Messages in this thread | | | Date | Fri, 12 Mar 2010 12:35:53 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [Xen-devel] [PATCH][v9 4/6] xen/hvm: Xen PV extension of HVM initialization |
| |
On 03/11/2010 06:57 PM, Sheng Yang wrote: > The PV extended HVM(once known as Hybrid) is started from real mode like > HVM guest, but also with a component based PV feature selection(e.g. PV halt, > PV timer, event channel, then PV drivers). So guest can takes the advantages > of both H/W virtualization and Para-Virtualization. > > This patch introduced the PV extension of HVM guest initialization. > > Guest would detect the capability using CPUID 0x40000002.edx, then call > HVMOP_enable_pv hypercall to enable pv support in hypervisor. > > Signed-off-by: Sheng Yang<sheng@linux.intel.com> > Signed-off-by: Yaozu (Eddie) Dong<eddie.dong@intel.com> > --- > arch/x86/include/asm/xen/cpuid.h | 5 + > arch/x86/include/asm/xen/hypervisor.h | 12 +++ > arch/x86/xen/Kconfig | 4 + > arch/x86/xen/Makefile | 1 + > arch/x86/xen/hvmpv.c | 135 +++++++++++++++++++++++++++++++++ > include/xen/interface/hvm/hvm_op.h | 8 ++ > 6 files changed, 165 insertions(+), 0 deletions(-) > create mode 100644 arch/x86/xen/hvmpv.c > > diff --git a/arch/x86/include/asm/xen/cpuid.h b/arch/x86/include/asm/xen/cpuid.h > index 8787f03..b3a0b3a 100644 > --- a/arch/x86/include/asm/xen/cpuid.h > +++ b/arch/x86/include/asm/xen/cpuid.h > @@ -65,4 +65,9 @@ > #define _XEN_CPUID_FEAT1_MMU_PT_UPDATE_PRESERVE_AD 0 > #define XEN_CPUID_FEAT1_MMU_PT_UPDATE_PRESERVE_AD (1u<<0) > > +#define _XEN_CPUID_FEAT2_HVM_PV 0 > +#define XEN_CPUID_FEAT2_HVM_PV (1u<<0) > +#define _XEN_CPUID_FEAT2_HVM_PV_CLOCK 1 > +#define XEN_CPUID_FEAT2_HVM_PV_CLOCK (1u<<1) > + > #endif /* __XEN_PUBLIC_ARCH_X86_CPUID_H__ */ > diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h > index d5b7e90..7569f64 100644 > --- a/arch/x86/include/asm/xen/hypervisor.h > +++ b/arch/x86/include/asm/xen/hypervisor.h > @@ -55,6 +55,18 @@ extern enum xen_domain_type xen_domain_type; > #define xen_hvm_domain() (xen_domain()&& \ > xen_domain_type == XEN_HVM_DOMAIN) > > +#ifdef CONFIG_XEN_HVM_PV > + > +#define XEN_HVM_PV_CLOCK_ENABLED (1u<< 0) >
Why is this flag needed? As far as I understand it, there's no real underlying hypervisor change needed to make HVM access to pv clock possible; its just a field in the shared_info's vcpu struct after all. Even if you enable this feature unconditionally, the user can still control whether the Xen clocksource is used with the "clocksource=" kernel command-line parameter.
Also, there's nothing about this which is 64-bit specific is there?
Thanks, J
| |