KVM: PPC: Book3S HV nestedv2: Do not cancel pending decrementer excep…

…tion 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: Jordan Niethe <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://msgid.link/[email protected]
linuxppc · Dec 7, 2023 · 180c6b0 · 180c6b0
1 parent 797a5af
commit 180c6b0
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
@@ -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)))