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 D4C9230FC1E for ; Thu, 23 Apr 2026 14:08:39 +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=1776953321; cv=none; b=hpBDc6tZbf9suLs3GkGkXSl0QMNcLHlwXEibTckX6iOebnvDgmSdUMhfW3Rq8I5oyaFAvf2Oc5bnP8b8xew8CBJ7SthBZ9VWYWS48h/Rm8650a58yt5pk3puBb0OzmZPc5CJZynlgrV+/Te9uo72VhhZrr8CfTR8kIPTBPrwfhg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776953321; c=relaxed/simple; bh=65TgkQMg08z9v98/QTGjXbbOnmeQBFmy04CCI+ysCzk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=r2tDAc3aRIi0uHs5bPqTMW4DpFWSETunws+jFsfjGvWCjtGzFbKLgc10ReOOTBpf705TuYxr1R4+VopgGhLPnYB2oVHdTN4uR8oXMclhb5jFCqkJObJJLZrRaf2/Ehz13SQH1qPy9j6lhXA4lIiozG+zLwvqQRQo8iRwL6oDcR8= 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=Oz3IgbMx; 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="Oz3IgbMx" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-bce224720d8so3897452a12.1 for ; Thu, 23 Apr 2026 07:08:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1776953319; x=1777558119; 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=UfIb6NzFIHZCd+Kbl1hnaEGGr8JTvNw7w7yttxL+M6I=; b=Oz3IgbMxPkbbExU48TIM1lg6tVEXLVS+FdQfqrixe4n0FfWGql2wfIH+c71OgwD7A2 tXpGuY/J51TmNhRcL+ZMDE2St+yFfcxBCWgfcSvM/5Z0j3wGWDtpoSnL9MJFZDa1Hj95 IPxAG5mJFBFG8dHMCOut4PYUa/GwHe+f17TMnV20W5//EuQupAHPrxdMAd7x0Sx9xROo yTzUqZetoPTGUyi+iZqIprZ7DLFnzq6C3bFuEWiPXK82yWmO9MEiDFUBOELn0pOJzVzZ Fq3K4i4aG/mElOh4gZWw6BVZHnGozA5UPYHvJx4a/FTLoCn30ZaaxSA7YESWc4uRS36b vI3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776953319; x=1777558119; 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=UfIb6NzFIHZCd+Kbl1hnaEGGr8JTvNw7w7yttxL+M6I=; b=LRx8JiN4LEs3qhU7Q2iKht6oRy0S6cXdDUBshCL6h746Z75uRdiYl8toh+P73guWCO SsukqWBeW63KwslKXCuWREWU3cnhoh/oTFoVLFT/TKwhrU+oavc+7hI0SW7/7YT52zoL IEZ9/YQpcfmTkENudtL3Xe1cjX+8RMckY9Xoe687KfZoDft1GAKeLvBWLx3YQrZYopCE VOgjcoSReBaPk6sLyGpiuEsGY2t+/0vDnKAN7Lv/pqZjDRA2lQkE2xSMVDvQp7t1vb3q X98Pct73WZodIdA73WsoKJFRGHJxooUbM5lvlq+y1tYcHTwXDaSeKIzFRl17v/10OzW2 r7Pg== X-Forwarded-Encrypted: i=1; AFNElJ8LYD81HnpaGVQqWPxtIsvvjk/cc76fB0EABTTyUMVT8CYiyAr7c3XicsngsAgEvuG7rE7xechjBT4Yfww=@vger.kernel.org X-Gm-Message-State: AOJu0YxLr15+D3awVsIWfPNqL9pssbEwg+wMN+bsUzCvUyfnEU+HRBUs LD9kuPDVP04NWj/cPdgCsm3LFaEajaw6deusIMdnlIAn2w+xzGAiwV5d8HQh7T6DfBxPSWNspO9 5lr0F/w== X-Received: from pgbfq24.prod.google.com ([2002:a05:6a02:2998:b0:c79:3224:837d]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:a110:b0:398:6bb5:54c4 with SMTP id adf61e73a8af0-3a08d67e3c8mr31388062637.5.1776953319082; Thu, 23 Apr 2026 07:08:39 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 23 Apr 2026 07:08:29 -0700 In-Reply-To: <20260423140833.439512-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260423140833.439512-1-seanjc@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260423140833.439512-2-seanjc@google.com> Subject: [PATCH 1/5] KVM: x86/hyperv: Get target FIFO in hv_tlb_flush_enqueue(), not caller From: Sean Christopherson To: Vitaly Kuznetsov , Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org 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 9b140bbdc1d8..3b7e860bd8d4 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1930,16 +1930,18 @@ 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); /* @@ -2012,7 +2014,6 @@ 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 @@ -2138,11 +2139,8 @@ 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)) { @@ -2152,9 +2150,7 @@ 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); @@ -2185,9 +2181,7 @@ 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); -- 2.54.0.545.g6539524ca2-goog