From 46f9caf1a246a5c0622fa8cc7e673658e925f97e Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 23 Nov 2021 19:51:47 +1000 Subject: powerpc/64s: Keep AMOR SPR a constant ~0 at runtime This register controls supervisor SPR modifications, and as such is only relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never restores it coming back out to the host, so it can be kept constant and avoid the mtSPR in KVM guest entry. Signed-off-by: Nicholas Piggin Reviewed-by: Fabiano Rosas Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211123095231.1036501-10-npiggin@gmail.com --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/powerpc/kvm/book3s_hv_rmhandlers.S') diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 32a4b4d412b9..c45ec4cd9d52 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -778,10 +778,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) /* Restore AMR and UAMOR, set AMOR to all 1s */ ld r5,VCPU_AMR(r4) ld r6,VCPU_UAMOR(r4) - li r7,-1 mtspr SPRN_AMR,r5 mtspr SPRN_UAMOR,r6 - mtspr SPRN_AMOR,r7 /* Restore state of CTRL run bit; assume 1 on entry */ lwz r5,VCPU_CTRL(r4) -- cgit