[PATCH 12/12] KVM: PPC: Book3S HV nestedv2: Do not cancel pending decrementer exception
From: Vaibhav Jain <hidden>
Date: 2023-12-01 13:36:11
Also in:
kvm
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: Jordan Niethe <redacted> 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 <redacted> --- arch/powerpc/kvm/book3s_hv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 2ee3f2478570..e48126a59ba7 100644
--- 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)))
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2.42.0