KVM: x86: xen_hvm_config: cleanup return values

Return 1 on errors that are caused by wrong guest behavior
(which will inject #GP to the guest)

And return a negative error value on issues that are
the kernel's fault (e.g -ENOMEM)

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20201001112954.6258-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 92f8500..3f5d08f 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2842,24 +2842,19 @@ static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
        u32 page_num = data & ~PAGE_MASK;
        u64 page_addr = data & PAGE_MASK;
        u8 *page;
-       int r;
 
-       r = -E2BIG;
        if (page_num >= blob_size)
-               goto out;
-       r = -ENOMEM;
+               return 1;
+
        page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE);
-       if (IS_ERR(page)) {
-               r = PTR_ERR(page);
-               goto out;
+       if (IS_ERR(page))
+               return PTR_ERR(page);
+
+       if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
+               kfree(page);
+               return 1;
        }
-       if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE))
-               goto out_free;
-       r = 0;
-out_free:
-       kfree(page);
-out:
-       return r;
+       return 0;
 }
 
 static inline bool kvm_pv_async_pf_enabled(struct kvm_vcpu *vcpu)