[Devel] [PATCH rh7 V2 3/5] kvm/x86: Pass return code of kvm_emulate_hypercall

[Andrey Smetanin]

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 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: Joerg Roedel <joro at 8bytes.org>
CC: "K. Y. Srinivasan" <kys at microsoft.com>
CC: Haiyang Zhang <haiyangz at microsoft.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>
(cherry picked from commit 0d9c055eaaf41bebb0e6b095fff447523121fad3)
---
 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 c4c1a80..7638214 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1056,7 +1056,7 @@ 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;
 	}
 
 	kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f8bde17..12850b2 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1942,8 +1942,7 @@ static int vmmcall_interception(struct vcpu_svm *svm)
 {
 	svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
 	skip_emulated_instruction(&svm->vcpu);
-	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 4474efc..06ae2d3 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5300,8 +5300,7 @@ static int handle_halt(struct kvm_vcpu *vcpu)
 static int handle_vmcall(struct kvm_vcpu *vcpu)
 {
 	skip_emulated_instruction(vcpu);
-	kvm_emulate_hypercall(vcpu);
-	return 1;
+	return kvm_emulate_hypercall(vcpu);
 }
 
 static int handle_invd(struct kvm_vcpu *vcpu)
-- 
2.4.3