diff options
Diffstat (limited to 'arch/x86/include/asm/kvm_host.h')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 15bda40517ff..a0e58ca0d7f2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -947,23 +947,6 @@ struct kvm_vcpu_arch { u64 msr_kvm_poll_control; - /* - * Indicates the guest is trying to write a gfn that contains one or - * more of the PTEs used to translate the write itself, i.e. the access - * is changing its own translation in the guest page tables. KVM exits - * to userspace if emulation of the faulting instruction fails and this - * flag is set, as KVM cannot make forward progress. - * - * If emulation fails for a write to guest page tables, KVM unprotects - * (zaps) the shadow page for the target gfn and resumes the guest to - * retry the non-emulatable instruction (on hardware). Unprotecting the - * gfn doesn't allow forward progress for a self-changing access because - * doing so also zaps the translation for the gfn, i.e. retrying the - * instruction will hit a !PRESENT fault, which results in a new shadow - * page and sends KVM back to square one. - */ - bool write_fault_to_shadow_pgtable; - /* set at EPT violation at this point */ unsigned long exit_qualification; @@ -1907,6 +1890,25 @@ u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu); * EMULTYPE_COMPLETE_USER_EXIT - Set when the emulator should update interruptibility * state and inject single-step #DBs after skipping * an instruction (after completing userspace I/O). + * + * EMULTYPE_WRITE_PF_TO_SP - Set when emulating an intercepted page fault that + * is attempting to write a gfn that contains one or + * more of the PTEs used to translate the write itself, + * and the owning page table is being shadowed by KVM. + * If emulation of the faulting instruction fails and + * this flag is set, KVM will exit to userspace instead + * of retrying emulation as KVM cannot make forward + * progress. + * + * If emulation fails for a write to guest page tables, + * KVM unprotects (zaps) the shadow page for the target + * gfn and resumes the guest to retry the non-emulatable + * instruction (on hardware). Unprotecting the gfn + * doesn't allow forward progress for a self-changing + * access because doing so also zaps the translation for + * the gfn, i.e. retrying the instruction will hit a + * !PRESENT fault, which results in a new shadow page + * and sends KVM back to square one. */ #define EMULTYPE_NO_DECODE (1 << 0) #define EMULTYPE_TRAP_UD (1 << 1) @@ -1916,6 +1918,7 @@ u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu); #define EMULTYPE_VMWARE_GP (1 << 5) #define EMULTYPE_PF (1 << 6) #define EMULTYPE_COMPLETE_USER_EXIT (1 << 7) +#define EMULTYPE_WRITE_PF_TO_SP (1 << 8) int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type); int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, |