[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2/3] VMX: allocate VMCS pages from domain heap
>>> "Tian, Kevin" <kevin.tian@xxxxxxxxx> 10/21/15 5:16 AM >>> >> From: Jan Beulich [mailto:JBeulich@xxxxxxxx] >> Sent: Tuesday, October 20, 2015 6:36 PM >> >>> On 20.10.15 at 12:12, <andrew.cooper3@xxxxxxxxxx> wrote: >> > On 19/10/15 16:22, Jan Beulich wrote: >> >> -static struct vmcs_struct *vmx_alloc_vmcs(void) >> >> +static paddr_t vmx_alloc_vmcs(void) >> >> { >> >> + struct page_info *pg; >> >> struct vmcs_struct *vmcs; >> >> >> >> - if ( (vmcs = alloc_xenheap_page()) == NULL ) >> >> + if ( (pg = alloc_domheap_page(NULL, 0)) == NULL ) >> > >> > As an observation, it would be good to pass v from the caller, and NUMA >> > allocate against v->domain here. >> >> Yes, in another patch. > >which 'another patch'? suppose not PATCH 3/3 since I didn't' see >related change there. A yet to be written one. >> >> @@ -580,7 +583,7 @@ int vmx_cpu_up_prepare(unsigned int cpu) >> >> void vmx_cpu_dead(unsigned int cpu) >> >> { >> >> vmx_free_vmcs(per_cpu(vmxon_region, cpu)); >> >> - per_cpu(vmxon_region, cpu) = NULL; >> >> + per_cpu(vmxon_region, cpu) = 0; >> > >> > While this is currently safe (as pa 0 is not part of the available heap >> > allocation range), might it be worth introducing a named sentential? I >> > can forsee a DMLite nested Xen scenario where we definitely don't need >> > to treat the low 1MB magically. >> >> I guess there are more things to adjust if we ever cared to recover >> the few hundred kb below 1Mb. And then I don't see why nested >> Xen would matter here: One major main reason for reserving that >> space is that we want to put the trampoline there. Do you think >> DMlite would allow us to get away without? But even if so, this >> would again fall under what I've said in the first sentence. > >Could you at least introduce a macro first? Regardless of how much >things to adjust, this way makes future change simple. I can, just that this won't catch any other of the MFN-0-is-not-used cases in the code base. Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |