From: Jing Liu <jing2.liu@xxxxxxxxx> vCPU threads are different from native tasks regarding to the initial xfd value. While all native tasks follow a fixed value (init_fpstate::xfd) defined by fpu core, vCPU threads need to obey the reset value (i.e. ZERO) defined by the spec, to meet the expectation of the guest. Move xfd initialization out of __fpstate_reset() to the callers for choosing a specific value. Signed-off-by: Jing Liu <jing2.liu@xxxxxxxxx> Signed-off-by: Yang Zhong <yang.zhong@xxxxxxxxx> --- arch/x86/kernel/fpu/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index fe592799508c..fae44fa27cdb 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -231,6 +231,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) if (!fpstate) return false; + /* Leave xfd to 0 (the reset value defined by spec) */ __fpstate_reset(fpstate); fpstate_init_user(fpstate); fpstate->is_valloc = true; @@ -461,7 +462,6 @@ static void __fpstate_reset(struct fpstate *fpstate) fpstate->user_size = fpu_user_cfg.default_size; fpstate->xfeatures = fpu_kernel_cfg.default_features; fpstate->user_xfeatures = fpu_user_cfg.default_features; - fpstate->xfd = init_fpstate.xfd; } void fpstate_reset(struct fpu *fpu) @@ -469,6 +469,7 @@ void fpstate_reset(struct fpu *fpu) /* Set the fpstate pointer to the default fpstate */ fpu->fpstate = &fpu->__fpstate; __fpstate_reset(fpu->fpstate); + fpu->fpstate->xfd = init_fpstate.xfd; /* Initialize the permission related info in fpu */ fpu->perm.__state_perm = fpu_kernel_cfg.default_features;
