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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D8B0C19F2A for ; Sun, 7 Aug 2022 22:04:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236630AbiHGWEg (ORCPT ); Sun, 7 Aug 2022 18:04:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235007AbiHGWDE (ORCPT ); Sun, 7 Aug 2022 18:03:04 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B2219FF5; Sun, 7 Aug 2022 15:02:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1659909763; x=1691445763; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8LP0DSlhNllsHxUGI5PiVoLspYIH9nx4tPzL+cKLV9g=; b=FArodm45NZKZCTCZi8dJlex/HHJkrrA5NBXMoAXBvsMXrem3xu0zw4At rjWgsDOWqOkdrh1IaJ78TTaADcOuaQZ0t8Iezz38Ofp5ZlmBMkSaZ0kaa QgOrk8CvaSsm7pQnLGd0emwdfM4Ot9Dc65sYL4RHEhr2yhAOzu+awoSYH r4dGUbc7qWzvhsumIWSCDsLOeRxX/3T0eZpGyfrBJVKAwjGHq8Tgr3zj2 WB5X8IgTGgM8EBNDthkSTlhHaTx++GSIE7HBPXu1hpjvytaObyOT4i+MS XmhiSKIjVdbu6SQ75Ls+OFuiHU5vSm8+E4ANcv0RIJFjM8+oVsNlqGKoY A==; X-IronPort-AV: E=McAfee;i="6400,9594,10432"; a="291695697" X-IronPort-AV: E=Sophos;i="5.93,220,1654585200"; d="scan'208";a="291695697" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Aug 2022 15:02:38 -0700 X-IronPort-AV: E=Sophos;i="5.93,220,1654585200"; d="scan'208";a="663682625" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Aug 2022 15:02:37 -0700 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , erdemaktas@google.com, Sean Christopherson , Sagi Shahar Subject: [PATCH v8 055/103] KVM: Add functions to track whether GFN is private or shared Date: Sun, 7 Aug 2022 15:01:40 -0700 Message-Id: <255c9a699e38112b106c4f3305a5f03d7390799b.1659854790.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Isaku Yamahata TDX KVM support needs to track whether GFN is private or shared. Introduce CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR to add functions to track whether GFN is private or shared. Use xarray to track it for memory efficiency in normal usage. Suggested-by: Sean Christopherson Signed-off-by: Isaku Yamahata --- arch/x86/kvm/Kconfig | 1 + include/linux/kvm_host.h | 16 ++++++++++++ virt/kvm/Kconfig | 3 +++ virt/kvm/kvm_main.c | 55 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 75 insertions(+) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index 5a59abc83179..a77830a3f371 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -48,6 +48,7 @@ config KVM select SRCU select INTERVAL_TREE select HAVE_KVM_PM_NOTIFIER if PM + select HAVE_KVM_PRIVATE_MEM_ATTR if KVM_MMU_PRIVATE help Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 025251806e70..7bc84ed44e43 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -786,8 +786,24 @@ struct kvm { struct notifier_block pm_notifier; #endif char stats_id[KVM_STATS_NAME_SIZE]; +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR + struct xarray mem_attr_array; +#endif }; +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR +#define KVM_MEM_ATTR_SHARED 0x1 +#define KVM_MEM_ATTR_PRIVATE 0x2 + +/* memory attr on [start, end) */ +int kvm_vm_reserve_mem_attr(struct kvm *kvm, gfn_t start, gfn_t end); +int kvm_vm_set_mem_attr(struct kvm *kvm, int attr, gfn_t start, gfn_t end); +static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn) +{ + return !xa_load(&kvm->mem_attr_array, gfn); +} +#endif + #define kvm_err(fmt, ...) \ pr_err("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__) #define kvm_info(fmt, ...) \ diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index a8c5c9f06b3c..bef6fc63f99f 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -72,3 +72,6 @@ config KVM_XFER_TO_GUEST_WORK config HAVE_KVM_PM_NOTIFIER bool + +config HAVE_KVM_PRIVATE_MEM_ATTR + bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3cc29fdba562..e182161baf00 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -917,6 +917,55 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR +/* + * Reserve memory for [start, end) so that the next set oepration won't fail + * with -ENOMEM. + */ +int kvm_vm_reserve_mem_attr(struct kvm *kvm, gfn_t start, gfn_t end) +{ + int r = 0; + gfn_t gfn; + + xa_lock(&kvm->mem_attr_array); + for (gfn = start; gfn < end; gfn++) { + r = __xa_insert(&kvm->mem_attr_array, gfn, NULL, GFP_KERNEL_ACCOUNT); + if (r == -EBUSY) + r = 0; + if (r) + break; + } + xa_unlock(&kvm->mem_attr_array); + + return r; +} +EXPORT_SYMBOL_GPL(kvm_vm_reserve_mem_attr); + +/* Set memory attr for [start, end) */ +int kvm_vm_set_mem_attr(struct kvm *kvm, int attr, gfn_t start, gfn_t end) +{ + void *entry; + + /* By default, the entry is private. */ + switch (attr) { + case KVM_MEM_ATTR_PRIVATE: + entry = NULL; + break; + case KVM_MEM_ATTR_SHARED: + entry = xa_mk_value(KVM_MEM_ATTR_SHARED); + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + + WARN_ON(start >= end); + return xa_err(xa_store_range(&kvm->mem_attr_array, start, end - 1, + entry, GFP_KERNEL_ACCOUNT)); +} +EXPORT_SYMBOL_GPL(kvm_vm_set_mem_attr); +#endif /* CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR */ + #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER static int kvm_pm_notifier_call(struct notifier_block *bl, unsigned long state, @@ -1141,6 +1190,9 @@ static struct kvm *kvm_create_vm(unsigned long type) spin_lock_init(&kvm->mn_invalidate_lock); rcuwait_init(&kvm->mn_memslots_update_rcuwait); xa_init(&kvm->vcpu_array); +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR + xa_init(&kvm->mem_attr_array); +#endif INIT_LIST_HEAD(&kvm->gpc_list); spin_lock_init(&kvm->gpc_lock); @@ -1308,6 +1360,9 @@ static void kvm_destroy_vm(struct kvm *kvm) kvm_free_memslots(kvm, &kvm->__memslots[i][0]); kvm_free_memslots(kvm, &kvm->__memslots[i][1]); } +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM_ATTR + xa_destroy(&kvm->mem_attr_array); +#endif cleanup_srcu_struct(&kvm->irq_srcu); cleanup_srcu_struct(&kvm->srcu); kvm_arch_free_vm(kvm); -- 2.25.1