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KVM: ppc: guest breakpoint support

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Allow host userspace to program hardware debug registers to set breakpoints
inside guests.

Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Hollis Blanchard
2008-07-25 13:54:49 -05:00
committed by Avi Kivity
parent b5e2fec0eb
commit 6a0ab738ef
4 changed files with 113 additions and 2 deletions
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84
arch/powerpc/kvm/powerpc.c
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@@ -239,18 +239,100 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
}
/* Note: clearing MSR[DE] just means that the debug interrupt will not be
* delivered *immediately*. Instead, it simply sets the appropriate DBSR bits.
* If those DBSR bits are still set when MSR[DE] is re-enabled, the interrupt
* will be delivered as an "imprecise debug event" (which is indicated by
* DBSR[IDE].
*/
static void kvmppc_disable_debug_interrupts(void)
{
mtmsr(mfmsr() & ~MSR_DE);
}
static void kvmppc_restore_host_debug_state(struct kvm_vcpu *vcpu)
{
kvmppc_disable_debug_interrupts();
mtspr(SPRN_IAC1, vcpu->arch.host_iac[0]);
mtspr(SPRN_IAC2, vcpu->arch.host_iac[1]);
mtspr(SPRN_IAC3, vcpu->arch.host_iac[2]);
mtspr(SPRN_IAC4, vcpu->arch.host_iac[3]);
mtspr(SPRN_DBCR1, vcpu->arch.host_dbcr1);
mtspr(SPRN_DBCR2, vcpu->arch.host_dbcr2);
mtspr(SPRN_DBCR0, vcpu->arch.host_dbcr0);
mtmsr(vcpu->arch.host_msr);
}
static void kvmppc_load_guest_debug_registers(struct kvm_vcpu *vcpu)
{
struct kvm_guest_debug *dbg = &vcpu->guest_debug;
u32 dbcr0 = 0;
vcpu->arch.host_msr = mfmsr();
kvmppc_disable_debug_interrupts();
/* Save host debug register state. */
vcpu->arch.host_iac[0] = mfspr(SPRN_IAC1);
vcpu->arch.host_iac[1] = mfspr(SPRN_IAC2);
vcpu->arch.host_iac[2] = mfspr(SPRN_IAC3);
vcpu->arch.host_iac[3] = mfspr(SPRN_IAC4);
vcpu->arch.host_dbcr0 = mfspr(SPRN_DBCR0);
vcpu->arch.host_dbcr1 = mfspr(SPRN_DBCR1);
vcpu->arch.host_dbcr2 = mfspr(SPRN_DBCR2);
/* set registers up for guest */
if (dbg->bp[0]) {
mtspr(SPRN_IAC1, dbg->bp[0]);
dbcr0 |= DBCR0_IAC1 | DBCR0_IDM;
}
if (dbg->bp[1]) {
mtspr(SPRN_IAC2, dbg->bp[1]);
dbcr0 |= DBCR0_IAC2 | DBCR0_IDM;
}
if (dbg->bp[2]) {
mtspr(SPRN_IAC3, dbg->bp[2]);
dbcr0 |= DBCR0_IAC3 | DBCR0_IDM;
}
if (dbg->bp[3]) {
mtspr(SPRN_IAC4, dbg->bp[3]);
dbcr0 |= DBCR0_IAC4 | DBCR0_IDM;
}
mtspr(SPRN_DBCR0, dbcr0);
mtspr(SPRN_DBCR1, 0);
mtspr(SPRN_DBCR2, 0);
}
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
if (vcpu->guest_debug.enabled)
kvmppc_load_guest_debug_registers(vcpu);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_debug.enabled)
kvmppc_restore_host_debug_state(vcpu);
}
int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
struct kvm_debug_guest *dbg)
{
return -ENOTSUPP;
int i;
vcpu->guest_debug.enabled = dbg->enabled;
if (vcpu->guest_debug.enabled) {
for (i=0; i < ARRAY_SIZE(vcpu->guest_debug.bp); i++) {
if (dbg->breakpoints[i].enabled)
vcpu->guest_debug.bp[i] = dbg->breakpoints[i].address;
else
vcpu->guest_debug.bp[i] = 0;
}
}
return 0;
}
static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu,