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| author | Avi Kivity <avi@qumranet.com> | 2007-10-22 16:50:39 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 18:01:20 +0200 |
| commit | b209749f528488c4c0d20a42c0fbcbf49e6933b3 (patch) | |
| tree | 0e0a24225a5c6bca1c1986cc0daaf8753424cfe6 /arch/x86/kvm/lapic.c | |
| parent | 565f1fbd9d2f766dcfed5db90b89ef80afe8b49a (diff) | |
| download | lwn-b209749f528488c4c0d20a42c0fbcbf49e6933b3.tar.gz lwn-b209749f528488c4c0d20a42c0fbcbf49e6933b3.zip | |
KVM: local APIC TPR access reporting facility
Add a facility to report on accesses to the local apic tpr even if the
local apic is emulated in the kernel. This is basically a hack that
allows userspace to patch Windows which tends to bang on the tpr a lot.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 4076331b01ee..50c3f3a8dd3d 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -551,6 +551,23 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic) return tmcct; } +static void __report_tpr_access(struct kvm_lapic *apic, bool write) +{ + struct kvm_vcpu *vcpu = apic->vcpu; + struct kvm_run *run = vcpu->run; + + set_bit(KVM_REQ_REPORT_TPR_ACCESS, &vcpu->requests); + kvm_x86_ops->cache_regs(vcpu); + run->tpr_access.rip = vcpu->arch.rip; + run->tpr_access.is_write = write; +} + +static inline void report_tpr_access(struct kvm_lapic *apic, bool write) +{ + if (apic->vcpu->arch.tpr_access_reporting) + __report_tpr_access(apic, write); +} + static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset) { u32 val = 0; @@ -568,6 +585,9 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset) val = apic_get_tmcct(apic); break; + case APIC_TASKPRI: + report_tpr_access(apic, false); + /* fall thru */ default: apic_update_ppr(apic); val = apic_get_reg(apic, offset); @@ -677,6 +697,7 @@ static void apic_mmio_write(struct kvm_io_device *this, break; case APIC_TASKPRI: + report_tpr_access(apic, true); apic_set_tpr(apic, val & 0xff); break; |