pcie: Specify 0 for ARI next function numbers

The current implementers of ARI are all SR-IOV devices. The ARI next
function number field is undefined for VF according to PCI Express Base
Specification Revision 5.0 Version 1.0 section 9.3.7.7. The PF still
requires some defined value so end the linked list formed with the field
by specifying 0 as required for any ARI implementation according to
section 7.8.7.2.

For migration, the field will keep having 1 as its value on the old
QEMU machine versions.

Fixes: 2503461691 ("pcie: Add some SR/IOV API documentation in docs/pcie_sriov.txt")
Fixes: 44c2c09488 ("hw/nvme: Add support for SR-IOV")
Fixes: 3a977deebe ("Intrdocue igb device emulation")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
Message-Id: <20230710153838.33917-3-akihiko.odaki@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 46f8f9a..f0d35c6 100644 (file)
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -41,6 +41,7 @@
 
 GlobalProperty hw_compat_8_0[] = {
     { "migration", "multifd-flush-after-each-section", "on"},
+    { TYPE_PCI_DEVICE, "x-pcie-ari-nextfn-1", "on" },
 };
 const size_t hw_compat_8_0_len = G_N_ELEMENTS(hw_compat_8_0);
 

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 4b14f31..784c02a 100644 (file)
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -83,6 +83,8 @@ static Property pci_props[] = {
     DEFINE_PROP_UINT32("acpi-index",  PCIDevice, acpi_index, 0),
     DEFINE_PROP_BIT("x-pcie-err-unc-mask", PCIDevice, cap_present,
                     QEMU_PCIE_ERR_UNC_MASK_BITNR, true),
+    DEFINE_PROP_BIT("x-pcie-ari-nextfn-1", PCIDevice, cap_present,
+                    QEMU_PCIE_ARI_NEXTFN_1_BITNR, false),
     DEFINE_PROP_END_OF_LIST()
 };
 

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 6075ff5..6db0cf6 100644 (file)
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -1041,7 +1041,7 @@ void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
 /* ARI */
 void pcie_ari_init(PCIDevice *dev, uint16_t offset)
 {
-    uint16_t nextfn = 1;
+    uint16_t nextfn = dev->cap_present & QEMU_PCIE_ARI_NEXTFN_1 ? 1 : 0;
 
     pcie_add_capability(dev, PCI_EXT_CAP_ID_ARI, PCI_ARI_VER,
                         offset, PCI_ARI_SIZEOF);

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index ab2bd65..abdc1ef 100644 (file)
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -209,6 +209,8 @@ enum {
     QEMU_PCIE_CAP_CXL = (1 << QEMU_PCIE_CXL_BITNR),
 #define QEMU_PCIE_ERR_UNC_MASK_BITNR 11
     QEMU_PCIE_ERR_UNC_MASK = (1 << QEMU_PCIE_ERR_UNC_MASK_BITNR),
+#define QEMU_PCIE_ARI_NEXTFN_1_BITNR 12
+    QEMU_PCIE_ARI_NEXTFN_1 = (1 << QEMU_PCIE_ARI_NEXTFN_1_BITNR),
 };
 
 typedef struct PCIINTxRoute {