- Get TSC and CPU frequency from CPUID leaf 0x40000010 when the kernel

is running as a guest on the ACRN hypervisor
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Merge tag 'x86_platform_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 platform update from Borislav Petkov:
 "A single x86/platform improvement when the kernel is running as an
  ACRN guest:

   - Get TSC and CPU frequency from CPUID leaf 0x40000010 when the
     kernel is running as a guest on the ACRN hypervisor"

* tag 'x86_platform_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/acrn: Set up timekeeping

arch/x86/include/asm/acrn.h

@@ -10,6 +10,15 @@
 /* Bit 0 indicates whether guest VM is privileged */
 #define	ACRN_FEATURE_PRIVILEGED_VM	BIT(0)
 
+/*
+ * Timing Information.
+ * This leaf returns the current TSC frequency in kHz.
+ *
+ * EAX: (Virtual) TSC frequency in kHz.
+ * EBX, ECX, EDX: RESERVED (reserved fields are set to zero).
+ */
+#define ACRN_CPUID_TIMING_INFO		0x40000010
+
 void acrn_setup_intr_handler(void (*handler)(void));
 void acrn_remove_intr_handler(void);
 
@@ -21,6 +30,11 @@ static inline u32 acrn_cpuid_base(void)
 	return 0;
 }
 
+static inline unsigned long acrn_get_tsc_khz(void)
+{
+	return cpuid_eax(ACRN_CPUID_TIMING_INFO);
+}
+
 /*
  * Hypercalls for ACRN
  *

arch/x86/kernel/cpu/acrn.c

@@ -28,6 +28,9 @@ static void __init acrn_init_platform(void)
 {
 	/* Setup the IDT for ACRN hypervisor callback */
 	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_acrn_hv_callback);
+
+	x86_platform.calibrate_tsc = acrn_get_tsc_khz;
+	x86_platform.calibrate_cpu = acrn_get_tsc_khz;
 }
 
 static bool acrn_x2apic_available(void)