From 40e04161b33167b17455209504286d2e02fea632 Mon Sep 17 00:00:00 2001 From: Chuang Xu Date: Tue, 11 Jun 2024 11:23:14 +0800 Subject: 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: d7caf13b5fcf ("x86: cpu: fixup number of addressable IDs for logical processors sharing cache") Signed-off-by: Guixiong Wei Signed-off-by: Yipeng Yin Signed-off-by: Chuang Xu Reviewed-by: Zhao Liu Message-ID: <20240611032314.64076-1-xuchuangxclwt@bytedance.com> Signed-off-by: Paolo Bonzini (cherry picked from commit 903916f0a017fe4b7789f1c6c6982333a5a71876) Signed-off-by: Michael Tokarev (Mjt: fixup for 8.2 due to other changes in this area past 9.0) --- target/i386/cpu.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 4dbfbfb..8f318a5 100644 --- a/target/i386/cpu.c +++ b/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; -- cgit v1.1