On 12/27/2024 4:07 PM, Zhao Liu wrote:
On Thu, Dec 19, 2024 at 06:01:22AM -0500, Xiaoyao Li wrote:
Date: Thu, 19 Dec 2024 06:01:22 -0500
From: Xiaoyao Li <xiaoyao...@intel.com>
Subject: [PATCH v2 07/10] i386/cpu: Hoist check of CPUID_EXT3_TOPOEXT
against threads_per_core
X-Mailer: git-send-email 2.34.1
Now it changes to use env->topo_info.threads_per_core and doesn't depend
on qemu_init_vcpu() anymore. Drop the comment of the order dependency on
qemu_init_vcpu() and hoist code to put it together with other feature
checking.
The comment was dropped in patch 6. You could move such description to
there.
Obviously, I didn't take care of the patch split and reorder.
I tent to move the dropping of the comment from patch 6 to this one.
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com>
---
target/i386/cpu.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index d41768648ab9..fd59da5d445d 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -7880,6 +7880,21 @@ static void x86_cpu_realizefn(DeviceState *dev, Error
**errp)
*/
cpu->mwait.ecx |= CPUID_MWAIT_EMX | CPUID_MWAIT_IBE;
+ /*
+ * Most Intel and certain AMD CPUs support hyperthreading. Even though QEMU
+ * fixes this issue by adjusting CPUID_0000_0001_EBX and
CPUID_8000_0008_ECX
+ * based on inputs (sockets,cores,threads), it is still better to give
+ * users a warning.
+ */
+ if (IS_AMD_CPU(env) &&
+ !(env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) &&
+ env->nr_threads > 1) {
Typo, env->topo_info.threads_per_core.
Thanks for catching it.
+ warn_report_once("This family of AMD CPU doesn't support "
+ "hyperthreading(%d). Please configure -smp "
+ "options properly or try enabling topoext "
+ "feature.", env->nr_threads);
+ }
+
/* For 64bit systems think about the number of physical bits to present.
* ideally this should be the same as the host; anything other than
matching
* the host can cause incorrect guest behaviour.
