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 F04671DDC14; Thu, 20 Feb 2025 20:23:04 +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=1740082986; cv=none; b=NzKNJhEGllz51dmKKpkYoagQM9rhHedjJsWLRFy5Ka0nIzj7FEuOthcionliZujKMK5qB+2IohG7ORVJUdjH1BHRCI/KFc0k4xrteUAdLchvlfJN+AbakW+ESftTeQ/Ak1G8YZRzCmz55EtBZHsxvt08nB5Sj5iyo7G7AGN47X0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740082986; c=relaxed/simple; bh=Ux/Fdr3dT4kZqn+2324S7+cSUHACMe0QH8JlEk+oZHk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=OrQh71rVURf8Ce+fZ1AQmTobuZqx3tTAqAtwW+xfmNcl5fSEdDRX4+O+Cjq/QoBcCkratDvQcDt8ALgBeTi4BJOxJlwt1iEIBL179biUFnM+TII6aekoJBlxEHasnAJ9UENPWw3tvI2n5CTUDcgyvuZfch6QDaYLuMHXTU2M2x4= 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=oFa9FR6g; 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="oFa9FR6g" Received: from romank-3650.corp.microsoft.com (unknown [131.107.160.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 47282203EC16; Thu, 20 Feb 2025 12:23:04 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 47282203EC16 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1740082984; bh=aIH3NGYqEanu6KoDYFwyLuHKO7OFTu2OStSMs8IQTWo=; h=From:To:Cc:Subject:Date:From; b=oFa9FR6gcpLD0hIx+dsIKfA9I8++Ve3hvVc08BdQfOi0bkgAAFOPWwGFW4QZsfzyK nKCTarZk/WwxRVd9DrpH3mnOfyN1bii495/scPO/Newjn4H7KVL2uwQ4EjZZuWgCET /eAbWpNkGK6RZ9JnHlBXVzgZ12Ro82XuIIG98/oM= From: Roman Kisel To: bp@alien8.de, dave.hansen@linux.intel.com, decui@microsoft.com, haiyangz@microsoft.com, hpa@zytor.com, kys@microsoft.com, mingo@redhat.com, tglx@linutronix.de, wei.liu@kernel.org, ssengar@linux.microsoft.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Cc: apais@microsoft.com, benhill@microsoft.com, sunilmut@microsoft.com Subject: [PATCH hyperv-next v2 0/2] x86/hyperv: VTL mode reboot fixes Date: Thu, 20 Feb 2025 12:23:00 -0800 Message-ID: <20250220202302.2819863-1-romank@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The first patch defines a specialized machine emergency restart callback not to write to the physical address of 0x472 which is what the native_machine_emergency_restart() does unconditionally. I first wanted to tweak that function[1], and in the course of the discussion it looked as the risks of doing that would outweigh the benefit: the bare-metal systems have likely adopted that behavior as a standard although I could not find any mentions of that magic address in the UEFI+ACPI specification. The second patch removes the need to always supply "reboot=t" to the kernel command line in the OpenHCL bootloader[2]. There is no other option at the moment; when/if it appears the newly added callback's code can be adjusted as required. Signed-off-by: Roman Kisel [1] https://lore.kernel.org/all/20250109204352.1720337-1-romank@linux.microsoft.com/ [2] https://github.com/microsoft/openvmm/blob/7a9d0e0a00461be6e5f3267af9ea54cc7157c900/openhcl/openhcl_boot/src/main.rs#L139 [V2]: - Fixed the warning from the kernel robot about using C23. ** Thank you, kernel robot!** - Tightened up wording in the comments and the commit descriptions. ** Thank you, Saurabh!** - Dropped the CC: stable tag as there is no specific commit this patch series fixes. ** Thank you, Saurabh!** [V1]: https://lore.kernel.org/linux-hyperv/20250117210702.1529580-1-romank@linux.microsoft.com/ Roman Kisel (2): x86/hyperv: VTL mode emergency restart callback x86/hyperv: VTL mode callback for restarting the system arch/x86/hyperv/hv_vtl.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) base-commit: 3a7f7785eae7cf012af128ca9e383c91e4955354 -- 2.43.0