From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 01E98109C057 for ; Wed, 25 Mar 2026 18:45:09 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w5TDp-0003Pb-Sz; Wed, 25 Mar 2026 14:44:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w5TDn-0003P6-9g for qemu-devel@nongnu.org; Wed, 25 Mar 2026 14:44:51 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w5TDl-0007Mw-Dl for qemu-devel@nongnu.org; Wed, 25 Mar 2026 14:44:51 -0400 Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4fgwmW4qzZzHnGjr; Thu, 26 Mar 2026 02:44:11 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id 7F6D74056B; Thu, 26 Mar 2026 02:44:47 +0800 (CST) Received: from a2303103017.china.huawei.com (10.47.66.203) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 25 Mar 2026 18:44:46 +0000 To: CC: , , , , , , , , , , , , Subject: [PATCH 3/9] hw/cxl: Hook up tagged host memory backends at runtime for DC extents Date: Wed, 25 Mar 2026 18:42:51 +0000 Message-ID: <20260325184259.366-4-alireza.sanaee@huawei.com> X-Mailer: git-send-email 2.51.0.windows.2 In-Reply-To: <20260325184259.366-1-alireza.sanaee@huawei.com> References: <20260325184259.366-1-alireza.sanaee@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.47.66.203] X-ClientProxiedBy: lhrpeml500011.china.huawei.com (7.191.174.215) To dubpeml500005.china.huawei.com (7.214.145.207) Received-SPF: pass client-ip=185.176.79.56; envelope-from=alireza.sanaee@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Alireza Sanaee From: Alireza Sanaee via qemu development Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org When a type3 device is created with dc-regions-total-size instead of an initial volatile-dc-memdev, prescriptive DC add requests need a way to name the backend to attach to the accepted extent. Teach the QMP and mailbox paths to carry that tag through the lazy dynamic-capacity flow. In the add path, resolve the tag to a generic host memory backend, reject reuse of an already-mapped backend, and verify that the backend size matches the requested extent. Store the selected backend metadata on the pending extent so a later patch can bind the accepted extent to the chosen backend when the host acknowledges the request. Signed-off-by: Alireza Sanaee --- hw/cxl/cxl-mailbox-utils.c | 8 ---- hw/mem/cxl_type3.c | 77 ++++++++++++++++++++++++++++++++------ 2 files changed, 65 insertions(+), 20 deletions(-) diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c index e6e136cf44..c83b5f90d4 100644 --- a/hw/cxl/cxl-mailbox-utils.c +++ b/hw/cxl/cxl-mailbox-utils.c @@ -4270,10 +4270,6 @@ static CXLRetCode cmd_fm_initiate_dc_add(const struct cxl_cmd *cmd, CXLType3Dev *ct3d = CXL_TYPE3(cci->d); int i, rc; - if (ct3d->dc.total_capacity_cmd) { - return CXL_MBOX_UNSUPPORTED; - } - switch (in->selection_policy) { case CXL_EXTENT_SELECTION_POLICY_PRESCRIPTIVE: { /* Adding extents exceeds device's extent tracking ability. */ @@ -4361,10 +4357,6 @@ static CXLRetCode cmd_fm_initiate_dc_release(const struct cxl_cmd *cmd, CXLType3Dev *ct3d = CXL_TYPE3(cci->d); int i, rc; - if (ct3d->dc.total_capacity_cmd) { - return CXL_MBOX_UNSUPPORTED; - } - switch (in->flags & CXL_EXTENT_REMOVAL_POLICY_MASK) { case CXL_EXTENT_REMOVAL_POLICY_PRESCRIPTIVE: { CXLDCExtentList updated_list; diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c index 45fb6c55bc..569184975f 100644 --- a/hw/mem/cxl_type3.c +++ b/hw/mem/cxl_type3.c @@ -30,6 +30,7 @@ #include "system/numa.h" #include "hw/cxl/cxl.h" #include "hw/pci/msix.h" +#include "qemu/uuid.h" /* type3 device private */ enum CXL_T3_MSIX_VECTOR { @@ -2289,13 +2290,42 @@ bool cxl_extent_groups_overlaps_dpa_range(CXLDCExtentGroupList *list, return false; } +static bool cxl_device_lazy_dynamic_capacity_init(CXLType3Dev *ct3d, + const char *tag, + Error **errp) +{ + MemoryRegion *dc_mr; + + ct3d->dc.host_dc = host_memory_backend_find_by_tag(tag); + if (!ct3d->dc.host_dc) { + error_setg(errp, "dynamic capacity must have a backing device"); + return false; + } + + dc_mr = host_memory_backend_get_memory(ct3d->dc.host_dc); + if (!dc_mr) { + error_setg(errp, "dynamic capacity must have a backing device"); + return false; + } + + if (host_memory_backend_is_mapped(ct3d->dc.host_dc)) { + error_setg(errp, + "memory backend %s is already mapped and cannot be reused", + object_get_canonical_path_component( + OBJECT(ct3d->dc.host_dc))); + return false; + } + + return true; +} + /* * The main function to process dynamic capacity event with extent list. * Currently DC extents add/release requests are processed. */ static void qmp_cxl_process_dynamic_capacity_prescriptive(const char *path, uint16_t hid, CXLDCEventType type, uint8_t rid, - CxlDynamicCapacityExtentList *records, Error **errp) + const char *tag, CxlDynamicCapacityExtentList *records, Error **errp) { Object *obj; CXLType3Dev *dcd; @@ -2303,7 +2333,8 @@ static void qmp_cxl_process_dynamic_capacity_prescriptive(const char *path, CxlDynamicCapacityExtentList *list; CXLDCExtentGroup *group = NULL; g_autofree CXLDCExtentRaw *extents = NULL; - uint64_t dpa, offset, len, block_size; + uint64_t dpa, offset, block_size; + uint64_t len = 0; g_autofree unsigned long *blk_bitmap = NULL; int i; @@ -2319,13 +2350,6 @@ static void qmp_cxl_process_dynamic_capacity_prescriptive(const char *path, return; } - if (dcd->dc.total_capacity_cmd) { - error_setg(errp, - "dc-regions-total-size is set: extent add/release via QMP " - "not yet supported without a backing device at init"); - return; - } - if (rid >= dcd->dc.num_regions) { error_setg(errp, "region id is too large"); return; @@ -2334,6 +2358,8 @@ static void qmp_cxl_process_dynamic_capacity_prescriptive(const char *path, blk_bitmap = bitmap_new(dcd->dc.regions[rid].len / block_size); /* Sanity check and count the extents */ + QemuUUID uuid; + qemu_uuid_parse(tag, &uuid); list = records; while (list) { offset = list->value->offset; @@ -2392,6 +2418,31 @@ static void qmp_cxl_process_dynamic_capacity_prescriptive(const char *path, num_extents++; } + if (type == DC_EVENT_ADD_CAPACITY && dcd->dc.total_capacity_cmd) { + MemoryRegion *host_dc_mr; + uint64_t size; + + if (num_extents > 1) { + error_setg(errp, "Only single extent add is supported currently"); + return; + } + + if (!cxl_device_lazy_dynamic_capacity_init(dcd, tag, errp)) { + return; + } + + host_dc_mr = host_memory_backend_get_memory(dcd->dc.host_dc); + size = memory_region_size(host_dc_mr); + + if (size != len) { + error_setg(errp, + "Host memory backend size 0x%" PRIx64 + " does not match extent length 0x%" PRIx64, + size, len); + return; + } + } + /* Create extent list for event being passed to host */ i = 0; list = records; @@ -2403,7 +2454,7 @@ static void qmp_cxl_process_dynamic_capacity_prescriptive(const char *path, extents[i].start_dpa = dpa; extents[i].len = len; - memset(extents[i].tag, 0, 0x10); + memcpy(extents[i].tag, &uuid.data, 0x10); extents[i].shared_seq = 0; if (type == DC_EVENT_ADD_CAPACITY) { group = cxl_insert_extent_to_extent_group(group, @@ -2434,7 +2485,8 @@ void qmp_cxl_add_dynamic_capacity(const char *path, uint16_t host_id, case CXL_EXTENT_SELECTION_POLICY_PRESCRIPTIVE: qmp_cxl_process_dynamic_capacity_prescriptive(path, host_id, DC_EVENT_ADD_CAPACITY, - region, extents, errp); + region, tag, + extents, errp); return; default: error_setg(errp, "Selection policy not supported"); @@ -2465,7 +2517,8 @@ void qmp_cxl_release_dynamic_capacity(const char *path, uint16_t host_id, switch (removal_policy) { case CXL_EXTENT_REMOVAL_POLICY_PRESCRIPTIVE: qmp_cxl_process_dynamic_capacity_prescriptive(path, host_id, type, - region, extents, errp); + region, tag, + extents, errp); return; default: error_setg(errp, "Removal policy not supported"); -- 2.50.1 (Apple Git-155)