search for: compat_restore_all_guest

The self_nmi() code cause''s an NMI to be triggered by sending an APIC message to the local processor. However, NMIs are blocked by the VMEXIT, until the next iret or VMENTER. Volume 3 Chapter 27 Section 1 of the Intel SDM states: An NMI causes subsequent NMIs to be blocked, but only after the VM exit completes. As a result, as soon as the VMENTER happens, an immediate VMEXIT happens

This set of patches converts the way frames gets created from using PUSHes/POPs to using MOVes, thus allowing (in certain cases) to avoid saving/restoring part of the register set. While the place where the (small) win from this comes from varies between CPUs, the net effect is a 1 to 2% reduction on a combined interruption entry and exit when the full state save can be avoided. 1: use MOV

...S 2006-10-04 15:11:03.000000000 +0200 @@ -71,9 +71,9 @@ compat_test_all_events: jc compat_process_nmi compat_test_guest_events: movq VCPU_vcpu_info(%rbx),%rax - testb $0xFF,VCPUINFO_upcall_mask(%rax) + testb $0xFF,COMPAT_VCPUINFO_upcall_mask(%rax) jnz compat_restore_all_guest - testb $0xFF,VCPUINFO_upcall_pending(%rax) + testb $0xFF,COMPAT_VCPUINFO_upcall_pending(%rax) jz compat_restore_all_guest /*compat_process_guest_events:*/ sti @@ -191,10 +191,10 @@ CFLT4: mov UREGS_ss+8(%rsp),%fs movb TRAPBOUNCE_flags(%rdx),%cl...