[PATCH v3 3/6] KVM: x86: hyperv: do rep check for each hypercall separately

Vitaly Kuznetsov
2018-04-16T11:08:03Z

Prepare to support TLB flush hypercalls, some of which are REP hypercalls.
Also, return HV_STATUS_INVALID_HYPERCALL_INPUT as it seems more
appropriate.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/hyperv.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 3cb3bb68db7e..67788d358200 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1309,7 +1309,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
{
u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
uint16_t code, rep_idx, rep_cnt;
- bool fast, longmode;
+ bool fast, longmode, rep;

/*
* hypercall generates UD from non zero cpl and real mode
@@ -1342,28 +1342,31 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
fast = !!(param & HV_HYPERCALL_FAST_BIT);
rep_cnt = (param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
rep_idx = (param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
+ rep = !!(rep_cnt || rep_idx);

trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);

- /* Hypercall continuation is not supported yet */
- if (rep_cnt || rep_idx) {
- ret = HV_STATUS_INVALID_HYPERCALL_CODE;
- goto set_result;
- }
-
switch (code) {
case HVCALL_NOTIFY_LONG_SPIN_WAIT:
+ if (unlikely(rep)) {
+ ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+ break;
+ }
kvm_vcpu_on_spin(vcpu, true);
break;
case HVCALL_SIGNAL_EVENT:
+ if (unlikely(rep)) {
+ ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+ break;
+ }
ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
if (ret != HV_STATUS_INVALID_PORT_ID)
break;
/* maybe userspace knows this conn_id: fall through */
case HVCALL_POST_MESSAGE:
/* don't bother userspace if it has no way to handle it */
- if (!vcpu_to_synic(vcpu)->active) {
- ret = HV_STATUS_INVALID_HYPERCALL_CODE;
+ if (unlikely(rep || !vcpu_to_synic(vcpu)->active)) {
+ ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
vcpu->run->exit_reason = KVM_EXIT_HYPERV;
--
2.14.3