i386/cpu: fixup number of addressable IDs for processor cores in the physical package

When QEMU is started with:
-cpu host,host-cache-info=on,l3-cache=off \
-smp 2,sockets=1,dies=1,cores=1,threads=2
Guest can't acquire maximum number of addressable IDs for processor cores in
the physical package from CPUID[04H].

When creating a CPU topology of 1 core per package, host-cache-info only
uses the Host's addressable core IDs field (CPUID.04H.EAX[bits 31-26]),
resulting in a conflict (on the multicore Host) between the Guest core
topology information in this field and the Guest's actual cores number.

Fix it by removing the unnecessary condition to cover 1 core per package
case. This is safe because cores_per_pkg will not be 0 and will be at
least 1.

Fixes: d7caf13 ("x86: cpu: fixup number of addressable IDs for logical processors sharing cache")
Signed-off-by: Guixiong Wei <[email protected]>
Signed-off-by: Yipeng Yin <[email protected]>
Signed-off-by: Chuang Xu <[email protected]>
Reviewed-by: Zhao Liu <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
(cherry picked from commit 903916f)
Signed-off-by: Michael Tokarev <[email protected]>
(Mjt: fixup for 9.0 due to other changes in this area past 9.0)

Author: Chuang Xu

target/i386/cpu.c

@@ -6097,10 +6097,8 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             if (*eax & 31) {
                 int host_vcpus_per_cache = 1 + ((*eax & 0x3FFC000) >> 14);
                 int vcpus_per_socket = cs->nr_cores * cs->nr_threads;
-                if (cs->nr_cores > 1) {
-                    *eax &= ~0xFC000000;
-                    *eax |= (pow2ceil(cs->nr_cores) - 1) << 26;
-                }
+                *eax &= ~0xFC000000;
+                *eax |= (pow2ceil(cs->nr_cores) - 1) << 26;
                 if (host_vcpus_per_cache > vcpus_per_socket) {
                     *eax &= ~0x3FFC000;
                     *eax |= (pow2ceil(vcpus_per_socket) - 1) << 14;