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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03D4FC433EF for ; Tue, 14 Dec 2021 14:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235053AbhLNOsp (ORCPT ); Tue, 14 Dec 2021 09:48:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235046AbhLNOsm (ORCPT ); Tue, 14 Dec 2021 09:48:42 -0500 Received: from mail-io1-xd34.google.com (mail-io1-xd34.google.com [IPv6:2607:f8b0:4864:20::d34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75581C061574 for ; Tue, 14 Dec 2021 06:48:42 -0800 (PST) Received: by mail-io1-xd34.google.com with SMTP id c3so24506965iob.6 for ; Tue, 14 Dec 2021 06:48:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GLws1fv1VvQ+JdMbCyDoHLq+rkRsysRGV91MeqRMLdM=; b=eviPoIzpJMZdqH8yuSUhoKHalI4tyZogPyEoK8h12DRJoxZ0Ab7m31ZEODVknuaUcK WvUVetw7Alaz4hJSjVAWjhx7KCT5kx/lOgBR+hC0BcDwiEStS301DAsf2gy4tAmQkiB4 WfwWMsaZHzfsY69AxbS9wLCyQZXDDni+SPH8F6ioe13dcus2bBNrG6zAVFu7RocBzMgh +uYvoeYFBRJReekBk/AkCZpxAXDLQPPWrxL4XoZObuiURRFgb0ZcFTgxeZDmPplF+63A owOfqrAQ9Fre27IS9uvk8WtFqJuHNK27IoUeVwcojxXSCUdOROipbAGl10vnihs+9rYV OggA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=GLws1fv1VvQ+JdMbCyDoHLq+rkRsysRGV91MeqRMLdM=; b=R3UJBb5rUXD9W6XiAHnvNyUYECR64smZtEQUnn1CUyqp8Q4QJHdAgovyFfNNCAJ/k9 E5kiIUF9gAquBhkbK91n7sC/TKf9i/416vlEWXrnjxDwmmfi7uRmv0V98gPUud8dU5Us x1n1UdTG5q7nG++I8HPo5ZDzFKXyBJ3srR8VVhXwO/bEOoZJOipM3mRR/kCxOuoD2z/z NvCSx7XgzcF/va8CrLfX7KpxK6M0GMc18YZQ6/yiXaKajuFRs0uMSHOjb4DnFGJcZpar r8ZEH+Ves5v8wrS1zELb2iOirwylqAwRxyKsax8ehOK03waogtIPXZBuqyZYZAuk2uUw I+iw== X-Gm-Message-State: AOAM5326/3heGOVVXTUyhhmXxilSyhgicTYfLqkCMjy/PaR2HpbytU1j 8YiiO2wybYN+OjVWUNiBa31PKOqr2yjWj5Dlm0Jsdw== X-Google-Smtp-Source: ABdhPJwDobqQ0ytVa0HxNlcgE4bESeMZUOEn4HcyugZoluHpS2Q4fWuEd3GtI+jUITR45jghm1HTYm2iOEJoB2ew/AQ= X-Received: by 2002:a02:6945:: with SMTP id e66mr3303073jac.620.1639493321703; Tue, 14 Dec 2021 06:48:41 -0800 (PST) MIME-Version: 1.0 References: <20211201170411.1561936-1-qperret@google.com> <20211201170411.1561936-11-qperret@google.com> In-Reply-To: <20211201170411.1561936-11-qperret@google.com> From: Andrew Walbran Date: Tue, 14 Dec 2021 14:48:30 +0000 Message-ID: Subject: Re: [PATCH v3 10/15] KVM: arm64: Introduce wrappers for host and hyp spin lock accessors To: Quentin Perret Cc: Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 1 Dec 2021 at 17:04, 'Quentin Perret' via kernel-team wrote: > > From: Will Deacon > > In preparation for adding additional locked sections for manipulating > page-tables at EL2, introduce some simple wrappers around the host and > hypervisor locks so that it's a bit easier to read and bit more difficult > to take the wrong lock (or even take them in the wrong order). Looks good, but how does this help prevent taking locks in the wrong order? > > Signed-off-by: Will Deacon > Signed-off-by: Quentin Perret > --- > arch/arm64/kvm/hyp/nvhe/mem_protect.c | 32 ++++++++++++++++++++++----- > 1 file changed, 26 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > index c1a90dd022b8..757dfefe3aeb 100644 > --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > @@ -27,6 +27,26 @@ static struct hyp_pool host_s2_pool; > > const u8 pkvm_hyp_id = 1; > > +static void host_lock_component(void) > +{ > + hyp_spin_lock(&host_kvm.lock); > +} > + > +static void host_unlock_component(void) > +{ > + hyp_spin_unlock(&host_kvm.lock); > +} > + > +static void hyp_lock_component(void) > +{ > + hyp_spin_lock(&pkvm_pgd_lock); > +} > + > +static void hyp_unlock_component(void) > +{ > + hyp_spin_unlock(&pkvm_pgd_lock); > +} > + > static void *host_s2_zalloc_pages_exact(size_t size) > { > void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size)); > @@ -338,14 +358,14 @@ static int host_stage2_idmap(u64 addr) > > prot = is_memory ? PKVM_HOST_MEM_PROT : PKVM_HOST_MMIO_PROT; > > - hyp_spin_lock(&host_kvm.lock); > + host_lock_component(); > ret = host_stage2_adjust_range(addr, &range); > if (ret) > goto unlock; > > ret = host_stage2_idmap_locked(range.start, range.end - range.start, prot); > unlock: > - hyp_spin_unlock(&host_kvm.lock); > + host_unlock_component(); > > return ret; > } > @@ -369,8 +389,8 @@ int __pkvm_host_share_hyp(u64 pfn) > if (!addr_is_memory(addr)) > return -EINVAL; > > - hyp_spin_lock(&host_kvm.lock); > - hyp_spin_lock(&pkvm_pgd_lock); > + host_lock_component(); > + hyp_lock_component(); > > ret = kvm_pgtable_get_leaf(&host_kvm.pgt, addr, &pte, NULL); > if (ret) > @@ -432,8 +452,8 @@ int __pkvm_host_share_hyp(u64 pfn) > BUG_ON(ret); > > unlock: > - hyp_spin_unlock(&pkvm_pgd_lock); > - hyp_spin_unlock(&host_kvm.lock); > + hyp_unlock_component(); > + host_unlock_component(); > > return ret; > } > -- > 2.34.0.rc2.393.gf8c9666880-goog > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >