KVM: PPC: Book3S HV: Simplify real-mode interrupt handling

This streamlines the first part of the code that handles a hypervisor
interrupt that occurred in the guest.  With this, all of the real-mode
handling that occurs is done before the "guest_exit_cont" label; once
we get to that label we are committed to exiting to host virtual mode.
Thus the machine check and HMI real-mode handling is moved before that
label.

Also, the code to handle external interrupts is moved out of line, as
is the code that calls kvmppc_realmode_hmi_handler().

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index b11043b23c18..ee564b682f0c 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -331,5 +331,13 @@ long kvmppc_realmode_hmi_handler(void)
 	} else {
 		wait_for_tb_resync();
 	}
+
+	/*
+	 * Reset tb_offset_applied so the guest exit code won't try
+	 * to subtract the previous timebase offset from the timebase.
+	 */
+	if (local_paca->kvm_hstate.kvm_vcore)
+		local_paca->kvm_hstate.kvm_vcore->tb_offset_applied = 0;
+
 	return 0;
 }