[PATCH v3 06/10] x86/fpu/xstate: Initialize guest perm with fpu_guest_cfg

Chao Gao
2025-03-07T16:39:13Z

From: Yang Weijiang <weijiang.yang@intel.com>

Use the new fpu_guest_cfg to initialize guest permissions.

Note fpu_guest_cfg and fpu_kernel_cfg remain the same for now. So there
is no functional change.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
[Gao Chao: Extrace this from the previous patch ]
Signed-off-by: Chao Gao <chao.gao@intel.com>
---
arch/x86/kernel/fpu/core.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index b0c1ef40d105..d7ae684adbad 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -534,8 +534,15 @@ void fpstate_reset(struct fpu *fpu)
fpu->perm.__state_perm = fpu_kernel_cfg.default_features;
fpu->perm.__state_size = fpu_kernel_cfg.default_size;
fpu->perm.__user_state_size = fpu_user_cfg.default_size;
- /* Same defaults for guests */
- fpu->guest_perm = fpu->perm;
+
+ /* Guest permission settings */
+ fpu->guest_perm.__state_perm = fpu_guest_cfg.default_features;
+ fpu->guest_perm.__state_size = fpu_guest_cfg.default_size;
+ /*
+ * Set guest's __user_state_size to fpu_user_cfg.default_size so that
+ * existing uAPIs can still work.
+ */
+ fpu->guest_perm.__user_state_size = fpu_user_cfg.default_size;
}

static inline void fpu_inherit_perms(struct fpu *dst_fpu)
--
2.46.1