Commit 83d31e52 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: nVMX: fixes for preemption timer migration 



Commit 850448f3 ("KVM: nVMX: Fix VMX preemption timer migration",
2020-06-01) accidentally broke nVMX live migration from older version
by changing the userspace ABI.  Restore it and, while at it, ensure
that vmx->nested.has_preemption_timer_deadline is always initialized
according to the KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE flag.

Cc: Makarand Sonare <makarandsonare@google.com>
Fixes: 850448f3 ("KVM: nVMX: Fix VMX preemption timer migration")
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8038a922

Documentation/virt/kvm/api.rst

+3 −2
Original line number Diff line number Diff line
@@ -4339,14 +4339,15 @@ Errors: 
#define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001



  struct kvm_vmx_nested_state_hdr {

	__u32 flags;

	__u64 vmxon_pa;

	__u64 vmcs12_pa;

	__u64 preemption_timer_deadline;



	struct {

		__u16 flags;

	} smm;



	__u32 flags;

	__u64 preemption_timer_deadline;

  };



  struct kvm_vmx_nested_state_data {

arch/x86/include/uapi/asm/kvm.h

+3 −2
Original line number Diff line number Diff line
@@ -408,14 +408,15 @@ struct kvm_vmx_nested_state_data { 
};



struct kvm_vmx_nested_state_hdr {

	__u32 flags;

	__u64 vmxon_pa;

	__u64 vmcs12_pa;

	__u64 preemption_timer_deadline;



	struct {

		__u16 flags;

	} smm;



	__u32 flags;

	__u64 preemption_timer_deadline;

};



struct kvm_svm_nested_state_data {

arch/x86/kvm/vmx/nested.c

+1 −0
Original line number Diff line number Diff line
@@ -6176,6 +6176,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
			goto error_guest_mode;

	}



	vmx->nested.has_preemption_timer_deadline = false;

	if (kvm_state->hdr.vmx.flags & KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE) {

		vmx->nested.has_preemption_timer_deadline = true;

		vmx->nested.preemption_timer_deadline =

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