From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (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 3F969223323 for ; Sat, 18 Oct 2025 00:07:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760746069; cv=none; b=sFZfVS9lWytyWs0/T7WXN0ManX/Oafl6JePtCIoC+GAXqUHLZnQdJnLMKWX4gHSYa1btR9XuBlZpwolD6FDxZh9KNBAM74BdrmXOw/uzblVI1s49Qd6XTjInqo4PpowBW+wUsaQ/adHoB2PaXhiZKaIQiZjw1wPAbZ0IMkC3aZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760746069; c=relaxed/simple; bh=MFgRpcmSvyiNW2ycsfOMqpytwYLNdswjkflUzJbVBqM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ktFXoXfu294K4c0fz4PX+r4rZe5vWhoau1widDaKbAPxSyjwoJczgGB+dh0795PvAx274W6xHAWF4ghv7RQw/VzOsrxduG5qk4HZIqVXtun6ghjoUT3uEiZcHMrEmv77s/CF2mO2+YQ04HeK1dW2PN6Ar/aOPxqPBkJCq/54t6c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vipinsh.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=2t7dpM7x; arc=none smtp.client-ip=209.85.214.201 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--vipinsh.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="2t7dpM7x" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-27c62320f16so25882645ad.1 for ; Fri, 17 Oct 2025 17:07:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760746067; x=1761350867; 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=KHCY6sFzZWLKuVo4O6MQDE+yc4FJeSrGIRkXpfAjMjg=; b=2t7dpM7xT5sRj2dzjCC8tHWBvbeIYM/D6BaPLa0/AOxR9uvIiAtcnb5rnAbini1hg/ 26rgE89UsuEuSf1DfU/RLE9E6xE/RK/sb37FddbHPk7cfRvnhP7HDuwpTUCa4yDfKIXS vXid0/Rp+MuN6zN/mYhVAKIsz8kFYCyU/3UvvCR1Csc97mnOEJCaIA4J6jwrckWfIny7 3ErNQRSnXAP8QfQdTTL/4dMBpGQaRA0f0yodX6ffxoF2LSsD/Fp4cCNBuNqhNFSrGtwi YW4suCx+CdutDtj8oRUVL00xfHWKRSJtmCB/6sr5pVPxrufxwz4V8khpmWENSCJc2XWH cWiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760746067; x=1761350867; 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=KHCY6sFzZWLKuVo4O6MQDE+yc4FJeSrGIRkXpfAjMjg=; b=q7BLB81Amr2tFJZmTRNhXHXsuu2KQag2A4PBn9KCQKfhlaDIEzr1Ol8kkDKf3G6CTr Q2rgiS7qJN0F5vTLryCvqOkpFmjK54QorSNxoZBnM/OL7b58WjYXxSNzAm+79h+oBMxg pNJC30yuK/D6FJEeg6/+k4NDGWRb4aWWdCoLJu6onKqzfpBGNhI1/FRdCvvzh8vGGbJD 1GTdYYdGDmPqsDkXf0dUe3Z082xDqLdU9TvIwAmaW0PaRBSsUtzSbrO5wr65u9fR8gPy ptg9HTWyqFnkWiY7qBr6LKwPNn1KzlqCXslfc21cKN0WtUCP/wKKV8ehqOW5aLvLzunF jfAQ== X-Forwarded-Encrypted: i=1; AJvYcCW2XWSD/ueceUWcVUgmksFd3qf90ZK+845HPEMIpAtUseHwHg8sxjzNF0vTegk+EYuB1C7W84JY2S+Cso51YYo=@vger.kernel.org X-Gm-Message-State: AOJu0Yx8ZDgVoGpUxT8Qzo7kijw3bFYpfQ/4+P9/2zwBLl5ksGlvz34Z 1MLqz6F648PrtVNpcunbO4FKAg634iYdri/CRnhd8ucBdcp7dg+LI2DwuOqmiFel9JDktkinTQl vrjECmX7YKw== X-Google-Smtp-Source: AGHT+IHm9Bkb4nNH3Rfeek7ZAO48gSccBg2tRk1yFiUzJut212ExP9VQ22QXBuOVaPaAWO2qNwfDgLkRrWNJ X-Received: from pjff13.prod.google.com ([2002:a17:90b:562d:b0:33d:69cf:1f82]) (user=vipinsh job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:f64f:b0:248:e3fb:4dc8 with SMTP id d9443c01a7336-290ca8d04f4mr63505285ad.39.1760746067402; Fri, 17 Oct 2025 17:07:47 -0700 (PDT) Date: Fri, 17 Oct 2025 17:07:06 -0700 In-Reply-To: <20251018000713.677779-1-vipinsh@google.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251018000713.677779-1-vipinsh@google.com> X-Mailer: git-send-email 2.51.0.858.gf9c4a03a3a-goog Message-ID: <20251018000713.677779-15-vipinsh@google.com> Subject: [RFC PATCH 14/21] vfio/pci: Skip device reset on live update restored device. From: Vipin Sharma To: bhelgaas@google.com, alex.williamson@redhat.com, pasha.tatashin@soleen.com, dmatlack@google.com, jgg@ziepe.ca, graf@amazon.com Cc: pratyush@kernel.org, gregkh@linuxfoundation.org, chrisl@kernel.org, rppt@kernel.org, skhawaja@google.com, parav@nvidia.com, saeedm@nvidia.com, kevin.tian@intel.com, jrhilke@google.com, david@redhat.com, jgowans@amazon.com, dwmw2@infradead.org, epetron@amazon.de, junaids@google.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Vipin Sharma Content-Type: text/plain; charset="UTF-8" Do not reset the device when a live update preserved VFIO PCI device is opened for the first time after kexec. Save 'reset_works' to the device serialized state. If not saved then this value can only be restored by performing an actual reset, which is not desired during live update. If a device can be reset before live update then most likely it can be reset after live update unless some reset methods have been removed. In that case when actual reset is tried it will return an error. Signed-off-by: Vipin Sharma --- drivers/vfio/pci/vfio_pci_core.c | 15 ++++++++++----- drivers/vfio/pci/vfio_pci_liveupdate.c | 9 +++++++++ drivers/vfio/pci/vfio_pci_priv.h | 2 ++ 3 files changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 29236b015242..186a669b68a4 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -486,12 +486,17 @@ int vfio_pci_core_enable(struct vfio_pci_core_device *vdev) if (ret) goto out_power; - /* If reset fails because of the device lock, fail this path entirely */ - ret = pci_try_reset_function(pdev); - if (ret == -EAGAIN) - goto out_disable_device; + if (vdev->liveupdate_restore) { + vfio_pci_liveupdate_restore_device(vdev); + } else { + /* If reset fails because of the device lock, fail this path entirely */ + ret = pci_try_reset_function(pdev); + if (ret == -EAGAIN) + goto out_disable_device; + + vdev->reset_works = !ret; + } - vdev->reset_works = !ret; pci_save_state(pdev); vdev->pci_saved_state = pci_store_saved_state(pdev); if (!vdev->pci_saved_state) diff --git a/drivers/vfio/pci/vfio_pci_liveupdate.c b/drivers/vfio/pci/vfio_pci_liveupdate.c index 824dba2750fe..82ff9f178fdc 100644 --- a/drivers/vfio/pci/vfio_pci_liveupdate.c +++ b/drivers/vfio/pci/vfio_pci_liveupdate.c @@ -22,6 +22,7 @@ struct vfio_pci_core_device_ser { u8 pci_config_map[PCI_CFG_SPACE_EXP_SIZE]; u8 vconfig[PCI_CFG_SPACE_EXP_SIZE]; u32 rbar[7]; + u8 reset_works; } __packed; static int vfio_pci_liveupdate_deserialize_config(struct vfio_pci_core_device *vdev, @@ -55,6 +56,7 @@ static int vfio_pci_lu_serialize(struct vfio_pci_core_device *vdev, { ser->bdf = pci_dev_id(vdev->pdev); vfio_pci_liveupdate_serialize_config(vdev, ser); + ser->reset_works = vdev->reset_works; return 0; } @@ -259,3 +261,10 @@ int vfio_pci_liveupdate_restore_config(struct vfio_pci_core_device *vdev) return vfio_pci_liveupdate_deserialize_config(vdev, ser); } + +void vfio_pci_liveupdate_restore_device(struct vfio_pci_core_device *vdev) +{ + struct vfio_pci_core_device_ser *ser = vdev->liveupdate_restore; + + vdev->reset_works = ser->reset_works; +} diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h index 0d5aca6c2471..ee1c7c229020 100644 --- a/drivers/vfio/pci/vfio_pci_priv.h +++ b/drivers/vfio/pci/vfio_pci_priv.h @@ -110,12 +110,14 @@ static inline bool vfio_pci_is_vga(struct pci_dev *pdev) #ifdef CONFIG_LIVEUPDATE void vfio_pci_liveupdate_init(void); int vfio_pci_liveupdate_restore_config(struct vfio_pci_core_device *vdev); +void vfio_pci_liveupdate_restore_device(struct vfio_pci_core_device *vdev); #else static inline void vfio_pci_liveupdate_init(void) { } int vfio_pci_liveupdate_restore_config(struct vfio_pci_core_device *vdev) { return -EINVAL; } +void vfio_pci_liveupdate_restore_device(struct vfio_pci_core_device *vdev) { } #endif /* CONFIG_LIVEUPDATE */ #endif -- 2.51.0.858.gf9c4a03a3a-goog