[PATCH 2/5] booke: exit to guest userspace for unimplemented hcalls in kvm

Bharat Bhushan
2013-07-15T11:18:29Z

Exit to guest user space if kvm does not implement the hcall.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
---
arch/powerpc/kvm/booke.c | 47 +++++++++++++++++++++++++++++++++++++------
arch/powerpc/kvm/powerpc.c | 1 +
include/uapi/linux/kvm.h | 1 +
3 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 17722d8..c8b41b4 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -1005,9 +1005,25 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
break;

#ifdef CONFIG_KVM_BOOKE_HV
- case BOOKE_INTERRUPT_HV_SYSCALL:
+ case BOOKE_INTERRUPT_HV_SYSCALL: {
+ int i;
if (!(vcpu->arch.shared->msr & MSR_PR)) {
- kvmppc_set_gpr(vcpu, 3, kvmppc_kvm_pv(vcpu));
+ r = kvmppc_kvm_pv(vcpu);
+ if (r != EV_UNIMPLEMENTED) {
+ /* except unimplemented return to guest */
+ kvmppc_set_gpr(vcpu, 3, r);
+ kvmppc_account_exit(vcpu, SYSCALL_EXITS);
+ r = RESUME_GUEST;
+ break;
+ }
+ /* Exit to userspace for unimplemented hcalls in kvm */
+ run->epapr_hcall.nr = kvmppc_get_gpr(vcpu, 11);
+ run->epapr_hcall.ret = 0;
+ for (i = 0; i < 8; i++)
+ run->epapr_hcall.args[i] = kvmppc_get_gpr(vcpu, 3 + i);
+ vcpu->arch.hcall_needed = 1;
+ kvmppc_account_exit(vcpu, SYSCALL_EXITS);
+ r = RESUME_HOST;
} else {
/*
* hcall from guest userspace -- send privileged
@@ -1016,22 +1032,39 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
kvmppc_core_queue_program(vcpu, ESR_PPR);
}

- r = RESUME_GUEST;
+ run->exit_reason = KVM_EXIT_EPAPR_HCALL;
break;
+ }
#else
- case BOOKE_INTERRUPT_SYSCALL:
+ case BOOKE_INTERRUPT_SYSCALL: {
+ int i;
+ r = RESUME_GUEST;
if (!(vcpu->arch.shared->msr & MSR_PR) &&
(((u32)kvmppc_get_gpr(vcpu, 0)) == KVM_SC_MAGIC_R0)) {
/* KVM PV hypercalls */
- kvmppc_set_gpr(vcpu, 3, kvmppc_kvm_pv(vcpu));
- r = RESUME_GUEST;
+ r = kvmppc_kvm_pv(vcpu);
+ if (r != EV_UNIMPLEMENTED) {
+ /* except unimplemented return to guest */
+ kvmppc_set_gpr(vcpu, 3, r);
+ kvmppc_account_exit(vcpu, SYSCALL_EXITS);
+ r = RESUME_GUEST;
+ break;
+ }
+ /* Exit to userspace for unimplemented hcalls in kvm */
+ run->epapr_hcall.nr = kvmppc_get_gpr(vcpu, 11);
+ run->epapr_hcall.ret = 0;
+ for (i = 0; i < 8; i++)
+ run->epapr_hcall.args[i] = kvmppc_get_gpr(vcpu, 3 + i);
+ vcpu->arch.hcall_needed = 1;
+ run->exit_reason = KVM_EXIT_EPAPR_HCALL;
+ r = RESUME_HOST;
} else {
/* Guest syscalls */
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_SYSCALL);
}
kvmppc_account_exit(vcpu, SYSCALL_EXITS);
- r = RESUME_GUEST;
break;
+ }
#endif

case BOOKE_INTERRUPT_DTLB_MISS: {
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 4e05f8c..6c6199d 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -307,6 +307,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_PPC_BOOKE_SREGS:
case KVM_CAP_PPC_BOOKE_WATCHDOG:
case KVM_CAP_PPC_EPR:
+ case KVM_CAP_EXIT_EPAPR_HCALL:
#else
case KVM_CAP_PPC_SEGSTATE:
case KVM_CAP_PPC_HIOR:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 01ee50e..b5266e5 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -674,6 +674,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_PPC_RTAS 91
#define KVM_CAP_IRQ_XICS 92
#define KVM_CAP_ARM_EL1_32BIT 93
+#define KVM_CAP_EXIT_EPAPR_HCALL 94

#ifdef KVM_CAP_IRQ_ROUTING

--
1.7.0.4