Merge tag 'x86_platform_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

3339914a · Linus Torvalds <[email protected]> · 2022-10-04 09:06:35 -07:00

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

Commit: 3339914a5832cffdecd578931b3db20d3deba5f6
Parents: bf767625 · 81a71f51

Merge commit. Changes below are compared with the first parent: bf767625.

Changes

2 files changed · +17 −0

File	Status	Add	Del	Content
arch/x86/include/asm/acrn.h	modified	+14	−0	View file
arch/x86/kernel/cpu/acrn.c	modified	+3	−0	View file

arch/x86/include/asm/acrn.h

View file

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
  *

arch/x86/kernel/cpu/acrn.c

View file

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)