[libvirt] [PATCH 09/13] conf: Introduce address caching for PCI extensions

[Xiao Feng Ren]

From: Yi Min Zhao <zyimin at linux.ibm.com>

This patch provides a caching mechanism for the device address
extensions uid and fid on S390. For efficient sparse address allocation,
we introduce two hash tables for uid/fid which hold the address set
information per domain. Also in order to improve performance of
searching available value, we introduce our own callbacks for the two
hashtables. In this way, uid/fid is saved in hash key and hash value
could be any non-NULL pointer due to no operation on hash value. That is
also the reason why we don't introduce hash value free callback.

Signed-off-by: Yi Min Zhao <zyimin at linux.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk at linux.vnet.ibm.com>
---
 src/conf/domain_addr.c         | 79 ++++++++++++++++++++++++++++++++++++++++++
 src/conf/domain_addr.h         |  9 +++++
 src/libvirt_private.syms       |  1 +
 src/qemu/qemu_domain_address.c |  5 +++
 4 files changed, 94 insertions(+)

diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c
index e685b9ccf7..37a3645c5d 100644
--- a/src/conf/domain_addr.c
+++ b/src/conf/domain_addr.c
@@ -27,11 +27,23 @@
 #include "virlog.h"
 #include "virstring.h"
 #include "domain_addr.h"
+#include "virhashcode.h"
 
 #define VIR_FROM_THIS VIR_FROM_DOMAIN
 
 VIR_LOG_INIT("conf.domain_addr");
 
+static void
+virDomainPCIAddressSetExtensionFree(virDomainPCIAddressSetPtr addrs)
+{
+    if (!addrs || !addrs->zpciIds)
+        return;
+
+    virHashFree(addrs->zpciIds->uids);
+    virHashFree(addrs->zpciIds->fids);
+    VIR_FREE(addrs->zpciIds);
+}
+
 virDomainPCIConnectFlags
 virDomainPCIControllerModelToConnectType(virDomainControllerModelPCI model)
 {
@@ -741,6 +753,72 @@ virDomainPCIAddressReleaseAddr(virDomainPCIAddressSetPtr addrs,
     addrs->buses[addr->bus].slot[addr->slot].functions &= ~(1 << addr->function);
 }
 
+
+static uint32_t virZPCIAddrCode(const void *name, uint32_t seed)
+{
+    unsigned int value = *((unsigned int *)name);
+    return virHashCodeGen(&value, sizeof(value), seed);
+}
+
+
+static bool virZPCIAddrEqual(const void *namea, const void *nameb)
+{
+    return *((unsigned int *)namea) == *((unsigned int *)nameb);
+}
+
+
+static void *virZPCIAddrCopy(const void *name)
+{
+    unsigned int *copy;
+
+    if (VIR_ALLOC(copy) < 0)
+        return NULL;
+
+    *copy = *((unsigned int *)name);
+    return (void *)copy;
+}
+
+
+static void virZPCIAddrKeyFree(void *name)
+{
+    VIR_FREE(name);
+}
+
+
+int
+virDomainPCIAddressSetExtensionAlloc(virDomainPCIAddressSetPtr addrs,
+                                     virDomainPCIAddressExtensionFlags extFlags)
+{
+    if (extFlags == VIR_PCI_ADDRESS_EXTENSION_ZPCI) {
+        if (addrs->zpciIds)
+            return 0;
+
+        if (VIR_ALLOC(addrs->zpciIds) < 0)
+            return -1;
+
+        if (!(addrs->zpciIds->uids = virHashCreateFull(10, NULL,
+                                                       virZPCIAddrCode,
+                                                       virZPCIAddrEqual,
+                                                       virZPCIAddrCopy,
+                                                       virZPCIAddrKeyFree)))
+            goto error;
+
+        if (!(addrs->zpciIds->fids = virHashCreateFull(10, NULL,
+                                                       virZPCIAddrCode,
+                                                       virZPCIAddrEqual,
+                                                       virZPCIAddrCopy,
+                                                       virZPCIAddrKeyFree)))
+            goto error;
+    }
+
+    return 0;
+
+ error:
+    virDomainPCIAddressSetExtensionFree(addrs);
+    return -1;
+}
+
+
 virDomainPCIAddressSetPtr
 virDomainPCIAddressSetAlloc(unsigned int nbuses)
 {
@@ -767,6 +845,7 @@ virDomainPCIAddressSetFree(virDomainPCIAddressSetPtr addrs)
     if (!addrs)
         return;
 
+    virDomainPCIAddressSetExtensionFree(addrs);
     VIR_FREE(addrs->buses);
     VIR_FREE(addrs);
 }
diff --git a/src/conf/domain_addr.h b/src/conf/domain_addr.h
index 1d1837bd23..f95d56c0a0 100644
--- a/src/conf/domain_addr.h
+++ b/src/conf/domain_addr.h
@@ -116,6 +116,11 @@ typedef struct {
 } virDomainPCIAddressBus;
 typedef virDomainPCIAddressBus *virDomainPCIAddressBusPtr;
 
+typedef struct {
+    virHashTablePtr uids, fids;
+} virDomainZPCIAddressIds;
+typedef virDomainZPCIAddressIds *virDomainZPCIAddressIdsPtr;
+
 struct _virDomainPCIAddressSet {
     virDomainPCIAddressBus *buses;
     size_t nbuses;
@@ -125,6 +130,7 @@ struct _virDomainPCIAddressSet {
     bool areMultipleRootsSupported;
     /* If true, the guest can use the pcie-to-pci-bridge controller */
     bool isPCIeToPCIBridgeSupported;
+    virDomainZPCIAddressIdsPtr zpciIds;
 };
 typedef struct _virDomainPCIAddressSet virDomainPCIAddressSet;
 typedef virDomainPCIAddressSet *virDomainPCIAddressSetPtr;
@@ -132,6 +138,9 @@ typedef virDomainPCIAddressSet *virDomainPCIAddressSetPtr;
 char *virDomainPCIAddressAsString(virPCIDeviceAddressPtr addr)
       ATTRIBUTE_NONNULL(1);
 
+int virDomainPCIAddressSetExtensionAlloc(virDomainPCIAddressSetPtr addrs,
+                                         virDomainPCIAddressExtensionFlags extFlags);
+
 virDomainPCIAddressSetPtr virDomainPCIAddressSetAlloc(unsigned int nbuses);
 
 void virDomainPCIAddressSetFree(virDomainPCIAddressSetPtr addrs);
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index a97b7fe223..2be1f8788a 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -119,6 +119,7 @@ virDomainPCIAddressReserveAddr;
 virDomainPCIAddressReserveNextAddr;
 virDomainPCIAddressSetAllMulti;
 virDomainPCIAddressSetAlloc;
+virDomainPCIAddressSetExtensionAlloc;
 virDomainPCIAddressSetFree;
 virDomainPCIAddressSlotInUse;
 virDomainPCIAddressValidate;
diff --git a/src/qemu/qemu_domain_address.c b/src/qemu/qemu_domain_address.c
index adce399be6..392723d616 100644
--- a/src/qemu/qemu_domain_address.c
+++ b/src/qemu/qemu_domain_address.c
@@ -1498,6 +1498,11 @@ qemuDomainPCIAddressSetCreate(virDomainDefPtr def,
 
     addrs->dryRun = dryRun;
 
+    /* create zpci address set for s390 domain */
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_ZPCI) &&
+        virDomainPCIAddressSetExtensionAlloc(addrs, VIR_PCI_ADDRESS_EXTENSION_ZPCI))
+        goto error;
+
     /* pSeries domains support multiple pci-root controllers */
     if (qemuDomainIsPSeries(def))
         addrs->areMultipleRootsSupported = true;
-- 
2.16.3