On Mon, Mar 18, 2024 at 07:33:46PM -0400, Paolo Bonzini wrote: > SEV-ES allows passing custom contents for x87, SSE and AVX state into the VMSA. > Allow userspace to do that with the usual KVM_SET_XSAVE API and only mark > FPU contents as confidential after it has been copied and encrypted into > the VMSA. > > Since the XSAVE state for AVX is the first, it does not need the > compacted-state handling of get_xsave_addr(). However, there are other > parts of XSAVE state in the VMSA that currently are not handled, and > the validation logic of get_xsave_addr() is pointless to duplicate > in KVM, so move get_xsave_addr() to public FPU API; it is really just > a facility to operate on XSAVE state and does not expose any internal > details of arch/x86/kernel/fpu. > > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > arch/x86/include/asm/fpu/api.h | 3 +++ > arch/x86/kernel/fpu/xstate.h | 2 -- > arch/x86/kvm/svm/sev.c | 36 ++++++++++++++++++++++++++++++++++ > arch/x86/kvm/svm/svm.c | 8 -------- > 4 files changed, 39 insertions(+), 10 deletions(-) > > diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h > index a2be3aefff9f..f86ad3335529 100644 > --- a/arch/x86/include/asm/fpu/api.h > +++ b/arch/x86/include/asm/fpu/api.h > @@ -143,6 +143,9 @@ extern void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfe > > extern u64 xstate_get_guest_group_perm(void); > > +extern void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); I get a linker error if I don't add an EXPORT_SYMBOL_GPL(get_xsave_addr) -Mike
