Rust, target/i386 changes for QEMU 10.1 soft freeze

[PULL 39/77] i386/tdx: Don't mask off CPUID_EXT_PDCM

Paolo Bonzini posted 77 patches 4 months ago

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Maintainers: "Philippe Mathieu-Daudé" <philmd@linaro.org>, "Daniel P. Berrangé" <berrange@redhat.com>, Kashyap Chamarthy <kchamart@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Cornelia Huck <cohuck@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Manos Pitsidianakis <manos.pitsidianakis@linaro.org>, Zhao Liu <zhao1.liu@intel.com>, Cameron Esfahani <dirty@apple.com>, Roman Bolshakov <rbolshakov@ddn.com>, Phil Dennis-Jordan <phil@philjordan.eu>, Reinoud Zandijk <reinoud@netbsd.org>, Sunil Muthuswamy <sunilmut@microsoft.com>, Warner Losh <imp@bsdimp.com>, Kyle Evans <kevans@freebsd.org>, Ed Maste <emaste@freebsd.org>, Li-Wen Hsu <lwhsu@freebsd.org>, "Alex Bennée" <alex.bennee@linaro.org>, Thomas Huth <thuth@redhat.com>

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[PULL 39/77] i386/tdx: Don't mask off CPUID_EXT_PDCM

Posted by Paolo Bonzini 4 months ago

From: Xiaoyao Li <xiaoyao.li@intel.com>

It gets below warning when booting TDX VMs:

  warning: TDX forcibly sets the feature: CPUID[eax=01h].ECX.pdcm [bit 15]

Because CPUID_EXT_PDCM is fixed1 for TDX, and MSR_IA32_PERF_CAPABILITIES is
supported for TDX guest unconditioanlly.

Don't mask off CPUID_EXT_PDCM for TDX.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250625035710.2770679-1-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/cpu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index b768838b100..f9e6bc8d0e6 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -28,6 +28,7 @@
 #include "system/hvf.h"
 #include "hvf/hvf-i386.h"
 #include "kvm/kvm_i386.h"
+#include "kvm/tdx.h"
 #include "sev.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
@@ -8336,7 +8337,8 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
         }
     }
 
-    if (!cpu->enable_pmu) {
+    /* PDCM is fixed1 bit for TDX */
+    if (!cpu->enable_pmu && !is_tdx_vm()) {
         mark_unavailable_features(cpu, FEAT_1_ECX,
                                   env->user_features[FEAT_1_ECX] & CPUID_EXT_PDCM,
                                   "This feature is not available due to PMU being disabled");
-- 
2.50.0