Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
From:   'Guanjun' <guanjun@linux.alibaba.com>
To:     dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org,
        kirill.shutemov@linux.intel.com, yu.c.zhang@linux.intel.com,
        tabba@google.com, xiaoyao.li@intel.com
Cc:     pbonzini@redhat.com, x86@kernel.org, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/1] KVM: Move kvm_gmem_migrate_folio inside CONFIG_MIGRATION
Date:   Mon, 11 Dec 2023 11:05:18 +0800
Message-Id: <20231211030518.2722714-1-guanjun@linux.alibaba.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Guanjun <guanjun@linux.alibaba.com>

'kvm_gmem_migrate_folio' is only used when CONFIG_MIGRATION
is defined, And it will triggers the compiler warning about
'kvm_gmem_migrate_folio' defined but not used when CONFIG_MIGRATION
isn't defined.

The compiler complained like that:
arch/x86/kvm/../../../virt/kvm/guest_memfd.c:262:12: error: ‘kvm_gmem_migrate_folio’ defined but not used [-Werror=unused-function]
  262 | static int kvm_gmem_migrate_folio(struct address_space *mapping,
      |            ^~~~~~~~~~~~~~~~~~~~~~

Fixes: a7800aa80ea4 (KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory)
Signed-off-by: Guanjun <guanjun@linux.alibaba.com>
---
 virt/kvm/guest_memfd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 16d58806e913..62bb8a1a47d1 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -259,6 +259,7 @@ void kvm_gmem_init(struct module *module)
 	kvm_gmem_fops.owner = module;
 }
 
+#ifdef CONFIG_MIGRATION
 static int kvm_gmem_migrate_folio(struct address_space *mapping,
 				  struct folio *dst, struct folio *src,
 				  enum migrate_mode mode)
@@ -266,6 +267,7 @@ static int kvm_gmem_migrate_folio(struct address_space *mapping,
 	WARN_ON_ONCE(1);
 	return -EINVAL;
 }
+#endif
 
 static int kvm_gmem_error_folio(struct address_space *mapping,
 		struct folio *folio)
-- 
2.39.3