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Subject[PATCH] x86/acrn: Set up timekeeping
Date
ACRN Hypervisor reports timing information via CPUID leaf 0x40000010.
Get the TSC and CPU frequency via CPUID leaf 0x40000010 and set the
kernel values accordingly.

Signed-off-by: Fei Li <fei1.li@intel.com>
Reviewed-by: Conghui <conghui.chen@intel.com>
---
arch/x86/include/asm/acrn.h | 14 ++++++++++++++
arch/x86/kernel/cpu/acrn.c | 3 +++
2 files changed, 17 insertions(+)

diff --git a/arch/x86/include/asm/acrn.h b/arch/x86/include/asm/acrn.h
index e003a01b7c67..1dd14381bcb6 100644
--- a/arch/x86/include/asm/acrn.h
+++ b/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
*
diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c
index 23f5f27b5a02..485441b7f030 100644
--- a/arch/x86/kernel/cpu/acrn.c
+++ b/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)
base-commit: e0dccc3b76fb35bb257b4118367a883073d7390e
--
2.34.1

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