From: Andrey Smetanin <asmetanin@virtuozzo.com>
Date: Thu, 11 Feb 2016 13:45:00 +0000 (+0300)
Subject: kvm/x86: Reject Hyper-V hypercall continuation
X-Git-Tag: v4.14-rc1~3659^2~58
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b2fdc2570a6c4b1fe950c11a2e9ce949f5190765;p=platform%2Fkernel%2Flinux-rpi.git

kvm/x86: Reject Hyper-V hypercall continuation

Currently we do not support Hyper-V hypercall continuation
so reject it.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 599b067..e8af597 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1083,6 +1083,12 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
 
 	trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
 
+	/* Hypercall continuation is not supported yet */
+	if (rep_cnt || rep_idx) {
+		res = HV_STATUS_INVALID_HYPERCALL_CODE;
+		goto set_result;
+	}
+
 	switch (code) {
 	case HVCALL_NOTIFY_LONG_SPIN_WAIT:
 		kvm_vcpu_on_spin(vcpu);
@@ -1092,6 +1098,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
 		break;
 	}
 
+set_result:
 	ret = res | (((u64)rep_done & 0xfff) << 32);
 	if (longmode) {
 		kvm_register_write(vcpu, VCPU_REGS_RAX, ret);