The following commit has been merged into the x86/platform branch of tip:
Commit-ID: 81a71f51b89e84f39df2a3b1daf4274ae6b7b194
Gitweb: https://git.kernel.org/tip/81a71f51b89e84f39df2a3b1daf4274ae6b7b194
Author: Fei Li <fei1.li@xxxxxxxxx>
AuthorDate: Thu, 04 Aug 2022 13:59:03 +08:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Thu, 04 Aug 2022 11:11:59 +02:00
x86/acrn: Set up timekeeping
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@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Conghui <conghui.chen@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220804055903.365211-1-fei1.li@xxxxxxxxx
---
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 e003a01..1dd1438 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 23f5f27..485441b 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)
|