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 DDA37C4707E for ; Wed, 17 Nov 2021 17:40:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE29C62F90 for ; Wed, 17 Nov 2021 17:40:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239530AbhKQRnl (ORCPT ); Wed, 17 Nov 2021 12:43:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239499AbhKQRnZ (ORCPT ); Wed, 17 Nov 2021 12:43:25 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4760DC061200; Wed, 17 Nov 2021 09:40:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=3olV7ZykWgs87FpuKGwDGy9MT4heqwPH6YtSnLHRz6M=; b=SJcA7ODM6+A+x6HIeoJfeygMTJ 2a3dABEQ0MK9aGzjFtquhX3/MtnfMXS0drDgbD0MNdCDtVZwukiR20+kZKxQdlFjhbj8YAPPQeeMo 7ELjjLIW106CwCQSfhZ5pJxPZ98zRY/+YWsxbyuNABRsBeUTi3xPZ3oYe+L/cu6HuYtqRAkeSOFLQ PBFEMBzta1jK8H7r19d8hGqZayJK72gLMJBhxOsGudRduyECk8NpoOSilXXf1+mGNBaP5CfMYBaNw fTxgzR7FbEKfSGHNSxfotchrRXU1iDlsrhw+iSghhjLKde/VTdmanEwM1FnBoVG8NsFwSqujAR4wm wmaNf3YQ==; Received: from i7.infradead.org ([2001:8b0:10b:1:21e:67ff:fecb:7a92]) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mnOum-007nnH-9j; Wed, 17 Nov 2021 17:40:09 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mnOum-001Gxp-Gs; Wed, 17 Nov 2021 17:40:08 +0000 From: David Woodhouse To: Paolo Bonzini , kvm Cc: Boris Ostrovsky , Joao Martins , "jmattson @ google . com" , "wanpengli @ tencent . com" , "seanjc @ google . com" , "vkuznets @ redhat . com" , "mtosatti @ redhat . com" , "joro @ 8bytes . org" , karahmed@amazon.com, Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Huacai Chen , Aleksandar Markovic , Michael Ellerman , Benjamin Herrenschmidt , Anup Patel , Christian Borntraeger , kvmarm@lists.cs.columbia.edu, linux-arm-kernel , linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org Subject: [PATCH v3 10/12] KVM: x86/xen: Maintain valid mapping of Xen shared_info page Date: Wed, 17 Nov 2021 17:40:01 +0000 Message-Id: <20211117174003.297096-11-dwmw2@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211117174003.297096-1-dwmw2@infradead.org> References: <20211117174003.297096-1-dwmw2@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: David Woodhouse Use the newly reinstated gfn_to_pfn_cache to maintain a kernel mapping of the Xen shared_info page so that it can be accessed in atomic context. Signed-off-by: David Woodhouse --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/xen.c | 25 ++++++++++++++----------- 2 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 6ac61f85e07b..4b2b4ecf3b46 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1014,7 +1014,7 @@ struct msr_bitmap_range { struct kvm_xen { bool long_mode; u8 upcall_vector; - gfn_t shinfo_gfn; + struct gfn_to_pfn_cache shinfo_cache; }; enum kvm_irqchip_mode { diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index dff2bdf9507a..32a915a4fe20 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -23,16 +23,21 @@ DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ); static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn) { + struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache; gpa_t gpa = gfn_to_gpa(gfn); int wc_ofs, sec_hi_ofs; int ret = 0; int idx = srcu_read_lock(&kvm->srcu); - if (kvm_is_error_hva(gfn_to_hva(kvm, gfn))) { - ret = -EFAULT; + if (gfn == GPA_INVALID) { + kvm_gfn_to_pfn_cache_destroy(kvm, gpc); goto out; } - kvm->arch.xen.shinfo_gfn = gfn; + + ret = kvm_gfn_to_pfn_cache_init(kvm, gpc, NULL, false, true, gpa, + PAGE_SIZE, true); + if (ret) + goto out; /* Paranoia checks on the 32-bit struct layout */ BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900); @@ -260,15 +265,9 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) break; case KVM_XEN_ATTR_TYPE_SHARED_INFO: - if (data->u.shared_info.gfn == GPA_INVALID) { - kvm->arch.xen.shinfo_gfn = GPA_INVALID; - r = 0; - break; - } r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn); break; - case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR: if (data->u.vector && data->u.vector < 0x10) r = -EINVAL; @@ -299,7 +298,10 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) break; case KVM_XEN_ATTR_TYPE_SHARED_INFO: - data->u.shared_info.gfn = kvm->arch.xen.shinfo_gfn; + if (kvm->arch.xen.shinfo_cache.active) + data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa); + else + data->u.shared_info.gfn = GPA_INVALID; r = 0; break; @@ -661,11 +663,12 @@ int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc) void kvm_xen_init_vm(struct kvm *kvm) { - kvm->arch.xen.shinfo_gfn = GPA_INVALID; } void kvm_xen_destroy_vm(struct kvm *kvm) { + kvm_gfn_to_pfn_cache_destroy(kvm, &kvm->arch.xen.shinfo_cache); + if (kvm->arch.xen_hvm_config.msr) static_branch_slow_dec_deferred(&kvm_xen_enabled); } -- 2.31.1