linux-stable/arch/powerpc/include/asm/kvm_para.h
Wanpeng Li a4429e53c9 KVM: Introduce paravirtualization hints and KVM_HINTS_DEDICATED
This patch introduces kvm_para_has_hint() to query for hints about
the configuration of the guests.  The first hint KVM_HINTS_DEDICATED,
is set if the guest has dedicated physical CPUs for each vCPU (i.e.
pinning and no over-commitment).  This allows optimizing spinlocks
and tells the guest to avoid PV TLB flush.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06 18:40:44 +01:00

74 lines
1.6 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright IBM Corp. 2008
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
*/
#ifndef __POWERPC_KVM_PARA_H__
#define __POWERPC_KVM_PARA_H__
#include <uapi/asm/kvm_para.h>
#ifdef CONFIG_KVM_GUEST
#include <linux/of.h>
static inline int kvm_para_available(void)
{
struct device_node *hyper_node;
hyper_node = of_find_node_by_path("/hypervisor");
if (!hyper_node)
return 0;
if (!of_device_is_compatible(hyper_node, "linux,kvm"))
return 0;
return 1;
}
#else
static inline int kvm_para_available(void)
{
return 0;
}
#endif
static inline unsigned int kvm_arch_para_features(void)
{
unsigned long r;
if (!kvm_para_available())
return 0;
if(epapr_hypercall0_1(KVM_HCALL_TOKEN(KVM_HC_FEATURES), &r))
return 0;
return r;
}
static inline unsigned int kvm_arch_para_hints(void)
{
return 0;
}
static inline bool kvm_check_and_clear_guest_paused(void)
{
return false;
}
#endif /* __POWERPC_KVM_PARA_H__ */