From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 A6DB9328610 for ; Tue, 30 Jun 2026 22:26:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782858382; cv=none; b=VHH6v83Yn2/anoKCyRR0CBfn9TW5hhhGvsmzXk24jDJ8nW7u5HQoGfWXjDcO8C1NTRkqJGI1IlbupXomvPrLh3tbkPSymciDMFNfvkYH1amLYWmRY7wmnU51uVStg2XLZgcu2IF0iX28FNEFna6/qRPtW9/+8AISuLtpBUwiAIM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782858382; c=relaxed/simple; bh=DfpuHd0TaA0GgqDWJl9pbNH0qXb5Lm2X4Nx8yduRal4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=n1RLbHidk5GHN+LrQLpUEPZvfdyVtMLnvEjO1fCmZMfUkNPX6QVI5TWUn+vMumMcr/I7OQDx+GrCjEG8Wn+Mr1eiZDqtylodN+152MENtWABDFHYxsgHNxdjcDOs2DkDwxp7qKzcAK/ldH2q0OicmhYZRdnffMtf7cJtFSo9KE8= 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=ZnZDjJYy; arc=none smtp.client-ip=209.85.215.201 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="ZnZDjJYy" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c8969083f23so2814090a12.1 for ; Tue, 30 Jun 2026 15:26:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782858379; x=1783463179; darn=vger.kernel.org; h=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=0+OQWyaXGjZtp4FlDYBArcJJ0vLQ5n2BcbCSTzfTwAg=; b=ZnZDjJYyP9dtYOK4LUBiplt+faXFx9mjEnAfZlf+rMrg5FThkT+9h6kk3f60esEr2C EFrXquE491h0O5C+ZnH7c/8fHI+B0cSt+9N2c/0G0fB9Wg4xRaKn30Kn2CEAXvachlCh p1ipO3zb/bFQ0GAWVyP5rqDFy3xr23KKqYgCn62PcOJ1vsKB9HR9V+jPg71maie2DRMh TLgLDn9DZmzagGKXt/z+7Gk9EGt7dJ5WDkcGjFNcebfLrT+4TFtmas5uaUPOF4l63MIr HuJk1oh/5WfdrCdQj1DMWjfH//RffKRmMinb0MGN3FBhkwqMqs2gyNbi5Ct1Guyhm5w1 IF+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782858379; x=1783463179; h=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=0+OQWyaXGjZtp4FlDYBArcJJ0vLQ5n2BcbCSTzfTwAg=; b=Ox8xxpHqL0MkjEKw9kucsMu+D+0mNdSFia+bMXeZwzUqDI06wG2lJXSkQTyrrt5HCa +FaSIvF3Rrr0ofbycWss/3j07DENI2BATXsz8Ytp5WWJNMfBQP+KyJCkARi5dIcRLJir 5O+feAnYejjYXuINcx72eE4UOwrDtIlROO/7DBaumaOmEbGL+D2WCsjv6eXP+bNfGvBD vu/rJiVIKwdTyjLsMrPRgotNlfibG3yOX1J6gghhFbW3Bh5AeIOrjEi/DRF56lc0DTyG ReZBuPAwmxIsoh1xxgKRuszR5YxBh5547DHqQaqdcr9aeoOAH0aGz+69M/XsmhyvPoMX K1ZQ== X-Gm-Message-State: AOJu0YzNXoO1ruEUp+tJE/0SlxYsqpz+tRGTOcotHvO9W7jDnnf5Fmg9 hrXixUEHe+QmiigA42GTNOF7iC9Bk8F9FZId/hdg8yugkUM96EEF1syu6BS547gMstvI6KVtRuK j0r5c2A== X-Received: from pgl36.prod.google.com ([2002:a63:b24:0:b0:c96:d708:ff]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:4593:b0:3bf:6c04:a812 with SMTP id adf61e73a8af0-3bfdc803713mr1979487637.51.1782858378807; Tue, 30 Jun 2026 15:26:18 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 30 Jun 2026 15:26:04 -0700 In-Reply-To: <20260630222607.497895-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260630222607.497895-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260630222607.497895-10-seanjc@google.com> Subject: [PATCH v3 09/12] KVM: x86/mmu: Use split "zap all fast" helpers when invalidating memslot From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Ackerley Tng , Hyunwoo Kim , Tom Lendacky , Michael Roth , "=?UTF-8?q?J=C3=B6rg=20R=C3=B6del?=" , Fuad Tabba Content-Type: text/plain; charset="UTF-8" Manually invoke the front half and back half of the "zap all fast" flow when invalidating a memslot so that mmu_lock is acquired at function scope in kvm_arch_flush_shadow_memslot(). This will allow putting more code inside the critical section without having to take mmu_lock twice in quick succession. Opportunistically open code checking whether or not to do the fast zap, to discourage removing the local "zap_all" in a future cleanup, i.e. to ensure the SLOT_ZAP_ALL quirk is queried exactly once. Processing the front half but not the back half of the fast zap (if SLOT_ZAP_ALL were disabled concurrently) would result in KVM unnecessarily keeping invalid TDP MMU roots until the VM is destroyed. No functional change intended. Cc: stable@vger.kernel.org # 6.12.x Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index a5c2a560a88a..3eb1f86593b1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -7573,12 +7573,6 @@ static void kvm_mmu_zap_memslot_pages_and_flush(struct kvm *kvm, kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); } -static inline bool kvm_memslot_flush_zap_all(struct kvm *kvm) -{ - return kvm->arch.vm_type == KVM_X86_DEFAULT_VM && - kvm_check_has_quirk(kvm, KVM_X86_QUIRK_SLOT_ZAP_ALL); -} - void kvm_arch_flush_shadow_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { @@ -7589,16 +7583,23 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, .may_block = true, .attr_filter = KVM_FILTER_PRIVATE | KVM_FILTER_SHARED, }; + bool zap_all = kvm->arch.vm_type == KVM_X86_DEFAULT_VM && + kvm_check_has_quirk(kvm, KVM_X86_QUIRK_SLOT_ZAP_ALL); bool flush; - if (kvm_memslot_flush_zap_all(kvm)) { - kvm_mmu_zap_all_fast(kvm); + write_lock(&kvm->mmu_lock); + + if (zap_all) { + __kvm_mmu_zap_all_fast_front_half(kvm); } else { - write_lock(&kvm->mmu_lock); flush = kvm_unmap_gfn_range(kvm, &range); kvm_mmu_zap_memslot_pages_and_flush(kvm, slot, flush); - write_unlock(&kvm->mmu_lock); } + + write_unlock(&kvm->mmu_lock); + + if (zap_all) + __kvm_mmu_zap_all_fast_back_half(kvm); } void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) -- 2.55.0.rc0.799.gd6f94ed593-goog