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666e7252a1
One of the most obvious registers to share with the guest directly is the MSR. The MSR contains the "interrupts enabled" flag which the guest has to toggle in critical sections. So in order to bring the overhead of interrupt en- and disabling down, let's put msr into the shared page. Keep in mind that even though you can fully read its contents, writing to it doesn't always update all state. There are a few safe fields that don't require hypervisor interaction. See the documentation for a list of MSR bits that are safe to be set from inside the guest. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
44 lines
1.1 KiB
C
44 lines
1.1 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright IBM Corp. 2008
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*
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* Authors: Hollis Blanchard <hollisb@us.ibm.com>
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*/
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#ifndef __POWERPC_KVM_PARA_H__
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#define __POWERPC_KVM_PARA_H__
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#include <linux/types.h>
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struct kvm_vcpu_arch_shared {
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__u64 msr;
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};
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#ifdef __KERNEL__
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static inline int kvm_para_available(void)
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{
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return 0;
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}
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static inline unsigned int kvm_arch_para_features(void)
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{
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return 0;
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}
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#endif /* __KERNEL__ */
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#endif /* __POWERPC_KVM_PARA_H__ */
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