[Qemu-devel] [RFC PATCH 8/8] device-assignment: pass through and stub more PCI caps

[Alex Williamson <alex.williamson@redhat.com>]

Some drivers depend on finding capabilities like power management,
PCI express/X, vital product data, or vendor specific fields.  Now
that we have better capability support, we can pass more of these
tables through to the guest.  Note that VPD and VNDR are direct pass
through capabilies, the rest are mostly empty shells with a few
writable bits where necessary.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

 hw/device-assignment.c |  160 +++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 149 insertions(+), 11 deletions(-)

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 179c7dc..1b228ad 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -366,6 +366,27 @@ static uint8_t assigned_dev_pci_read_byte(PCIDevice *d, int pos)
     return (uint8_t)assigned_dev_pci_read(d, pos, 1);
 }
 
+static void assigned_dev_pci_write(PCIDevice *d, int pos, uint32_t val, int len)
+{
+    AssignedDevice *pci_dev = container_of(d, AssignedDevice, dev);
+    ssize_t ret;
+    int fd = pci_dev->real_device.config_fd;
+
+again:
+    ret = pwrite(fd, &val, len, pos);
+    if (ret != len) {
+	if ((ret < 0) && (errno == EINTR || errno == EAGAIN))
+	    goto again;
+
+	fprintf(stderr, "%s: pwrite failed, ret = %zd errno = %d\n",
+		__func__, ret, errno);
+
+	exit(1);
+    }
+
+    return;
+}
+
 static uint8_t pci_find_cap_offset(PCIDevice *d, uint8_t cap)
 {
     int id;
@@ -1244,37 +1265,75 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int ctrl_pos)
 #endif
 #endif
 
+static uint32_t assigned_device_pci_cap_read_config(PCIDevice *pci_dev,
+                                                    uint8_t cap_id,
+                                                    uint32_t address, int len)
+{
+    uint8_t cap;
+
+    switch (cap_id) {
+
+    case PCI_CAP_ID_VPD:
+        cap = pci_find_capability(pci_dev, cap_id);
+        if (address - cap >= PCI_CAP_FLAGS) {
+            return assigned_dev_pci_read(pci_dev, address, len);
+        }
+        break;
+
+    case PCI_CAP_ID_VNDR:
+        cap = pci_find_capability(pci_dev, cap_id);
+        if (address - cap > PCI_CAP_FLAGS) {
+            return assigned_dev_pci_read(pci_dev, address, len);
+        }
+        break;
+    }
+
+    return pci_default_cap_read_config(pci_dev, cap_id, address, len);
+}
+
 static void assigned_device_pci_cap_write_config(PCIDevice *pci_dev,
                                                  uint8_t cap_id,
                                                  uint32_t address,
                                                  uint32_t val, int len)
 {
+    uint8_t cap;
+
     pci_default_cap_write_config(pci_dev, cap_id, address, val, len);
 
     switch (cap_id) {
 #ifdef KVM_CAP_IRQ_ROUTING
     case PCI_CAP_ID_MSI:
 #ifdef KVM_CAP_DEVICE_MSI
-        {
-            uint8_t cap = pci_find_capability(pci_dev, cap_id);
-            if (ranges_overlap(address - cap, len, PCI_MSI_FLAGS, 1)) {
-                assigned_dev_update_msi(pci_dev, cap + PCI_MSI_FLAGS);
-            }
+        cap = pci_find_capability(pci_dev, cap_id);
+        if (ranges_overlap(address - cap, len, PCI_MSI_FLAGS, 1)) {
+            assigned_dev_update_msi(pci_dev, cap + PCI_MSI_FLAGS);
         }
 #endif
         break;
 
     case PCI_CAP_ID_MSIX:
 #ifdef KVM_CAP_DEVICE_MSIX
-        {
-            uint8_t cap = pci_find_capability(pci_dev, cap_id);
-            if (ranges_overlap(address - cap, len, PCI_MSIX_FLAGS + 1, 1)) {
-                assigned_dev_update_msix(pci_dev, cap + PCI_MSIX_FLAGS);
-            }
+        cap = pci_find_capability(pci_dev, cap_id);
+        if (ranges_overlap(address - cap, len, PCI_MSIX_FLAGS + 1, 1)) {
+            assigned_dev_update_msix(pci_dev, cap + PCI_MSIX_FLAGS);
         }
 #endif
         break;
 #endif
+
+    case PCI_CAP_ID_VPD:
+        cap = pci_find_capability(pci_dev, cap_id);
+        if (address - cap >= PCI_CAP_FLAGS) {
+            assigned_dev_pci_write(pci_dev, address, val, len);
+        }
+        break;
+
+    case PCI_CAP_ID_VNDR:
+        cap = pci_find_capability(pci_dev, cap_id);
+        if (address - cap > PCI_CAP_FLAGS) {
+            assigned_dev_pci_write(pci_dev, address, val, len);
+        }
+        break;
     }
     return;
 }
@@ -1340,6 +1399,84 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev)
 #endif
 #endif
 
+    /* Minimal PM support, make the state bits writable so the guest
+     * thinks it's doing something. */
+    if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_PM))) {
+        uint16_t pmc, pmcsr;
+        pci_add_capability_at_offset(pci_dev, PCI_CAP_ID_PM, pos,
+                                     PCI_PM_SIZEOF);
+
+        pmc = pci_get_word(pci_dev->config + pos + PCI_CAP_FLAGS);
+        pmc &= (PCI_PM_CAP_VER_MASK | PCI_PM_CAP_DSI);
+        pci_set_word(pci_dev->config + pos + PCI_CAP_FLAGS, pmc);
+
+        pmcsr = pci_get_word(pci_dev->config + pos + PCI_PM_CTRL);
+        pmcsr &= (PCI_PM_CTRL_STATE_MASK);
+        pmcsr |= PCI_PM_CTRL_NO_SOFT_RST;
+        pci_set_word(pci_dev->config + pos + PCI_PM_CTRL, pmcsr);
+
+        pci_set_word(pci_dev->wmask + pos + PCI_PM_CTRL,
+                     PCI_PM_CTRL_STATE_MASK);
+    }
+
+    if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_EXP))) {
+        uint16_t devctl, lnkcap, lnksta;
+
+        pci_add_capability_at_offset(pci_dev, PCI_CAP_ID_EXP, pos, 0x40);
+
+        devctl = pci_get_word(pci_dev->config + pos + PCI_EXP_DEVCTL);
+        devctl = (devctl & (PCI_EXP_DEVCTL_READRQ | PCI_EXP_DEVCTL_PAYLOAD)) |
+                  PCI_EXP_DEVCTL_RELAX_EN | PCI_EXP_DEVCTL_NOSNOOP_EN;
+        pci_set_word(pci_dev->config + pos + PCI_EXP_DEVCTL, devctl);
+        devctl = PCI_EXP_DEVCTL_BCR_FLR | PCI_EXP_DEVCTL_AUX_PME;
+        pci_set_word(pci_dev->wmask + pos + PCI_EXP_DEVCTL, ~devctl);
+
+        lnkcap = pci_get_word(pci_dev->config + pos + PCI_EXP_LNKCAP);
+        lnkcap &= (PCI_EXP_LNKCAP_SLS | PCI_EXP_LNKCAP_MLW |
+                   PCI_EXP_LNKCAP_ASPMS | PCI_EXP_LNKCAP_L0SEL |
+                   PCI_EXP_LNKCAP_L1EL);
+        pci_set_word(pci_dev->config + pos + PCI_EXP_LNKCAP, lnkcap);
+
+        pci_set_word(pci_dev->wmask + pos + PCI_EXP_LNKCAP,
+                     PCI_EXP_LNKCTL_ASPMC | PCI_EXP_LNKCTL_RCB |
+                     PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES |
+                     PCI_EXP_LNKCTL_CLKREQ_EN | PCI_EXP_LNKCTL_HAWD);
+        
+        lnksta = pci_get_word(pci_dev->config + pos + PCI_EXP_LNKSTA);
+        lnksta &= (PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
+        pci_set_word(pci_dev->config + pos + PCI_EXP_LNKSTA, lnksta);
+
+        pci_set_word(pci_dev->wmask + pos + 0x28, 0x1f);
+        pci_set_word(pci_dev->wmask + pos + 0x30, 0xfbf);
+    }
+
+    if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_VPD))) {
+        pci_add_capability_at_offset(pci_dev, PCI_CAP_ID_VPD, pos, 0x8);
+    }
+
+    if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_VNDR))) {
+        uint8_t len = pci_get_byte(pci_dev->config + pos + PCI_CAP_FLAGS);
+        pci_add_capability_at_offset(pci_dev, PCI_CAP_ID_VNDR, pos, len);
+    }
+
+    if ((pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_PCIX))) {
+        uint16_t cmd;
+        uint32_t status;
+
+        pci_add_capability_at_offset(pci_dev, PCI_CAP_ID_PCIX, pos, 0x8);
+
+        cmd = pci_get_word(pci_dev->config + pos + PCI_X_CMD);
+        cmd &= (PCI_X_CMD_DPERR_E | PCI_X_CMD_ERO | PCI_X_CMD_MAX_READ |
+                PCI_X_CMD_MAX_SPLIT);
+        pci_set_word(pci_dev->config + pos + PCI_X_CMD, cmd);
+
+        status = pci_get_long(pci_dev->config + pos + PCI_X_STATUS);
+        status &= ~(PCI_X_STATUS_BUS | PCI_X_STATUS_DEVFN);
+        status |= (pci_bus_num(pci_dev->bus) << 8) | pci_dev->devfn;
+        status &= ~(PCI_X_STATUS_SPL_DISC | PCI_X_STATUS_UNX_SPL |
+                    PCI_X_STATUS_SPL_ERR);
+        pci_set_long(pci_dev->config + pos + PCI_X_STATUS, status);
+    }
     return 0;
 }
 
@@ -1466,7 +1603,8 @@ static int assigned_initfn(struct PCIDevice *pci_dev)
     dev->h_busnr = dev->host.bus;
     dev->h_devfn = PCI_DEVFN(dev->host.dev, dev->host.func);
 
-    pci_register_capability_handlers(pci_dev, NULL,
+    pci_register_capability_handlers(pci_dev,
+                                     assigned_device_pci_cap_read_config,
                                      assigned_device_pci_cap_write_config);
 
     if (assigned_device_pci_cap_init(pci_dev) < 0)