From: Thomas Gleixner tglx@linutronix.de
Userspace needs to inquire KVM about the buffer size to work with the new KVM_SET_XSAVE and KVM_GET_XSAVE2. Add the size info to guest_fpu for KVM to access.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Wei Wang wei.w.wang@intel.com Signed-off-by: Jing Liu jing2.liu@intel.com Signed-off-by: Yang Zhong yang.zhong@intel.com --- arch/x86/include/asm/fpu/types.h | 5 +++++ arch/x86/kernel/fpu/core.c | 1 + arch/x86/kernel/fpu/xstate.c | 1 + 3 files changed, 7 insertions(+)
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 3795d0573773..eb7cd1139d97 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -522,6 +522,11 @@ struct fpu_guest { */ u64 xfd_err;
+ /* + * @uabi_size: Size required for save/restore + */ + unsigned int uabi_size; + /* * @fpstate: Pointer to the allocated guest fpstate */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 3daea097c618..89d679cc819b 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -240,6 +240,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) gfpu->fpstate = fpstate; gfpu->xfeatures = fpu_user_cfg.default_features; gfpu->perm = fpu_user_cfg.default_features; + gfpu->uabi_size = fpu_user_cfg.default_size; fpu_init_guest_permissions(gfpu);
return true; diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 0c0b2323cdec..10fe072f1c92 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1545,6 +1545,7 @@ static int fpstate_realloc(u64 xfeatures, unsigned int ksize, newfps->is_confidential = curfps->is_confidential; newfps->in_use = curfps->in_use; guest_fpu->xfeatures |= xfeatures; + guest_fpu->uabi_size = usize; }
fpregs_lock();