From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 B6F7B31E830 for ; Tue, 30 Jun 2026 22:56:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782860185; cv=none; b=hkfE6u7ucdwE051SOOJAth11vteWpwEx+KqMvSxOXNbajL6hTF80NiNXGW2u4NJtRcrJ/nXR85QEfBlm9t3wZryC7WvraYxej3Wm/pHusVnwZoeRRQ1NEf/7FxJJuWlfn6BdzAxDndcXPKA0jJ0xS1Ae509/e63WB61u75Rc7/4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782860185; c=relaxed/simple; bh=ckzSbRdfj3GjtaU6LvW/bPgFTeEU1LukN2m/Yio5YiY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=jRu+Of1d2uVLGpaInilOT9H92imlavkZU+GJYW8QuMF23bnYF3pm/ZdN49T00oYchENDCsH2u2jCN1dKa1jqJ58FXXv4GGJnIPoOfCbLcAWwNoPGqH2yZahE5r54tUgyq6B3Zid4SHqq0N5D7CF0AWCX0aLVRJ76pZiiTwxASCw= 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=mjsc3ea7; arc=none smtp.client-ip=209.85.216.73 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="mjsc3ea7" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-37fc0aaa94cso51733a91.1 for ; Tue, 30 Jun 2026 15:56:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782860182; x=1783464982; 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=RqLzSEbiwp8bFgXqWMU4fMK8R9fc+pYc6UvhgAoac7g=; b=mjsc3ea7w/1n0ueN96bi30N42umT1rdfpNY4jHyCU3ApArh/GeY7kPYibZV6s/z88+ kMDRHpGr5hWGHvUAYci+Ea+E8cZpUHkRHYiV+NBGXZElgmX2v7eu6pbsApxgXAxcAwMc 3L3Qo38HhVv0OY7ESPfpSHXpEcqchksyp7/IAWHZe7kNTV5L6FUqKXJd8D+ob3XOfoTY Vs6UZ9ss+34f5bCPWEy0gvxNjyVyLJQZ4xNFowdirPDOGjf3+U6chGQ5DXZ+2S5h+ZP5 KKFft3O4lN3DziUyx1gx2XgzRhK6viSXsqTVUie0L3MjBUDNW0HWdcRmjILrHjoVrkR6 ClAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782860182; x=1783464982; 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=RqLzSEbiwp8bFgXqWMU4fMK8R9fc+pYc6UvhgAoac7g=; b=RU1pZxJHe7/aofBfqfoji8eW19XcENHdxA0fiozNZKkZUUtDx/rGb1aFJBUQGo6GLb QtvC1f9tagIsu9K4oZXrFMMqBtLJDdtnccyaALkh4vtGY+jRRhR4HodzChP9RF8KMivo ntIGadsO81Kd1iarMDiIePJXBZLEV5doT+c7v59LZ95RidoUNh4u8zBBbvq9iUmCG0Jg JbK4FRZ7qBrQvp0bIftRjXK/e1zfx3h7qvo/0mUibi+ZJgJvAaAVJ+i+KThcIt0sUP+u ksm8A/P3W3UsEhP6fyaTdzo1ZHlWHhWFct7IQDj22ymWSmnhvqp4gQedbeOjuv+avw1Y 8E9A== X-Forwarded-Encrypted: i=1; AHgh+RplJ9p5ttDKZADbBX5WptbGkkP9T7wXrzJGg2FuhxMRuLdcBBb8N8pQRIPpNuoUYFrMbAN3yF/FXk2hQcU=@vger.kernel.org X-Gm-Message-State: AOJu0YzHfZWyW83g/QrWRPl4dYnL6/54Dg+OZawYO9ZeKgXVL/h4Gfv1 oGoZzaxzXcGOc07Eb2Qtare+dTXfGGAbgrjhsdmmsb2Y5qkIHxHwzQaQ+Uz9dW3mvgwORcxHCbj S9URYsQ== X-Received: from pjbgc7.prod.google.com ([2002:a17:90b:3107:b0:37d:95c5:815d]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:37cb:b0:37e:a09:2640 with SMTP id 98e67ed59e1d1-380526b1b7amr4561425a91.7.1782860181922; Tue, 30 Jun 2026 15:56:21 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 30 Jun 2026 15:56:08 -0700 In-Reply-To: <20260630225619.511632-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260630225619.511632-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260630225619.511632-2-seanjc@google.com> Subject: [PATCH v4 01/11] KVM: x86/hyperv: Get target FIFO in hv_tlb_flush_enqueue(), not caller From: Sean Christopherson To: Vitaly Kuznetsov , Sean Christopherson , Paolo Bonzini , David Woodhouse , Paul Durrant Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+5b32c49cd8f005e65654@syzkaller.appspotmail.com, syzbot+5d2b94b77112148d1744@syzkaller.appspotmail.com, David Woodhouse Content-Type: text/plain; charset="UTF-8" When handling Hyper-V PV TLB flushes, retrieve the to-be-used FIFO in hv_tlb_flush_enqueue() instead of having the caller pass in the FIFO. This will make it easier to fix a cross-vCPU race where KVM can access a vCPU's FIFO before it's fully initialized. No functional change intended. Signed-off-by: Sean Christopherson --- arch/x86/kvm/hyperv.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 1ee0d23f8949..2dc3e64b3f2f 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1935,16 +1935,18 @@ static int kvm_hv_get_tlb_flush_entries(struct kvm *kvm, struct kvm_hv_hcall *hc return kvm_hv_get_hc_data(kvm, hc, hc->rep_cnt, hc->rep_cnt, entries); } -static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu, - struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo, - u64 *entries, int count) +static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu, u64 *entries, int count, + bool is_guest_mode) { + struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo; struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); u64 flush_all_entry = KVM_HV_TLB_FLUSHALL_ENTRY; if (!hv_vcpu) return; + tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode); + spin_lock(&tlb_flush_fifo->write_lock); /* @@ -2017,7 +2019,6 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) struct kvm *kvm = vcpu->kvm; struct hv_tlb_flush_ex flush_ex; struct hv_tlb_flush flush; - struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo; /* * Normally, there can be no more than 'KVM_HV_TLB_FLUSH_FIFO_SIZE' * entries on the TLB flush fifo. The last entry, however, needs to be @@ -2144,11 +2145,8 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) * analyze it here, flush TLB regardless of the specified address space. */ if (all_cpus && !is_guest_mode(vcpu)) { - kvm_for_each_vcpu(i, v, kvm) { - tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false); - hv_tlb_flush_enqueue(v, tlb_flush_fifo, - tlb_flush_entries, hc->rep_cnt); - } + kvm_for_each_vcpu(i, v, kvm) + hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt, false); kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH); } else if (!is_guest_mode(vcpu)) { @@ -2158,9 +2156,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) v = kvm_get_vcpu(kvm, i); if (!v) continue; - tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false); - hv_tlb_flush_enqueue(v, tlb_flush_fifo, - tlb_flush_entries, hc->rep_cnt); + hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt, false); } kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask); @@ -2191,9 +2187,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) continue; __set_bit(i, vcpu_mask); - tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, true); - hv_tlb_flush_enqueue(v, tlb_flush_fifo, - tlb_flush_entries, hc->rep_cnt); + hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt, true); } kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask); -- 2.55.0.rc0.799.gd6f94ed593-goog