Passthrough the MSR_IA32_DEBUGCTLMSR to the guest, and take advantage of
the hardware VT-x feature to auto switch the msr upon VMExit and VMEntry.
Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
---
arch/x86/kvm/vmx.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8434fc8..5f5c2f1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5502,13 +5502,12 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
if (cpu_has_vmx_vmfunc())
vmcs_write64(VM_FUNCTION_CONTROL, 0);
- vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
- vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host));
vmcs_write64(VM_EXIT_MSR_STORE_ADDR, __pa(vmx->msr_autoload.guest));
- vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);
vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest));
+ add_atomic_switch_msr(vmx, MSR_IA32_DEBUGCTLMSR, 0, 0);
+
if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);
@@ -6821,6 +6820,7 @@ static __init int hardware_setup(void)
vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS, false);
vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP, false);
vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false);
+ vmx_disable_intercept_for_msr(MSR_IA32_DEBUGCTLMSR, false);
memcpy(vmx_msr_bitmap_legacy_x2apic_apicv,
vmx_msr_bitmap_legacy, PAGE_SIZE);
@@ -9285,7 +9285,7 @@ static void vmx_save_host_msrs(struct msr_autoload *m)
static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
- unsigned long debugctlmsr, cr3, cr4;
+ unsigned long cr3, cr4;
/* Don't enter VMX if guest state is invalid, let the exit handler
start emulation until we arrive back to a valid state */
@@ -9333,7 +9333,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
__write_pkru(vcpu->arch.pkru);
atomic_switch_perf_msrs(vmx);
- debugctlmsr = get_debugctlmsr();
vmx_arm_hv_timer(vcpu);
@@ -9445,10 +9444,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
#endif
);
- /* MSR_IA32_DEBUGCTLMSR is zeroed on vmexit. Restore it if needed */
- if (debugctlmsr)
- update_debugctlmsr(debugctlmsr);
-
#ifndef CONFIG_X86_64
/*
* The sysexit path does not restore ds/es, so we must set them to
--
2.7.4
