From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1104AEADC; Sat, 24 Jan 2026 00:09:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769213392; cv=none; b=G3dFqR7QhP1cXRtjqL03YVnXGWmnXhaqTLUwY0qw4/iOSoGI9D95m38dIdC7zc3jEG9yU63FJKqfx774XqrjW4MachiY7vVCZHvO5Qj5V3N2Z+GZkJzCVFkH8zhVNpBE8E3bH+CRzhXVUAgRVpde4uH/aa1xDAFFaeJPlWsdfCY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769213392; c=relaxed/simple; bh=jyutI1l3bFazjTEoobWSZTS4jh2mnj5UOOkYLC/dNq8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nVoB13vL4SgdSLaxrVbpmEoz+nzbKjYPtOcbuY+/zI//9pmfmQe/6WRd5PJLEBVFRnUJ8vFj2oIKKngWZvc8+PiRV+enWX8OJbZ0vsxp8a4WnyHOAy/RfRaoGYj54tf5L91B5h422abdybdD1LdbDDLJbbPigaTATnV7tJgNMb0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=T8mzR/Na; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="T8mzR/Na" Received: from [100.64.97.48] (unknown [52.148.171.5]) by linux.microsoft.com (Postfix) with ESMTPSA id 46EEE20B7167; Fri, 23 Jan 2026 16:09:50 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 46EEE20B7167 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1769213390; bh=F1FTAVODPqwuJaeZy74EbM5GaTPbzR1nURa1bVTjqf0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=T8mzR/NanuoZjsPKu/lUQ2TVTMgNN1nxL1Z6bnZgRwWmI7ZlzM/9oxhtzt8IQvOWk jwFE2O+MJISFUdbsPvY9R6GjsZCnc6EwavSpjKz63I99Q/y6Dz7BZOulu0gbFrDEdn ufVWu8kf8egWVDZXDv7Z6CaUF38K9Ee18x3XTTSA= Message-ID: <11a20912-65cb-4b67-9a13-e1c9db680c93@linux.microsoft.com> Date: Fri, 23 Jan 2026 16:09:49 -0800 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mshv: Make MSHV mutually exclusive with KEXEC To: Stanislav Kinsburskii , kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, longli@microsoft.com Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org References: <176920684805.250171.6817228088359793537.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> Content-Language: en-US From: Nuno Das Neves In-Reply-To: <176920684805.250171.6817228088359793537.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/23/2026 2:20 PM, Stanislav Kinsburskii wrote: > The MSHV driver deposits kernel-allocated pages to the hypervisor during > runtime and never withdraws them. This creates a fundamental incompatibility > with KEXEC, as these deposited pages remain unavailable to the new kernel > loaded via KEXEC, leading to potential system crashes upon kernel accessing > hypervisor deposited pages. > > Make MSHV mutually exclusive with KEXEC until proper page lifecycle > management is implemented. > > Signed-off-by: Stanislav Kinsburskii > --- > drivers/hv/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig > index 7937ac0cbd0f..cfd4501db0fa 100644 > --- a/drivers/hv/Kconfig > +++ b/drivers/hv/Kconfig > @@ -74,6 +74,7 @@ config MSHV_ROOT > # e.g. When withdrawing memory, the hypervisor gives back 4k pages in > # no particular order, making it impossible to reassemble larger pages > depends on PAGE_SIZE_4KB > + depends on !KEXEC > select EVENTFD > select VIRT_XFER_TO_GUEST_WORK > select HMM_MIRROR > > Reviewed-by: Nuno Das Neves