From: Mohamed Mediouni <mohamed@unpredictable.fr>
To: qemu-devel@nongnu.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
Pedro Barbuda <pbarbuda@microsoft.com>,
Mohamed Mediouni <mohamed@unpredictable.fr>,
Paolo Bonzini <pbonzini@redhat.com>,
Zhao Liu <zhao1.liu@intel.com>,
Roman Bolshakov <rbolshakov@ddn.com>,
Wei Liu <wei.liu@kernel.org>,
Phil Dennis-Jordan <phil@philjordan.eu>
Subject: [PATCH v11 10/15] whpx: i386: disable kernel-irqchip on Windows 10 when PIC enabled
Date: Mon, 13 Apr 2026 18:52:12 +0200 [thread overview]
Message-ID: <20260413165217.47105-11-mohamed@unpredictable.fr> (raw)
In-Reply-To: <20260413165217.47105-1-mohamed@unpredictable.fr>
Move WHvCapabilityCodeProcessorPerfmonFeatures queries
as that's how we distinguish if on a legacy OS.
Now that Windows guests are booting, disable kernel-irqchip=on
by default for Windows 10 when the PIC is enabled.
Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
---
target/i386/whpx/whpx-all.c | 69 +++++++++++++++++++++----------------
1 file changed, 39 insertions(+), 30 deletions(-)
diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index 74b94b799e..7c80d653d1 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -2447,6 +2447,13 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
0x8000000A, 0x80000021, 0x80000022, 0xC0000000, 0xC0000001};
UINT32 cpuidExitList_legacy_os[] = {1, 0x40000000, 0x40000001, 0x40000010};
+ X86MachineState *x86ms = X86_MACHINE(ms);
+ bool pic_enabled = false;
+
+ if (x86ms->pic == ON_OFF_AUTO_ON || x86ms->pic == ON_OFF_AUTO_AUTO) {
+ pic_enabled = true;
+ }
+
whpx = &whpx_global;
if (!init_whp_dispatch()) {
@@ -2518,6 +2525,35 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
goto error;
}
+ /* Enable supported performance monitoring capabilities */
+ hr = whp_dispatch.WHvGetCapability(
+ WHvCapabilityCodeProcessorPerfmonFeatures, &perfmon_features,
+ sizeof(WHV_PROCESSOR_PERFMON_FEATURES), &whpx_cap_size);
+ /*
+ * Relying on this is a crutch to maintain Windows 10 support.
+ *
+ * WHvCapabilityCodeProcessorPerfmonFeatures and
+ * WHvPartitionPropertyCodeSyntheticProcessorFeaturesBanks
+ * are implemented starting from Windows Server 2022 (build 20348).
+ */
+ if (FAILED(hr)) {
+ warn_report("WHPX: Failed to get performance "
+ "monitoring features, hr=%08lx", hr);
+ is_modern_os = false;
+ } else {
+ hr = whp_dispatch.WHvSetPartitionProperty(
+ whpx->partition,
+ WHvPartitionPropertyCodeProcessorPerfmonFeatures,
+ &perfmon_features,
+ sizeof(WHV_PROCESSOR_PERFMON_FEATURES));
+ if (FAILED(hr)) {
+ error_report("WHPX: Failed to set performance "
+ "monitoring features, hr=%08lx", hr);
+ ret = -EINVAL;
+ goto error;
+ }
+ }
+
/*
* Error out if WHP doesn't support apic emulation and user is requiring
* it.
@@ -2530,8 +2566,9 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
goto error;
}
- if (whpx->kernel_irqchip_allowed && features.LocalApicEmulation &&
- whp_dispatch.WHvSetVirtualProcessorInterruptControllerState2) {
+ if (whpx->kernel_irqchip_allowed && !(whpx_is_legacy_os() && pic_enabled
+ && !whpx->kernel_irqchip_required) && features.LocalApicEmulation
+ && whp_dispatch.WHvSetVirtualProcessorInterruptControllerState2) {
WHV_X64_LOCAL_APIC_EMULATION_MODE mode =
WHvX64LocalApicEmulationModeX2Apic;
hr = whp_dispatch.WHvSetPartitionProperty(
@@ -2590,34 +2627,6 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
goto error;
}
- /* Enable supported performance monitoring capabilities */
- hr = whp_dispatch.WHvGetCapability(
- WHvCapabilityCodeProcessorPerfmonFeatures, &perfmon_features,
- sizeof(WHV_PROCESSOR_PERFMON_FEATURES), &whpx_cap_size);
- /*
- * Relying on this is a crutch to maintain Windows 10 support.
- *
- * WHvCapabilityCodeProcessorPerfmonFeatures and
- * WHvPartitionPropertyCodeSyntheticProcessorFeaturesBanks
- * are implemented starting from Windows Server 2022 (build 20348).
- */
- if (FAILED(hr)) {
- warn_report("WHPX: Failed to get performance "
- "monitoring features, hr=%08lx", hr);
- is_modern_os = false;
- } else {
- hr = whp_dispatch.WHvSetPartitionProperty(
- whpx->partition,
- WHvPartitionPropertyCodeProcessorPerfmonFeatures,
- &perfmon_features,
- sizeof(WHV_PROCESSOR_PERFMON_FEATURES));
- if (FAILED(hr)) {
- error_report("WHPX: Failed to set performance "
- "monitoring features, hr=%08lx", hr);
- ret = -EINVAL;
- goto error;
- }
- }
/* Enable synthetic processor features */
WHV_SYNTHETIC_PROCESSOR_FEATURES_BANKS synthetic_features;
--
2.50.1 (Apple Git-155)
next prev parent reply other threads:[~2026-04-13 16:55 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-13 16:52 [PATCH v11 00/15] whpx: i386: bug fixes, feature probing and CPUID Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 01/15] target/i386: emulate: include name of unhandled instruction Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 02/15] whpx: i386: x2apic emulation Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 03/15] whpx: i386: wire up feature probing Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 04/15] whpx: i386: disable TbFlushHypercalls for emulated LAPIC Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 05/15] whpx: i386: enable x2apic by default for user-mode LAPIC Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 06/15] whpx: i386: reintroduce enlightenments for Windows 10 Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 07/15] whpx: i386: introduce proper cpuid support Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 08/15] whpx: i386: kernel-irqchip=off fixes Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 09/15] whpx: i386: use WHvX64RegisterCr8 only when kernel-irqchip=off Mohamed Mediouni
2026-04-13 16:52 ` Mohamed Mediouni [this message]
2026-04-13 16:52 ` [PATCH v11 11/15] whpx: i386: IO port fast path cleanup Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 12/15] whpx: i386: disable enlightenments and LAPIC for isapc Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 13/15] whpx: i386: interrupt priority support Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 14/15] hw/intc: apic: disallow APIC reads when disabled Mohamed Mediouni
2026-04-13 16:52 ` [PATCH v11 15/15] whpx: i386: fix CPUID[1:EDX].APIC reporting Mohamed Mediouni
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