Re: [PATCH v2 2/2] KVM: SVM: Limit AVIC physical max index based on configured max_vcpu_ids

[kernel test robot <lkp@intel.com>]

Hi Naveen,

kernel test robot noticed the following build errors:

[auto build test ERROR on eb723766b1030a23c38adf2348b7c3d1409d11f0]

url:    https://github.com/intel-lab-lkp/linux/commits/Naveen-N-Rao-AMD/KVM-SVM-Increase-X2AVIC-limit-to-4096-vcpus/20250203-144127
base:   eb723766b1030a23c38adf2348b7c3d1409d11f0
patch link:    https://lore.kernel.org/r/b79610c60de53048f3fda942fd45973c4ab1de97.1738563890.git.naveen%40kernel.org
patch subject: [PATCH v2 2/2] KVM: SVM: Limit AVIC physical max index based on configured max_vcpu_ids
config: x86_64-buildonly-randconfig-003-20250203 (https://download.01.org/0day-ci/archive/20250203/202502031922.dBj76pSx-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250203/202502031922.dBj76pSx-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502031922.dBj76pSx-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/x86/include/asm/kvm_host.h:31,
                    from include/linux/kvm_host.h:45,
                    from arch/x86/kvm/svm/avic.c:20:
>> arch/x86/include/asm/apic.h:258:34: error: expected ')' before numeric constant
     258 | #define x2apic_mode             (0)
         |                                  ^
   arch/x86/kvm/svm/avic.c:88:66: note: in expansion of macro 'x2apic_mode'
      88 | static inline u32 avic_get_max_physical_id(struct kvm *kvm, bool x2apic_mode)
         |                                                                  ^~~~~~~~~~~
   arch/x86/kvm/svm/avic.c: In function 'avic_activate_vmcb':
>> arch/x86/kvm/svm/avic.c:117:51: error: implicit declaration of function 'avic_get_max_physical_id' [-Werror=implicit-function-declaration]
     117 |                 vmcb->control.avic_physical_id |= avic_get_max_physical_id(svm->vcpu.kvm, true);
         |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/avic_get_max_physical_id +117 arch/x86/kvm/svm/avic.c

    98	
    99	static void avic_activate_vmcb(struct vcpu_svm *svm)
   100	{
   101		struct vmcb *vmcb = svm->vmcb01.ptr;
   102	
   103		vmcb->control.int_ctl &= ~(AVIC_ENABLE_MASK | X2APIC_MODE_MASK);
   104		vmcb->control.avic_physical_id &= ~avic_physical_max_index_mask;
   105	
   106		vmcb->control.int_ctl |= AVIC_ENABLE_MASK;
   107	
   108		/*
   109		 * Note: KVM supports hybrid-AVIC mode, where KVM emulates x2APIC MSR
   110		 * accesses, while interrupt injection to a running vCPU can be
   111		 * achieved using AVIC doorbell.  KVM disables the APIC access page
   112		 * (deletes the memslot) if any vCPU has x2APIC enabled, thus enabling
   113		 * AVIC in hybrid mode activates only the doorbell mechanism.
   114		 */
   115		if (x2avic_enabled && apic_x2apic_mode(svm->vcpu.arch.apic)) {
   116			vmcb->control.int_ctl |= X2APIC_MODE_MASK;
 > 117			vmcb->control.avic_physical_id |= avic_get_max_physical_id(svm->vcpu.kvm, true);
   118			/* Disabling MSR intercept for x2APIC registers */
   119			svm_set_x2apic_msr_interception(svm, false);
   120		} else {
   121			/*
   122			 * Flush the TLB, the guest may have inserted a non-APIC
   123			 * mapping into the TLB while AVIC was disabled.
   124			 */
   125			kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, &svm->vcpu);
   126	
   127			/* For xAVIC and hybrid-xAVIC modes */
   128			vmcb->control.avic_physical_id |= avic_get_max_physical_id(svm->vcpu.kvm, false);
   129			/* Enabling MSR intercept for x2APIC registers */
   130			svm_set_x2apic_msr_interception(svm, true);
   131		}
   132	}
   133	

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