POP @spec_ctrl_intercepted into RAX instead of RBX when discarding it from
the stack so that __svm_sev_es_vcpu_run() doesn't modify any non-volatile
registers. __svm_sev_es_vcpu_run() doesn't return a value, and RAX is
already are clobbered multiple times in the #VMEXIT path.
This will allowing using the host save area to save/restore non-volatile
registers in __svm_sev_es_vcpu_run().
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240223204233.3337324-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
*/
UNTRAIN_RET_VM
- /* "Pop" @spec_ctrl_intercepted. */
- pop %rbx
+ /* "Pop" and discard @spec_ctrl_intercepted. */
+ pop %rax
pop %rbx