Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > On 09/10/19 12:42, Vitaly Kuznetsov wrote: >> Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: >>> There is no practical difference with Vitaly's patch. The first >>> _vcpu_run has no pre-/post-conditions on the value of %rbx: >> >> I think what Sean was suggesting is to prevent GCC from inserting >> anything (and thus clobbering RBX) between the call to guest_call() and >> the beginning of 'asm volatile' block by calling *inside* 'asm volatile' >> block instead. > > Yes, but there is no way that clobbering RBX will break the test, > because RBX is not initialized until after the first _vcpu_run succeeds. > Right, we're always resuming after so potential clobbering doesn't matter. Thanks! -- Vitaly
