qemu/kvm.h
Jan Kiszka ea375f9ab8 KVM: Rework VCPU state writeback API
This grand cleanup drops all reset and vmsave/load related
synchronization points in favor of four(!) generic hooks:

- cpu_synchronize_all_states in qemu_savevm_state_complete
  (initial sync from kernel before vmsave)
- cpu_synchronize_all_post_init in qemu_loadvm_state
  (writeback after vmload)
- cpu_synchronize_all_post_init in main after machine init
- cpu_synchronize_all_post_reset in qemu_system_reset
  (writeback after system reset)

These writeback points + the existing one of VCPU exec after
cpu_synchronize_state map on three levels of writeback:

- KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run)
- KVM_PUT_RESET_STATE   (on synchronous system reset, all VCPUs stopped)
- KVM_PUT_FULL_STATE    (on init or vmload, all VCPUs stopped as well)

This level is passed to the arch-specific VCPU state writing function
that will decide which concrete substates need to be written. That way,
no writer of load, save or reset functions that interact with in-kernel
KVM states will ever have to worry about synchronization again. That
also means that a lot of reasons for races, segfaults and deadlocks are
eliminated.

cpu_synchronize_state remains untouched, just as Anthony suggested. We
continue to need it before reading or writing of VCPU states that are
also tracked by in-kernel KVM subsystems.

Consequently, this patch removes many cpu_synchronize_state calls that
are now redundant, just like remaining explicit register syncs.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-04 00:29:28 -03:00

163 lines
4.3 KiB
C

/*
* QEMU KVM support
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef QEMU_KVM_H
#define QEMU_KVM_H
#include "config.h"
#include "qemu-queue.h"
#ifdef CONFIG_KVM
extern int kvm_allowed;
#define kvm_enabled() (kvm_allowed)
#else
#define kvm_enabled() (0)
#endif
struct kvm_run;
/* external API */
int kvm_init(int smp_cpus);
int kvm_init_vcpu(CPUState *env);
int kvm_cpu_exec(CPUState *env);
int kvm_log_start(target_phys_addr_t phys_addr, ram_addr_t size);
int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size);
int kvm_has_sync_mmu(void);
int kvm_has_vcpu_events(void);
int kvm_has_robust_singlestep(void);
void kvm_setup_guest_memory(void *start, size_t size);
int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
void kvm_flush_coalesced_mmio_buffer(void);
int kvm_insert_breakpoint(CPUState *current_env, target_ulong addr,
target_ulong len, int type);
int kvm_remove_breakpoint(CPUState *current_env, target_ulong addr,
target_ulong len, int type);
void kvm_remove_all_breakpoints(CPUState *current_env);
int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap);
#ifndef _WIN32
int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset);
#endif
int kvm_pit_in_kernel(void);
int kvm_irqchip_in_kernel(void);
/* internal API */
struct KVMState;
typedef struct KVMState KVMState;
int kvm_ioctl(KVMState *s, int type, ...);
int kvm_vm_ioctl(KVMState *s, int type, ...);
int kvm_vcpu_ioctl(CPUState *env, int type, ...);
/* Arch specific hooks */
int kvm_arch_post_run(CPUState *env, struct kvm_run *run);
int kvm_arch_handle_exit(CPUState *env, struct kvm_run *run);
int kvm_arch_pre_run(CPUState *env, struct kvm_run *run);
int kvm_arch_get_registers(CPUState *env);
/* state subset only touched by the VCPU itself during runtime */
#define KVM_PUT_RUNTIME_STATE 1
/* state subset modified during VCPU reset */
#define KVM_PUT_RESET_STATE 2
/* full state set, modified during initialization or on vmload */
#define KVM_PUT_FULL_STATE 3
int kvm_arch_put_registers(CPUState *env, int level);
int kvm_arch_init(KVMState *s, int smp_cpus);
int kvm_arch_init_vcpu(CPUState *env);
void kvm_arch_reset_vcpu(CPUState *env);
struct kvm_guest_debug;
struct kvm_debug_exit_arch;
struct kvm_sw_breakpoint {
target_ulong pc;
target_ulong saved_insn;
int use_count;
QTAILQ_ENTRY(kvm_sw_breakpoint) entry;
};
QTAILQ_HEAD(kvm_sw_breakpoint_head, kvm_sw_breakpoint);
int kvm_arch_debug(struct kvm_debug_exit_arch *arch_info);
struct kvm_sw_breakpoint *kvm_find_sw_breakpoint(CPUState *env,
target_ulong pc);
int kvm_sw_breakpoints_active(CPUState *env);
int kvm_arch_insert_sw_breakpoint(CPUState *current_env,
struct kvm_sw_breakpoint *bp);
int kvm_arch_remove_sw_breakpoint(CPUState *current_env,
struct kvm_sw_breakpoint *bp);
int kvm_arch_insert_hw_breakpoint(target_ulong addr,
target_ulong len, int type);
int kvm_arch_remove_hw_breakpoint(target_ulong addr,
target_ulong len, int type);
void kvm_arch_remove_all_hw_breakpoints(void);
void kvm_arch_update_guest_debug(CPUState *env, struct kvm_guest_debug *dbg);
int kvm_check_extension(KVMState *s, unsigned int extension);
uint32_t kvm_arch_get_supported_cpuid(CPUState *env, uint32_t function,
int reg);
void kvm_cpu_synchronize_state(CPUState *env);
void kvm_cpu_synchronize_post_reset(CPUState *env);
void kvm_cpu_synchronize_post_init(CPUState *env);
/* generic hooks - to be moved/refactored once there are more users */
static inline void cpu_synchronize_state(CPUState *env)
{
if (kvm_enabled()) {
kvm_cpu_synchronize_state(env);
}
}
static inline void cpu_synchronize_post_reset(CPUState *env)
{
if (kvm_enabled()) {
kvm_cpu_synchronize_post_reset(env);
}
}
static inline void cpu_synchronize_post_init(CPUState *env)
{
if (kvm_enabled()) {
kvm_cpu_synchronize_post_init(env);
}
}
#endif