linux/arch/x86/include/asm/acrn.h
Fei Li 81a71f51b8 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@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Conghui <conghui.chen@intel.com>
Link: https://lore.kernel.org/r/20220804055903.365211-1-fei1.li@intel.com
2022-08-04 11:11:59 +02:00

93 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_ACRN_H
#define _ASM_X86_ACRN_H
/*
* This CPUID returns feature bitmaps in EAX.
* Guest VM uses this to detect the appropriate feature bit.
*/
#define ACRN_CPUID_FEATURES 0x40000001
/* 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);
static inline u32 acrn_cpuid_base(void)
{
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
return hypervisor_cpuid_base("ACRNACRNACRN", 0);
return 0;
}
static inline unsigned long acrn_get_tsc_khz(void)
{
return cpuid_eax(ACRN_CPUID_TIMING_INFO);
}
/*
* Hypercalls for ACRN
*
* - VMCALL instruction is used to implement ACRN hypercalls.
* - ACRN hypercall ABI:
* - Hypercall number is passed in R8 register.
* - Up to 2 arguments are passed in RDI, RSI.
* - Return value will be placed in RAX.
*
* Because GCC doesn't support R8 register as direct register constraints, use
* supported constraint as input with a explicit MOV to R8 in beginning of asm.
*/
static inline long acrn_hypercall0(unsigned long hcall_id)
{
long result;
asm volatile("movl %1, %%r8d\n\t"
"vmcall\n\t"
: "=a" (result)
: "g" (hcall_id)
: "r8", "memory");
return result;
}
static inline long acrn_hypercall1(unsigned long hcall_id,
unsigned long param1)
{
long result;
asm volatile("movl %1, %%r8d\n\t"
"vmcall\n\t"
: "=a" (result)
: "g" (hcall_id), "D" (param1)
: "r8", "memory");
return result;
}
static inline long acrn_hypercall2(unsigned long hcall_id,
unsigned long param1,
unsigned long param2)
{
long result;
asm volatile("movl %1, %%r8d\n\t"
"vmcall\n\t"
: "=a" (result)
: "g" (hcall_id), "D" (param1), "S" (param2)
: "r8", "memory");
return result;
}
#endif /* _ASM_X86_ACRN_H */