On Thu, Sep 14, 2023, Yang Weijiang wrote: > Fix guest xsave area allocation size from fpu_user_cfg.default_size to > fpu_kernel_cfg.default_size so that the xsave area size is consistent > with fpstate->size set in __fpstate_reset(). > > With the fix, guest fpstate size is sufficient for KVM supported guest > xfeatures. > > Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx> > --- > arch/x86/kernel/fpu/core.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c > index a86d37052a64..a42d8ad26ce6 100644 > --- a/arch/x86/kernel/fpu/core.c > +++ b/arch/x86/kernel/fpu/core.c > @@ -220,7 +220,9 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) > struct fpstate *fpstate; > unsigned int size; > > - size = fpu_user_cfg.default_size + ALIGN(offsetof(struct fpstate, regs), 64); > + size = fpu_kernel_cfg.default_size + > + ALIGN(offsetof(struct fpstate, regs), 64); Shouldn't all the other calculations in this function also switch to fpu_kernel_cfg? At the very least, this looks wrong when paired with the above: gfpu->uabi_size = sizeof(struct kvm_xsave); if (WARN_ON_ONCE(fpu_user_cfg.default_size > gfpu->uabi_size)) gfpu->uabi_size = fpu_user_cfg.default_size;
