From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 7ABD63D413A for ; Fri, 12 Jun 2026 23:06:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781305588; cv=none; b=CYAl9qSKb96TZ50co2FfUQ+bq1e4hRfNHk2UvXzyM6Ch4SmasEV3WqNjwvfnzxzADHmcpVcVJ7COslEDcwY7Vt0CUEeOhbbJB6DSys6crX/CLK7LSon5C4+U30gp4tu2vhpMujUe2qVACU9+MZfZEVk4FzpRwCq97I6Bsolz6AA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781305588; c=relaxed/simple; bh=Me0Bhs5/EQQZjcTAZ/V1yRJ2/LW8GnZyPuXt9LJK+oQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=sGwZx/J8WvzMHXy0NmbTzG1qHC95S9bZpZQVStklI6P/945I48R7QVDoY05JLC6GELLOPIKyCmvirMqlIM6JujIgGGQbU2cDS/gd/woI5xpIJ8gjFPaDVQ+brB+eK38TEuW2e477bEackppZx+2uZt+5PSmgRqk9yMM6QRQe+kc= 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=lpubkjuN; arc=none smtp.client-ip=209.85.214.202 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="lpubkjuN" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2bf243973c2so10132015ad.1 for ; Fri, 12 Jun 2026 16:06:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781305587; x=1781910387; 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=/Hg8GhN12QlOv0K4ONCzUqIsw11l/FiOwKl0Rw2yUVA=; b=lpubkjuNsILIbU8jPPILJcr3UxUo+jOfksrzD6QNIe7wtue0twuS8RaRelVwwxCIzD G4ZcpDmt04x4ukEuEeadwIcr8+6Z62megymXlj8SdW4weQPpYHANxHksRVfwbN7LYWa0 IBiu2njHQ/iLQckwYJI1ISvGxtOaHr4Js+xy0upv5KE0aAnU8WxrI8yb4qaMOUqH4S4U CKsfhAfuP8BJxnlG8NTNF5gwgxcqW6VbZ7+2Zp9GxXmRu7pTy5Cmj6Nz5WBeVeIjEB+N BQKKToz/+zbA2k3+NFcsbFYzIq5mrXIxbYdmCpzInxMXP0SwjOCZ73GDsBsPn8K6XgIH CfeA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781305587; x=1781910387; 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=/Hg8GhN12QlOv0K4ONCzUqIsw11l/FiOwKl0Rw2yUVA=; b=Ua45SJKPhXaJcqlIiGoVTSODtmW0S/1TRBbnbdILhz6u6fu6zjmDBGzV3ykuCg46ai ARQFJMJsOxDdUGUbLVbxPnIRc1U2N2KJLsOJPLYBRcLd7y4yeqHQMnTbhgYV8ULFmIUG OjYkXZCTuoE08hkysrlRj5KVVoiTN7HaezM3w6hbQQpjxaGVQk1hK7q5jX8HvkjMx5uH atSa5UJs2ETLNfIzdOBd8/7iU4LGUCTJmxy03+qYkal8V5D/j7PWO+fppgXpwBo5F513 t/dgR2uep5UxWVk9C6oGNd3BObghd5m9hWzfqVTCPxx+kBx2TWvu+d+PZnzRNofJLC95 gzPA== X-Forwarded-Encrypted: i=1; AFNElJ8YfkTl0r4B2rEHg/eW/LbeBaBG9gx7qtb43Ke/gCeGdXhhztFlz8BuncILfV1OyjTEfoLP1Pql/3LGfrI=@vger.kernel.org X-Gm-Message-State: AOJu0YxJTtOy+IjafOXiXKaHiK2ahsPhhXanFkaNzmUutmpsryMUP85q pjSgka5oZPdVrkG//Q/DgeANSeYscPLpDLerni2A/ahh9KdypePIu+t+0q49MzdYc017XCC+YX5 h8EoILg== X-Received: from pllh1.prod.google.com ([2002:a17:902:7481:b0:2b0:b22a:e6ef]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:234b:b0:2bf:bd17:90d4 with SMTP id d9443c01a7336-2c411d79937mr55905765ad.28.1781305586571; Fri, 12 Jun 2026 16:06:26 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 12 Jun 2026 16:06:15 -0700 In-Reply-To: <20260612230622.687665-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260612230622.687665-1-seanjc@google.com> X-Mailer: git-send-email 2.54.0.1136.gdb2ca164c4-goog Message-ID: <20260612230622.687665-2-seanjc@google.com> Subject: [PATCH v2 1/8] 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, syzbot+5b32c49cd8f005e65654@syzkaller.appspotmail.com 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 fd4eb1e561f7..a894e3d2e594 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 @@ -2145,11 +2146,8 @@ 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)) { @@ -2159,9 +2157,7 @@ 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); @@ -2192,9 +2188,7 @@ 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); -- 2.54.0.1136.gdb2ca164c4-goog