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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C385C83F38 for ; Thu, 17 Jul 2025 16:28:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 25E506B00C2; Thu, 17 Jul 2025 12:27:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 20D836B00C3; Thu, 17 Jul 2025 12:27:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 103A56B00C4; Thu, 17 Jul 2025 12:27:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id F2BBC6B00C2 for ; Thu, 17 Jul 2025 12:27:46 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id C5EEA1D58B8 for ; Thu, 17 Jul 2025 16:27:46 +0000 (UTC) X-FDA: 83674287732.22.4F72A7C Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) by imf01.hostedemail.com (Postfix) with ESMTP id EEF2140013 for ; Thu, 17 Jul 2025 16:27:44 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b="QdysOY//"; spf=pass (imf01.hostedemail.com: domain of 3fyR5aAUKCPYrYZZYemmejc.amkjglsv-kkitYai.mpe@flex--tabba.bounces.google.com designates 209.85.128.73 as permitted sender) smtp.mailfrom=3fyR5aAUKCPYrYZZYemmejc.amkjglsv-kkitYai.mpe@flex--tabba.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1752769665; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=NswHrgkdcqxmOhQmg+I1ZftODzAqq/smUBNc/8jSsg0=; b=UYpkDXp7E40uB3RgYecNamPDfWY6Ysc+ngI9+uHtIVLW/jQjQyc3pup8oIS9sHr7ps5S0Y k10+tkEscoZdHyJG7OMHZykxc7oYMlfCmH9+yj2nD5zBelsmpMxLEFYa+YnYs2V0HR1RFd Hks6Qr2fxq4k4AH1WA/wFwOZlCYCm6M= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1752769665; a=rsa-sha256; cv=none; b=cCwFv2iKrQTLyVw9KpBSgkQFBYBeojikVk5ZawqGRGu3tSfW0KgAXBUYm02+y35A53SvnC 8BM/192Q+UR9ReY9b1QgzxusLYT29VEVfukjeYU7g/G33nPLkludaX+Q9uYWLYwv61FRuu b2GdHRjmu7NFxPazPHQ5tTF1yTwfKw4= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b="QdysOY//"; spf=pass (imf01.hostedemail.com: domain of 3fyR5aAUKCPYrYZZYemmejc.amkjglsv-kkitYai.mpe@flex--tabba.bounces.google.com designates 209.85.128.73 as permitted sender) smtp.mailfrom=3fyR5aAUKCPYrYZZYemmejc.amkjglsv-kkitYai.mpe@flex--tabba.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-451d7de4ae3so7769225e9.2 for ; Thu, 17 Jul 2025 09:27:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1752769663; x=1753374463; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=NswHrgkdcqxmOhQmg+I1ZftODzAqq/smUBNc/8jSsg0=; b=QdysOY//xqaMWE463IjhMGpTUm8EkyuhOHxnKQu/akHIZPiOcCr7Hn7ShCGg/qqYtT R503iFRC+/nQ5hqDd/10rlyQapKyFrVCFlA0DDWw6MVBs5FhxerQJNIRU7DcuWZP/B3c DoKnhyCHLXgKgCXaPL8EAi0LRFJeoiY1eQRGkGggIZiZ8OLQ2c+f0fRlXnI5nRd7160A 6h+2r0vxLwBz/xIxWM30oRxPAmWGyiTw//YHw4qa5vs8jojDlLKo1aEY33ZzT0FynMDV J8c7Ieyl/LPMM3WxXivg7gJ21mWUmMTAPIPCkb564upD8lKx08A3+LXoNw5CjqnnE7oc b1Ug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752769663; x=1753374463; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=NswHrgkdcqxmOhQmg+I1ZftODzAqq/smUBNc/8jSsg0=; b=KqY78vZoQ722tmnaQHb/lUmnbToD7uV7tSqRDt/LVA8WpCY5w/VJZ9ZZuei3/zgWyp OgI83Zf8QI3SdAO2PjZuqvsPrxQykQ9xkeJP0JmeLvXW26szFVhysP3BC+r039/GOGmA rq0vxIl+3T1HQP+wbOxvfdlFN0rUPILUShydcJjqr1e3jUKwlYCJKhuMUiQWHNjcRO3p wBER/Ck3biPTu9mt6vZYPxHc6FJnUe3Q5VIGHZa/0BJSAfQzzb5TD9yNRYHYENaPN48y EQfEwW8ylYCOoJtqQGvux4hMUJvOuZA6I1BbipTkV9h+TifG53XkeGY2pOUUFlVNoh/B jYtA== X-Forwarded-Encrypted: i=1; AJvYcCXNFSUVBB4MjL0felA2t+t6qpEz/LY6DLm7hFsRpW/vfLA0Uv2ZWQSoVNfaXCKRQTusuuj/0dCE1A==@kvack.org X-Gm-Message-State: AOJu0Yysm32NzLBVi6YdFt7+lt1Z6aM3CMg/nzXENXwVL8kkR1S818Km N1QxzmjWySKqvJTRnGZSHljM6fXwdr+TXPBEdIB0cBowf6WPMWzWaLExjRreh579xMnWOQKm+jt +gQ== X-Google-Smtp-Source: AGHT+IFgMT0SNfYFF6wTIOhI0LgfBaX0JYI2vvKy+B/T/ROVKWlCDpvfTeMqXVsxiyrC4q2xBnylePD55Q== X-Received: from wmbdq15.prod.google.com ([2002:a05:600c:64cf:b0:456:1518:6d6e]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3b9d:b0:456:26a1:a0c1 with SMTP id 5b1f17b1804b1-4562e274a82mr91598805e9.17.1752769663500; Thu, 17 Jul 2025 09:27:43 -0700 (PDT) Date: Thu, 17 Jul 2025 17:27:21 +0100 In-Reply-To: <20250717162731.446579-1-tabba@google.com> Mime-Version: 1.0 References: <20250717162731.446579-1-tabba@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250717162731.446579-12-tabba@google.com> Subject: [PATCH v15 11/21] KVM: x86/mmu: Allow NULL-able fault in kvm_max_private_mapping_level From: Fuad Tabba To: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev Cc: pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, xiaoyao.li@intel.com, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, david@redhat.com, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com, tabba@google.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: EEF2140013 X-Rspam-User: X-Rspamd-Server: rspam09 X-Stat-Signature: ftbhfgddh4xzab7domxotuhbqti1w1yr X-HE-Tag: 1752769664-791227 X-HE-Meta: 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 BjxWlPSS 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ackerley Tng Refactor kvm_max_private_mapping_level() to accept a NULL kvm_page_fault pointer and rename it to kvm_gmem_max_mapping_level(). The max_mapping_level x86 operation (previously private_max_mapping_level) is designed to potentially be called without an active page fault, for instance, when kvm_mmu_max_mapping_level() is determining the maximum mapping level for a gfn proactively. Allow NULL fault pointer: Modify kvm_max_private_mapping_level() to safely handle a NULL fault argument. This aligns its interface with the kvm_x86_ops.max_mapping_level operation it wraps, which can also be called with NULL. Rename function to kvm_gmem_max_mapping_level(): This reinforces that the function's scope is for guest_memfd-backed memory, which can be either private or non-private, removing any remaining "private" connotation from its name. Optimize max_level checks: Introduce a check in the caller to skip querying for max_mapping_level if the current max_level is already PG_LEVEL_4K, as no further reduction is possible. Acked-by: David Hildenbrand Suggested-by: Sean Christoperson Signed-off-by: Ackerley Tng Signed-off-by: Fuad Tabba --- arch/x86/kvm/mmu/mmu.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index bb925994cbc5..6bd28fda0fd3 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4467,17 +4467,13 @@ static inline u8 kvm_max_level_for_order(int order) return PG_LEVEL_4K; } -static u8 kvm_max_private_mapping_level(struct kvm *kvm, - struct kvm_page_fault *fault, - int gmem_order) +static u8 kvm_gmem_max_mapping_level(struct kvm *kvm, int order, + struct kvm_page_fault *fault) { - u8 max_level = fault->max_level; u8 req_max_level; + u8 max_level; - if (max_level == PG_LEVEL_4K) - return PG_LEVEL_4K; - - max_level = min(kvm_max_level_for_order(gmem_order), max_level); + max_level = kvm_max_level_for_order(order); if (max_level == PG_LEVEL_4K) return PG_LEVEL_4K; @@ -4513,7 +4509,9 @@ static int kvm_mmu_faultin_pfn_private(struct kvm_vcpu *vcpu, } fault->map_writable = !(fault->slot->flags & KVM_MEM_READONLY); - fault->max_level = kvm_max_private_mapping_level(vcpu->kvm, fault, max_order); + if (fault->max_level >= PG_LEVEL_4K) + fault->max_level = kvm_gmem_max_mapping_level(vcpu->kvm, + max_order, fault); return RET_PF_CONTINUE; } -- 2.50.0.727.gbf7dc18ff4-goog