[Qemu-devel] [PATCH v2 3/5] kvm/x86: Pass return code of kvm_emulate_hypercall

[Andrey Smetanin <asmetanin@virtuozzo.com>]

Pass the return code from kvm_emulate_hypercall on to the caller,
in order to allow it to indicate to the userspace that
the hypercall has to be handled there.

Also adjust all the existing code paths to return 1 to make sure the
hypercall isn't passed to the userspace without setting kvm_run
appropriately.

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
---
 arch/x86/kvm/hyperv.c | 2 +-
 arch/x86/kvm/svm.c    | 3 +--
 arch/x86/kvm/vmx.c    | 3 +--
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index f1a42e1..0e7c90f 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1055,7 +1055,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
 	 */
 	if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
 		kvm_queue_exception(vcpu, UD_VECTOR);
-		return 0;
+		return 1;
 	}
 
 	longmode = is_64_bit_mode(vcpu);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c13a64b..9507038 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1858,8 +1858,7 @@ static int halt_interception(struct vcpu_svm *svm)
 static int vmmcall_interception(struct vcpu_svm *svm)
 {
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
-	kvm_emulate_hypercall(&svm->vcpu);
-	return 1;
+	return kvm_emulate_hypercall(&svm->vcpu);
 }
 
 static unsigned long nested_svm_get_tdp_cr3(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 04d61d4..82879aa 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5747,8 +5747,7 @@ static int handle_halt(struct kvm_vcpu *vcpu)
 
 static int handle_vmcall(struct kvm_vcpu *vcpu)
 {
-	kvm_emulate_hypercall(vcpu);
-	return 1;
+	return kvm_emulate_hypercall(vcpu);
 }
 
 static int handle_invd(struct kvm_vcpu *vcpu)
-- 
2.4.3