From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AE1232AD2F; Fri, 5 Sep 2025 19:17:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757099851; cv=none; b=KcJzn7Tvk4ShmqG3KPcIvmK7iAlBoKSvZkWlxJjtWRaOjldU+kjrsG/dO1BR89STS+CmhzrjSXEZyLZc9hbTZG+AzvBEqP/aA/ZZfMfYaS+xLXVyYWiuHoQjROZhDzV4tRonZjqFT7acxHidt8OUtyg+0u5bLPlgBhICqH/1IIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757099851; c=relaxed/simple; bh=6DvTqiz5oE0MUYIdGEJzKhFGMzFYNPmlC08fSMO//K0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tPRW9M7dXjaTgH4q5OODGzqIMZ1s5OxhkPOKMsXAtFL57TUDbC6Z0B4BhViecZwoG6r/+RVgSW0fv2bF1v0ZB7ZBp/NKL4AGcVLNW+B/HtQBW6NXeE5aaAwXcz7a+UJdh8k7bV+K7yl9P1eFpKGMqsq7sEVbnsDQVpy5eh2rSGY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=FErJ9/w/; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="FErJ9/w/" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=7GxwLQxCzAg843L+h1jj3ZmsSQYEHcvwK6GOI2qdcLA=; b=FErJ9/w/te2gPH6BxKrroAxz+G bVXzoOzrg4dNgUtPnai8uuA+wA4YKlh7N0xmNfqRszc/4z1LDvGh0IZEmqo3DrAktFhBwj5ITX+1o 7SZLMrVi83c18nCN6MFmGIWL2KEHLYYu2sCZUYvnerk4tJtR1j8zWdU0+SXdCvZqT1+2Lnxvw52BH RdSEIQIVRF7BDpq183iBWkZ5+jWzALSB18bm/2Wu342DMXdwsumhB2AIC/Q5WWc3niUrUrDh+LSfn bPIAiDjsBhVfg7oluC6EikIiBGbg5B5rkxejyrntRe2SR5tIUeWb98ul1cqe9c+EfH/pq0qP0keH7 oRF+acqQ==; Received: from [50.53.25.54] (helo=[192.168.254.17]) by bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uubw8-0000000444V-3ovf; Fri, 05 Sep 2025 19:17:28 +0000 Message-ID: Date: Fri, 5 Sep 2025 12:17:28 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] Documentation: KVM: Add reference specs for PIT and LAPIC ioctls To: Jiaming Zhang Cc: corbet@lwn.net, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, seanjc@google.com References: <00378f4c-ac64-459d-a990-6246a29c0ced@infradead.org> <20250905174736.260694-1-r772577952@gmail.com> Content-Language: en-US From: Randy Dunlap In-Reply-To: <20250905174736.260694-1-r772577952@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 9/5/25 10:47 AM, Jiaming Zhang wrote: > --- > > The behavior of KVM_SET_PIT2 and KVM_SET_LAPIC conforms to their > respective hardware specifications. Add references to the Intel 8254 > PIT datasheet and the Software Developer's Manual (SDM) to ensure > users can rely on the official datasheets for behavioral details. > > Signed-off-by: Jiaming Zhang Thanks. LGTM. Reviewed-by: Randy Dunlap > --- > Documentation/virt/kvm/api.rst | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index 6aa40ee05a4a..f55e1b7562db 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -2083,6 +2083,11 @@ The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's > regs field) depends on the state of the KVM_CAP_X2APIC_API capability. > See the note in KVM_GET_LAPIC. > > +.. Tip:: > + ``KVM_SET_LAPIC`` ioctl strictly adheres to Intel® 64 and IA-32 Architectures > + Software Developer's Manual (SDM). Refer to volume 3A of the `Intel SDM > + `_. > + > > 4.59 KVM_IOEVENTFD > ------------------ > @@ -3075,6 +3080,13 @@ This IOCTL replaces the obsolete KVM_GET_PIT. > Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. > See KVM_GET_PIT2 for details on struct kvm_pit_state2. > > +.. Tip:: > + > + ``KVM_SET_PIT2`` ioctl strictly adheres to the spec of Intel 8254 PIT. > + For example, a ``count`` value of 0 in ``struct kvm_pit_channel_state`` is > + interpreted as 65536, which is the maximum count value. Refer to `Intel 8254 > + programmable interval timer `_. > + > This IOCTL replaces the obsolete KVM_SET_PIT. > > -- ~Randy