01/12/2017 09:12, Jerin Jacob:
> -----Original Message-----
> > Date: Thu, 30 Nov 2017 22:47:20 +0100
> > From: Thomas Monjalon <tho...@monjalon.net>
> > To: dev@dpdk.org
> > Subject: [dpdk-dev] [PATCH] eal/x86: get hypervisor name
> > X-Mailer: git-send-email 2.15.0
> >
> > The CPUID instruction is catched by hypervisor which can return
> > a flag indicating one is running, and its name.
> >
> > Suggested-by: Stephen Hemminger <sthem...@microsoft.com>
> > Signed-off-by: Thomas Monjalon <tho...@monjalon.net>
> > ---
> > warning: to be tested
> > ---
> > lib/librte_eal/common/arch/arm/rte_cpuflags.c | 6 +++++
> > lib/librte_eal/common/arch/ppc_64/rte_cpuflags.c | 6 +++++
> > lib/librte_eal/common/arch/x86/rte_cpuflags.c | 30
> > ++++++++++++++++++++++
> > .../common/include/arch/x86/rte_cpuflags.h | 1 +
> > .../common/include/generic/rte_cpuflags.h | 14 ++++++++++
> > lib/librte_eal/rte_eal_version.map | 9 ++++++-
> > 6 files changed, 65 insertions(+), 1 deletion(-)
> > RTE_CPUFLAG_FPU, /**< FPU */
> > diff --git a/lib/librte_eal/common/include/generic/rte_cpuflags.h
> > b/lib/librte_eal/common/include/generic/rte_cpuflags.h
> > index c1c5551fc..3832fb851 100644
> > --- a/lib/librte_eal/common/include/generic/rte_cpuflags.h
> > +++ b/lib/librte_eal/common/include/generic/rte_cpuflags.h
> > @@ -93,4 +93,18 @@ rte_cpu_check_supported(void);
> > int
> > rte_cpu_is_supported(void);
> >
> > +enum rte_hypervisor {
> > + RTE_HYPERVISOR_NONE,
> > + RTE_HYPERVISOR_KVM,
> > + RTE_HYPERVISOR_HYPERV,
> > + RTE_HYPERVISOR_VMWARE,
> > + RTE_HYPERVISOR_UNKNOWN
> > +};
> > +
> > +/**
> > + * Get the type of hypervisor it is running on.
> > + */
> > +enum rte_hypervisor
> > +rte_hypervisor_get_name(void);
>
> Cc: chao...@linux.vnet.ibm.com
>
> IMO, cpu_flag area is the not the correct abstraction to get
> the hypervisor name. It is x86 specific. I think, correct
> usage will be to call hypervisor specific APIs like KVM_GET_API_VERSION
> https://lwn.net/Articles/658511/
I think it is quite logical because the CPU is virtualized by the hypervisor.
It is similar to get the CPU model, but for a different ring level.
> BTW, What is the need for an DPDK application to know the
> hypervisor name? What action an DPDK application should
> take based on hypervisor name? if is not interest of data plane
> application why it needs to be abstracted in DPDK?
I see two usages for now.
We can automate the use of the specific VMware TSC (it is an option currently).
We can adapt the device management policy on Hyper-V without waiting a device
scan.
