lkml.org 
[lkml]   [2022]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 12/28] KVM: VMX: Enable VM_{EXIT,ENTRY}_LOAD_IA32_PERF_GLOBAL_CTRL for KVM on Hyper-V
Date
The updated Enlightened VMCS v1 specification gained
{guest,host}_ia32_perf_global_ctrl fields so there's no need to filter
VM_{EXIT,ENTRY}_LOAD_IA32_PERF_GLOBAL_CTRL out. Unfortunately, enabling
these controls for Hyper-V on KVM results in boot time crashes and the
exact reason is not clear yet. It is, however, possible to enable the
feature for KVM on Hyper-V as it seems to work.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/vmx/evmcs.c | 10 ++++++++--
arch/x86/kvm/vmx/evmcs.h | 5 ++---
2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 4fe65b6a9a92..697590cf5b10 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -384,11 +384,17 @@ static u32 evmcs_get_unsupported_ctls(struct kvm_vcpu *vcpu,
if (!evmcs_rev)
return 0;

+ /*
+ * While GUEST_IA32_PERF_GLOBAL_CTRL and HOST_IA32_PERF_GLOBAL_CTRL
+ * are present in eVMCSv1, Windows 11 still has issues booting when
+ * VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL/VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL
+ * are exposed to it, keep them filtered out.
+ */
switch (ctrl_type) {
case EVMCS_EXIT_CTLS:
- return EVMCS1_UNSUPPORTED_VMEXIT_CTRL;
+ return EVMCS1_UNSUPPORTED_VMEXIT_CTRL | VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
case EVMCS_ENTRY_CTLS:
- return EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
+ return EVMCS1_UNSUPPORTED_VMENTRY_CTRL | VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
case EVMCS_2NDEXEC:
if (evmcs_rev == 1)
return EVMCS1_UNSUPPORTED_2NDEXEC | SECONDARY_EXEC_TSC_SCALING;
diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index 2992e29b81b7..c9090ac39740 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -68,9 +68,8 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
SECONDARY_EXEC_SHADOW_VMCS | \
SECONDARY_EXEC_PAUSE_LOOP_EXITING)
#define EVMCS1_UNSUPPORTED_VMEXIT_CTRL \
- (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | \
- VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
-#define EVMCS1_UNSUPPORTED_VMENTRY_CTRL (VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
+ (VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
+#define EVMCS1_UNSUPPORTED_VMENTRY_CTRL (0)
#define EVMCS1_UNSUPPORTED_VMFUNC (VMX_VMFUNC_EPTP_SWITCHING)

struct evmcs_field {
--
2.35.3
\
 
 \ /
  Last update: 2022-06-29 17:08    [W:0.287 / U:0.564 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site