Hi Gavin,
On Fri, 16 May 2025 at 01:42, Gavin Shan <gshan@xxxxxxxxxx> wrote:
>
> Hi Fuad,
>
> On 5/14/25 2:34 AM, Fuad Tabba wrote:
> > This patch enables support for shared memory in guest_memfd, including
> > mapping that memory at the host userspace. This support is gated by the
> > configuration option KVM_GMEM_SHARED_MEM, and toggled by the guest_memfd
> > flag GUEST_MEMFD_FLAG_SUPPORT_SHARED, which can be set when creating a
> > guest_memfd instance.
> >
> > Co-developed-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
> > Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
> > Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
> > ---
> > arch/x86/include/asm/kvm_host.h | 10 ++++
> > include/linux/kvm_host.h | 13 +++++
> > include/uapi/linux/kvm.h | 1 +
> > virt/kvm/Kconfig | 5 ++
> > virt/kvm/guest_memfd.c | 88 +++++++++++++++++++++++++++++++++
> > 5 files changed, 117 insertions(+)
> >
>
> [...]
>
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index b6ae8ad8934b..9857022a0f0c 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -1566,6 +1566,7 @@ struct kvm_memory_attributes {
> > #define KVM_MEMORY_ATTRIBUTE_PRIVATE (1ULL << 3)
> >
> > #define KVM_CREATE_GUEST_MEMFD _IOWR(KVMIO, 0xd4, struct kvm_create_guest_memfd)
> > +#define GUEST_MEMFD_FLAG_SUPPORT_SHARED (1UL << 0)
> >
>
> This would be (1ULL << 0) to be consistent with '__u64 struct kvm_create_guest_memfd::flags'
Ack.
Thanks!
/fuad
> Thanks,
> Gavin
>
