From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) (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 BDA8A32AABC for ; Sat, 8 Aug 2026 02:27:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786156063; cv=none; b=bZM7ciLydLIPjblPUjpqby1XccV3tfelpaB5MK9S9JvCEMml5uo7BSWvWc5NKJdlMLWPI6KQEd93TF3JcO+K/3x0dhkXfSE2WkdH6PLlU8xgt1fP/lbTtJwj97vu5bpZ6YOeUkuxacRcvTR615YLmASxYR2q8V+/rC2L+TVmaUE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786156063; c=relaxed/simple; bh=Fh+m0hfc6/ceDcFHl5a53A7yt6t0M8iBw9tVjOtAjkY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GvzeDGrwNMWXev2L6kqMM3gFieD/xa4XzF8Vmumtd0TaXR/iizZRnI1JLRG85iyQphW+zAGRWK6TgdNba/tGSqPJQ+y2sYFwfCf8nciGCmgBuCpwrQpgFtDa+HUEQvwMCC5c5lgJNF3F5I9ztqJFTyigYOpIuYqYHtcd2Rye8j8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--skhawaja.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=b0nU19Cq; arc=none smtp.client-ip=209.85.216.72 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--skhawaja.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="b0nU19Cq" Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-38fa7b09921so273862a91.1 for ; Fri, 07 Aug 2026 19:27:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786156057; x=1786760857; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=WeC7LGI9U9rgVUe10iSyYYu5Jqh1mOG6ku0uTPreMQM=; b=b0nU19Cq0jhR/HYvKx94iYP9S7nW2qSSv/D88RoGemDDbsj2Qh9Y/NS+DHSaLC+U0Y fcwypXDzfIxa+zV3jQL+Ra1/cfJodCAgnRusef+dTPes5PaLfRcPlBUdbHJrNeT3gUCN QZliPuZd72V+Cbwa2yq0JDpnJKoe3md1lfrsORB8+eAHSjGjdqayePvg6QBPsMZhW+jP qP742xdZOSDDPVWEnSgcFqhLp2J+3bFuTlLp8VODGee6rYIIrvFGmEMT4DeMsHRfh2Za QBczp8MW7UAQPlfka3dF5hbcFucPVT7TvAVbOSCCkPHJHriacnjw6m71mNzHlMKzY96O 25Nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786156057; x=1786760857; h=content-type: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:content-type; bh=WeC7LGI9U9rgVUe10iSyYYu5Jqh1mOG6ku0uTPreMQM=; b=Z6rNQOakvqRe/7yioCEXHK1xAPmptPaYKhLEhMNwbABiN2tOHaHrrKdWBGZ/JP/ryX YoDiUbELwKGPjufsHqDPSlukjd4O0qyhNyrsGsFLRBa/iLyX+f25cJH+no3zcPftUl0h 0g7jkHkRkOuWH43MrKnxtmUO9ZqXG5iNLuXq72mf9BdLVXQ/FrmdKGbZ0PeSAl0kTvgE cQuOfYH1G7jkswdigloDyGGsFfBdMhjO1Sb3NX6jpW/jfjNdQjdE649CPKEmUWdBXx6U sROOtdPAHwrToXYmCcBfBoEO/1ZtqI9FcVfkThihW6sHu9UjOPOPkgSDSczPChpJZ8kS kNlQ== X-Forwarded-Encrypted: i=1; AHgh+RqpnOkJnZoO0x3jqFRf00yGzz/8D1t24ARb12TncQXGPMs19ORXEeKAW56RFHAzv4PzUR8bM6caawB7610=@vger.kernel.org X-Gm-Message-State: AOJu0YzV6C1S+T2XTTbF9oU3ey1vGCjWyEtIsyxIwelvzaAIQHkh32Sp 2z2bRjgjCheVCxLsq3+KWKIYD0ggg5V2McorRl/H/HwKfuFwVENFDi3Cchszd2XpL4pv/pXEhFi YjYxf/GzrFtD5vw== X-Received: from pjur16.prod.google.com ([2002:a17:90a:d410:b0:38e:b97a:cfa1]) (user=skhawaja job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4e8d:b0:38d:ec31:4840 with SMTP id 98e67ed59e1d1-3903c5932femr29110858a91.13.1786156056611; Fri, 07 Aug 2026 19:27:36 -0700 (PDT) Date: Sat, 8 Aug 2026 02:27:20 +0000 In-Reply-To: <20260808022723.3893618-1-skhawaja@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260808022723.3893618-1-skhawaja@google.com> X-Mailer: git-send-email 2.55.0.679.g6767b8d81c-goog Message-ID: <20260808022723.3893618-16-skhawaja@google.com> Subject: [PATCH v4 15/18] iommufd: Persist iommu hardware pagetables for live update From: Samiullah Khawaja To: David Woodhouse , Lu Baolu , Joerg Roedel , Will Deacon , Jason Gunthorpe Cc: YiFei Zhu , Samiullah Khawaja , Robin Murphy , Kevin Tian , Alex Williamson , Shuah Khan , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Pratyush Yadav , Pasha Tatashin , David Matlack , Andrew Morton , Pranjal Shrivastava , Vipin Sharma Content-Type: text/plain; charset="UTF-8" From: YiFei Zhu Register iommufd with the LUO framework and implement the preserve and unpreserve ops to save marked HWPTs. To make sure mappings do not change during preserved state, add a liveupdate_immutable flag to IOAS. When an HWPT is preserved, its IOAS is marked immutable and any map/unmap attempts will fail with -EBUSY. This is synchronized using the domains_rwsem to prevent races with concurrent mapping operations. The preserve callback iterates over the marked HWPTs, verifies that the backing memory pages are preserved, and calls iommu_preserve_domain() to preserve the associated IOMMU domain. Signed-off-by: YiFei Zhu Signed-off-by: Samiullah Khawaja --- MAINTAINERS | 1 + drivers/iommu/iommufd/io_pagetable.c | 11 + drivers/iommu/iommufd/io_pagetable.h | 1 + drivers/iommu/iommufd/iommufd_private.h | 26 ++ drivers/iommu/iommufd/liveupdate.c | 304 ++++++++++++++++++++++++ drivers/iommu/iommufd/main.c | 10 +- drivers/iommu/iommufd/pages.c | 11 + include/linux/kho/abi/iommufd.h | 51 ++++ 8 files changed, 414 insertions(+), 1 deletion(-) create mode 100644 include/linux/kho/abi/iommufd.h diff --git a/MAINTAINERS b/MAINTAINERS index 985c4d53c2c2..e8e96526ef07 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13632,6 +13632,7 @@ F: drivers/iommu/iommufd/liveupdate.c F: drivers/iommu/liveupdate.c F: include/linux/iommu-liveupdate.h F: include/linux/kho/abi/iommu.h +F: include/linux/kho/abi/iommufd.h IOMMUFD M: Jason Gunthorpe diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c index 24d4917105d9..b18dba9dd147 100644 --- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -384,6 +384,11 @@ int iopt_map_pages(struct io_pagetable *iopt, struct list_head *pages_list, return rc; down_read(&iopt->domains_rwsem); + if (iopt_liveupdate_immutable(iopt)) { + rc = -EBUSY; + goto out_unlock_domains; + } + rc = iopt_fill_domains_pages(pages_list); if (rc) goto out_unlock_domains; @@ -755,6 +760,12 @@ static int iopt_unmap_iova_range(struct io_pagetable *iopt, unsigned long start, again: down_read(&iopt->domains_rwsem); down_write(&iopt->iova_rwsem); + + if (iopt_liveupdate_immutable(iopt)) { + rc = -EBUSY; + goto out_unlock_iova; + } + while ((area = iopt_area_iter_first(iopt, start, last))) { unsigned long area_last = iopt_area_last_iova(area); unsigned long area_first = iopt_area_iova(area); diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h index 27e3e311d395..207ff368d412 100644 --- a/drivers/iommu/iommufd/io_pagetable.h +++ b/drivers/iommu/iommufd/io_pagetable.h @@ -234,6 +234,7 @@ struct iopt_pages { struct { /* IOPT_ADDRESS_FILE */ struct file *file; unsigned long start; + u32 seals; }; /* IOPT_ADDRESS_DMABUF */ struct iopt_pages_dmabuf dmabuf; diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 9b4b745acef1..3b37c13fb118 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -98,6 +98,9 @@ struct io_pagetable { /* IOVA that cannot be allocated, struct iopt_reserved */ struct rb_root_cached reserved_itree; u8 disable_large_pages; +#ifdef CONFIG_IOMMU_LIVEUPDATE + u32 nr_preserved_domains; +#endif unsigned long iova_alignment; }; @@ -379,6 +382,7 @@ struct iommufd_hwpt_paging { bool enforce_cache_coherency : 1; bool nest_parent : 1; #ifdef CONFIG_IOMMU_LIVEUPDATE + bool liveupdate_preserved; u64 liveupdate_token; #endif /* Head at iommufd_ioas::hwpt_list */ @@ -715,12 +719,34 @@ iommufd_get_vdevice(struct iommufd_ctx *ictx, u32 id) } #ifdef CONFIG_IOMMU_LIVEUPDATE +int iommufd_liveupdate_register(void); +void iommufd_liveupdate_unregister(void); + int iommufd_hwpt_liveupdate_mark_preserve(struct iommufd_ucmd *ucmd); + +static inline bool iopt_liveupdate_immutable(const struct io_pagetable *iopt) +{ + return iopt->nr_preserved_domains > 0; +} #else +static inline int iommufd_liveupdate_register(void) +{ + return 0; +} + +static inline void iommufd_liveupdate_unregister(void) +{ +} + static inline int iommufd_hwpt_liveupdate_mark_preserve(struct iommufd_ucmd *ucmd) { return -ENOTTY; } + +static inline bool iopt_liveupdate_immutable(const struct io_pagetable *iopt) +{ + return false; +} #endif #ifdef CONFIG_IOMMUFD_TEST diff --git a/drivers/iommu/iommufd/liveupdate.c b/drivers/iommu/iommufd/liveupdate.c index 96f01ee5a1e8..84f6e11fccad 100644 --- a/drivers/iommu/iommufd/liveupdate.c +++ b/drivers/iommu/iommufd/liveupdate.c @@ -9,9 +9,31 @@ #include #include +#include +#include #include +#include +#include +#include #include "iommufd_private.h" +#include "io_pagetable.h" + +static bool ioas_set_immutable(struct iommufd_ioas *ioas, bool set) +{ + bool was_immutable; + + down_write(&ioas->iopt.domains_rwsem); + was_immutable = ioas->iopt.nr_preserved_domains > 0; + if (set) + ioas->iopt.nr_preserved_domains++; + else if (!WARN_ON(!was_immutable)) + ioas->iopt.nr_preserved_domains--; + + up_write(&ioas->iopt.domains_rwsem); + + return was_immutable; +} int iommufd_hwpt_liveupdate_mark_preserve(struct iommufd_ucmd *ucmd) { @@ -69,3 +91,285 @@ int iommufd_hwpt_liveupdate_mark_preserve(struct iommufd_ucmd *ucmd) iommufd_put_object(ictx, &hwpt_target->common.obj); return rc; } + +static int check_iopt_pages_preserved(struct liveupdate_session *s, + struct iommufd_hwpt_paging *hwpt) +{ + u32 req_seals = F_SEAL_SEAL | F_SEAL_GROW | F_SEAL_SHRINK; + struct iopt_area *area; + int ret = 0; + + down_read(&hwpt->ioas->iopt.iova_rwsem); + for (area = iopt_area_iter_first(&hwpt->ioas->iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + struct iopt_pages *pages = area->pages; + + if (!pages) + continue; + + /* Only allow file based mapping */ + if (pages->type != IOPT_ADDRESS_FILE) { + ret = -EINVAL; + break; + } + + /* + * When this memory file was mapped it should be sealed and seal + * should be sealed. This means that since mapping was done the + * memory file was not grown or shrink and the pages being used + * until now remain pinned and preserved. + */ + if ((pages->seals & req_seals) != req_seals) { + ret = -EINVAL; + break; + } + + /* Make sure that the file was preserved. */ + ret = liveupdate_get_token_outgoing(s, pages->file, NULL); + if (ret) + break; + } + up_read(&hwpt->ioas->iopt.iova_rwsem); + + return ret; +} + +static int iommufd_preserve_hwpt(struct iommufd_hwpt_paging *hwpt, + struct iommufd_hwpt_ser *hwpt_ser, + struct liveupdate_session *session) +{ + struct iommu_domain_ser *domain_ser; + bool was_immutable; + int rc; + + /* + * Make IOAS immutable so the DMA mappings do not change while + * the HWPT is preserved. Since one IOAS can have multiple + * HWPTs, if an error occurs this call needs to make the IOAS + * mutable again if it was the one that made it immutable. + */ + was_immutable = ioas_set_immutable(hwpt->ioas, true); + + if (!was_immutable) { + rc = check_iopt_pages_preserved(session, hwpt); + if (rc) + goto err; + } + + hwpt_ser->token = hwpt->liveupdate_token; + hwpt_ser->reclaimed = false; + + rc = iommu_preserve_domain(hwpt->common.domain, &domain_ser); + if (rc < 0) + goto err; + + hwpt_ser->domain_data = virt_to_phys(domain_ser); + return 0; + +err: + ioas_set_immutable(hwpt->ioas, false); + return rc; +} + +static void _iommufd_unpreserve(struct iommufd_ctx *ictx, + struct iommufd_ser *ser) +{ + struct iommufd_hwpt_paging *hwpt; + struct iommufd_object *obj; + unsigned long index; + + xa_lock(&ictx->objects); + xa_for_each_marked(&ictx->objects, index, obj, IOMMUFD_OBJ_LIVEUPDATE_MARK) { + if (obj->type != IOMMUFD_OBJ_HWPT_PAGING) + continue; + + hwpt = to_hwpt_paging(container_of(obj, struct iommufd_hw_pagetable, obj)); + if (!hwpt->liveupdate_preserved) + continue; + + xa_unlock(&ictx->objects); + + iommu_unpreserve_domain(hwpt->common.domain); + ioas_set_immutable(hwpt->ioas, false); + + hwpt->liveupdate_preserved = false; + iommufd_put_object(ictx, obj); + + xa_lock(&ictx->objects); + } + xa_unlock(&ictx->objects); + + kho_unpreserve_free(ser); +} + +static int iommufd_liveupdate_preserve(struct liveupdate_file_op_args *args) +{ + struct iommufd_ctx *ictx; + struct iommufd_hwpt_paging *hwpt; + struct iommufd_ser *iommufd_ser; + struct iommufd_object *obj; + unsigned int nr_hwpts; + unsigned long index; + unsigned int i; + void *mem; + int rc; + + ictx = iommufd_ctx_from_file(args->file); + if (IS_ERR(ictx)) + return PTR_ERR(ictx); + + mutex_lock(&ictx->liveupdate_mutex); + + /* Count the number of HWPTs to preserve */ + nr_hwpts = 0; + xa_lock(&ictx->objects); + xa_for_each_marked(&ictx->objects, index, obj, IOMMUFD_OBJ_LIVEUPDATE_MARK) { + if (obj->type != IOMMUFD_OBJ_HWPT_PAGING) + continue; + + hwpt = to_hwpt_paging(container_of(obj, struct iommufd_hw_pagetable, obj)); + if (!hwpt->common.domain) { + rc = -EINVAL; + xa_unlock(&ictx->objects); + goto out_unlock; + } + nr_hwpts++; + } + xa_unlock(&ictx->objects); + + mem = kho_alloc_preserve(struct_size(iommufd_ser, + hwpt_array, nr_hwpts)); + if (IS_ERR(mem)) { + rc = PTR_ERR(mem); + goto out_unlock; + } + + iommufd_ser = mem; + iommufd_ser->nr_hwpts = nr_hwpts; + + /* Preserve HWPTs */ + i = 0; + xa_lock(&ictx->objects); + xa_for_each_marked(&ictx->objects, index, obj, IOMMUFD_OBJ_LIVEUPDATE_MARK) { + if (obj->type != IOMMUFD_OBJ_HWPT_PAGING) + continue; + + if (!iommufd_lock_obj(obj)) { + rc = -ENOENT; + xa_unlock(&ictx->objects); + goto out_unpreserve; + } + + /* + * HWPT is locked so it will not be destroyed. The xarray lock + * can be released here before preserving the HWPT. + */ + xa_unlock(&ictx->objects); + hwpt = to_hwpt_paging(container_of(obj, struct iommufd_hw_pagetable, obj)); + rc = iommufd_preserve_hwpt(hwpt, &iommufd_ser->hwpt_array[i++], args->session); + if (rc) { + iommufd_put_object(ictx, obj); + goto out_unpreserve; + } + + /* + * Mark the HWPT as successfully preserved. This is distinct + * from IOMMUFD_OBJ_LIVEUPDATE_MARK, which only indicates the + * userspace intent to preserve. + */ + hwpt->liveupdate_preserved = true; + xa_lock(&ictx->objects); + } + xa_unlock(&ictx->objects); + + /* Store the actual number of HWPTs that are preserved */ + iommufd_ser->nr_hwpts = i; + + args->serialized_data = virt_to_phys(iommufd_ser); + mutex_unlock(&ictx->liveupdate_mutex); + iommufd_ctx_put(ictx); + return 0; + +out_unpreserve: + _iommufd_unpreserve(ictx, iommufd_ser); +out_unlock: + mutex_unlock(&ictx->liveupdate_mutex); + iommufd_ctx_put(ictx); + return rc; +} + +static void iommufd_liveupdate_unpreserve(struct liveupdate_file_op_args *args) +{ + struct iommufd_ctx *ictx; + + ictx = iommufd_ctx_from_file(args->file); + if (WARN_ON(IS_ERR(ictx))) + return; + + mutex_lock(&ictx->liveupdate_mutex); + _iommufd_unpreserve(ictx, phys_to_virt(args->serialized_data)); + mutex_unlock(&ictx->liveupdate_mutex); + + iommufd_ctx_put(ictx); +} + +static int iommufd_liveupdate_retrieve(struct liveupdate_file_op_args *args) +{ + return -EOPNOTSUPP; +} + +static bool iommufd_liveupdate_can_finish(struct liveupdate_file_op_args *args) +{ + return false; +} + +static void iommufd_liveupdate_finish(struct liveupdate_file_op_args *args) +{ +} + +static bool iommufd_liveupdate_can_preserve(struct liveupdate_file_handler *handler, + struct file *file) +{ + struct iommufd_ctx *ictx = iommufd_ctx_from_file(file); + + if (IS_ERR(ictx)) + return false; + + iommufd_ctx_put(ictx); + return true; +} + +static struct liveupdate_file_ops iommufd_ser_file_ops = { + .can_preserve = iommufd_liveupdate_can_preserve, + .preserve = iommufd_liveupdate_preserve, + .unpreserve = iommufd_liveupdate_unpreserve, + .retrieve = iommufd_liveupdate_retrieve, + .can_finish = iommufd_liveupdate_can_finish, + .finish = iommufd_liveupdate_finish, +}; + +static struct liveupdate_file_handler iommufd_ser_handler = { + .compatible = IOMMUFD_LUO_COMPATIBLE, + .ops = &iommufd_ser_file_ops, +}; + +int iommufd_liveupdate_register(void) +{ + int ret; + + ret = liveupdate_register_file_handler(&iommufd_ser_handler); + if (ret) + return ret; + + ret = iommu_liveupdate_register_flb(&iommufd_ser_handler); + if (ret) + liveupdate_unregister_file_handler(&iommufd_ser_handler); + + return ret; +} + +void iommufd_liveupdate_unregister(void) +{ + iommu_liveupdate_unregister_flb(&iommufd_ser_handler); + liveupdate_unregister_file_handler(&iommufd_ser_handler); +} diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 0114c1520db4..0a7e7bb586d7 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -782,11 +782,18 @@ static int __init iommufd_init(void) if (ret) goto err_misc; } - ret = iommufd_test_init(); + + ret = iommufd_liveupdate_register(); if (ret) goto err_vfio_misc; + + ret = iommufd_test_init(); + if (ret) + goto err_liveupdate; return 0; +err_liveupdate: + iommufd_liveupdate_unregister(); err_vfio_misc: if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER)) misc_deregister(&vfio_misc_dev); @@ -798,6 +805,7 @@ static int __init iommufd_init(void) static void __exit iommufd_exit(void) { iommufd_test_exit(); + iommufd_liveupdate_unregister(); if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER)) misc_deregister(&vfio_misc_dev); misc_deregister(&iommu_misc_dev); diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index 03c8379bbc34..79e2c887cbd9 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include "double_span.h" @@ -1421,6 +1422,7 @@ struct iopt_pages *iopt_alloc_file_pages(struct file *file, { struct iopt_pages *pages; + int seals; pages = iopt_alloc_pages(start_byte, length, writable); if (IS_ERR(pages)) @@ -1428,6 +1430,15 @@ struct iopt_pages *iopt_alloc_file_pages(struct file *file, pages->file = get_file(file); pages->start = start - start_byte; pages->type = IOPT_ADDRESS_FILE; + + /* + * Get seals from the memfd during mapping to verify that these did not + * change before iommufd preservation. + */ + seals = memfd_get_seals(file); + if (seals > 0) + pages->seals = seals; + return pages; } diff --git a/include/linux/kho/abi/iommufd.h b/include/linux/kho/abi/iommufd.h new file mode 100644 index 000000000000..e0c13b965cb9 --- /dev/null +++ b/include/linux/kho/abi/iommufd.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Copyright (C) 2026, Google LLC + * Author: Samiullah Khawaja + */ + +#ifndef _LINUX_KHO_ABI_IOMMUFD_H +#define _LINUX_KHO_ABI_IOMMUFD_H + +#include +#include +#include + +/** + * DOC: IOMMUFD Live Update ABI + * + * This header defines the ABI for preserving the state of an IOMMUFD file + * across a kexec reboot using LUO. + * + * This interface is a contract. Any modification to any of the serialization + * structs defined here constitutes a breaking change. Such changes require + * incrementing the version number in the IOMMUFD_LUO_COMPATIBLE string. + */ + +#define IOMMUFD_LUO_COMPATIBLE "iommufd-v1" + +/** + * struct iommu_hwpt_ser - IOMMUFD HWPT serialized state + * @domain_data: Physical address of the serialized state of associated domain + * @token: User provided token + * @reclaimed: Whether the HWPT is reclaimed + */ +struct iommufd_hwpt_ser { + u64 domain_data; + u64 token; + u8 reclaimed; + u8 padding[7]; +} __packed; + +/** + * struct iommu_ser - IOMMUFD serialized state + * @nr_hwpts: Number of preserved HWPTs + * @hwpt_array: Array of serialized state of preserved HWPTs + */ +struct iommufd_ser { + u64 nr_hwpts; + struct iommufd_hwpt_ser hwpt_array[]; +} __packed; + +#endif /* _LINUX_KHO_ABI_IOMMUFD_H */ -- 2.55.0.679.g6767b8d81c-goog