From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 07B3263B9 for ; Thu, 14 Aug 2025 18:14:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755195277; cv=none; b=kY1bgSj3XjZGfKf9W7jUOlfSwgCI3k32pzqhRj6FV6LNKv86S/JF0XCpuJvxMgmtE4p2h/bIzTKDDlWFVNyc9aRJZ7lrbByNCO0WW8UqzXU/fE7ERLqHGHJQ63mkxLWYhD2WLBSt/QEIANvNqpMsmrugUGeS11oe6rxxjXKU0MI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755195277; c=relaxed/simple; bh=xqzXTVOo+HfT+Rper86W1+Na9+JYHsYieDn1A76TjJ4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=QL9GIbBjEfo43FNu0jAT4CGDwMtYFzKYapZCgxShkvzEunhRFO3aO4UMIA0mLGlf5RSkqy5ho02UZnL7UUtqr0pqfwBvryeC/4gShrIInainjfSoBWKPHHqdZSPIcG89W5y7nsVnAR+TxHJ5EP2mLTXqiKsGdQ2Bpxk/KCHtcmM= 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=hGfSf5v3; arc=none smtp.client-ip=209.85.216.74 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="hGfSf5v3" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-323266ce853so2157432a91.0 for ; Thu, 14 Aug 2025 11:14:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1755195275; x=1755800075; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Z41RRsboEJtxmQimda9s5PepaOeeDoU3YZi9zLLblsM=; b=hGfSf5v3O0UuFvUCrfWdmPP3bxuNTJslHPbDqonpBLv9oveALSc03hMsPqHqgVSD5y oT6il3CJi1sXHiuBwxYe6Lf1PikBLjaWfwJpdBZBSRKMmBpZYmYS7n0+NVeuFRk4kUly BKy0Oc6BZmGfTaxDSCPxgiOarcWxVFo4wHgfFrYQYS/yizMKCZPRDSMsjb810hKhj9NO mpEg9HfCA6KAB4++F8g6xryTDSErFGxC8+YZVcZP08bBWAv1YeCTSxghG/VZ7CyCBJ+B bPfrxLP24Z9ykp9j3Ly8bPW46YO0/txpr06xfYG7sZszW2cr3Fv7qsTfp06bknYcEWln 7g+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755195275; x=1755800075; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Z41RRsboEJtxmQimda9s5PepaOeeDoU3YZi9zLLblsM=; b=q7ttT4+oARcvLqywjuv04EuVq6CZhvQdssztT3gyeFiv4eJ/Vtz7MyrSQlxeZz+HfK LR4rFtBGVBIn7vgT/AXuT9dO+f6Zq2kjcVbve9UmLlOWD//fjjBma8L1Evf//BxVHSnO 8nOMVZebmMOG28DPEviIyV6/Yw7y4SUx3xe7pXGTT9mY/tayEllSdnw+IlDvyix+wh8k ZaOQzRTYhg4JNqZvcruzIsbuZvXueEy86o9GS1yf12SKxN295i5AvL7m0aWGgcjdVWEo REs2ukNnrloMQoXS2Aef5j2qOor9bO4jUVJJawQKQAywLCrp0uhGoPuJx5p4GmZZINf+ tkZg== X-Gm-Message-State: AOJu0YxXnyhvYk167snl1hd11zxyC6THlz0+SEIj0SWhkmr7OR7AMOPY f19QSO9nZtw8+HV8Rqz90KEHbYLWlAvPQ2fkrYAkgkuBcorbMcDIGGQ7xJI3csRLKISIHQ7WsqE NdN93Xw== X-Google-Smtp-Source: AGHT+IGX3Hq+afOm3A1jgp7o1SOC4X8WQrNY9vWC6ngvMb374VCtWJV07DS+hLguQecRlz0hEvIIt5Eaw1s= X-Received: from pjn16.prod.google.com ([2002:a17:90b:5710:b0:321:c441:a0a]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1d50:b0:31f:3cfd:d334 with SMTP id 98e67ed59e1d1-32327b09c1amr6184244a91.4.1755195275354; Thu, 14 Aug 2025 11:14:35 -0700 (PDT) Date: Thu, 14 Aug 2025 11:14:34 -0700 In-Reply-To: <20250814161212.2107674-2-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <2025081231-vengeful-creasing-d789@gregkh> <20250814161212.2107674-1-sashal@kernel.org> <20250814161212.2107674-2-sashal@kernel.org> Message-ID: Subject: Re: [PATCH 6.16.y 2/6] KVM: x86: Drop kvm_x86_ops.set_dr6() in favor of a new KVM_RUN flag From: Sean Christopherson To: Sasha Levin Cc: stable@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Thu, Aug 14, 2025, Sasha Levin wrote: > From: Sean Christopherson > > [ Upstream commit 80c64c7afea1da6a93ebe88d3d29d8a60377ef80 ] > > Instruct vendor code to load the guest's DR6 into hardware via a new > KVM_RUN flag, and remove kvm_x86_ops.set_dr6(), whose sole purpose was to > load vcpu->arch.dr6 into hardware when DR6 can be read/written directly > by the guest. > > Note, TDX already WARNs on any run_flag being set, i.e. will yell if KVM > thinks DR6 needs to be reloaded. TDX vCPUs force KVM_DEBUGREG_AUTO_SWITCH > and never clear the flag, i.e. should never observe KVM_RUN_LOAD_GUEST_DR6. > > Cc: stable@vger.kernel.org > Link: https://lore.kernel.org/r/20250610232010.162191-4-seanjc@google.com > Signed-off-by: Sean Christopherson > Stable-dep-of: 6b1dd26544d0 ("KVM: VMX: Preserve host's DEBUGCTLMSR_FREEZE_IN_SMM while running the guest") > Signed-off-by: Sasha Levin > --- Acked-by: Sean Christopherson