{"id":2219421,"url":"http://patchwork.ozlabs.org/api/1.0/patches/2219421/?format=json","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.0/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":""},"msgid":"<20260402234724.88276-5-mohamed@unpredictable.fr>","date":"2026-04-02T23:47:21","name":"[v3,4/7] whpx: i386: disable TbFlushHypercalls for emulated LAPIC","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"95abdcc840da528223268e8368242da3d6a86629","submitter":{"id":91318,"url":"http://patchwork.ozlabs.org/api/1.0/people/91318/?format=json","name":"Mohamed Mediouni","email":"mohamed@unpredictable.fr"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260402234724.88276-5-mohamed@unpredictable.fr/mbox/","series":[{"id":498566,"url":"http://patchwork.ozlabs.org/api/1.0/series/498566/?format=json","date":"2026-04-02T23:47:19","name":"whpx: i386: x2apic emulation for kernel-irqchip=off, feature probing","version":3,"mbox":"http://patchwork.ozlabs.org/series/498566/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2219421/checks/","tags":{},"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=W7d7ytGZ;\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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helo=outbound.mr.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":"AccessHypercallRegs was present twice so clean that up.\n\nRemove TbFlushHypercalls (and its extended Gva range sub-feature)\nfrom the user-mode LAPIC case as it behaves oddly there.\n\nSigned-off-by: Mohamed Mediouni \n---\n target/i386/whpx/whpx-all.c | 9 ++++++---\n 1 file changed, 6 insertions(+), 3 deletions(-)","diff":"diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c\nindex ee44e4e060..53bf71d926 100644\n--- a/target/i386/whpx/whpx-all.c\n+++ b/target/i386/whpx/whpx-all.c\n@@ -2489,10 +2489,7 @@ int whpx_accel_init(AccelState *as, MachineState *ms)\n synthetic_features.Bank0.AccessPartitionReferenceTsc = 1;\n synthetic_features.Bank0.AccessHypercallRegs = 1;\n synthetic_features.Bank0.AccessFrequencyRegs = 1;\n- synthetic_features.Bank0.EnableExtendedGvaRangesForFlushVirtualAddressList = 1;\n synthetic_features.Bank0.AccessVpIndex = 1;\n- synthetic_features.Bank0.AccessHypercallRegs = 1;\n- synthetic_features.Bank0.TbFlushHypercalls = 1;\n \n if (whpx_irqchip_in_kernel()) {\n synthetic_features.Bank0.AccessSynicRegs = 1;\n@@ -2500,6 +2497,12 @@ int whpx_accel_init(AccelState *as, MachineState *ms)\n synthetic_features.Bank0.AccessIntrCtrlRegs = 1;\n synthetic_features.Bank0.SyntheticClusterIpi = 1;\n synthetic_features.Bank0.DirectSyntheticTimers = 1;\n+ /*\n+ * These technically work without the Hyper-V LAPIC\n+ * but behave oddly for multi-core VMs.\n+ */\n+ synthetic_features.Bank0.TbFlushHypercalls = 1;\n+ synthetic_features.Bank0.EnableExtendedGvaRangesForFlushVirtualAddressList = 1;\n }\n \n if (!is_legacy_os && whpx->hyperv_enlightenments_allowed) {\n","prefixes":["v3","4/7"]}