From nobody Mon Feb 9 01:16:50 2026 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DF5F19922C for ; Fri, 9 Aug 2024 19:44:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723232646; cv=none; b=swAxS4vIOO1Gc474g36y6KkdpxydvDMxH+70iwSs1lsSFfOe0OTW0jVmigOhj7/GOeZ46c/hknCIFQBqcVkbqzwdBqOJWqSlOsQJKtJfedlEqplAIe903k5cMwkjAbhVddicBrelU4mttO2pAobXzGPKwopN4l8AV/pNwaUnrtY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723232646; c=relaxed/simple; bh=3xSCN07is/d7+9qa5tb05xLdmkaS8Uh8BYF+HVNaYMo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=c4XwSZvIHam9sBFthCD9m4B/6u2B6Fkk+X537S7py7zSdIwXh6PxNUIWbEP9pWZj1tgDsQkE5hqa+pckYeV94knTIq0EXBymI/65NLJF11m9DfNk6QV1QO2fBCdmFspvU8TpYNDAMYgdn73c7eCr+vt1Ib5Qq/i7DUAPgxgXk5k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=zJKcxA9G; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="zJKcxA9G" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-1fc5651e888so22886055ad.0 for ; Fri, 09 Aug 2024 12:44:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1723232645; x=1723837445; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:reply-to:from:to:cc:subject:date :message-id:reply-to; bh=C/Kjdpw4GZGWgN0ZxVg8kngRskxTTrucp/2D4JfCR5g=; b=zJKcxA9G0HILjOPS7dzZMv3QTb+R5BJNGYIwuowxdDZ91Sl7KCJMNREMOEGyz2zh2G agDsp++3cPC+IO/vGRG3tKdAE/roBrNSOIeeGCufasezPUgrNNu1Dpj/rI5+rDxdneEB 6u7uWgY1focTsh+dE7EFpyZJ74N36oNJwtqmZpoHPrFYmIyKQgssZl8K3LUlvpL9dHSq wwAeMql5sJe7jB4IUgCmsIuY7ugY0qD2gYLauxpKRVwq1SmRJRI+cw3RLq3QMmiRI81k opMFs+eSKjMQIIZ6jWu36LjcsDui+dlMImiJpkNRg7HuwjtMy4dVfu0wx9Sy7Gka6bvA X5Lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723232645; x=1723837445; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:reply-to:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=C/Kjdpw4GZGWgN0ZxVg8kngRskxTTrucp/2D4JfCR5g=; b=dRQJpC64By6h9BnmXKLqAyAfaSIfB0bVQUGYKRzCIjMeEjH/1H4BG9ZS7G3cnaB3Dk 71F2PlfoBbLawnwVo1phjyhFGhwokKmoM08fmXWeDNhduk9j9Upb9THRYkrW9Um8bEEJ 3ARXs2/hqHetAuL3thYKQIX9N9MpMBiF3Dof0k2MacpaA8D1/DCDBtyjEM5JydkJibT5 RuIM6z1zniWd8jiMYyEYXDPoPMVBCFYsOo9usa/NCvJZDekMi4aivtt+Xva7HoQh/n3e ZKkexVURlbUdDHDFTbWN5iCYEZdMQkalxxMaPyN2d1Q7aG4Thn2i6W+tiikRoW1YtXH6 U7bA== X-Forwarded-Encrypted: i=1; AJvYcCUJR/AToDmSMqlI1lGT4z9tyO9w6H0IJgxlhhvgVGRn19fW1asfR2mmLNJOwDw7lJZHB45LP8x6pRFr5WrTZsUZSMIEAdxzV99iMc7E X-Gm-Message-State: AOJu0YzC65LJ5s/vnQVEPk9MXGH9Qy9L6BwxyYtekyBlvvIQVj9+/Oms 3l1c8cBlGU54NQRf7HO0VlnBeZjVERNw0YGzdBTtBqJQBaTYVlnNJswfn7hQcGexuk1/E1/vsmU wRw== X-Google-Smtp-Source: AGHT+IHlnphgTRNzeVdx0O31fPI0LuneFaWMABXGnKSnF6B8xUcCs6tohBFzlE1Hi/BkKbGcyYXHhyb9HbY= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:d507:b0:1fc:2ee3:d46c with SMTP id d9443c01a7336-200ae2549b2mr2179795ad.0.1723232644737; Fri, 09 Aug 2024 12:44:04 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 9 Aug 2024 12:43:25 -0700 In-Reply-To: <20240809194335.1726916-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240809194335.1726916-1-seanjc@google.com> X-Mailer: git-send-email 2.46.0.76.ge559c4bf1a-goog Message-ID: <20240809194335.1726916-14-seanjc@google.com> Subject: [PATCH 13/22] KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Oliver Upton , Marc Zyngier , Peter Xu , James Houghton Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Convert kvm_unmap_gfn_range(), which is the helper that zaps rmap SPTEs in response to an mmu_notifier invalidation, to use __kvm_rmap_zap_gfn_range() and feed in range->may_block. In other words, honor NEED_RESCHED by way of cond_resched() when zapping rmaps. This fixes a long-standing issue where KVM could process an absurd number of rmap entries without ever yielding, e.g. if an mmu_notifier fired on a PUD (or larger) range. Opportunistically rename __kvm_zap_rmap() to kvm_zap_rmap(), and drop the old kvm_zap_rmap(). Ideally, the shuffling would be done in a different patch, but that just makes the compiler unhappy, e.g. arch/x86/kvm/mmu/mmu.c:1462:13: error: =E2=80=98kvm_zap_rmap=E2=80=99 def= ined but not used Reported-by: Peter Xu Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4016f63d03e8..0a33857d668a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1453,16 +1453,10 @@ static bool kvm_vcpu_write_protect_gfn(struct kvm_v= cpu *vcpu, u64 gfn) return kvm_mmu_slot_gfn_write_protect(vcpu->kvm, slot, gfn, PG_LEVEL_4K); } =20 -static bool __kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_hea= d, - const struct kvm_memory_slot *slot) -{ - return kvm_zap_all_rmap_sptes(kvm, rmap_head); -} - static bool kvm_zap_rmap(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot, gfn_t gfn, int level) + const struct kvm_memory_slot *slot) { - return __kvm_zap_rmap(kvm, rmap_head, slot); + return kvm_zap_all_rmap_sptes(kvm, rmap_head); } =20 struct slot_rmap_walk_iterator { @@ -1597,7 +1591,7 @@ static bool __kvm_rmap_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end, bool can_yield, bool flush) { - return __walk_slot_rmaps(kvm, slot, __kvm_zap_rmap, + return __walk_slot_rmaps(kvm, slot, kvm_zap_rmap, PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, start, end - 1, can_yield, true, flush); } @@ -1626,7 +1620,9 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_= gfn_range *range) bool flush =3D false; =20 if (kvm_memslots_have_rmaps(kvm)) - flush =3D kvm_handle_gfn_range(kvm, range, kvm_zap_rmap); + flush =3D __kvm_rmap_zap_gfn_range(kvm, range->slot, + range->start, range->end, + range->may_block, flush); =20 if (tdp_mmu_enabled) flush =3D kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); --=20 2.46.0.76.ge559c4bf1a-goog