[Qemu-devel] [PATCH v9 03/11] pci: Convert msix_init() to Error and fix callers

[Cao jin]

msix_init() reports errors with error_report(), which is wrong when
it's used in realize().  The same issue was fixed for msi_init() in
commit 1108b2f. In order to make the API change as small as possible,
leave the return value check to later patch.

For some devices(like e1000e, vmxnet3, nvme) who won't fail because of
msix_init's failure, suppress the error report by passing NULL error
object.

Bonus: add comment for msix_init.

CC: Jiri Pirko <address@hidden>
CC: Gerd Hoffmann <address@hidden>
CC: Dmitry Fleytman <address@hidden>
CC: Jason Wang <address@hidden>
CC: Michael S. Tsirkin <address@hidden>
CC: Hannes Reinecke <address@hidden>
CC: Paolo Bonzini <address@hidden>
CC: Alex Williamson <address@hidden>
CC: Markus Armbruster <address@hidden>
CC: Marcel Apfelbaum <address@hidden>
Signed-off-by: Cao jin <address@hidden>
---
 hw/block/nvme.c        |  2 +-
 hw/misc/ivshmem.c      |  8 ++++----
 hw/net/e1000e.c        |  2 +-
 hw/net/rocker/rocker.c |  4 +++-
 hw/net/vmxnet3.c       |  2 +-
 hw/pci/msix.c          | 36 +++++++++++++++++++++++++++++++-----
 hw/scsi/megasas.c      |  4 +++-
 hw/usb/hcd-xhci.c      |  4 ++--
 hw/vfio/pci.c          |  8 ++++++--
 hw/virtio/virtio-pci.c |  4 ++--
 include/hw/pci/msix.h  |  5 +++--
 11 files changed, 57 insertions(+), 22 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index d479fd22f573..ae91a18f1724 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -872,7 +872,7 @@ static int nvme_init(PCIDevice *pci_dev)
     pci_register_bar(&n->parent_obj, 0,
         PCI_BASE_ADDRESS_SPACE_MEMORY | PCI_BASE_ADDRESS_MEM_TYPE_64,
         &n->iomem);
-    msix_init_exclusive_bar(&n->parent_obj, n->num_queues, 4);
+    msix_init_exclusive_bar(&n->parent_obj, n->num_queues, 4, NULL);
 
     id->vid = cpu_to_le16(pci_get_word(pci_conf + PCI_VENDOR_ID));
     id->ssvid = cpu_to_le16(pci_get_word(pci_conf + PCI_SUBSYSTEM_VENDOR_ID));
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index abeaf3da0800..70e71a597b9c 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -749,13 +749,13 @@ static void ivshmem_reset(DeviceState *d)
     }
 }
 
-static int ivshmem_setup_interrupts(IVShmemState *s)
+static int ivshmem_setup_interrupts(IVShmemState *s, Error **errp)
 {
     /* allocate QEMU callback data for receiving interrupts */
     s->msi_vectors = g_malloc0(s->vectors * sizeof(MSIVector));
 
     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
-        if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1)) {
+        if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1, errp)) {
             return -1;
         }
 
@@ -897,8 +897,8 @@ static void ivshmem_common_realize(PCIDevice *dev, Error 
**errp)
         qemu_chr_fe_set_handlers(&s->server_chr, ivshmem_can_receive,
                                  ivshmem_read, NULL, s, NULL, true);
 
-        if (ivshmem_setup_interrupts(s) < 0) {
-            error_setg(errp, "failed to initialize interrupts");
+        if (ivshmem_setup_interrupts(s, errp) < 0) {
+            error_prepend(errp, "Failed to initialize interrupts: ");
             return;
         }
     }
diff --git a/hw/net/e1000e.c b/hw/net/e1000e.c
index 4994e1ca0062..ed04adce061c 100644
--- a/hw/net/e1000e.c
+++ b/hw/net/e1000e.c
@@ -292,7 +292,7 @@ e1000e_init_msix(E1000EState *s)
                         E1000E_MSIX_IDX, E1000E_MSIX_TABLE,
                         &s->msix,
                         E1000E_MSIX_IDX, E1000E_MSIX_PBA,
-                        0xA0);
+                        0xA0, NULL);
 
     if (res < 0) {
         trace_e1000e_msix_init_fail(res);
diff --git a/hw/net/rocker/rocker.c b/hw/net/rocker/rocker.c
index e9d215aa4df1..6e70fddee36b 100644
--- a/hw/net/rocker/rocker.c
+++ b/hw/net/rocker/rocker.c
@@ -1256,14 +1256,16 @@ static int rocker_msix_init(Rocker *r)
 {
     PCIDevice *dev = PCI_DEVICE(r);
     int err;
+    Error *local_err = NULL;
 
     err = msix_init(dev, ROCKER_MSIX_VEC_COUNT(r->fp_ports),
                     &r->msix_bar,
                     ROCKER_PCI_MSIX_BAR_IDX, ROCKER_PCI_MSIX_TABLE_OFFSET,
                     &r->msix_bar,
                     ROCKER_PCI_MSIX_BAR_IDX, ROCKER_PCI_MSIX_PBA_OFFSET,
-                    0);
+                    0, &local_err);
     if (err) {
+        error_report_err(local_err);
         return err;
     }
 
diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index 92f6af9620f1..7b2971fe5902 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -2191,7 +2191,7 @@ vmxnet3_init_msix(VMXNET3State *s)
                         VMXNET3_MSIX_BAR_IDX, VMXNET3_OFF_MSIX_TABLE,
                         &s->msix_bar,
                         VMXNET3_MSIX_BAR_IDX, VMXNET3_OFF_MSIX_PBA(s),
-                        VMXNET3_MSIX_OFFSET(s));
+                        VMXNET3_MSIX_OFFSET(s), NULL);
 
     if (0 > res) {
         VMW_WRPRN("Failed to initialize MSI-X, error %d", res);
diff --git a/hw/pci/msix.c b/hw/pci/msix.c
index 0cee631ecc55..bd8cdd41d880 100644
--- a/hw/pci/msix.c
+++ b/hw/pci/msix.c
@@ -21,6 +21,7 @@
 #include "hw/pci/pci.h"
 #include "hw/xen/xen.h"
 #include "qemu/range.h"
+#include "qapi/error.h"
 
 #define MSIX_CAP_LENGTH 12
 
@@ -238,11 +239,31 @@ static void msix_mask_all(struct PCIDevice *dev, unsigned 
nentries)
     }
 }
 
-/* Initialize the MSI-X structures */
+/*
+ * Make PCI device @dev MSI-X capable
+ * @nentries is the max number of MSI-X vectors that the device support.
+ * @table_bar is the MemoryRegion that MSI-X table structure resides.
+ * @table_bar_nr is number of base address register corresponding to 
@table_bar.
+ * @table_offset indicates the offset that the MSI-X table structure starts 
with
+ * in @table_bar.
+ * @pba_bar is the MemoryRegion that the Pending Bit Array structure resides.
+ * @pba_bar_nr is number of base address register corresponding to @pba_bar.
+ * @pba_offset indicates the offset that the Pending Bit Array structure
+ * starts with in @pba_bar.
+ * Non-zero @cap_pos puts capability MSI-X at that offset in PCI config space.
+ * @errp is for returning errors.
+ *
+ * Return 0 on success; set @errp and return -errno on error:
+ * -ENOTSUP means lacking msi support for a msi-capable platform.
+ * -EINVAL means capability overlap, happens when @cap_pos is non-zero,
+ * also means a programming error, except device assignment, which can check
+ * if a real HW is broken.
+ */
 int msix_init(struct PCIDevice *dev, unsigned short nentries,
               MemoryRegion *table_bar, uint8_t table_bar_nr,
               unsigned table_offset, MemoryRegion *pba_bar,
-              uint8_t pba_bar_nr, unsigned pba_offset, uint8_t cap_pos)
+              uint8_t pba_bar_nr, unsigned pba_offset, uint8_t cap_pos,
+              Error **errp)
 {
     int cap;
     unsigned table_size, pba_size;
@@ -250,10 +271,12 @@ int msix_init(struct PCIDevice *dev, unsigned short 
nentries,
 
     /* Nothing to do if MSI is not supported by interrupt controller */
     if (!msi_nonbroken) {
+        error_setg(errp, "MSI-X is not supported by interrupt controller");
         return -ENOTSUP;
     }
 
     if (nentries < 1 || nentries > PCI_MSIX_FLAGS_QSIZE + 1) {
+        error_setg(errp, "The number of MSI-X vectors is invalid");
         return -EINVAL;
     }
 
@@ -266,10 +289,13 @@ int msix_init(struct PCIDevice *dev, unsigned short 
nentries,
         table_offset + table_size > memory_region_size(table_bar) ||
         pba_offset + pba_size > memory_region_size(pba_bar) ||
         (table_offset | pba_offset) & PCI_MSIX_FLAGS_BIRMASK) {
+        error_setg(errp, "table & pba overlap, or they don't fit in BARs,"
+                   " or don't align");
         return -EINVAL;
     }
 
-    cap = pci_add_capability(dev, PCI_CAP_ID_MSIX, cap_pos, MSIX_CAP_LENGTH);
+    cap = pci_add_capability2(dev, PCI_CAP_ID_MSIX,
+                              cap_pos, MSIX_CAP_LENGTH, errp);
     if (cap < 0) {
         return cap;
     }
@@ -306,7 +332,7 @@ int msix_init(struct PCIDevice *dev, unsigned short 
nentries,
 }
 
 int msix_init_exclusive_bar(PCIDevice *dev, unsigned short nentries,
-                            uint8_t bar_nr)
+                            uint8_t bar_nr, Error **errp)
 {
     int ret;
     char *name;
@@ -338,7 +364,7 @@ int msix_init_exclusive_bar(PCIDevice *dev, unsigned short 
nentries,
     ret = msix_init(dev, nentries, &dev->msix_exclusive_bar, bar_nr,
                     0, &dev->msix_exclusive_bar,
                     bar_nr, bar_pba_offset,
-                    0);
+                    0, errp);
     if (ret) {
         return ret;
     }
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 67fc1e7893f8..095dba8b36de 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -2366,9 +2366,11 @@ static void megasas_scsi_realize(PCIDevice *dev, Error 
**errp)
 
     if (megasas_use_msix(s) &&
         msix_init(dev, 15, &s->mmio_io, b->mmio_bar, 0x2000,
-                  &s->mmio_io, b->mmio_bar, 0x3800, 0x68)) {
+                  &s->mmio_io, b->mmio_bar, 0x3800, 0x68, NULL)) {
+        /* TODO: check msix_init's error, and should fail on msix=on */
         s->msix = ON_OFF_AUTO_OFF;
     }
+
     if (pci_is_express(dev)) {
         pcie_endpoint_cap_init(dev, 0xa0);
     }
diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 0ace273da472..fe64dd8525c7 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -3703,11 +3703,11 @@ static void usb_xhci_realize(struct PCIDevice *dev, 
Error **errp)
     }
 
     if (xhci->msix != ON_OFF_AUTO_OFF) {
-        /* TODO check for errors */
+        /* TODO check for errors, and should fail when msix=on */
         msix_init(dev, xhci->numintrs,
                   &xhci->mem, 0, OFF_MSIX_TABLE,
                   &xhci->mem, 0, OFF_MSIX_PBA,
-                  0x90);
+                  0x90, NULL);
     }
 }
 
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index d7dbe0e3e04e..5df190510a05 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1432,6 +1432,7 @@ static void vfio_msix_early_setup(VFIOPCIDevice *vdev, 
Error **errp)
 static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
 {
     int ret;
+    Error *err = NULL;
 
     vdev->msix->pending = g_malloc0(BITS_TO_LONGS(vdev->msix->entries) *
                                     sizeof(unsigned long));
@@ -1439,12 +1440,15 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int 
pos, Error **errp)
                     vdev->bars[vdev->msix->table_bar].region.mem,
                     vdev->msix->table_bar, vdev->msix->table_offset,
                     vdev->bars[vdev->msix->pba_bar].region.mem,
-                    vdev->msix->pba_bar, vdev->msix->pba_offset, pos);
+                    vdev->msix->pba_bar, vdev->msix->pba_offset, pos,
+                    &err);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
+            error_report_err(err);
             return 0;
         }
-        error_setg(errp, "msix_init failed");
+
+        error_propagate(errp, err);
         return ret;
     }
 
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 21c2b9dbfc97..4c2c4941d245 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1670,9 +1670,9 @@ static void virtio_pci_device_plugged(DeviceState *d, 
Error **errp)
 
     if (proxy->nvectors) {
         int err = msix_init_exclusive_bar(&proxy->pci_dev, proxy->nvectors,
-                                          proxy->msix_bar_idx);
+                                          proxy->msix_bar_idx, NULL);
         if (err) {
-            /* Notice when a system that supports MSIx can't initialize it.  */
+            /* Notice when a system that supports MSIx can't initialize it */
             if (err != -ENOTSUP) {
                 error_report("unable to init msix vectors to %" PRIu32,
                              proxy->nvectors);
diff --git a/include/hw/pci/msix.h b/include/hw/pci/msix.h
index 048a29dd2f65..1f27658d352f 100644
--- a/include/hw/pci/msix.h
+++ b/include/hw/pci/msix.h
@@ -9,9 +9,10 @@ MSIMessage msix_get_message(PCIDevice *dev, unsigned int 
vector);
 int msix_init(PCIDevice *dev, unsigned short nentries,
               MemoryRegion *table_bar, uint8_t table_bar_nr,
               unsigned table_offset, MemoryRegion *pba_bar,
-              uint8_t pba_bar_nr, unsigned pba_offset, uint8_t cap_pos);
+              uint8_t pba_bar_nr, unsigned pba_offset, uint8_t cap_pos,
+              Error **errp);
 int msix_init_exclusive_bar(PCIDevice *dev, unsigned short nentries,
-                            uint8_t bar_nr);
+                            uint8_t bar_nr, Error **errp);
 
 void msix_write_config(PCIDevice *dev, uint32_t address, uint32_t val, int 
len);
 
-- 
2.1.0