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

From: Maxim Levitsky
Date: Tue Sep 22 2020 - 17:10:43 EST


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@xxxxxxxxxx>
---
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