On 6/16/26 02:42, Philippe Mathieu-Daudé wrote:
Hi,
On 15/6/26 22:48, Nathan Chen wrote:
From: Nathan Chen <[email protected]>
Emit a warning when ats=on is requested but the physical device does not
advertise ATS, since ATS cannot be exposed to the guest in this case.
Signed-off-by: Nathan Chen <[email protected]>
---
hw/vfio/pci.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 0f592ada89..49ba6813ee 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2592,6 +2592,7 @@ static void vfio_add_ext_cap(VFIOPCIDevice *vdev, bool
ats_needed)
{
PCIDevice *pdev = PCI_DEVICE(vdev);
bool pasid_cap_added = false;
+ bool ats_cap_present = false;
Error *err = NULL;
^^^^^^^^^^
uint32_t header;
uint16_t cap_id, next, size;
@@ -2680,6 +2681,7 @@ static void vfio_add_ext_cap(VFIOPCIDevice *vdev, bool
ats_needed)
pcie_add_capability(pdev, cap_id, cap_ver, next, size);
break;
case PCI_EXT_CAP_ID_ATS:
+ ats_cap_present = true;
/*
* If ATS is requested and supported according to the kernel, add
* the ATS capability. If not supported according to the kernel or
@@ -2699,6 +2701,11 @@ static void vfio_add_ext_cap(VFIOPCIDevice *vdev, bool
ats_needed)
error_report_err(err);
^^^^^^^^^^^^^^^^
}
+ if (vdev->ats == ON_OFF_AUTO_ON && !ats_cap_present) {
+ warn_report("vfio-pci: ats=on requested, but host device has no "
+ "ATS extended capability");
+ }
At a quick glance vfio_pci_add_capabilities() should pass its @errp
to vfio_add_ext_cap() so the latter can propagate any error instead
of calling error_report_err() or warn_report(). I note this is
pre-existing and could be cleaned later, IMHO the sooner the better
but up to the maintainers.
It would be nice to have and can be done later. It's not strictly part
of this series.
Thanks,
C.
