fMmX2ELYVHNfvnYshgrGY1QPYHtzxD2UrOgV3PkeCujsVtLhyaC7O9FoW3Ppl P8iizGRJTkEPDqs+zvQodXLZP/nhkcLJMA3ySJ5DA+FpQO+nginrBfDiSj8Rlk/nN/fM N4LAy5E8anFDzGfCbnMUmYZ6lfUnSJ/2ZfVreeRN2N+0ISdPuQVD+D+UKKuv1JBaTw5r XqUgHq8AR/wKJDtRW06u51EP+Kn92ZF/THtMU+7kA83TRHin40ZyxcHcjiHA+Cc+vxIv gBtq+0o5RQNM5lgPUZIBuKx8nZQ+bZEZoDmWh2yHB1Z7soqQzthwhUMjoF9Re2+qw2Ha 2PXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Ck8KqbWWMae7AkcYUcDJVvLhTKwYixox75Gde7aqwnI=; b=SWLyr/fuTdv1GKg2YdVGHKthfZ2hmp6v9ZW9hlb8BDuB140BTlGrjEKcg0q2ymflje /685wCTPtQbKGHd4HdgoxkrhX5eWvRjm6vD8inSymUyop+XoGXjDD+KhDCzTUBFxxeBO sOVEHhiwkuf8chhq68/7KojrsTnXgqQ4HWZZDmIDY78sb+NrNVruMLIG/TrpwiHdWKxF c7e+5p2bXLsxo9hSiwcpNso+JkdhFGlkFUmUw4PneMu2vcpVRJlA6ixdyQ/0rTXe22s0 ktDBHe9i7i87L259NZHvJPiLEsJWSxhQJ3+BeiU/8S0gaW/LMBQwp1ZFGzKz7S/LHViY yLtg== X-Gm-Message-State: AOAM53337/fEiZ9o4GPowFKKZqu32ue3kaI3BJRBgDqt0l35t5QSL/a0 8EeR+tXQwNBmRThHqWe1yx9/IQws05n3 X-Google-Smtp-Source: ABdhPJwuoB1vbPKcvGKMvoxjhGJXSCqivwYwRjiSn+hagjA4deHJDWh9elWq7/kmk5iywJnzibKQqL+7r11H X-Received: from luke.lon.corp.google.com ([2a00:79e0:d:210:59ca:401f:83a8:de6d]) (user=qperret job=sendgmr) by 2002:adf:f10c:: with SMTP id r12mr31956400wro.298.1634645614634; Tue, 19 Oct 2021 05:13:34 -0700 (PDT) Date: Tue, 19 Oct 2021 13:13:01 +0100 In-Reply-To: <20211019121304.2732332-1-qperret@google.com> Message-Id: <20211019121304.2732332-13-qperret@google.com> Mime-Version: 1.0 References: <20211019121304.2732332-1-qperret@google.com> X-Mailer: git-send-email 2.33.0.1079.g6e70778dc9-goog Subject: [PATCH v2 12/15] KVM: arm64: Implement __pkvm_host_share_hyp() using do_share() From: Quentin Perret To: Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Fuad Tabba , David Brazdil , Andrew Walbran Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, kernel-team@android.com, qperret@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Will Deacon __pkvm_host_share_hyp() shares memory between the host and the hypervisor so implement it as an invocation of the new do_share() mechanism. Note that double-sharing is no longer permitted (as this allows us to reduce the number of page-table walks significantly), but is thankfully no longer relied upon by the host. Signed-off-by: Will Deacon Signed-off-by: Quentin Perret --- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 121 +++++++------------------- 1 file changed, 33 insertions(+), 88 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index d87cdd53dd21..ab1732c38b3b 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -359,94 +359,6 @@ static int host_stage2_idmap(u64 addr) return ret; } -static inline bool check_prot(enum kvm_pgtable_prot prot, - enum kvm_pgtable_prot required, - enum kvm_pgtable_prot denied) -{ - return (prot & (required | denied)) == required; -} - -int __pkvm_host_share_hyp(u64 pfn) -{ - phys_addr_t addr = hyp_pfn_to_phys(pfn); - enum kvm_pgtable_prot prot, cur; - void *virt = __hyp_va(addr); - enum pkvm_page_state state; - kvm_pte_t pte; - int ret; - - if (!addr_is_memory(addr)) - return -EINVAL; - - host_lock_component(); - hyp_lock_component(); - - ret = kvm_pgtable_get_leaf(&host_kvm.pgt, addr, &pte, NULL); - if (ret) - goto unlock; - if (!pte) - goto map_shared; - - /* - * Check attributes in the host stage-2 PTE. We need the page to be: - * - mapped RWX as we're sharing memory; - * - not borrowed, as that implies absence of ownership. - * Otherwise, we can't let it got through - */ - cur = kvm_pgtable_stage2_pte_prot(pte); - prot = pkvm_mkstate(0, PKVM_PAGE_SHARED_BORROWED); - if (!check_prot(cur, PKVM_HOST_MEM_PROT, prot)) { - ret = -EPERM; - goto unlock; - } - - state = pkvm_getstate(cur); - if (state == PKVM_PAGE_OWNED) - goto map_shared; - - /* - * Tolerate double-sharing the same page, but this requires - * cross-checking the hypervisor stage-1. - */ - if (state != PKVM_PAGE_SHARED_OWNED) { - ret = -EPERM; - goto unlock; - } - - ret = kvm_pgtable_get_leaf(&pkvm_pgtable, (u64)virt, &pte, NULL); - if (ret) - goto unlock; - - /* - * If the page has been shared with the hypervisor, it must be - * already mapped as SHARED_BORROWED in its stage-1. - */ - cur = kvm_pgtable_hyp_pte_prot(pte); - prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_SHARED_BORROWED); - if (!check_prot(cur, prot, ~prot)) - ret = -EPERM; - goto unlock; - -map_shared: - /* - * If the page is not yet shared, adjust mappings in both page-tables - * while both locks are held. - */ - prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_SHARED_BORROWED); - ret = pkvm_create_mappings_locked(virt, virt + PAGE_SIZE, prot); - BUG_ON(ret); - - prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED); - ret = host_stage2_idmap_locked(addr, PAGE_SIZE, prot); - BUG_ON(ret); - -unlock: - hyp_unlock_component(); - host_unlock_component(); - - return ret; -} - void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt) { struct kvm_vcpu_fault_info fault; @@ -697,3 +609,36 @@ static int do_share(struct pkvm_mem_share *share) return WARN_ON(__do_share(share)); } + +int __pkvm_host_share_hyp(u64 pfn) +{ + int ret; + u64 host_addr = hyp_pfn_to_phys(pfn); + u64 hyp_addr = (u64)__hyp_va(host_addr); + struct pkvm_mem_share share = { + .tx = { + .nr_pages = 1, + .initiator = { + .id = PKVM_ID_HOST, + .addr = host_addr, + .host = { + .completer_addr = hyp_addr, + }, + }, + .completer = { + .id = PKVM_ID_HYP, + }, + }, + .prot = PAGE_HYP, + }; + + host_lock_component(); + hyp_lock_component(); + + ret = do_share(&share); + + hyp_unlock_component(); + host_unlock_component(); + + return ret; +} -- 2.33.0.1079.g6e70778dc9-goog