KVM: VMX: Enable and initialize VMX TSC scaling
This patch exhances kvm-intel module to enable VMX TSC scaling and
collects information of TSC scaling ratio during initialization.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index aa336ff..14c63c7 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -73,6 +73,7 @@
#define SECONDARY_EXEC_ENABLE_PML 0x00020000
#define SECONDARY_EXEC_XSAVES 0x00100000
#define SECONDARY_EXEC_PCOMMIT 0x00200000
+#define SECONDARY_EXEC_TSC_SCALING 0x02000000
#define PIN_BASED_EXT_INTR_MASK 0x00000001
#define PIN_BASED_NMI_EXITING 0x00000008
@@ -167,6 +168,8 @@
VMWRITE_BITMAP = 0x00002028,
XSS_EXIT_BITMAP = 0x0000202C,
XSS_EXIT_BITMAP_HIGH = 0x0000202D,
+ TSC_MULTIPLIER = 0x00002032,
+ TSC_MULTIPLIER_HIGH = 0x00002033,
GUEST_PHYSICAL_ADDRESS = 0x00002400,
GUEST_PHYSICAL_ADDRESS_HIGH = 0x00002401,
VMCS_LINK_POINTER = 0x00002800,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c0fb398..e45b03e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -107,6 +107,8 @@
static bool __read_mostly enable_pml = 1;
module_param_named(pml, enable_pml, bool, S_IRUGO);
+#define KVM_VMX_TSC_MULTIPLIER_MAX 0xffffffffffffffffULL
+
#define KVM_GUEST_CR0_MASK (X86_CR0_NW | X86_CR0_CD)
#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST (X86_CR0_WP | X86_CR0_NE)
#define KVM_VM_CR0_ALWAYS_ON \
@@ -1172,6 +1174,12 @@
return vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_ENABLE_PML;
}
+static inline bool cpu_has_vmx_tsc_scaling(void)
+{
+ return vmcs_config.cpu_based_2nd_exec_ctrl &
+ SECONDARY_EXEC_TSC_SCALING;
+}
+
static inline bool report_flexpriority(void)
{
return flexpriority_enabled;
@@ -3133,7 +3141,8 @@
SECONDARY_EXEC_SHADOW_VMCS |
SECONDARY_EXEC_XSAVES |
SECONDARY_EXEC_ENABLE_PML |
- SECONDARY_EXEC_PCOMMIT;
+ SECONDARY_EXEC_PCOMMIT |
+ SECONDARY_EXEC_TSC_SCALING;
if (adjust_vmx_controls(min2, opt2,
MSR_IA32_VMX_PROCBASED_CTLS2,
&_cpu_based_2nd_exec_control) < 0)
@@ -6178,6 +6187,12 @@
if (!cpu_has_vmx_apicv())
enable_apicv = 0;
+ if (cpu_has_vmx_tsc_scaling()) {
+ kvm_has_tsc_control = true;
+ kvm_max_tsc_scaling_ratio = KVM_VMX_TSC_MULTIPLIER_MAX;
+ kvm_tsc_scaling_ratio_frac_bits = 48;
+ }
+
if (enable_apicv)
kvm_x86_ops->update_cr8_intercept = NULL;
else {