From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 4527A47125A for ; Mon, 5 Oct 2026 10:54:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791197692; cv=none; b=rz0pibiDw5MiETzTAb/bSqByeVPChFA5FWIWvept6yfDHoXhxVpl11uPYnFI8VGEfYV8TDB9EXI9OLz+l8SaPRnhI6fi+L9Wm+WpaNOXgYHulq497RAmxWB6soXKyAtOJ56KERyBC9uPl3ClFFbx6EsqrzwnL07H4jEDqWNUQB4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791197692; c=relaxed/simple; bh=7yv2fDxwDW/izhtv/3qeKMCYEbfudsMQmfoewhpnBrU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=TPVHuVwC/KgcS7OpG7GsntkzIC1XeGi1S5aoCn3snUWu/bGadfShoVRqTg+g52/ByFZafCG9yE3RwMhR41brGTCN6+h65M+4NXB6sqdCnA7bAgdSKedXzWBh+TgLJErJfg/tfrj2qpUFy/aWHRiGssZLp6N5amCjv06KECcyGMM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=HfW+zfZF; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HfW+zfZF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1791197690; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=GQIzOrD80cBVNE5h0CQa8C1wdzcpWOcigbQ+mlRDcY0=; b=HfW+zfZFUILUBMsFVWLdBi1m8rqs6T8FpnEggOA9POM9VkcI623RuZBSMB8YCtTrSJGAPL iyh/XdtlWiFiWfT4sZ5nWDJi/53ExgrHbTj/Yxc/J7nflV9txkbRCIS7N5pka+V3ljVGX0 LLaXs4u7WOLsp/L4l/2zEPL/NAiIKRY= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-220-TFv9j6g5Mwa9XZ7D9O6MFQ-1; Mon, 05 Oct 2026 06:54:47 -0400 X-MC-Unique: TFv9j6g5Mwa9XZ7D9O6MFQ-1 X-Mimecast-MFC-AGG-ID: TFv9j6g5Mwa9XZ7D9O6MFQ_1791197685 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B373C18007E7; Mon, 5 Oct 2026 10:54:44 +0000 (UTC) Received: from jtornosm-thinkpadp1gen7.rmtes.csb (headnet03.pony-001.prod.iad2.dc.redhat.com [10.2.32.114]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 4CFD71800446; Mon, 5 Oct 2026 10:54:41 +0000 (UTC) From: Jose Ignacio Tornos Martinez To: bhelgaas@google.com, alex@shazbot.org, mani@kernel.org Cc: jjohnson@kernel.org, linux-pci@vger.kernel.org, linux-wireless@vger.kernel.org, ath11k@lists.infradead.org, ath12k@lists.infradead.org, mhi@lists.linux.dev, linux-kernel@vger.kernel.org, Jose Ignacio Tornos Martinez Subject: [PATCH v15 0/2] PCI: Add device-specific reset for Qualcomm devices Date: Mon, 5 Oct 2026 12:54:34 +0200 Message-ID: <20261005105436.83962-1-jtornosm@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Some Qualcomm PCIe devices (WCN6855, WCN7850 WLAN; SDX62/SDX65 modems) lack working reset methods for VFIO passthrough scenarios. These devices have no FLR capability, advertise NoSoftRst+ (blocking PM reset), and have broken bus reset. Standard reset methods were already disabled for these devices by commit 6a4f64c3a3ad ("PCI: Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems") because they were not working (quirk_no_bus_reset). VFIO attempts to reset devices on every reassignment: - For the listed modems, without a proper reset capability, these devices never successfully initialize even on first VM assignment. - For the listed WLAN devices, without a working reset method, the attempt fails. On clean VM shutdown, the guest driver properly deinitializes the device via .shutdown/.remove callbacks, leaving it in a usable state despite the failed reset. However, on unclean VM termination (crash, force-off), the guest driver callbacks are not triggered, the device remains in an undefined state (DMA active, interrupts enabled, etc.), and without a working reset it cannot be reused. Add device-specific reset methods using BAR-space hardware reset registers that exist in these devices: Patch 1: SDX62/SDX65 modem reset via MHI SoC reset Patch 2: WCN6855/WCN7850 WLAN reset via SoC global reset These are true hardware reset mechanisms (not power management or firmware error recovery), providing proper device reset for VFIO scenarios, allowing to enforce isolation between successive passthrough users. Testing shows stable operation over 100+ VM crash/reset cycles. Device- specific reset is position #1 in the reset hierarchy, so these devices will use hardware reset as their primary reset method. Jose Ignacio Tornos Martinez (2): PCI: Add device-specific reset for Qualcomm SDX62/SDX65 modems PCI: Add device-specific reset for Qualcomm WCN6855/WCN7850 WLAN drivers/pci/quirks.c | 116 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) --- v15: Address Bjorn Helgaas feedback: - Explain the relationship with 6a4f64c3a3ad ("PCI: Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems") and previous status. - No code changes from v14, only commit message clarifications (Mani's Reviewed-by and Alex's Acked-by retained) v14: https://lore.kernel.org/all/20260917071651.14174-1-jtornosm@redhat.com/ -- 2.54.0