mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 17:12:06 +00:00
c1118b3602
On x86_64, kernel text mappings are mapped read-only with CONFIG_DEBUG_RODATA. In that case, KVM will fail to patch VMCALL instructions to VMMCALL as required on AMD processors. The failure mode is currently a divide-by-zero exception, which obviously is a KVM bug that has to be fixed. However, picking the right instruction between VMCALL and VMMCALL will be faster and will help if you cannot upgrade the hypervisor. Reported-by: Chris Webb <chris@arachsys.com> Tested-by: Chris Webb <chris@arachsys.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
138 lines
3.2 KiB
C
138 lines
3.2 KiB
C
#ifndef _ASM_X86_KVM_PARA_H
|
|
#define _ASM_X86_KVM_PARA_H
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/alternative.h>
|
|
#include <uapi/asm/kvm_para.h>
|
|
|
|
extern void kvmclock_init(void);
|
|
extern int kvm_register_clock(char *txt);
|
|
|
|
#ifdef CONFIG_KVM_GUEST
|
|
bool kvm_check_and_clear_guest_paused(void);
|
|
#else
|
|
static inline bool kvm_check_and_clear_guest_paused(void)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_KVM_GUEST */
|
|
|
|
#ifdef CONFIG_DEBUG_RODATA
|
|
#define KVM_HYPERCALL \
|
|
ALTERNATIVE(".byte 0x0f,0x01,0xc1", ".byte 0x0f,0x01,0xd9", X86_FEATURE_VMMCALL)
|
|
#else
|
|
/* On AMD processors, vmcall will generate a trap that we will
|
|
* then rewrite to the appropriate instruction.
|
|
*/
|
|
#define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
|
|
#endif
|
|
|
|
/* For KVM hypercalls, a three-byte sequence of either the vmcall or the vmmcall
|
|
* 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 explicitly
|
|
* 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;
|
|
}
|
|
|
|
#ifdef CONFIG_KVM_GUEST
|
|
bool kvm_para_available(void);
|
|
unsigned int kvm_arch_para_features(void);
|
|
void __init kvm_guest_init(void);
|
|
void kvm_async_pf_task_wait(u32 token);
|
|
void kvm_async_pf_task_wake(u32 token);
|
|
u32 kvm_read_and_reset_pf_reason(void);
|
|
extern void kvm_disable_steal_time(void);
|
|
|
|
#ifdef CONFIG_PARAVIRT_SPINLOCKS
|
|
void __init kvm_spinlock_init(void);
|
|
#else /* !CONFIG_PARAVIRT_SPINLOCKS */
|
|
static inline void kvm_spinlock_init(void)
|
|
{
|
|
}
|
|
#endif /* CONFIG_PARAVIRT_SPINLOCKS */
|
|
|
|
#else /* CONFIG_KVM_GUEST */
|
|
#define kvm_guest_init() do {} while (0)
|
|
#define kvm_async_pf_task_wait(T) do {} while(0)
|
|
#define kvm_async_pf_task_wake(T) do {} while(0)
|
|
|
|
static inline bool kvm_para_available(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned int kvm_arch_para_features(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline u32 kvm_read_and_reset_pf_reason(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void kvm_disable_steal_time(void)
|
|
{
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
#endif /* _ASM_X86_KVM_PARA_H */
|