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 7D49AEB64DC for ; Wed, 28 Jun 2023 17:05:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230311AbjF1RFn (ORCPT ); Wed, 28 Jun 2023 13:05:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231655AbjF1RFj (ORCPT ); Wed, 28 Jun 2023 13:05:39 -0400 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7215A1BE4; Wed, 28 Jun 2023 10:05:38 -0700 (PDT) Received: by mail-pf1-x431.google.com with SMTP id d2e1a72fcca58-666eb03457cso3394043b3a.1; Wed, 28 Jun 2023 10:05:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687971938; x=1690563938; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=jU0D3jztQr/atZmp0Mr2fgpDIGn4JXGFEn6H1cHgCp4=; b=NyCu/TdMfAvYkiVvTLQwSa/yIuSCWTLnlry0tgAPk03LDSY5ujX6BDmoZSrGOFR4L1 M7DWsZN8iafbaGnRzvT/uxNwJN6XHjnVjNAFsGaiW6ToHnRiK8BmA7JEjJqjGenPLqH2 AzCv2TqsR0gWeNj+bpeuBUZnmTC7MCBbkFEPA4fswffgOqg9yUz/IkZsJGdKCL0CGItq 8Dq/Lnnfm/TXS2ZWtT1bP2ehUidF7Lmj+h5advee7o1xYDooK6XnS0F+CMIwiOyXUTmU vjFXfilhBJqjR4bB5OevYPH8kuXykhwzHTubuVke29OD3s7JIUkibEUku1SpTPQMsQx9 DCWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687971938; x=1690563938; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=jU0D3jztQr/atZmp0Mr2fgpDIGn4JXGFEn6H1cHgCp4=; b=W85EZj47vRV9TEmFSjtUR0unAYVspQhfuGksckqjkushMhf2S5i+tFkLYXibGsCd5h /CaX/QRm2ZtYi9upqsOO+I5pauTZ6CkCgoTEKsdCICXxEF5092i1+nQSs6yQiR78gbnY BnBUfRWcKXG6timEMthEvzbFbBlQ0JKCV/wZWJVhrsgr2x+iSf5KIpbKIElE214gWtsK if6xQBpoh+V9SgWVeQdwftUK8vtIrQA8LaqXE3c9UCDTz09PYp5RZPA3xjLNDA+QNZED HZr/sRAjhfaqLJLcv7M9fzvwmPIVaBecTy3NuX7hylHNsIS6u/ug7M1qrfclVVGw8H2g emJA== X-Gm-Message-State: AC+VfDwQz9yxCaA/Gy0d+QM78IavAHFcby8XnV8kK3489UjhSwWVC8pJ wuU72JI1x+y1BgUrOw0Xmpc= X-Google-Smtp-Source: ACHHUZ5hV65eaKopW0K70HcSN9zamVCK+9R3I3nJG6hYTsDd+b5tJ9Zsfntbl1NDSUsBFPtzCbcXrw== X-Received: by 2002:a05:6a21:3392:b0:123:7989:ba55 with SMTP id yy18-20020a056a21339200b001237989ba55mr18930270pzb.41.1687971937707; Wed, 28 Jun 2023 10:05:37 -0700 (PDT) Received: from localhost ([192.55.54.50]) by smtp.gmail.com with ESMTPSA id q136-20020a632a8e000000b0055b0c330b30sm3036053pgq.84.2023.06.28.10.05.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Jun 2023 10:05:37 -0700 (PDT) Date: Wed, 28 Jun 2023 10:05:36 -0700 From: Isaku Yamahata To: Michael Roth Cc: isaku.yamahata@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, isaku.yamahata@gmail.com, Paolo Bonzini , erdemaktas@google.com, Sean Christopherson , Sagi Shahar , David Matlack , Kai Huang , Zhi Wang , chen.bo@intel.com, linux-coco@lists.linux.dev, Chao Peng , Ackerley Tng , Vishal Annapurve Subject: Re: [RFC PATCH v2 5/6] KVM: Add flags to struct kvm_gfn_range Message-ID: <20230628170536.GF3436214@ls.amr.corp.intel.com> References: <689da77417c2f4055f02a71aab51ff603bc195af.1687474039.git.isaku.yamahata@intel.com> <20230628152132.xyfquj67vhklsvlu@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230628152132.xyfquj67vhklsvlu@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 28, 2023 at 10:21:32AM -0500, Michael Roth wrote: > On Thu, Jun 22, 2023 at 04:16:29PM -0700, isaku.yamahata@intel.com wrote: > > From: Isaku Yamahata > > > > Add flags to strut kvm_gfn_range to indicate who triggered the callback > > and new memory attributes. > > > > TDX needs to know the reason for a callback by kvm_unmap_gfn_range(). mmu > > notifier, set memory attributes ioctl or KVM gmem callback. With TDX, > > zapping a private page from the encrypted page table and adding the page > > back to the same private GPA results in zeroing the page, and the guest has > > to accept the page again. On the change of memory attribute from private > > to shared, zapping the GPA range irrespective to private-or-shared and > > expecting the fault doesn't work for TDX. Instead, zap shared pages only > > and keep the private pages. Concretely > > - If it's from mmu notifier, zap shared pages. > > - If it's from KVM gmem, zap private pages. > > - If setting memory attributes to private, zap shared pages. > > - If setting memory attributes to shared, zap private pages. > > > > Signed-off-by: Isaku Yamahata > > > > --- > > Changes v1 -> v2: > > - consolidate KVM_GFN_RANGE_FLAGS_GMEM_{PUNCH_HOLE, RELEASE} into > > KVM_GFN_RANGE_FLAGS_GMEM. > > - Update the commit message to describe TDX more. Drop SEV_SNP. > > --- > > include/linux/kvm_host.h | 10 +++++++++- > > virt/kvm/guest_mem.c | 9 ++++++--- > > virt/kvm/kvm_main.c | 4 +++- > > 3 files changed, 18 insertions(+), 5 deletions(-) > > > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > > index 1a47cedae8a1..1fe0516fcddf 100644 > > --- a/include/linux/kvm_host.h > > +++ b/include/linux/kvm_host.h > > @@ -256,12 +256,20 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu); > > #endif > > > > #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER > > + > > +#define KVM_GFN_RANGE_FLAGS_SET_MEM_ATTR BIT(0) > > +#define KVM_GFN_RANGE_FLAGS_GMEM BIT(1) > > + > > struct kvm_gfn_range { > > struct kvm_memory_slot *slot; > > gfn_t start; > > gfn_t end; > > - pte_t pte; > > + union { > > + pte_t pte; > > + u64 attrs; > > + }; > > bool may_block; > > + unsigned int flags; > > }; > > bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range); > > bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range); > > diff --git a/virt/kvm/guest_mem.c b/virt/kvm/guest_mem.c > > index cdf2d84683c8..387226136960 100644 > > --- a/virt/kvm/guest_mem.c > > +++ b/virt/kvm/guest_mem.c > > @@ -99,7 +99,8 @@ static struct folio *kvm_gmem_get_folio(struct file *file, pgoff_t index) > > } > > > > static void kvm_gmem_invalidate_begin(struct kvm *kvm, struct kvm_gmem *gmem, > > - pgoff_t start, pgoff_t end) > > + pgoff_t start, pgoff_t end, > > + unsigned int flags) > > { > > struct kvm_memory_slot *slot; > > unsigned long index; > > @@ -118,6 +119,7 @@ static void kvm_gmem_invalidate_begin(struct kvm *kvm, struct kvm_gmem *gmem, > > .slot = slot, > > .pte = __pte(0), > > .may_block = true, > > + .flags = flags, > > }; > > > > kvm_mmu_invalidate_range_add(kvm, gfn_range.start, gfn_range.end); > > @@ -156,7 +158,8 @@ static long kvm_gmem_punch_hole(struct file *file, loff_t offset, loff_t len) > > */ > > filemap_invalidate_lock(file->f_mapping); > > > > - kvm_gmem_invalidate_begin(kvm, gmem, start, end); > > + kvm_gmem_invalidate_begin(kvm, gmem, start, end, > > + KVM_GFN_RANGE_FLAGS_GMEM); > > Do you anticipate ever needing to pass a different flag via > kvm_gmem_invalidate_begin()? If not it might make sense to just > hard-code it rather than passing as a parameter. I'll update this patch following the suggestion by Sean. [1] I'll drop the flag. the struct kvm_gfn_range will be struct kvm_gfn_range { struct kvm_memory_slot *slot; gfn_t start; gfn_t end; union { struct test_clear_young_metadata *metadata; unsigned long attributes; pte_t pte; unsigned long callback_arg; /* needs a better name */ }; bool only_private; bool only_shared; bool may_block; }; [1] https://lore.kernel.org/all/ZJX0hk+KpQP0KUyB@google.com/ -- Isaku Yamahata