[PATCH v6 1/4] KVM: x86: xen_hvm_config: cleanup return values

From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Joerg Roedel <joro@8bytes.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, Jim Mattson <jmattson@google.com>,
	x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH v6 1/4] KVM: x86: xen_hvm_config: cleanup return values
Date: Wed, 23 Sep 2020 00:10:22 +0300	[thread overview]
Message-ID: <20200922211025.175547-2-mlevitsk@redhat.com> (raw)
In-Reply-To: <20200922211025.175547-1-mlevitsk@redhat.com>

Return 1 on errors that are caused by wrong guest behavior
(which will inject #GP to the guest)

And return a negative error value on issues that are
the kernel's fault (e.g -ENOMEM)

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 arch/x86/kvm/x86.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 17f4995e80a7e..063d70e736f7f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2694,24 +2694,19 @@ static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
 	u32 page_num = data & ~PAGE_MASK;
 	u64 page_addr = data & PAGE_MASK;
 	u8 *page;
-	int r;
 
-	r = -E2BIG;
 	if (page_num >= blob_size)
-		goto out;
-	r = -ENOMEM;
+		return 1;
+
 	page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE);
-	if (IS_ERR(page)) {
-		r = PTR_ERR(page);
-		goto out;
+	if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
+		kfree(page);
+		return 1;
 	}
-	if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE))
-		goto out_free;
-	r = 0;
-out_free:
-	kfree(page);
-out:
-	return r;
+	return 0;
 }
 
 static inline bool kvm_pv_async_pf_enabled(struct kvm_vcpu *vcpu)
-- 
2.26.2

