{"id":2215425,"url":"http://patchwork.ozlabs.org/api/covers/2215425/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/cover/20260324151323.74473-1-mohamed@unpredictable.fr/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260324151323.74473-1-mohamed@unpredictable.fr>","list_archive_url":null,"date":"2026-03-24T15:13:11","name":"[v3,00/12] whpx: i386: Windows 10 and performance fixes","submitter":{"id":91318,"url":"http://patchwork.ozlabs.org/api/people/91318/?format=json","name":"Mohamed Mediouni","email":"mohamed@unpredictable.fr"},"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/cover/20260324151323.74473-1-mohamed@unpredictable.fr/mbox/","series":[{"id":497303,"url":"http://patchwork.ozlabs.org/api/series/497303/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=497303","date":"2026-03-24T15:13:13","name":"whpx: i386: Windows 10 and performance fixes","version":3,"mbox":"http://patchwork.ozlabs.org/series/497303/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/covers/2215425/comments/","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=unpredictable.fr header.i=@unpredictable.fr\n header.a=rsa-sha256 header.s=sig1 header.b=QQJNasMh;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","X-Proofpoint-Spam-Details-Enc":"AW1haW4tMjYwMzI0MDExOSBTYWx0ZWRfXwihaOKXjl/NM\n IOXxGbW8hUE37m5i3e+21SgRdkQXnVpt5/jMjjGKh/vUK4a0h37DrJYq71TIbknOSllU0mQaN4w\n a6mZcRPqBN6kgcBW9j0WSr2FoCzCiPaOklsriiW3gsJ8A2EGS3n/sZTz5VsAI4tpL4dgaYfz7MD\n TpY8btwBSBHBiUoRPnYATXlpFZXcuY6lfth9g0ZBXtnmZ6xiHKMhBMhHz2b1DHkw3osKklH28Ze\n Eb8smL1vMSOYXs1FKGoEkt2whw4z8o06gfpfNNI33iWX9IJZluFSQisNgrrF0BzSVhRdrGogCH1\n bwhAeFesML6WDbgHOa1dvsIx4ab0Ed0pPcvwAx6jtHu7p5jCt3FwrpY0xsRziY=","X-Proofpoint-ORIG-GUID":"ACL_HkhRyiKjPiMMetcvd0t5fjGyH9-P","X-Authority-Info-Out":"v=2.4 cv=TaybdBQh c=1 sm=1 tr=0 ts=69c2aa4a\n cx=c_apl:c_pps:t_out a=YrL12D//S6tul8v/L+6tKg==:117\n a=YrL12D//S6tul8v/L+6tKg==:17 a=IkcTkHD0fZMA:10 a=Yq5XynenixoA:10\n a=VkNPw1HP01LnGYTKEx00:22 a=p0WdMEafAAAA:8 a=td4nV04XUHi7FXuGOJ4A:9\n a=QEXdDO2ut3YA:10","X-Proofpoint-GUID":"ACL_HkhRyiKjPiMMetcvd0t5fjGyH9-P","X-Proofpoint-Virus-Version":"vendor=baseguard\n engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49\n definitions=2026-03-24_03,2026-03-23_02,2025-10-01_01","X-Proofpoint-Spam-Details":"rule=notspam policy=default score=0 mlxlogscore=652\n mlxscore=0 spamscore=0 clxscore=1030 malwarescore=0\n lowpriorityscore=0\n adultscore=0 bulkscore=0 phishscore=0 suspectscore=0 classifier=spam\n authscore=0 adjust=0 reason=mlx scancount=1 engine=8.22.0-2601150000\n definitions=main-2603240119","Received-SPF":"pass client-ip=57.103.76.213;\n envelope-from=mohamed@unpredictable.fr; helo=outbound.st.icloud.com","X-Spam_score_int":"-27","X-Spam_score":"-2.8","X-Spam_bar":"--","X-Spam_report":"(-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,\n DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001,\n 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":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"On Windows 10, the paravirtualisation enlightenments aren't available.\nAnd neither is performance monitoring. Using the former as a gate to\noperate in a reduced-functionality mode on Windows 10.\n\nAnd on the performance side, some state is really expensive to fetch\nor write with Hyper-V so switch some less-essential state to on demand.\n\nThe effect of this is magnified on Windows 10 because Hyper-V enlightenments\nare not available there.\n\nSide note: On Windows 11, use WHP with kernel-irqchip=on. On Windows 10, looks\nlike issues there are still lingering, with issues #289 and #346 still problematic.\n\nv1 -> v2:\n- fix x86 HVF compatibility\n- small nits\n- added workaround for an issue that showed up during 32-bit Linux boot\non AMD\n\nv2 -> v3:\n- Remove ad-hoc workaround in segment fetching and replace it by something\nmore proper.\nThe affected commits are \"whpx: i386: fetch segments on-demand\". The old\nworkaround separate commit is no longer present (or needed)\n\nIssue number: https://gitlab.com/qemu-project/qemu/-/work_items/3349\n\nMohamed Mediouni (12):\n whpx: i386: workaround for Windows 10 support\n whpx: i386: enable exceptions VM exit only when needed\n whpx: i386: skip TSC read for MMIO exits\n whpx: i386: skip XCRs read for MMIO exits\n whpx: i386: don't restore segment registers after MMIO handling\n target/i386: emulate: add new callbacks\n whpx: i386: add implementation of new x86_emul_ops\n target/i386: emulate: indirect access to CRs\n whpx: i386: indirect access to CRs\n target/i386: emulate: segmentation rework\n whpx: i386: fetch segments on-demand\n whpx: i386: fast runtime state reads\n\n target/i386/emulate/x86_emu.h | 6 +\n target/i386/emulate/x86_helpers.c | 83 +++++----\n target/i386/emulate/x86_mmu.c | 11 +-\n target/i386/hvf/x86.c | 11 ++\n target/i386/whpx/whpx-all.c | 280 +++++++++++++++++++++++++-----\n 5 files changed, 302 insertions(+), 89 deletions(-)"}