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 06/15] whpx: i386: reintroduce enlightenments for Windows 10
Date: Mon, 13 Apr 2026 18:52:08 +0200 [thread overview]
Message-ID: <20260413165217.47105-7-mohamed@unpredictable.fr> (raw)
In-Reply-To: <20260413165217.47105-1-mohamed@unpredictable.fr>
Was removed in 2c08624 but it's still useful for
Windows 10 so reintroduce it there.
And this time, actually make it work by reporting
the hypervisor bit in CPUID.
Pretend to be vmware to be able to use vmport's functionality.
If the vmware frequency leaf is disabled, pretend to be
KVM, with the only capability reported being X2APIC support.
Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
---
accel/whpx/whpx-common.c | 2 ++
include/system/whpx-internal.h | 1 +
target/arm/whpx/whpx-all.c | 1 +
target/i386/whpx/whpx-all.c | 63 +++++++++++++++++++++++++++++-----
4 files changed, 58 insertions(+), 9 deletions(-)
diff --git a/accel/whpx/whpx-common.c b/accel/whpx/whpx-common.c
index b813a5d9d2..59be996aef 100644
--- a/accel/whpx/whpx-common.c
+++ b/accel/whpx/whpx-common.c
@@ -550,6 +550,8 @@ static void whpx_accel_instance_init(Object *obj)
whpx->hyperv_enlightenments_allowed = true;
whpx->hyperv_enlightenments_required = false;
+ /* Value determined at whpx_accel_init */
+ whpx->hyperv_enlightenments_enabled = false;
}
static const TypeInfo whpx_accel_type = {
diff --git a/include/system/whpx-internal.h b/include/system/whpx-internal.h
index 5902124b63..cf782cf5f8 100644
--- a/include/system/whpx-internal.h
+++ b/include/system/whpx-internal.h
@@ -45,6 +45,7 @@ struct whpx_state {
bool hyperv_enlightenments_allowed;
bool hyperv_enlightenments_required;
+ bool hyperv_enlightenments_enabled;
};
diff --git a/target/arm/whpx/whpx-all.c b/target/arm/whpx/whpx-all.c
index bbf0f6be96..4019a513aa 100644
--- a/target/arm/whpx/whpx-all.c
+++ b/target/arm/whpx/whpx-all.c
@@ -968,6 +968,7 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
* as they're not needed for performance.
*/
if (whpx->hyperv_enlightenments_required) {
+ whpx->hyperv_enlightenments_enabled = true;
hr = whp_dispatch.WHvSetPartitionProperty(
whpx->partition,
WHvPartitionPropertyCodeSyntheticProcessorFeaturesBanks,
diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index 66f263558f..c2a78312f8 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -2083,14 +2083,57 @@ int whpx_vcpu_run(CPUState *cpu)
vcpu->exit_ctx.VpContext.Rip +
vcpu->exit_ctx.VpContext.InstructionLength;
- reg_values[1].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
- reg_values[2].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRcx;
- reg_values[3].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
- reg_values[4].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
-
- if (vcpu->exit_ctx.CpuidAccess.Rax == 1) {
- if (cpu_has_x2apic_feature(env)) {
- reg_values[2].Reg64 |= CPUID_EXT_X2APIC;
+ if (whpx_is_legacy_os()) {
+ reg_values[1].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
+ reg_values[2].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRcx;
+ reg_values[3].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
+ reg_values[4].Reg64 = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
+ } else {
+ cpu_x86_cpuid(env, vcpu->exit_ctx.CpuidAccess.Rax,
+ vcpu->exit_ctx.CpuidAccess.Rcx,
+ (UINT32 *)®_values[1].Reg32,
+ (UINT32 *)®_values[4].Reg32, (UINT32 *)®_values[2].Reg32,
+ (UINT32 *)®_values[3].Reg32);
+ }
+
+ if (!whpx->hyperv_enlightenments_enabled) {
+ switch (vcpu->exit_ctx.CpuidAccess.Rax) {
+ case 1:
+ reg_values[2].Reg64 |= CPUID_EXT_HYPERVISOR;
+ break;
+ case 0x40000000:
+ /*
+ * Use vmware_cpuid_freq as a proxy to report VMware.
+ * This is to get the TSC/APIC frequency query functionality
+ * provided through vmport, as Linux doesn't use leaf
+ * 0x40000010 for getting those frequencies.
+ */
+ if (x86_cpu->vmware_cpuid_freq) {
+ reg_values[1].Reg64 = 0x40000010;
+ reg_values[4].Reg64 = 0x61774d56;
+ reg_values[2].Reg64 = 0x4d566572;
+ reg_values[3].Reg64 = 0x65726177;
+ } else {
+ /* report KVM otherwise if that's disabled */
+ reg_values[1].Reg64 = 0x40000001;
+ reg_values[4].Reg64 = 0x4b4d564b;
+ reg_values[2].Reg64 = 0x564b4d56;
+ reg_values[3].Reg64 = 0x4d;
+ }
+ break;
+ case 0x40000001:
+ if (!x86_cpu->vmware_cpuid_freq) {
+ /* KVM reporting of X2APIC support */
+ reg_values[1].Reg64 = reg_values[4].Reg64 =
+ reg_values[2].Reg64 = 1 << 15;
+ }
+ break;
+ case 0x40000010:
+ if (x86_cpu->vmware_cpuid_freq) {
+ reg_values[1].Reg64 = env->tsc_khz;
+ reg_values[4].Reg64 = env->apic_bus_freq / 1000; /* Hz to KHz */
+ }
+ break;
}
}
@@ -2311,6 +2354,7 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
WHV_PROCESSOR_FEATURES_BANKS processor_features;
WHV_PROCESSOR_PERFMON_FEATURES perfmon_features;
UINT32 cpuidExitList[] = {1};
+ UINT32 cpuidExitList_nohyperv[] = {1, 0x40000000, 0x40000001, 0x40000010};
whpx = &whpx_global;
@@ -2513,6 +2557,7 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
}
if (is_modern_os && whpx->hyperv_enlightenments_allowed) {
+ whpx->hyperv_enlightenments_enabled = true;
hr = whp_dispatch.WHvSetPartitionProperty(
whpx->partition,
WHvPartitionPropertyCodeSyntheticProcessorFeaturesBanks,
@@ -2565,7 +2610,7 @@ int whpx_accel_init(AccelState *as, MachineState *ms)
hr = whp_dispatch.WHvSetPartitionProperty(
whpx->partition,
WHvPartitionPropertyCodeCpuidExitList,
- cpuidExitList,
+ whpx->hyperv_enlightenments_enabled ? cpuidExitList : cpuidExitList_nohyperv,
RTL_NUMBER_OF(cpuidExitList) * sizeof(UINT32));
if (FAILED(hr)) {
--
2.50.1 (Apple Git-155)
next prev parent reply other threads:[~2026-04-13 16:54 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 ` Mohamed Mediouni [this message]
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 ` [PATCH v11 10/15] whpx: i386: disable kernel-irqchip on Windows 10 when PIC enabled Mohamed Mediouni
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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