From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C8F1187A; Thu, 2 Nov 2023 06:00:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="OiUIPTMY" Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0217FD7; Wed, 1 Nov 2023 23:00:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698904807; x=1730440807; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=ou5/8bq0/RVZthvT/yQo+QsMVA9om+MCO0TErMQh5Kw=; b=OiUIPTMYdM3Qa7HpDEbjmeZjJDIhxPjHoNLRTODRHbP+kCowzQ1Q2xfF g9fbUSi8hz0O7rvlE4GC2vwJvYEWPR5r0RhH64NbcacAsGiZFoRL/y/WO DBaz0+yxMxQJEWHe6zuNISMzNLvz65QHE4zh6wIbHpjU/Tx598YMKL/cl zTB2EhyGiw86ZpkM6mFPU62OfY1bexN5tsvlGTOjekPiXdRT55sA3jyU4 BUfAgNMiBGYIhefuHzOkcaDkDaGG3mqrojqBzQJQw/PJ7xFFodReSx5sx zykyYeYTcNAftpAr1U7+6ZSl73RtoKQhDED8Jsv1y7f0cU7g14oAz+tV9 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="10174671" X-IronPort-AV: E=Sophos;i="6.03,270,1694761200"; d="scan'208";a="10174671" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 23:00:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10881"; a="884777553" X-IronPort-AV: E=Sophos;i="6.03,270,1694761200"; d="scan'208";a="884777553" Received: from binbinwu-mobl.ccr.corp.intel.com (HELO [10.238.2.253]) ([10.238.2.253]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2023 22:59:55 -0700 Message-ID: <9963b77c-3a38-4f89-b21e-48d0fdda8f53@linux.intel.com> Date: Thu, 2 Nov 2023 13:59:53 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v13 12/35] KVM: Prepare for handling only shared mappings in mmu_notifier events To: Sean Christopherson Cc: Paolo Bonzini , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Xu Yilun , Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , David Matlack , Yu Zhang , Isaku Yamahata , =?UTF-8?B?TWlja2HDq2wgU2FsYcO8?= =?UTF-8?Q?n?= , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" References: <20231027182217.3615211-1-seanjc@google.com> <20231027182217.3615211-13-seanjc@google.com> From: Binbin Wu In-Reply-To: <20231027182217.3615211-13-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 10/28/2023 2:21 AM, Sean Christopherson wrote: > Add flags to "struct kvm_gfn_range" to let notifier events target only > shared and only private mappings, and write up the existing mmu_notifier > events to be shared-only (private memory is never associated with a > userspace virtual address, i.e. can't be reached via mmu_notifiers). > > Add two flags so that KVM can handle the three possibilities (shared, > private, and shared+private) without needing something like a tri-state > enum. I see the two flags are set/cleared in __kvm_handle_hva_range() in this patch and kvm_handle_gfn_range() from the later patch 13/35, but I didn't see they are used/read in this patch series if I didn't miss anything.  How are they supposed to be used in KVM? > > Link: https://lore.kernel.org/all/ZJX0hk+KpQP0KUyB@google.com > Signed-off-by: Sean Christopherson > --- > include/linux/kvm_host.h | 2 ++ > virt/kvm/kvm_main.c | 7 +++++++ > 2 files changed, 9 insertions(+) > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 96aa930536b1..89c1a991a3b8 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -263,6 +263,8 @@ struct kvm_gfn_range { > gfn_t start; > gfn_t end; > union kvm_mmu_notifier_arg arg; > + bool only_private; > + bool only_shared; > bool may_block; > }; > bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range); > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index cb9376833c18..302ccb87b4c1 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -635,6 +635,13 @@ static __always_inline kvm_mn_ret_t __kvm_handle_hva_range(struct kvm *kvm, > * the second or later invocation of the handler). > */ > gfn_range.arg = range->arg; > + > + /* > + * HVA-based notifications aren't relevant to private > + * mappings as they don't have a userspace mapping. > + */ > + gfn_range.only_private = false; > + gfn_range.only_shared = true; > gfn_range.may_block = range->may_block; > > /*