From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (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 751E33EB0E8 for ; Thu, 9 Jul 2026 20:50:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783630203; cv=none; b=lD7VG7+BXUf9pST+O2TG0w7ox43CPeFM7KC1sWbxMhj1SlKRJW30YxR+CZCvY/mJI/GqB8Wjkam88tqb5jB5Fxqpdce2dXc7645Pw4LpT48WiDrjXcJ3N4jK1JGl7leyEO8riQxwJEp4YKUAVieK1XP5XfurOtVrLNaUcacP66s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783630203; c=relaxed/simple; bh=I6cf1ipgAMfP2hWVj7O5rBXYIx5YxCt3YTk1+uufLmM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=IpNuaL8Y5C6fvneo9b8aQUmowJmxHTHZMswM5tcJcrUu9/YeUTHiSbeNHmvEI3rQRRtgd8E5Ul/Jm30azqYOPFgkDzkfzf5kmOXEKPO2LYIffxwSQ95XZ8LEbiFwZ7T2IxH936O+LTg4viksPfjhP4qMp8HQuqqiL4H/th4tles= 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=kmfmuzMe; arc=none smtp.client-ip=209.85.210.201 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="kmfmuzMe" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-84854c2f888so277456b3a.3 for ; Thu, 09 Jul 2026 13:50:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783630201; x=1784235001; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:from:to:cc:subject:date:message-id :reply-to:content-type; bh=TsRcXKumPg5adzlKIgjA7SyT7NQZsPMu5TrBeJka9aw=; b=kmfmuzMe1lMVizv47tbnn4qzookKB2s+73/vXz/8EFGAfvnyDJglgbL86dYVrY4BNg H8RIYAQlzckSYAEgvhQc/N8Yd2fPs3kwU1mBjObiTVhKDU9DZ7XF/JAAmgmX744s8Bex h11gygPwPgdy6y7vLVzHff/9ijzTvrCMZKMYKeKZ02xrXqQFq3X9wfCVdgxT4Eo1AB2j 5q1MLbwnkz5WVg2aqCaZv+di78xmMufB2PEsmCc5IaNyBHZbtHLd9HIOCBUTZN2fhS9Z VLAXHJ0CB2jGhOBIIT/s9hZGoUUSQ6L/IMUR/wINqLepRm3tVTXJyqJSpDFY5gKFkwZh CPdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783630201; x=1784235001; h=content-type: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:content-type; bh=TsRcXKumPg5adzlKIgjA7SyT7NQZsPMu5TrBeJka9aw=; b=DdeTac+teg8HRV8mmIujP45aF85MWdVm5IFpsSW9JloI14Gvc5IE7RUtnjh51GkmHI v2Rm04QOsG2OJeDP/wyAFdfpXMQ+cwpirRMyKdyK/M6Hq2ZQYTkCd09SSLy5LexdfYQK m+KMDOmtHwGviLOUCovEphvOFeruekDBeo9EV95H9yHjHjltWj1PBuOVtNltPmD5GsUx 9POFTXICIKpplZ0wXosPXuNM6a2RBuYJUF34kqA6hxw2VCFwMnf4UF2L67Qv7jAsqEFK 5oKDEMOJhpgzSXMLNtTzFRObCS3pgPXaef6Lupr54IEcO9BSs8I0GHE+lKRFR6flobkG BumA== X-Gm-Message-State: AOJu0YzQQaZbaXlvrmpIHr3JzX1v38hcRC58nXRaMzv/lPLiX3/AxLmz 5wMvuz2ACqCvbUX0LXIoDATttmpOc/xWCxibqDSXDhTCJoKFN7XPsUSt4Q58O0B5OM4XRJgB3sP TNyBXhg== X-Received: from pfbg24.prod.google.com ([2002:a05:6a00:ae18:b0:847:a600:d064]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:3e12:b0:847:8107:1bd7 with SMTP id d2e1a72fcca58-84843467bb7mr7202062b3a.53.1783630200555; Thu, 09 Jul 2026 13:50:00 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 9 Jul 2026 13:49:39 -0700 In-Reply-To: <20260709204948.1988414-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260709204948.1988414-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.795.g602f6c329a-goog Message-ID: <20260709204948.1988414-10-seanjc@google.com> Subject: [PATCH v4 09/18] 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, Michael Roth , Hyunwoo Kim , Tom Lendacky , "=?UTF-8?q?J=C3=B6rg=20R=C3=B6del?=" , Fuad Tabba , Ackerley Tng 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 Reviewed-by: Michael Roth 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) -- 2.55.0.795.g602f6c329a-goog