[libvirt] [PATCH v3 06/12] conf: Introduce address caching for PCI extensions

[Yi Min Zhao]

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>
Reviewed-by: Ján Tomko <jtomko at redhat.com>
---
 src/conf/domain_addr.c         | 85 ++++++++++++++++++++++++++++++++++++++++++
 src/conf/domain_addr.h         |  9 +++++
 src/libvirt_private.syms       |  1 +
 src/qemu/qemu_domain_address.c |  7 ++++
 4 files changed, 102 insertions(+)

diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c
index 16f7ffa928..8d3e75f19a 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 +753,78 @@ 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 +851,7 @@ 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 5219d2f208..d1ec869da4 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 70dfcc5e29..d57a836c2e 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -116,6 +116,7 @@ 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 c582a531db..200d96a790 100644
--- a/src/qemu/qemu_domain_address.c
+++ b/src/qemu/qemu_domain_address.c
@@ -1482,6 +1482,13 @@ 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;
-- 
Yi Min