forked from luck/tmp_suning_uos_patched
7495e22bb1
For ring-based dirty log tracking, it will be more efficient to account
writes during schedule-out or schedule-in to the currently running VCPU.
We would like to do it even if the write doesn't use the current VCPU's
address space, as is the case for cached writes (see commit 4e335d9e7d,
"Revert "KVM: Support vCPU-based gfn->hva cache"", 2017-05-02).
Therefore, add a mechanism to track the currently-loaded kvm_vcpu struct.
There is already something similar in KVM/ARM; one important difference
is that kvm_arch_vcpu_{load,put} have two callers in virt/kvm/kvm_main.c:
we have to update both the architecture-independent vcpu_{load,put} and
the preempt notifiers.
Another change made in the process is to allow using kvm_get_running_vcpu()
in preemptible code. This is allowed because preempt notifiers ensure
that the value does not change even after the VCPU thread is migrated.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
58 lines
995 B
C
58 lines
995 B
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Based on the x86 implementation.
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*
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* Copyright (C) 2012 ARM Ltd.
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*/
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#include <linux/perf_event.h>
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#include <linux/kvm_host.h>
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#include <asm/kvm_emulate.h>
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static int kvm_is_in_guest(void)
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{
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return kvm_get_running_vcpu() != NULL;
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}
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static int kvm_is_user_mode(void)
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{
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struct kvm_vcpu *vcpu;
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vcpu = kvm_get_running_vcpu();
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if (vcpu)
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return !vcpu_mode_priv(vcpu);
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return 0;
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}
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static unsigned long kvm_get_guest_ip(void)
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{
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struct kvm_vcpu *vcpu;
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vcpu = kvm_get_running_vcpu();
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if (vcpu)
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return *vcpu_pc(vcpu);
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return 0;
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}
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static struct perf_guest_info_callbacks kvm_guest_cbs = {
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.is_in_guest = kvm_is_in_guest,
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.is_user_mode = kvm_is_user_mode,
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.get_guest_ip = kvm_get_guest_ip,
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};
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int kvm_perf_init(void)
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{
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return perf_register_guest_info_callbacks(&kvm_guest_cbs);
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}
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int kvm_perf_teardown(void)
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{
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return perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
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}
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