Re: [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument

Excerpts from Daniel Axtens's message of February 26, 2021 3:01 pm:

Hi Nick,

quoted

The va argument is not used in the function or set by its asm caller,
so remove it to be safe.

Huh, so it isn't. I tracked the original implementation down to commit
a8606e20e41a ("KVM: PPC: Handle some PAPR hcalls in the kernel") where
paulus first added the ability to handle it in the kernel - there it
takes a va argument but even then doesn't do anything with it.

ajd also pointed out that we don't pass a va when linux is running as a
guest, and LoPAR does not mention va as an argument.

Yeah interesting, maybe it was from a pre-release version of PAPR? Who
knows.

One small nit: checkpatch is complaining about spaces vs tabs:
ERROR: code indent should use tabs where possible
#25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
+                      unsigned long pte_index, unsigned long avpn);$

WARNING: please, no spaces at the start of a line
#25: FILE: arch/powerpc/include/asm/kvm_ppc.h:770:
+                      unsigned long pte_index, unsigned long avpn);$

All the declarations are using the same style in this file so I think
I'll leave it for someone to do a cleanup patch on. Okay?

Once that is resolved,
  Reviewed-by: Daniel Axtens [off-list ref]

Thanks,
Nick

Kind regards,
Daniel Axtens

quoted

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h  | 3 +--
 arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 8aacd76bb702..9531b1c1b190 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h

@@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
                      unsigned long pte_index, unsigned long avpn);
 long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
-                      unsigned long pte_index, unsigned long avpn,
-                      unsigned long va);
+                      unsigned long pte_index, unsigned long avpn);
 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
                    unsigned long pte_index);
 long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,

diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 88da2764c1bb..7af7c70f1468 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c

@@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
 }
 
 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
-		      unsigned long pte_index, unsigned long avpn,
-		      unsigned long va)
+		      unsigned long pte_index, unsigned long avpn)
 {
 	struct kvm *kvm = vcpu->kvm;
 	__be64 *hpte;

-- 
2.23.0