Patch for enhanced link speed and width support for Qemu 3.0.0

pcie-enhanced-link-speed-and-width.patch

---
 hw/pci/pcie.c              |    7 ++++---
 hw/vfio/pci.c              |    3 ++-
 include/hw/pci/pcie_regs.h |   23 +++++++++++++++++++++--
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 6c91bd44a0a5..914a5261a79b 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -68,11 +68,12 @@ pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type, uint8_t version)
     pci_set_long(exp_cap + PCI_EXP_LNKCAP,
                  (port << PCI_EXP_LNKCAP_PN_SHIFT) |
                  PCI_EXP_LNKCAP_ASPMS_0S |
-                 PCI_EXP_LNK_MLW_1 |
-                 PCI_EXP_LNK_LS_25);
+                 QEMU_PCI_EXP_LNKCAP_MLW(QEMU_PCI_EXP_LNK_X1) |
+                 QEMU_PCI_EXP_LNKCAP_MLS(QEMU_PCI_EXP_LNK_2_5GT));
 
     pci_set_word(exp_cap + PCI_EXP_LNKSTA,
-                 PCI_EXP_LNK_MLW_1 | PCI_EXP_LNK_LS_25);
+                 QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1) |
+                 QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT));
 
     if (dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
         pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 866f0deeb7eb..08aab328b442 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1895,7 +1895,8 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
                                    PCI_EXP_TYPE_ENDPOINT << 4,
                                    PCI_EXP_FLAGS_TYPE);
             vfio_add_emulated_long(vdev, pos + PCI_EXP_LNKCAP,
-                                   PCI_EXP_LNK_MLW_1 | PCI_EXP_LNK_LS_25, ~0);
+                           QEMU_PCI_EXP_LNKCAP_MLW(QEMU_PCI_EXP_LNK_X1) |
+                           QEMU_PCI_EXP_LNKCAP_MLS(QEMU_PCI_EXP_LNK_2_5GT), ~0);
             vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKCTL, 0, ~0);
         }
 
diff --git a/include/hw/pci/pcie_regs.h b/include/hw/pci/pcie_regs.h
index a95522a13b04..ad4e7808b8ac 100644
--- a/include/hw/pci/pcie_regs.h
+++ b/include/hw/pci/pcie_regs.h
@@ -34,10 +34,29 @@
 
 /* PCI_EXP_LINK{CAP, STA} */
 /* link speed */
-#define PCI_EXP_LNK_LS_25               1
+typedef enum PCIExpLinkSpeed {
+    QEMU_PCI_EXP_LNK_2_5GT = 1,
+    QEMU_PCI_EXP_LNK_5GT,
+    QEMU_PCI_EXP_LNK_8GT,
+    QEMU_PCI_EXP_LNK_16GT,
+} PCIExpLinkSpeed;
+
+#define QEMU_PCI_EXP_LNKCAP_MLS(speed)  (speed)
+#define QEMU_PCI_EXP_LNKSTA_CLS         QEMU_PCI_EXP_LNKCAP_MLS
+
+typedef enum PCIExpLinkWidth {
+    QEMU_PCI_EXP_LNK_X1 = 1,
+    QEMU_PCI_EXP_LNK_X2 = 2,
+    QEMU_PCI_EXP_LNK_X4 = 4,
+    QEMU_PCI_EXP_LNK_X8 = 8,
+    QEMU_PCI_EXP_LNK_X12 = 12,
+    QEMU_PCI_EXP_LNK_X16 = 16,
+    QEMU_PCI_EXP_LNK_X32 = 32,
+} PCIExpLinkWidth;
 
 #define PCI_EXP_LNK_MLW_SHIFT           ctz32(PCI_EXP_LNKCAP_MLW)
-#define PCI_EXP_LNK_MLW_1               (1 << PCI_EXP_LNK_MLW_SHIFT)
+#define QEMU_PCI_EXP_LNKCAP_MLW(width)  (width << PCI_EXP_LNK_MLW_SHIFT)
+#define QEMU_PCI_EXP_LNKSTA_NLW         QEMU_PCI_EXP_LNKCAP_MLW
 
 /* PCI_EXP_LINKCAP */
 #define PCI_EXP_LNKCAP_ASPMS_SHIFT      ctz32(PCI_EXP_LNKCAP_ASPMS)


---
 hw/pci/pci.c          |    4 ++++
 hw/pci/pcie.c         |   39 +++++++++++++++++++++++++++++++++++++++
 include/hw/pci/pci.h  |   13 +++++++++++++
 include/hw/pci/pcie.h |    1 +
 4 files changed, 57 insertions(+)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index b937f0dc0af4..576c85f376b6 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1353,6 +1353,10 @@ uint32_t pci_default_read_config(PCIDevice *d,
 {
     uint32_t val = 0;
 
+    if (pci_is_express_downstream_port(d) &&
+        ranges_overlap(address, len, d->exp.exp_cap + PCI_EXP_LNKSTA, 2)) {
+	pcie_sync_bridge_lnk(d);
+    }
     memcpy(&val, d->config + address, len);
     return le32_to_cpu(val);
 }
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 914a5261a79b..61b7b96c52cd 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -729,6 +729,45 @@ void pcie_add_capability(PCIDevice *dev,
     memset(dev->cmask + offset, 0xFF, size);
 }
 
+/*
+ * Sync the PCIe Link Status negotiated speed and width of a bridge with the
+ * downstream device.  If downstream device is not present, re-write with the
+ * Link Capability fields.  Limit width and speed to bridge capabilities for
+ * compatibility.  Use config_read to access the downstream device since it
+ * could be an assigned device with volatile link information.
+ */
+void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
+{
+    PCIBridge *br = PCI_BRIDGE(bridge_dev);
+    PCIBus *bus = pci_bridge_get_sec_bus(br);
+    PCIDevice *target = bus->devices[0];
+    uint8_t *exp_cap = bridge_dev->config + bridge_dev->exp.exp_cap;
+    uint16_t lnksta, lnkcap = pci_get_word(exp_cap + PCI_EXP_LNKCAP);
+
+    if (!target || !target->exp.exp_cap) {
+        lnksta = lnkcap;
+    } else {
+        lnksta = target->config_read(target,
+                                     target->exp.exp_cap + PCI_EXP_LNKSTA,
+                                     sizeof(lnksta));
+
+        if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) {
+            lnksta &= ~PCI_EXP_LNKSTA_NLW;
+            lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW;
+        }
+
+        if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) {
+            lnksta &= ~PCI_EXP_LNKSTA_CLS;
+            lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS;
+        }
+    }
+
+    pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
+                                 PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
+    pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta &
+                               (PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW));
+}
+
 /**************************************************************************
  * pci express extended capability helper functions
  */
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index e6514bba23aa..eb12fa112ed2 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -737,6 +737,19 @@ static inline int pci_is_express(const PCIDevice *d)
     return d->cap_present & QEMU_PCI_CAP_EXPRESS;
 }
 
+static inline int pci_is_express_downstream_port(const PCIDevice *d)
+{
+    uint8_t type;
+
+    if (!pci_is_express(d) || !d->exp.exp_cap) {
+        return 0;
+    }
+
+    type = pcie_cap_get_type(d);
+
+    return type == PCI_EXP_TYPE_DOWNSTREAM || type == PCI_EXP_TYPE_ROOT_PORT;
+}
+
 static inline uint32_t pci_config_size(const PCIDevice *d)
 {
     return pci_is_express(d) ? PCIE_CONFIG_SPACE_SIZE : PCI_CONFIG_SPACE_SIZE;
diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index b71e36970345..1976909ab4c8 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -126,6 +126,7 @@ uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id);
 void pcie_add_capability(PCIDevice *dev,
                          uint16_t cap_id, uint8_t cap_ver,
                          uint16_t offset, uint16_t size);
+void pcie_sync_bridge_lnk(PCIDevice *dev);
 
 void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn);
 void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num);


---
 hw/core/qdev-properties.c    |  178 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/qdev-properties.h |    8 ++
 qapi/common.json             |   42 ++++++++++
 3 files changed, 228 insertions(+)

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 35072dec1ecf..f5ca5b821a79 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -1327,3 +1327,181 @@ const PropertyInfo qdev_prop_off_auto_pcibar = {
     .set = set_enum,
     .set_default_value = set_default_value_enum,
 };
+
+/* --- PCIELinkSpeed 2_5/5/8/16 -- */
+
+static void get_prop_pcielinkspeed(Object *obj, Visitor *v, const char *name,
+                                   void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    PCIExpLinkSpeed *p = qdev_get_prop_ptr(dev, prop);
+    PCIELinkSpeed speed;
+
+    switch (*p) {
+    case QEMU_PCI_EXP_LNK_2_5GT:
+        speed = PCIE_LINK_SPEED_2_5;
+        break;
+    case QEMU_PCI_EXP_LNK_5GT:
+        speed = PCIE_LINK_SPEED_5;
+        break;
+    case QEMU_PCI_EXP_LNK_8GT:
+        speed = PCIE_LINK_SPEED_8;
+        break;
+    case QEMU_PCI_EXP_LNK_16GT:
+        speed = PCIE_LINK_SPEED_16;
+        break;
+    default:
+        /* Unreachable */
+        abort();
+    }
+
+    visit_type_enum(v, prop->name, (int *)&speed, prop->info->enum_table, errp);
+}
+
+static void set_prop_pcielinkspeed(Object *obj, Visitor *v, const char *name,
+                                   void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    PCIExpLinkSpeed *p = qdev_get_prop_ptr(dev, prop);
+    PCIELinkSpeed speed;
+    Error *local_err = NULL;
+
+    if (dev->realized) {
+        qdev_prop_set_after_realize(dev, name, errp);
+        return;
+    }
+
+    visit_type_enum(v, prop->name, (int *)&speed,
+                    prop->info->enum_table, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    switch (speed) {
+    case PCIE_LINK_SPEED_2_5:
+        *p = QEMU_PCI_EXP_LNK_2_5GT;
+        break;
+    case PCIE_LINK_SPEED_5:
+        *p = QEMU_PCI_EXP_LNK_5GT;
+        break;
+    case PCIE_LINK_SPEED_8:
+        *p = QEMU_PCI_EXP_LNK_8GT;
+        break;
+    case PCIE_LINK_SPEED_16:
+        *p = QEMU_PCI_EXP_LNK_16GT;
+        break;
+    default:
+        /* Unreachable */
+        abort();
+    }
+}
+
+const PropertyInfo qdev_prop_pcie_link_speed = {
+    .name = "PCIELinkSpeed",
+    .description = "2_5/5/8/16",
+    .enum_table = &PCIELinkSpeed_lookup,
+    .get = get_prop_pcielinkspeed,
+    .set = set_prop_pcielinkspeed,
+    .set_default_value = set_default_value_enum,
+};
+
+/* --- PCIELinkWidth 1/2/4/8/12/16/32 -- */
+
+static void get_prop_pcielinkwidth(Object *obj, Visitor *v, const char *name,
+                                   void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    PCIExpLinkWidth *p = qdev_get_prop_ptr(dev, prop);
+    PCIELinkWidth width;
+
+    switch (*p) {
+    case QEMU_PCI_EXP_LNK_X1:
+        width = PCIE_LINK_WIDTH_1;
+        break;
+    case QEMU_PCI_EXP_LNK_X2:
+        width = PCIE_LINK_WIDTH_2;
+        break;
+    case QEMU_PCI_EXP_LNK_X4:
+        width = PCIE_LINK_WIDTH_4;
+        break;
+    case QEMU_PCI_EXP_LNK_X8:
+        width = PCIE_LINK_WIDTH_8;
+        break;
+    case QEMU_PCI_EXP_LNK_X12:
+        width = PCIE_LINK_WIDTH_12;
+        break;
+    case QEMU_PCI_EXP_LNK_X16:
+        width = PCIE_LINK_WIDTH_16;
+        break;
+    case QEMU_PCI_EXP_LNK_X32:
+        width = PCIE_LINK_WIDTH_32;
+        break;
+    default:
+        /* Unreachable */
+        abort();
+    }
+
+    visit_type_enum(v, prop->name, (int *)&width, prop->info->enum_table, errp);
+}
+
+static void set_prop_pcielinkwidth(Object *obj, Visitor *v, const char *name,
+                                   void *opaque, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    Property *prop = opaque;
+    PCIExpLinkWidth *p = qdev_get_prop_ptr(dev, prop);
+    PCIELinkWidth width;
+    Error *local_err = NULL;
+
+    if (dev->realized) {
+        qdev_prop_set_after_realize(dev, name, errp);
+        return;
+    }
+
+    visit_type_enum(v, prop->name, (int *)&width,
+                    prop->info->enum_table, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    switch (width) {
+    case PCIE_LINK_WIDTH_1:
+        *p = QEMU_PCI_EXP_LNK_X1;
+        break;
+    case PCIE_LINK_WIDTH_2:
+        *p = QEMU_PCI_EXP_LNK_X2;
+        break;
+    case PCIE_LINK_WIDTH_4:
+        *p = QEMU_PCI_EXP_LNK_X4;
+        break;
+    case PCIE_LINK_WIDTH_8:
+        *p = QEMU_PCI_EXP_LNK_X8;
+        break;
+    case PCIE_LINK_WIDTH_12:
+        *p = QEMU_PCI_EXP_LNK_X12;
+        break;
+    case PCIE_LINK_WIDTH_16:
+        *p = QEMU_PCI_EXP_LNK_X16;
+        break;
+    case PCIE_LINK_WIDTH_32:
+        *p = QEMU_PCI_EXP_LNK_X32;
+        break;
+    default:
+        /* Unreachable */
+        abort();
+    }
+}
+
+const PropertyInfo qdev_prop_pcie_link_width = {
+    .name = "PCIELinkWidth",
+    .description = "1/2/4/8/12/16/32",
+    .enum_table = &PCIELinkWidth_lookup,
+    .get = get_prop_pcielinkwidth,
+    .set = set_prop_pcielinkwidth,
+    .set_default_value = set_default_value_enum,
+};
diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
index 4f60cc88f325..6a13a284c48c 100644
--- a/include/hw/qdev-properties.h
+++ b/include/hw/qdev-properties.h
@@ -36,6 +36,8 @@ extern const PropertyInfo qdev_prop_uuid;
 extern const PropertyInfo qdev_prop_arraylen;
 extern const PropertyInfo qdev_prop_link;
 extern const PropertyInfo qdev_prop_off_auto_pcibar;
+extern const PropertyInfo qdev_prop_pcie_link_speed;
+extern const PropertyInfo qdev_prop_pcie_link_width;
 
 #define DEFINE_PROP(_name, _state, _field, _prop, _type) { \
         .name      = (_name),                                    \
@@ -217,6 +219,12 @@ extern const PropertyInfo qdev_prop_off_auto_pcibar;
 #define DEFINE_PROP_OFF_AUTO_PCIBAR(_n, _s, _f, _d) \
     DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_off_auto_pcibar, \
                         OffAutoPCIBAR)
+#define DEFINE_PROP_PCIE_LINK_SPEED(_n, _s, _f, _d) \
+    DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_pcie_link_speed, \
+                        PCIExpLinkSpeed)
+#define DEFINE_PROP_PCIE_LINK_WIDTH(_n, _s, _f, _d) \
+    DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_pcie_link_width, \
+                        PCIExpLinkWidth)
 
 #define DEFINE_PROP_UUID(_name, _state, _field) {                  \
         .name      = (_name),                                      \
diff --git a/qapi/common.json b/qapi/common.json
index 021174f04ea4..b6f3cca35c7e 100644
--- a/qapi/common.json
+++ b/qapi/common.json
@@ -127,6 +127,48 @@
 { 'enum': 'OffAutoPCIBAR',
   'data': [ 'off', 'auto', 'bar0', 'bar1', 'bar2', 'bar3', 'bar4', 'bar5' ] }
 
+##
+# @PCIELinkSpeed:
+#
+# An enumeration of PCIe link speeds in units of GT/s
+#
+# @2_5: 2.5GT/s
+#
+# @5: 5.0GT/s
+#
+# @8: 8.0GT/s
+#
+# @16: 16.0GT/s
+#
+# Since: 3.2
+##
+{ 'enum': 'PCIELinkSpeed',
+  'data': [ '2_5', '5', '8', '16' ] }
+
+##
+# @PCIELinkWidth:
+#
+# An enumeration of PCIe link width
+#
+# @1: x1
+#
+# @2: x2
+#
+# @4: x4
+#
+# @8: x8
+#
+# @12: x12
+#
+# @16: x16
+#
+# @32: x32
+#
+# Since: 3.2
+##
+{ 'enum': 'PCIELinkWidth',
+  'data': [ '1', '2', '4', '8', '12', '16', '32' ] }
+
 ##
 # @SysEmuTarget:
 #


---
 hw/pci-bridge/pcie_root_port.c |   14 ++++++++++++++
 include/hw/pci/pcie_port.h     |    4 ++++
 2 files changed, 18 insertions(+)

diff --git a/hw/pci-bridge/pcie_root_port.c b/hw/pci-bridge/pcie_root_port.c
index 45f9e8cd4a36..34ad76743c44 100644
--- a/hw/pci-bridge/pcie_root_port.c
+++ b/hw/pci-bridge/pcie_root_port.c
@@ -140,6 +140,19 @@ static Property rp_props[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
+static void rp_instance_post_init(Object *obj)
+{
+    PCIESlot *s = PCIE_SLOT(obj);
+
+    if (!s->speed) {
+        s->speed = QEMU_PCI_EXP_LNK_2_5GT;
+    }
+
+    if (!s->width) {
+        s->width = QEMU_PCI_EXP_LNK_X1;
+    }
+}
+
 static void rp_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -157,6 +170,7 @@ static void rp_class_init(ObjectClass *klass, void *data)
 static const TypeInfo rp_info = {
     .name          = TYPE_PCIE_ROOT_PORT,
     .parent        = TYPE_PCIE_SLOT,
+    .instance_post_init = rp_instance_post_init,
     .class_init    = rp_class_init,
     .abstract      = true,
     .class_size = sizeof(PCIERootPortClass),
diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h
index 0736014bfdb4..df242a0cafff 100644
--- a/include/hw/pci/pcie_port.h
+++ b/include/hw/pci/pcie_port.h
@@ -49,6 +49,10 @@ struct PCIESlot {
     /* pci express switch port with slot */
     uint8_t     chassis;
     uint16_t    slot;
+
+    PCIExpLinkSpeed speed;
+    PCIExpLinkWidth width;
+
     QLIST_ENTRY(PCIESlot) next;
 };
 


---
 hw/pci/pcie.c |   72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 61b7b96c52cd..556ec19925b9 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -27,6 +27,7 @@
 #include "hw/pci/msi.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/pci/pcie_regs.h"
+#include "hw/pci/pcie_port.h"
 #include "qemu/range.h"
 
 //#define DEBUG_PCIE
@@ -87,6 +88,74 @@ pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type, uint8_t version)
     pci_set_word(cmask + PCI_EXP_LNKSTA, 0);
 }
 
+static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
+{
+    PCIESlot *s = (PCIESlot *)object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT);
+    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
+
+    /* Skip anything that isn't a PCIESlot */
+    if (!s) {
+        return;
+    }
+
+    /* Clear and fill LNKCAP from what was configured above */
+    pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP,
+                                 PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
+    pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
+                               QEMU_PCI_EXP_LNKCAP_MLW(s->width) |
+                               QEMU_PCI_EXP_LNKCAP_MLS(s->speed));
+
+    /*
+     * Link bandwidth notification is required for all root ports and
+     * downstream ports supporting links wider than x1.
+     */
+    if (s->width > QEMU_PCI_EXP_LNK_X1) {
+        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
+                                   PCI_EXP_LNKCAP_LBNC);
+    }
+
+    if (s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
+        /*
+         * Hot-plug capable downstream ports and downstream ports supporting
+         * link speeds greater than 5GT/s must hardwire PCI_EXP_LNKCAP_DLLLARC
+         * to 1b.  PCI_EXP_LNKCAP_DLLLARC implies PCI_EXP_LNKSTA_DLLLA, which
+         * we also hardwire to 1b here.  2.5GT/s hot-plug slots should also
+         * technically implement this, but it's not done here for compatibility.
+         */
+        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
+                                   PCI_EXP_LNKCAP_DLLLARC);
+        pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
+                                   PCI_EXP_LNKSTA_DLLLA);
+
+        /*
+         * Target Link Speed defaults to the highest link speed supported by
+         * the component.  2.5GT/s devices are permitted to hardwire to zero.
+         */
+        pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKCTL2,
+                                     PCI_EXP_LNKCTL2_TLS);
+        pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKCTL2,
+                                   QEMU_PCI_EXP_LNKCAP_MLS(s->speed) &
+                                   PCI_EXP_LNKCTL2_TLS);
+    }
+
+    /*
+     * 2.5 & 5.0GT/s can be fully described by LNKCAP, but 8.0GT/s is
+     * actually a reference to the highest bit supported in this register.
+     * We assume the device supports all link speeds.
+     */
+    if (s->speed > QEMU_PCI_EXP_LNK_5GT) {
+        pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP2, ~0U);
+        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
+                                   PCI_EXP_LNKCAP2_SLS_2_5GB |
+                                   PCI_EXP_LNKCAP2_SLS_5_0GB |
+                                   PCI_EXP_LNKCAP2_SLS_8_0GB);
+        if (s->speed > QEMU_PCI_EXP_LNK_8GT) {
+            pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
+                                       PCI_EXP_LNKCAP2_SLS_16_0GB);
+        }
+    }
+}
+
 int pcie_cap_init(PCIDevice *dev, uint8_t offset,
                   uint8_t type, uint8_t port,
                   Error **errp)
@@ -108,6 +177,9 @@ int pcie_cap_init(PCIDevice *dev, uint8_t offset,
     /* Filling values common with v1 */
     pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER2);
 
+    /* Fill link speed and width options */
+    pcie_cap_fill_slot_lnk(dev);
+
     /* Filling v2 specific values */
     pci_set_long(exp_cap + PCI_EXP_DEVCAP2,
                  PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);


---
 hw/pci-bridge/gen_pcie_root_port.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/pci-bridge/gen_pcie_root_port.c b/hw/pci-bridge/gen_pcie_root_port.c
index 299de429ec1e..e3bba2ab68ef 100644
--- a/hw/pci-bridge/gen_pcie_root_port.c
+++ b/hw/pci-bridge/gen_pcie_root_port.c
@@ -123,6 +123,8 @@ static Property gen_rp_props[] = {
     DEFINE_PROP_SIZE("mem-reserve", GenPCIERootPort, mem_reserve, -1),
     DEFINE_PROP_SIZE("pref32-reserve", GenPCIERootPort, pref32_reserve, -1),
     DEFINE_PROP_SIZE("pref64-reserve", GenPCIERootPort, pref64_reserve, -1),
+    DEFINE_PROP_PCIE_LINK_SPEED("speed", PCIESlot, speed, PCIE_LINK_SPEED_2_5),
+    DEFINE_PROP_PCIE_LINK_WIDTH("width", PCIESlot, width, PCIE_LINK_WIDTH_1),
     DEFINE_PROP_END_OF_LIST()
 };
 


---
 hw/vfio/pci.c |    6 ------
 1 file changed, 6 deletions(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 08aab328b442..0d1dd4666fd1 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1899,12 +1899,6 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size,
                            QEMU_PCI_EXP_LNKCAP_MLS(QEMU_PCI_EXP_LNK_2_5GT), ~0);
             vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKCTL, 0, ~0);
         }
-
-        /* Mark the Link Status bits as emulated to allow virtual negotiation */
-        vfio_add_emulated_word(vdev, pos + PCI_EXP_LNKSTA,
-                               pci_get_word(vdev->pdev.config + pos +
-                                            PCI_EXP_LNKSTA),
-                               PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
     }
 
     /*