{"id":2223224,"url":"http://patchwork.ozlabs.org/api/patches/2223224/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260414182231.18776-3-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":"<20260414182231.18776-3-mohamed@unpredictable.fr>","list_archive_url":null,"date":"2026-04-14T18:22:26","name":"[2/7] whpx: i386: unknown MSR configurability","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"63acdfcd69ab8dce1c8dc33cb86ecfe6bf91f889","submitter":{"id":91318,"url":"http://patchwork.ozlabs.org/api/people/91318/?format=json","name":"Mohamed Mediouni","email":"mohamed@unpredictable.fr"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260414182231.18776-3-mohamed@unpredictable.fr/mbox/","series":[{"id":499883,"url":"http://patchwork.ozlabs.org/api/series/499883/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=499883","date":"2026-04-14T18:22:24","name":"whpx: i386: Some more changes","version":1,"mbox":"http://patchwork.ozlabs.org/series/499883/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2223224/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2223224/checks/","tags":{},"related":[],"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=VrykrCOB;\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.pv.icloud.com","X-Spam_score_int":"-20","X-Spam_score":"-2.1","X-Spam_bar":"--","X-Spam_report":"(-2.1 / 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_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n SPF_HELO_PASS=-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":",\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":"Add an option to inject back a GPF for unknown MSRs.\n\nKeep it on by default for now as Linux expects accesses to some\nAMD-specific MSRs to always succeed when on an AMD host.\n\nSigned-off-by: Mohamed Mediouni \n---\n accel/whpx/whpx-common.c | 38 ++++++++++++++++++++++++++++++++++\n include/system/whpx-internal.h | 1 +\n target/i386/whpx/whpx-all.c | 4 ++++\n 3 files changed, 43 insertions(+)","diff":"diff --git a/accel/whpx/whpx-common.c b/accel/whpx/whpx-common.c\nindex 59be996aef..706871f138 100644\n--- a/accel/whpx/whpx-common.c\n+++ b/accel/whpx/whpx-common.c\n@@ -505,6 +505,38 @@ static void whpx_set_hyperv(Object *obj, Visitor *v,\n }\n }\n \n+static void whpx_set_unknown_msr(Object *obj, Visitor *v,\n+ const char *name, void *opaque,\n+ Error **errp)\n+{\n+ struct whpx_state *whpx = &whpx_global;\n+ OnOffAuto mode;\n+\n+ if (!visit_type_OnOffAuto(v, name, &mode, errp)) {\n+ return;\n+ }\n+\n+ switch (mode) {\n+ case ON_OFF_AUTO_ON:\n+ whpx->ignore_unknown_msr = true;\n+ break;\n+\n+ case ON_OFF_AUTO_OFF:\n+ whpx->ignore_unknown_msr = false;\n+ break;\n+\n+ case ON_OFF_AUTO_AUTO:\n+ whpx->ignore_unknown_msr = true;\n+ break;\n+ default:\n+ /*\n+ * The value was checked in visit_type_OnOffAuto() above. If\n+ * we get here, then something is wrong in QEMU.\n+ */\n+ abort();\n+ }\n+}\n+\n static void whpx_cpu_accel_class_init(ObjectClass *oc, const void *data)\n {\n AccelCPUClass *acc = ACCEL_CPU_CLASS(oc);\n@@ -538,6 +570,11 @@ static void whpx_accel_class_init(ObjectClass *oc, const void *data)\n NULL, NULL);\n object_class_property_set_description(oc, \"hyperv\",\n \"Configure Hyper-V enlightenments\");\n+ object_class_property_add(oc, \"ignore-unknown-msr\", \"OnOffAuto\",\n+ NULL, whpx_set_unknown_msr,\n+ NULL, NULL);\n+ object_class_property_set_description(oc, \"ignore-unknown-msr\",\n+ \"Configure unknown MSR behavior\");\n }\n \n static void whpx_accel_instance_init(Object *obj)\n@@ -552,6 +589,7 @@ static void whpx_accel_instance_init(Object *obj)\n whpx->hyperv_enlightenments_required = false;\n /* Value determined at whpx_accel_init */\n whpx->hyperv_enlightenments_enabled = false;\n+ whpx->ignore_unknown_msr = true;\n }\n \n static const TypeInfo whpx_accel_type = {\ndiff --git a/include/system/whpx-internal.h b/include/system/whpx-internal.h\nindex cf782cf5f8..86639627b3 100644\n--- a/include/system/whpx-internal.h\n+++ b/include/system/whpx-internal.h\n@@ -47,6 +47,7 @@ struct whpx_state {\n bool hyperv_enlightenments_required;\n bool hyperv_enlightenments_enabled;\n \n+ bool ignore_unknown_msr;\n };\n \n extern struct whpx_state whpx_global;\ndiff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c\nindex 56a789c5fd..b248afb5e7 100644\n--- a/target/i386/whpx/whpx-all.c\n+++ b/target/i386/whpx/whpx-all.c\n@@ -2048,6 +2048,10 @@ int whpx_vcpu_run(CPUState *cpu)\n vcpu->exit_ctx.MsrAccess.AccessInfo.IsWrite);\n }\n \n+ if (!is_known_msr && !whpx->ignore_unknown_msr) {\n+ x86_emul_raise_exception(&X86_CPU(cpu)->env, EXCP0D_GPF, 0);\n+ }\n+\n hr = whp_dispatch.WHvSetVirtualProcessorRegisters(\n whpx->partition,\n cpu->cpu_index,\n","prefixes":["2/7"]}