2023-12-11 03:05:48

by guanjun

Subject: [PATCH 1/1] KVM: Move kvm_gmem_migrate_folio inside CONFIG_MIGRATION

From: Guanjun <[email protected]>

'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 <[email protected]>
---
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

2023-12-11 15:15:53

by Sean Christopherson

Subject: Re: [PATCH 1/1] KVM: Move kvm_gmem_migrate_folio inside CONFIG_MIGRATION

On Mon, Dec 11, 2023, 'Guanjun' wrote:
> From: Guanjun <[email protected]>
>
> '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,
> | ^~~~~~~~~~~~~~~~~~~~~~

Already fixed, commit 80583d0cfd8f ("KVM: guest-memfd: fix unused-function warning")
in kvm/next.

https://lore.kernel.org/all/[email protected]