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kvm: x86: add tsc_offset field to struct kvm_vcpu_arch
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A future commit will want to easily read a vCPU's TSC offset,
so we store it in struct kvm_arch_vcpu_arch for easy access.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Luiz Capitulino authored and Paolo Bonzini committed Sep 16, 2016
1 parent ad53e35 commit a545ab6
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Showing 2 changed files with 9 additions and 2 deletions.
1 change: 1 addition & 0 deletions arch/x86/include/asm/kvm_host.h
Original file line number Diff line number Diff line change
Expand Up @@ -568,6 +568,7 @@ struct kvm_vcpu_arch {
struct kvm_steal_time steal;
} st;

u64 tsc_offset;
u64 last_guest_tsc;
u64 last_host_tsc;
u64 tsc_offset_adjustment;
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10 changes: 8 additions & 2 deletions arch/x86/kvm/x86.c
Original file line number Diff line number Diff line change
Expand Up @@ -1413,6 +1413,12 @@ u64 kvm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc)
}
EXPORT_SYMBOL_GPL(kvm_read_l1_tsc);

static void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
kvm_x86_ops->write_tsc_offset(vcpu, offset);
vcpu->arch.tsc_offset = offset;
}

void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
struct kvm *kvm = vcpu->kvm;
Expand Down Expand Up @@ -1522,7 +1528,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)

if (guest_cpuid_has_tsc_adjust(vcpu) && !msr->host_initiated)
update_ia32_tsc_adjust_msr(vcpu, offset);
kvm_x86_ops->write_tsc_offset(vcpu, offset);
kvm_vcpu_write_tsc_offset(vcpu, offset);
raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);

spin_lock(&kvm->arch.pvclock_gtod_sync_lock);
Expand Down Expand Up @@ -2750,7 +2756,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
if (check_tsc_unstable()) {
u64 offset = kvm_compute_tsc_offset(vcpu,
vcpu->arch.last_guest_tsc);
kvm_x86_ops->write_tsc_offset(vcpu, offset);
kvm_vcpu_write_tsc_offset(vcpu, offset);
vcpu->arch.tsc_catchup = 1;
}
/*
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