linux/arch/x86/include/asm/kvm_para.h
Glauber Costa 3a0d7256a6 x86, paravirt: don't compute pvclock adjustments if we trust the tsc
If the HV told us we can fully trust the TSC, skip any
correction

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19 11:41:05 +03:00

164 lines
3.9 KiB
C

#ifndef _ASM_X86_KVM_PARA_H
#define _ASM_X86_KVM_PARA_H
#include <linux/types.h>
#include <asm/hyperv.h>
/* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx. It
* should be used to determine that a VM is running under KVM.
*/
#define KVM_CPUID_SIGNATURE 0x40000000
/* This CPUID returns a feature bitmap in eax. Before enabling a particular
* paravirtualization, the appropriate feature bit should be checked.
*/
#define KVM_CPUID_FEATURES 0x40000001
#define KVM_FEATURE_CLOCKSOURCE 0
#define KVM_FEATURE_NOP_IO_DELAY 1
#define KVM_FEATURE_MMU_OP 2
/* This indicates that the new set of kvmclock msrs
* are available. The use of 0x11 and 0x12 is deprecated
*/
#define KVM_FEATURE_CLOCKSOURCE2 3
/* The last 8 bits are used to indicate how to interpret the flags field
* in pvclock structure. If no bits are set, all flags are ignored.
*/
#define KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24
#define MSR_KVM_WALL_CLOCK 0x11
#define MSR_KVM_SYSTEM_TIME 0x12
/* Custom MSRs falls in the range 0x4b564d00-0x4b564dff */
#define MSR_KVM_WALL_CLOCK_NEW 0x4b564d00
#define MSR_KVM_SYSTEM_TIME_NEW 0x4b564d01
#define KVM_MAX_MMU_OP_BATCH 32
/* Operations for KVM_HC_MMU_OP */
#define KVM_MMU_OP_WRITE_PTE 1
#define KVM_MMU_OP_FLUSH_TLB 2
#define KVM_MMU_OP_RELEASE_PT 3
/* Payload for KVM_HC_MMU_OP */
struct kvm_mmu_op_header {
__u32 op;
__u32 pad;
};
struct kvm_mmu_op_write_pte {
struct kvm_mmu_op_header header;
__u64 pte_phys;
__u64 pte_val;
};
struct kvm_mmu_op_flush_tlb {
struct kvm_mmu_op_header header;
};
struct kvm_mmu_op_release_pt {
struct kvm_mmu_op_header header;
__u64 pt_phys;
};
#ifdef __KERNEL__
#include <asm/processor.h>
extern void kvmclock_init(void);
/* This instruction is vmcall. On non-VT architectures, it will generate a
* trap that we will then rewrite to the appropriate instruction.
*/
#define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
/* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
* instruction. The hypervisor may replace it with something else but only the
* instructions are guaranteed to be supported.
*
* Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
* The hypercall number should be placed in rax and the return value will be
* placed in rax. No other registers will be clobbered unless explicited
* noted by the particular hypercall.
*/
static inline long kvm_hypercall0(unsigned int nr)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr)
: "memory");
return ret;
}
static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1)
: "memory");
return ret;
}
static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
unsigned long p2)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2)
: "memory");
return ret;
}
static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
unsigned long p2, unsigned long p3)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2), "d"(p3)
: "memory");
return ret;
}
static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
unsigned long p2, unsigned long p3,
unsigned long p4)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
: "memory");
return ret;
}
static inline int kvm_para_available(void)
{
unsigned int eax, ebx, ecx, edx;
char signature[13];
cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
memcpy(signature + 0, &ebx, 4);
memcpy(signature + 4, &ecx, 4);
memcpy(signature + 8, &edx, 4);
signature[12] = 0;
if (strcmp(signature, "KVMKVMKVM") == 0)
return 1;
return 0;
}
static inline unsigned int kvm_arch_para_features(void)
{
return cpuid_eax(KVM_CPUID_FEATURES);
}
#endif
#endif /* _ASM_X86_KVM_PARA_H */