If we are trying to set multiple bits at once, testing that just one of
them is already set gives a false positive. As a result we won't
interrupt guest if e.g. presence detection change and attention button
press are both set. This happens with multi-function device removal.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/pci/pcie.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 88c30ff74c..b22527000d 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -383,7 +383,7 @@ static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
 {
     /* Minor optimization: if nothing changed - no event is needed. */
     if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
-                                   PCI_EXP_SLTSTA, event)) {
+                                   PCI_EXP_SLTSTA, event) == event) {
         return;
     }
     hotplug_event_notify(dev);
-- 
MST

On 6/21/19 9:46 AM, Michael S. Tsirkin wrote:
> If we are trying to set multiple bits at once, testing that just one of
> them is already set gives a false positive. As a result we won't
> interrupt guest if e.g. presence detection change and attention button
> press are both set. This happens with multi-function device removal.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>   hw/pci/pcie.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 88c30ff74c..b22527000d 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -383,7 +383,7 @@ static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
>   {
>       /* Minor optimization: if nothing changed - no event is needed. */
>       if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
> -                                   PCI_EXP_SLTSTA, event)) {
> +                                   PCI_EXP_SLTSTA, event) == event) {
>           return;
>       }
>       hotplug_event_notify(dev);

Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>

Thanks,
Marcel

On 6/21/19 8:46 AM, Michael S. Tsirkin wrote:
> If we are trying to set multiple bits at once, testing that just one of
> them is already set gives a false positive. As a result we won't
> interrupt guest if e.g. presence detection change and attention button
> press are both set. This happens with multi-function device removal.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/pci/pcie.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 88c30ff74c..b22527000d 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -383,7 +383,7 @@ static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
>  {
>      /* Minor optimization: if nothing changed - no event is needed. */
>      if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
> -                                   PCI_EXP_SLTSTA, event)) {
> +                                   PCI_EXP_SLTSTA, event) == event) {
>          return;
>      }
>      hotplug_event_notify(dev);
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

On Fri, 21 Jun 2019 02:46:46 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> If we are trying to set multiple bits at once, testing that just one of
> them is already set gives a false positive. As a result we won't
> interrupt guest if e.g. presence detection change and attention button
> press are both set. This happens with multi-function device removal.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/pci/pcie.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 88c30ff74c..b22527000d 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -383,7 +383,7 @@ static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
>  {
>      /* Minor optimization: if nothing changed - no event is needed. */
>      if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
> -                                   PCI_EXP_SLTSTA, event)) {
> +                                   PCI_EXP_SLTSTA, event) == event) {
>          return;
>      }
>      hotplug_event_notify(dev);