Messages in this thread | | | Date | Fri, 11 Jul 2014 19:09:02 -0400 | Subject | Re: [PATCH] xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests. | From | Konrad Rzeszutek Wilk <> |
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On Jul 11, 2014 6:52 PM, "H. Peter Anvin" <hpa@zytor.com> wrote: > > On 07/11/2014 12:53 PM, konrad@kernel.org wrote: > > > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > > index c1b9aa8..5dcfa6e 100644 > > --- a/Documentation/kernel-parameters.txt > > +++ b/Documentation/kernel-parameters.txt > > @@ -3691,6 +3691,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > Disables the ticketlock slowpath using Xen PV > > optimizations. > > > > + xen_nopv [X86,XEN] > > + Disables the PV optimizations forcing the guest to run > > + as generic HVM guest with no PV drivers. > > + > > xirc2ps_cs= [NET,PCMCIA] > > Format: > > <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > > index ffb101e..eb82239 100644 > > --- a/arch/x86/xen/enlighten.c > > +++ b/arch/x86/xen/enlighten.c > > @@ -1826,8 +1826,19 @@ static void __init xen_hvm_guest_init(void) > > xen_hvm_init_mmu_ops(); > > } > > > > +static bool xen_nopv = false; > > +static __init int xen_parse_nopv(char *arg) > > +{ > > + xen_nopv = true; > > + return 0; > > +} > > +early_param("xen_nopv", xen_parse_nopv); > > + > > static uint32_t __init xen_hvm_platform(void) > > { > > + if (xen_nopv) > > + return 0; > > + > > if (xen_pv_domain()) > > return 0; > > > > @@ -1836,6 +1847,8 @@ static uint32_t __init xen_hvm_platform(void) > > > > bool xen_hvm_need_lapic(void) > > { > > + if (xen_nopv) > > + return false; > > if (xen_pv_domain()) > > return false; > > if (!xen_hvm_domain()) > > > > Any reason to not simply let xen_pv_domain() return false here?
It does return false already.
Did you mean to collapse them together? > > Also, the latter seems a bit odd? > > -hpa >
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