qemu /
qemu /
9fcba76ab9c264d06394696c304f2462d9296918 i386: Add cache topology info in CPUCacheInfo
Currently, by default, the cache topology is encoded as:
1. i/d cache is shared in one core.
2. L2 cache is shared in one core.
3. L3 cache is shared in one die.
This default general setting has caused a misunderstanding, that is, the
cache topology is completely equated with a specific cpu topology, such
as the connection between L2 cache and core level, and the connection
between L3 cache and die level.
In fact, the settings of these topologies depend on the specific
platform and are not static. For example, on Alder Lake-P, every
four Atom cores share the same L2 cache.
Thus, we should explicitly define the corresponding cache topology for
different cache models to increase scalability.
Except legacy_l2_cache_cpuid2 (its default topo level is
CPU_TOPO_LEVEL_UNKNOW), explicitly set the corresponding topology level
for all other cache models. In order to be compatible with the existing
cache topology, set the CPU_TOPO_LEVEL_CORE level for the i/d cache, set
the CPU_TOPO_LEVEL_CORE level for L2 cache, and set the
CPU_TOPO_LEVEL_DIE level for L3 cache.
The field for CPUID[4].EAX[bits 25:14] or CPUID[0x8000001D].EAX[bits
25:14] will be set based on CPUCacheInfo.share_level.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20240424154929.1487382-20-zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 files changed
