Commit 180c6b07 authored by Jordan Niethe's avatar Jordan Niethe Committed by Michael Ellerman
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KVM: PPC: Book3S HV nestedv2: Do not cancel pending decrementer exception 



In the nestedv2 case, if there is a pending decrementer exception, the
L1 must get the L2's timebase from the L0 to see if the exception should
be cancelled. This adds the overhead of a H_GUEST_GET_STATE call to the
likely case in which the decrementer should not be cancelled.

Avoid this logic for the nestedv2 case.

Signed-off-by: default avatarJordan Niethe <jniethe5@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231201132618.555031-13-vaibhav@linux.ibm.com
parent 797a5af8

arch/powerpc/kvm/book3s_hv.c

+1 −1
Original line number Diff line number Diff line
@@ -4834,7 +4834,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, 
	 * entering a nested guest in which case the decrementer is now owned

	 * by L2 and the L1 decrementer is provided in hdec_expires

	 */

	if (kvmppc_core_pending_dec(vcpu) &&

	if (!kvmhv_is_nestedv2() && kvmppc_core_pending_dec(vcpu) &&

			((tb < kvmppc_dec_expires_host_tb(vcpu)) ||

			 (trap == BOOK3S_INTERRUPT_SYSCALL &&

			  kvmppc_get_gpr(vcpu, 3) == H_ENTER_NESTED)))