[PATCH 5/6] KVM: PPC: Use CLASS(kvm_vcpu_map_local_readonly) for patching dcbz

[Sean Christopherson <seanjc@google.com>]

Convert the kvm_vcpu_map() usage in PPC dcbz patching to the new
CLASS(kvm_vcpu_map_local) implementation, to eliminate the very last of the
the open-coded on-stack "struct kvm_host_map" declarations.  This will
allow adding hardening kvm_vcpu_map() against memory leaks (due to
clobbering the existing mapping).

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/powerpc/kvm/book3s_pr.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 2ba2dd26a7ea..da7a038e2700 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -639,27 +639,24 @@ static void kvmppc_set_pvr_pr(struct kvm_vcpu *vcpu, u32 pvr)
  */
 static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 {
-	struct kvm_host_map map;
 	u64 hpage_offset;
 	u32 *page;
 	int i, r;
 
-	r = kvm_vcpu_map(vcpu, pte->raddr >> PAGE_SHIFT, &map);
-	if (r)
+	CLASS(kvm_vcpu_map_local, m)(vcpu, pte->raddr >> PAGE_SHIFT);
+	if (m.ret)
 		return;
 
 	hpage_offset = pte->raddr & ~PAGE_MASK;
 	hpage_offset &= ~0xFFFULL;
 	hpage_offset /= 4;
 
-	page = map.hva;
+	page = m.map.hva;
 
 	/* patch dcbz into reserved instruction, so we trap */
 	for (i=hpage_offset; i < hpage_offset + (HW_PAGE_SIZE / 4); i++)
 		if ((be32_to_cpu(page[i]) & 0xff0007ff) == INS_DCBZ)
 			page[i] &= cpu_to_be32(0xfffffff7);
-
-	kvm_vcpu_unmap(vcpu, &map);
 }
 
 static bool kvmppc_visible_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
-- 
2.55.0.229.g6434b31f56-goog