diff mbox series

[v3,2/8] KVM: nVMX: Load GUEST_IA32_PERF_GLOBAL_CTRL MSR on vm-entry

Message ID 20190903215801.183193-3-oupton@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: VMX: Add full nested support for IA32_PERF_GLOBAL_CTRL | expand

Commit Message

Oliver Upton Sept. 3, 2019, 9:57 p.m. UTC 
Add condition to prepare_vmcs02 which loads IA32_PERF_GLOBAL_CTRL on
VM-entry if the "load IA32_PERF_GLOBAL_CTRL" bit on the VM-entry control
is set. Use kvm_set_msr() rather than directly writing to the field to
avoid overwrite by atomic_switch_perf_msrs().

Suggested-by: Jim Mattson <jmattson@google.com>
Co-developed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/x86/kvm/vmx/nested.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index b0ca34bf4d21..9ba90b38d74b 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2281,6 +2281,7 @@  static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;
+	struct msr_data msr_info;
 	bool load_guest_pdptrs_vmcs12 = false;
 
 	if (vmx->nested.dirty_vmcs12 || hv_evmcs) {
@@ -2404,6 +2405,16 @@  static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 	if (!enable_ept)
 		vcpu->arch.walk_mmu->inject_page_fault = vmx_inject_page_fault_nested;
 
+	if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL) {
+		msr_info.host_initiated = false;
+		msr_info.index = MSR_CORE_PERF_GLOBAL_CTRL;
+		msr_info.data = vmcs12->guest_ia32_perf_global_ctrl;
+		if (kvm_set_msr(vcpu, &msr_info))
+			pr_debug_ratelimited(
+				"%s cannot write MSR (0x%x, 0x%llx)\n",
+				__func__, msr_info.index, msr_info.data);
+	}
+
 	kvm_rsp_write(vcpu, vmcs12->guest_rsp);
 	kvm_rip_write(vcpu, vmcs12->guest_rip);
 	return 0;