From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 37EE1266B71 for ; Thu, 13 Mar 2025 12:35:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741869350; cv=none; b=Xp5MOFT57afbixOSymt15S7AVz30o1maQGWsb95llIbesBFv3hgjiXzr1NlLbz6JNp4QQYYjhF78/JsvsU1sy9Z4RomCWNXfrcWDDV+eWHBbkpDrvZw85MZ7n8q4W3mzTn+0yRDsLeFh9u/iapXAlA8/jPC7z+2q1+/4K3m7DZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741869350; c=relaxed/simple; bh=7B/VqXhvmPIjVnSGliCdA8yXM3HhosGkoFL4PtC3GQQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=H5RuqiGPApyRmygRhK3jf3Y2gLoTn+7a7v8FiSFLIUu7sBQTOXyVoTLIH9c5BHIlql9SbD70wgNStd35LkIdA99QTwkExcHDYNdch1WGfa9oW4ZS+5el9tYzcgMUnMXBRx/eky7fDE8WkVJqV7I7TV6HGrxILX4FHuZMu3lANPE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=RmAeZfOX; arc=none smtp.client-ip=192.198.163.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="RmAeZfOX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1741869348; x=1773405348; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7B/VqXhvmPIjVnSGliCdA8yXM3HhosGkoFL4PtC3GQQ=; b=RmAeZfOX9dDbo54I3qPAgxQ+CAVXOZANEbESVgClrl18XH2rADTNmiej k/RWc8Io3uLJwPcPdyoV2HNMKSWKe4jNWHbkts/zLISauXwLl6aP026+w 2OnjMdnmhx69BEETBPTq4urVQxnzAu+R8J73FAn4L5oF+sC5agicjqToy Onj2apQQT1nPLc9iGBtIn8lPrVJ7bXVWbMZHCBgVow0ZRwwOxXrsEnIN3 CNTfY+I3BlN5JKBV4PQgMMq5EGesY10MxRSXE2BFimfwdF7viMGox/+O6 vGzidquCy4unq/1R6pWRLE6G8is2RjX4l3GkMjBKvBeJt6BGkGH0d2Q4T w==; X-CSE-ConnectionGUID: LyHCSEyHQXuasAxqp+nWQQ== X-CSE-MsgGUID: OhAGGDelQtScwSCsmXtjYg== X-IronPort-AV: E=McAfee;i="6700,10204,11372"; a="42863939" X-IronPort-AV: E=Sophos;i="6.14,244,1736841600"; d="scan'208";a="42863939" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Mar 2025 05:35:35 -0700 X-CSE-ConnectionGUID: YayeqfNdQwiM65hu4npILA== X-CSE-MsgGUID: b7yag+1QQSSP19o415JCCg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,244,1736841600"; d="scan'208";a="126005489" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by orviesa004.jf.intel.com with ESMTP; 13 Mar 2025 05:35:35 -0700 From: Yi Liu To: kevin.tian@intel.com, jgg@nvidia.com Cc: joro@8bytes.org, baolu.lu@linux.intel.com, yi.l.liu@intel.com, iommu@lists.linux.dev, nicolinc@nvidia.com Subject: [PATCH v9 03/21] iommu: Introduce a replace API for device pasid Date: Thu, 13 Mar 2025 05:35:14 -0700 Message-Id: <20250313123532.103522-4-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250313123532.103522-1-yi.l.liu@intel.com> References: <20250313123532.103522-1-yi.l.liu@intel.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Provide a high-level API to allow replacements of one domain with another for specific pasid of a device. This is similar to iommu_replace_group_handle() and it is expected to be used only by IOMMUFD. Co-developed-by: Lu Baolu Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Signed-off-by: Yi Liu -- v8 -> v9: Adapted this patch to use iommu_group_pasid_store() which checks the current pasid array entry and change the handle->domain under xa_lock(). -- drivers/iommu/iommu-priv.h | 4 ++ drivers/iommu/iommu.c | 111 ++++++++++++++++++++++++++++++++++--- 2 files changed, 107 insertions(+), 8 deletions(-) diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h index b4508423e13b..2985f05d699f 100644 --- a/drivers/iommu/iommu-priv.h +++ b/drivers/iommu/iommu-priv.h @@ -43,4 +43,8 @@ void iommu_detach_group_handle(struct iommu_domain *domain, int iommu_replace_group_handle(struct iommu_group *group, struct iommu_domain *new_domain, struct iommu_attach_handle *handle); + +int iommu_replace_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle); #endif /* __LINUX_IOMMU_PRIV_H */ diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 6a314122a9da..a828c96ad6c5 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -513,6 +513,13 @@ static void iommu_deinit_device(struct device *dev) dev_iommu_free(dev); } +static inline struct iommu_domain *pasid_array_entry_to_domain(void *entry) +{ + if (xa_pointer_tag(entry) == IOMMU_PASID_ARRAY_DOMAIN) + return xa_untag_pointer(entry); + return ((struct iommu_attach_handle *)xa_untag_pointer(entry))->domain; +} + DEFINE_MUTEX(iommu_probe_device_lock); static int __iommu_probe_device(struct device *dev, struct list_head *group_list) @@ -2170,7 +2177,7 @@ static void iommu_pasid_array_entry_clear_handle(void *entry) /* Caller should have reserved memory for __xa_store() */ static void iommu_group_pasid_store(struct iommu_group *group, ioasid_t pasid, - struct iommu_domain *domain, + void *curr, struct iommu_domain *domain, struct iommu_attach_handle *handle) { void *entry; @@ -2179,8 +2186,13 @@ static void iommu_group_pasid_store(struct iommu_group *group, ioasid_t pasid, xa_lock(&group->pasid_array); entry = iommu_make_pasid_array_entry(domain, handle); + if (curr == entry) + goto out_unlock; + WARN_ON(xa_is_err(__xa_store(&group->pasid_array, pasid, entry, GFP_KERNEL))); + +out_unlock: xa_unlock(&group->pasid_array); } @@ -3334,14 +3346,15 @@ static void iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid, } static int __iommu_set_group_pasid(struct iommu_domain *domain, - struct iommu_group *group, ioasid_t pasid) + struct iommu_group *group, ioasid_t pasid, + struct iommu_domain *old) { struct group_device *device, *last_gdev; int ret; for_each_group_device(group, device) { ret = domain->ops->set_dev_pasid(domain, device->dev, - pasid, NULL); + pasid, old); if (ret) goto err_revert; } @@ -3353,7 +3366,15 @@ static int __iommu_set_group_pasid(struct iommu_domain *domain, for_each_group_device(group, device) { if (device == last_gdev) break; - iommu_remove_dev_pasid(device->dev, pasid, domain); + /* + * If no old domain, undo the succeeded devices/pasid. + * Otherwise, rollback the succeeded devices/pasid to the old + * domain. And it is a driver bug to fail attaching with a + * previously good domain. + */ + if (!old || WARN_ON(old->ops->set_dev_pasid(old, device->dev, + pasid, domain))) + iommu_remove_dev_pasid(device->dev, pasid, domain); } return ret; } @@ -3416,7 +3437,7 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, if (ret) goto out_unlock; - ret = __iommu_set_group_pasid(domain, group, pasid); + ret = __iommu_set_group_pasid(domain, group, pasid, NULL); if (ret) { xa_release(&group->pasid_array, pasid); goto out_unlock; @@ -3428,7 +3449,7 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, * operation succeeds as we cannot tolerate PRIs becoming concurrently * queued and then failing attach. */ - iommu_group_pasid_store(group, pasid, domain, handle); + iommu_group_pasid_store(group, pasid, NULL, domain, handle); out_unlock: mutex_unlock(&group->mutex); @@ -3436,6 +3457,79 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, } EXPORT_SYMBOL_GPL(iommu_attach_device_pasid); +/** + * iommu_replace_device_pasid - Replace the domain that a pasid + * is attached to + * @domain: the new iommu domain + * @dev: the attached device. + * @pasid: the pasid of the device. + * @handle: the attach handle. + * + * This API allows the pasid to switch domains. The @pasid should have been + * attached. Otherwise, this fails. + * The pasid will keep the old configuration if replacement failed. + * Return 0 on success, or an error. + */ +int iommu_replace_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) +{ + /* Caller must be a probed driver on dev */ + struct iommu_group *group = dev->iommu_group; + struct iommu_domain *curr_domain; + void *curr; + int ret; + + if (!group) + return -ENODEV; + + if (!domain->ops->set_dev_pasid) + return -EOPNOTSUPP; + + if (dev_iommu_ops(dev) != domain->owner || + pasid == IOMMU_NO_PASID || !handle) + return -EINVAL; + + mutex_lock(&group->mutex); + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, + XA_ZERO_ENTRY, GFP_KERNEL); + if (xa_is_err(curr)) { + ret = xa_err(curr); + goto out_unlock; + } + + /* + * No domain (with or without handle) attached, hence not + * a replace case. + */ + if (!curr) { + xa_release(&group->pasid_array, pasid); + ret = -EINVAL; + goto out_unlock; + } + + curr_domain = pasid_array_entry_to_domain(curr); + ret = 0; + + if (curr_domain != domain) { + ret = __iommu_set_group_pasid(domain, group, + pasid, curr_domain); + if (ret) + goto out_unlock; + } + + /* + * The above xa_cmpxchg() reserved the memory, and the + * group->mutex is held, this cannot fail. + */ + iommu_group_pasid_store(group, pasid, curr, domain, handle); + +out_unlock: + mutex_unlock(&group->mutex); + return ret; +} +EXPORT_SYMBOL_NS_GPL(iommu_replace_device_pasid, "IOMMUFD_INTERNAL"); + /* * iommu_detach_device_pasid() - Detach the domain from pasid of device * @domain: the iommu domain. @@ -3562,7 +3656,7 @@ int iommu_attach_group_handle(struct iommu_domain *domain, * operation succeeds as we cannot tolerate PRIs becoming concurrently * queued and then failing attach. */ - iommu_group_pasid_store(group, IOMMU_NO_PASID, domain, handle); + iommu_group_pasid_store(group, IOMMU_NO_PASID, NULL, domain, handle); out_unlock: mutex_unlock(&group->mutex); @@ -3623,7 +3717,8 @@ int iommu_replace_group_handle(struct iommu_group *group, if (ret) goto err_release; - iommu_group_pasid_store(group, IOMMU_NO_PASID, new_domain, handle); + iommu_group_pasid_store(group, IOMMU_NO_PASID, NULL, + new_domain, handle); mutex_unlock(&group->mutex); -- 2.34.1