[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] Xen 4.4 Testing: Platform Op XENPF_microcode_update Leaves VCPU Lock Set?
On Thu, 2014-04-24 at 09:35 -0400, John McDermott wrote: > Xen Developers, > > In arch/x86/platform_hypercall.c, in function do_platform_op, the case > XENPF_microcode_update appears to leave the vcpu_alloc_lock set when > creating a hypercall continuation, Are you referring to: /* * alloc_vcpu() will access data which is modified during * microcode update */ while ( !spin_trylock(&vcpu_alloc_lock) ) { if ( hypercall_preempt_check() ) { ret = hypercall_create_continuation( __HYPERVISOR_platform_op, "h", u_xenpf_op); goto out; } } ? Notice that the continuation is inside the !spin_trylock loop -- IOW it will only reach that point with the lock *not* held. If spin_trylock succeeds in taking the lock then we don't go into the loop body. Ian. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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