[libvirt] [PATCH v7 06/14] 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.ibm.com>
Reviewed-by: Bjoern Walk <bwalk at linux.ibm.com>
Reviewed-by: Ján Tomko <jtomko at redhat.com>
Reviewed-by: Andrea Bolognani <abologna at redhat.com>
---
 src/bhyve/bhyve_device.c       |  3 +-
 src/conf/domain_addr.c         | 93 +++++++++++++++++++++++++++++++++-
 src/conf/domain_addr.h         | 10 +++-
 src/qemu/qemu_domain_address.c |  6 ++-
 4 files changed, 108 insertions(+), 4 deletions(-)

diff --git a/src/bhyve/bhyve_device.c b/src/bhyve/bhyve_device.c
index 207ac6a2dd..a59dfe4519 100644
--- a/src/bhyve/bhyve_device.c
+++ b/src/bhyve/bhyve_device.c
@@ -71,7 +71,8 @@ bhyveDomainPCIAddressSetCreate(virDomainDefPtr def, unsigned int nbuses)
 {
     virDomainPCIAddressSetPtr addrs;
 
-    if ((addrs = virDomainPCIAddressSetAlloc(nbuses)) == NULL)
+    if ((addrs = virDomainPCIAddressSetAlloc(nbuses,
+                                             VIR_PCI_ADDRESS_EXTENSION_NONE)) == NULL)
         return NULL;
 
     if (virDomainPCIAddressBusSetModel(&addrs->buses[0],
diff --git a/src/conf/domain_addr.c b/src/conf/domain_addr.c
index 442e6aab94..902837d4ee 100644
--- a/src/conf/domain_addr.c
+++ b/src/conf/domain_addr.c
@@ -27,6 +27,7 @@
 #include "virlog.h"
 #include "virstring.h"
 #include "domain_addr.h"
+#include "virhashcode.h"
 
 #define VIR_FROM_THIS VIR_FROM_DOMAIN
 
@@ -727,8 +728,93 @@ virDomainPCIAddressReleaseAddr(virDomainPCIAddressSetPtr addrs,
     addrs->buses[addr->bus].slot[addr->slot].functions &= ~(1 << addr->function);
 }
 
+
+static uint32_t
+virZPCIAddrKeyCode(const void *name,
+                   uint32_t seed)
+{
+    unsigned int value = *((unsigned int *)name);
+    return virHashCodeGen(&value, sizeof(value), seed);
+}
+
+
+static bool
+virZPCIAddrKeyEqual(const void *namea,
+                    const void *nameb)
+{
+    return *((unsigned int *)namea) == *((unsigned int *)nameb);
+}
+
+
+static void *
+virZPCIAddrKeyCopy(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);
+}
+
+
+static void
+virDomainPCIAddressSetExtensionFree(virDomainPCIAddressSetPtr addrs)
+{
+    if (!addrs || !addrs->zpciIds)
+        return;
+
+    virHashFree(addrs->zpciIds->uids);
+    virHashFree(addrs->zpciIds->fids);
+    VIR_FREE(addrs->zpciIds);
+}
+
+
+static int
+virDomainPCIAddressSetExtensionAlloc(virDomainPCIAddressSetPtr addrs,
+                                     virPCIDeviceAddressExtensionFlags 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,
+                                                       virZPCIAddrKeyCode,
+                                                       virZPCIAddrKeyEqual,
+                                                       virZPCIAddrKeyCopy,
+                                                       virZPCIAddrKeyFree)))
+            goto error;
+
+        if (!(addrs->zpciIds->fids = virHashCreateFull(10, NULL,
+                                                       virZPCIAddrKeyCode,
+                                                       virZPCIAddrKeyEqual,
+                                                       virZPCIAddrKeyCopy,
+                                                       virZPCIAddrKeyFree)))
+            goto error;
+    }
+
+    return 0;
+
+ error:
+    virDomainPCIAddressSetExtensionFree(addrs);
+    return -1;
+}
+
+
 virDomainPCIAddressSetPtr
-virDomainPCIAddressSetAlloc(unsigned int nbuses)
+virDomainPCIAddressSetAlloc(unsigned int nbuses,
+                            virPCIDeviceAddressExtensionFlags extFlags)
 {
     virDomainPCIAddressSetPtr addrs;
 
@@ -739,6 +825,10 @@ virDomainPCIAddressSetAlloc(unsigned int nbuses)
         goto error;
 
     addrs->nbuses = nbuses;
+
+    if (virDomainPCIAddressSetExtensionAlloc(addrs, extFlags) < 0)
+        goto error;
+
     return addrs;
 
  error:
@@ -753,6 +843,7 @@ 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 435b3c5d7f..8d64d6b795 100644
--- a/src/conf/domain_addr.h
+++ b/src/conf/domain_addr.h
@@ -116,6 +116,12 @@ typedef struct {
 } virDomainPCIAddressBus;
 typedef virDomainPCIAddressBus *virDomainPCIAddressBusPtr;
 
+typedef struct {
+    virHashTablePtr uids;
+    virHashTablePtr fids;
+} virDomainZPCIAddressIds;
+typedef virDomainZPCIAddressIds *virDomainZPCIAddressIdsPtr;
+
 struct _virDomainPCIAddressSet {
     virDomainPCIAddressBus *buses;
     size_t nbuses;
@@ -125,11 +131,13 @@ 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;
 
-virDomainPCIAddressSetPtr virDomainPCIAddressSetAlloc(unsigned int nbuses);
+virDomainPCIAddressSetPtr virDomainPCIAddressSetAlloc(unsigned int nbuses,
+                                                      virPCIDeviceAddressExtensionFlags extFlags);
 
 void virDomainPCIAddressSetFree(virDomainPCIAddressSetPtr addrs);
 
diff --git a/src/qemu/qemu_domain_address.c b/src/qemu/qemu_domain_address.c
index c0374ccaf3..665f6c1445 100644
--- a/src/qemu/qemu_domain_address.c
+++ b/src/qemu/qemu_domain_address.c
@@ -1505,8 +1505,12 @@ qemuDomainPCIAddressSetCreate(virDomainDefPtr def,
     size_t i;
     bool hasPCIeRoot = false;
     virDomainControllerModelPCI defaultModel;
+    virPCIDeviceAddressExtensionFlags extFlags = VIR_PCI_ADDRESS_EXTENSION_NONE;
 
-    if ((addrs = virDomainPCIAddressSetAlloc(nbuses)) == NULL)
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_ZPCI))
+        extFlags |= VIR_PCI_ADDRESS_EXTENSION_ZPCI;
+
+    if ((addrs = virDomainPCIAddressSetAlloc(nbuses, extFlags)) == NULL)
         return NULL;
 
     addrs->dryRun = dryRun;
-- 
Yi Min