Hi Stewart,
On 17/05/2024 18:06, Stewart Hildebrand wrote:
From: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
There are three originators for the PCI configuration space access:
1. The domain that owns physical host bridge: MMIO handlers are
there so we can update vPCI register handlers with the values
written by the hardware domain, e.g. physical view of the registers
vs guest's view on the configuration space.
2. Guest access to the passed through PCI devices: we need to properly
map virtual bus topology to the physical one, e.g. pass the configuration
space access to the corresponding physical devices.
3. Emulated host PCI bridge access. It doesn't exist in the physical
topology, e.g. it can't be mapped to some physical host bridge.
So, all access to the host bridge itself needs to be trapped and
emulated.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushche...@epam.com>
Signed-off-by: Volodymyr Babchuk <volodymyr_babc...@epam.com>
Signed-off-by: Stewart Hildebrand <stewart.hildebr...@amd.com>
With one remark below, for Arm:
Acked-by: Julien Grall <jgr...@amazon.com>
[...]
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index 23722634d50b..98b294f09688 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/xen/drivers/vpci/vpci.c
@@ -81,6 +81,30 @@ static int add_virtual_device(struct pci_dev *pdev)
return 0;
}
+/*
+ * Find the physical device which is mapped to the virtual device
+ * and translate virtual SBDF to the physical one.
+ */
+bool vpci_translate_virtual_device(const struct domain *d, pci_sbdf_t *sbdf)
+{
+ const struct pci_dev *pdev;
+
+ ASSERT(!is_hardware_domain(d));
+ ASSERT(rw_is_locked(&d->pci_lock));
+
+ for_each_pdev ( d, pdev )
(This doesn't need to be addressed now)
I see that we have other places with for_each_pdev() in the vCPI. So are
we expecting the list to be smallish?
If not, then we may want to consider reworking the datastructure or put
a limit on the number of PCI devices assigned.
+ {
+ if ( pdev->vpci && (pdev->vpci->guest_sbdf.sbdf == sbdf->sbdf) )
+ {
+ /* Replace guest SBDF with the physical one. */
+ *sbdf = pdev->sbdf;
+ return true;
+ }
+ }
+
+ return false;
+}
+
#endif /* CONFIG_HAS_VPCI_GUEST_SUPPORT */
void vpci_deassign_device(struct pci_dev *pdev)
diff --git a/xen/include/xen/vpci.h b/xen/include/xen/vpci.h
index 980aded26fc1..7e5a0f0c50c1 100644
--- a/xen/include/xen/vpci.h
+++ b/xen/include/xen/vpci.h
@@ -303,6 +303,18 @@ static inline bool __must_check
vpci_process_pending(struct vcpu *v)
}
#endif
+#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT
+bool vpci_translate_virtual_device(const struct domain *d, pci_sbdf_t *sbdf);
+#else
+static inline bool vpci_translate_virtual_device(const struct domain *d,
+ pci_sbdf_t *sbdf)
+{
+ ASSERT_UNREACHABLE();
+
+ return false;
+}
+#endif
+
#endif
/*
Cheers,
--
Julien Grall
