[Devel] [PATCH RHEL7 COMMIT] ms/kvm/x86: Skip SynIC vector check for QEMU side

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-327.4.5.vz7.11.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.4.5.vz7.11.2
------>
commit 06bc36b7bb074d2eefb69e31c5618b8933f6e704
Author: Andrey Smetanin <asmetanin at virtuozzo.com>
Date:   Tue Feb 16 13:50:27 2016 +0400

    ms/kvm/x86: Skip SynIC vector check for QEMU side
    
    QEMU zero-inits Hyper-V SynIC vectors. We should allow that,
    and don't reject zero values if set by the host.
    
    ms commit - 7be58a6488a9d36886d9423a1ed54fe104c7b182.
    
    Signed-off-by: Andrey Smetanin <asmetanin at virtuozzo.com>
    
    Reviewed-by: Roman Kagan <rkagan at virtuozzo.com>
    CC: Gleb Natapov <gleb at kernel.org>
    CC: Paolo Bonzini <pbonzini at redhat.com>
    CC: Roman Kagan <rkagan at virtuozzo.com>
    CC: Denis V. Lunev <den at openvz.org>
    CC: qemu-devel at nongnu.org
    Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
 arch/x86/kvm/hyperv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 119e3b2..a85e91d 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -72,12 +72,13 @@ static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
 	return false;
 }
 
-static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint, u64 data)
+static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
+			  u64 data, bool host)
 {
 	int vector;
 
 	vector = data & HV_SYNIC_SINT_VECTOR_MASK;
-	if (vector < 16)
+	if (vector < 16 && !host)
 		return 1;
 	/*
 	 * Guest may configure multiple SINTs to use the same vector, so
@@ -247,7 +248,7 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
 		break;
 	}
 	case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
-		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data);
+		ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
 		break;
 	default:
 		ret = 1;