Hi Stewart,
On 09/11/2023 18:27, Stewart Hildebrand wrote:
Enable the use of IOMMU + PCI in dom0 without having to specify
"pci-passthrough=yes". We rely on dom0 to initialize the PCI controller
and perform a PHYSDEVOP_pci_device_add call to add each device to SMMU.
Enable pci_init() for initializing Xen's internal PCI subsystem, and
allow PHYSDEVOP_pci_device_add when pci-passthrough is disabled.
Signed-off-by: Stewart Hildebrand <stewart.hildebr...@amd.com>
---
v5->v6:
* new patch - this effectively replaces
("Revert "xen/arm: Add cmdline boot option "pci-passthrough = <boolean>""")
---
xen/arch/arm/pci/pci.c | 3 ++-
xen/drivers/pci/physdev.c | 6 ------
2 files changed, 2 insertions(+), 7 deletions(-)
diff --git a/xen/arch/arm/pci/pci.c b/xen/arch/arm/pci/pci.c
index 78b97beaef12..ba72fbaf1dfc 100644
--- a/xen/arch/arm/pci/pci.c
+++ b/xen/arch/arm/pci/pci.c
@@ -16,6 +16,7 @@
#include <xen/device_tree.h>
#include <xen/errno.h>
#include <xen/init.h>
+#include <xen/iommu.h>
#include <xen/param.h>
#include <xen/pci.h>
@@ -85,7 +86,7 @@ static int __init pci_init(void)
* Enable PCI passthrough when has been enabled explicitly
* (pci-passthrough=on).
*/
The comment needs to be updated after ...
- if ( !pci_passthrough_enabled )
+ if ( !is_pci_passthrough_enabled() && !iommu_enabled )
... this change.
return 0;
pci_segments_init();
diff --git a/xen/drivers/pci/physdev.c b/xen/drivers/pci/physdev.c
index 42db3e6d133c..4f3e1a96c0fd 100644
--- a/xen/drivers/pci/physdev.c
+++ b/xen/drivers/pci/physdev.c
@@ -18,9 +18,6 @@ ret_t pci_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void)
arg)
struct pci_dev_info pdev_info;
nodeid_t node = NUMA_NO_NODE;
- if ( !is_pci_passthrough_enabled() )
- return -EOPNOTSUPP;
-
AFAIU, this means that pci_add_device() can now be reached even if
pci_segments_init() is not called (this can happen when iommu=false).
What error will now be returned and how dom0 will behave?
Cheers,
--
Julien Grall
