[PATCH 01/10] KVM: Do not zero initialize 'pfn' in hva_to_pfn()

[Sean Christopherson <seanjc@google.com>]

Drop the unnecessary initialization of the local 'pfn' variable in
hva_to_pfn().  First and foremost, '0' is not an invalid pfn, it's a
perfectly valid pfn on most architectures.  I.e. if hva_to_pfn() were to
return an "uninitializd" pfn, it would actually be interpeted as a legal
pfn by most callers.

Second, hva_to_pfn() can't return an uninitialized pfn as hva_to_pfn()
explicitly sets pfn to an error value (or returns an error value directly)
if a helper returns failure, and all helpers set the pfn on success.

Note, the zeroing of 'pfn' was introduced by commit 2fc843117d64 ("KVM:
reorganize hva_to_pfn"), and was unnecessary and misguided paranoia even
then.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 virt/kvm/kvm_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 0848430f36c6..04ed4334473c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2567,7 +2567,7 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
 		     bool write_fault, bool *writable)
 {
 	struct vm_area_struct *vma;
-	kvm_pfn_t pfn = 0;
+	kvm_pfn_t pfn;
 	int npages, r;
 
 	/* we can do it either atomically or asynchronously, not both */
-- 
2.36.0.464.gb9c8b46e94-goog