[PATCH] kvm: fix error handling for out of range irq

[PATCH] kvm: fix error handling for out of range irq

[Michael S. Tsirkin]

find_index_from_host_irq returns 0 on error
but callers assume < 0 on error. This should
not matter much: an out of range irq should never happen since
irq handler was registered with this irq #,
and even if it does we get a spurious msix irq in guest
and typically nothing terrible happens.

Still, better to make it consistent.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 virt/kvm/assigned-dev.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 73bb001..0cbd8a1 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -49,10 +49,8 @@ static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
 			index = i;
 			break;
 		}
-	if (index < 0) {
+	if (index < 0)
 		printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");
-		return 0;
-	}
 
 	return index;
 }
-- 
1.7.8.2.325.g247f9

Re: [PATCH] kvm: fix error handling for out of range irq

[Marcelo Tosatti]

On Wed, Jan 18, 2012 at 08:07:09PM +0200, Michael S. Tsirkin wrote:
> find_index_from_host_irq returns 0 on error
> but callers assume < 0 on error. This should
> not matter much: an out of range irq should never happen since
> irq handler was registered with this irq #,
> and even if it does we get a spurious msix irq in guest
> and typically nothing terrible happens.
> 
> Still, better to make it consistent.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  virt/kvm/assigned-dev.c |    4 +---
>  1 files changed, 1 insertions(+), 3 deletions(-)

Applied, thanks.