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 6BD3C212564 for ; Thu, 25 Jun 2026 22:36:26 +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=1782426987; cv=none; b=d3fPA/FWVXH89+KRJX/h2z+NEcQjpEZBYVa57v0MTT5GB0wbRlLuSuR3BFHY4fC8Wa8KQHK3ZeOjSCTKaNX38S87Mig73oXQZuPLjEXJ8EX0ZR9jy6Ri4cEV1ZXLTpFkxXZ+aGPxDWfjNqEPGbu8gjsHrWVjd2rJofRmtAkVKjY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782426987; c=relaxed/simple; bh=ckzSbRdfj3GjtaU6LvW/bPgFTeEU1LukN2m/Yio5YiY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=NqDDBLQptBLoaqiKoXwoMCkj10FpmgP3LfZewlzCyQgCQsdP+ym5ZVykeC1lHAffts/L8p2tbrbLS5qTiC9HJEEIhEmsGv5l12E3n1UD7UJfu8qSzP+Furi9zk7cehcycpiDEOGweiwyDyD98+OQ2wOxU/iwq0bhwH7bxjiTDpQ= 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=enkhndEZ; 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="enkhndEZ" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-84245e2bb00so184831b3a.1 for ; Thu, 25 Jun 2026 15:36:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782426986; x=1783031786; 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=enkhndEZYxDlJMvMxYQRf+ER1GMo4gM9ztk3hZsc0s90OsXoN6M1SWyrcleLyumuD/ pHUECJftIyWWchVvvR5z6JC2AcvW9+eiE9Y7bnmzW3Wl0q/MVj2HDr6ScEFLrpeP3siA e2haSMjLNhoCR2Hup20uiW0y9XL6urNVnoUDdgjIOoyrDBzpzhgXLVleUJxcBKT1UoRC /el7sK/L5jOvHV7pdHjZMqv+wzKIyEXcwpWL4YN/yFm4tHFX7NKtLWu9kL0T7FWt2CJx ZuYQ3SuGCn5Q2hq50KoCpKvIHMzCVZL47mVrDKqdY540zcix75ZeABe7Eim4wX4FLh+8 stjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782426986; x=1783031786; 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=Oep6CEIEnSDGuMRUgGlMOKA07kFVHpI+0cxhEuVxTODSUOc0252k7Ch+DbdFamQogj VT62/bTjyZ2keIowqXi55f4n4ostH29Z4a6YJmbIanhnzgcK1xZlhHXt9OAQIzwHbgVG F4gNWq5/hjTaXHb8gbOf1t2oIy8f8wMUQ1qq9o8DkONSTRbDVQLmHI55nq6fUxkgR63Y utzFLqaChElAIOU9/sOQ8YMD6zp+ut2uiwWi/jIv8SF9ZEzxhyfpOANB+u6oLg8iHVna bVNfiWodjzv8lEGXPDybCgHYoWQt56Ch3zjaDBwAoIbAJK5ocim4oBsQm2/Qs/yu/6yP NB9w== X-Forwarded-Encrypted: i=1; AHgh+Rpn3cD+lngNq3E4HtkVtFh17vXsdDALJoCSwlVuej2O1pEnWP9/yl438aukdnmtI/DatZ5NeY6k8n5hIjk=@vger.kernel.org X-Gm-Message-State: AOJu0YxVrjZGwSzUbYvH3yfTFdBHUZfNXHyx6wsp36jychnxLT6SAjXG tsPACyXdT5XeW51gFuEP5nf+XF1ndYRtmWJKOWPfYWUVyOIPYfYmYqKVrnar3ThPdZVTkL6IEAq rvj79Uw== X-Received: from pfme12.prod.google.com ([2002:aa7:98cc:0:b0:842:1ca8:3c1]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:ccc:b0:845:3fea:965 with SMTP id d2e1a72fcca58-845b3b71200mr5210367b3a.23.1782426985442; Thu, 25 Jun 2026 15:36:25 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 25 Jun 2026 15:36:14 -0700 In-Reply-To: <20260625223623.3376478-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260625223623.3376478-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260625223623.3376478-2-seanjc@google.com> Subject: [PATCH v3 01/10] 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 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