Commit 548e8365 authored by Jing Liu's avatar Jing Liu Committed by Paolo Bonzini
Browse files

kvm: x86: Emulate IA32_XFD_ERR for guest 



Emulate read/write to IA32_XFD_ERR MSR.

Only the saved value in the guest_fpu container is touched in the
emulation handler. Actual MSR update is handled right before entering
the guest (with preemption disabled)

Signed-off-by: default avatarJing Liu <jing2.liu@intel.com>
Signed-off-by: default avatarZeng Guang <guang.zeng@intel.com>
Signed-off-by: default avatarWei Wang <wei.w.wang@intel.com>
Signed-off-by: default avatarJing Liu <jing2.liu@intel.com>
Signed-off-by: default avatarYang Zhong <yang.zhong@intel.com>
Message-Id: <20220105123532.12586-14-yang.zhong@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ec5be88a

arch/x86/kvm/x86.c

+20 −1
Original line number Diff line number Diff line
@@ -1377,7 +1377,7 @@ static const u32 msrs_to_save_all[] = { 
	MSR_F15H_PERF_CTL3, MSR_F15H_PERF_CTL4, MSR_F15H_PERF_CTL5,

	MSR_F15H_PERF_CTR0, MSR_F15H_PERF_CTR1, MSR_F15H_PERF_CTR2,

	MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5,

	MSR_IA32_XFD,

	MSR_IA32_XFD, MSR_IA32_XFD_ERR,

};



static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
@@ -3699,6 +3699,17 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 


		fpu_update_guest_xfd(&vcpu->arch.guest_fpu, data);

		break;

	case MSR_IA32_XFD_ERR:

		if (!msr_info->host_initiated &&

		    !guest_cpuid_has(vcpu, X86_FEATURE_XFD))

			return 1;



		if (data & ~(XFEATURE_MASK_USER_DYNAMIC &

			     vcpu->arch.guest_supported_xcr0))

			return 1;



		vcpu->arch.guest_fpu.xfd_err = data;

		break;

#endif

	default:

		if (kvm_pmu_is_valid_msr(vcpu, msr))
@@ -4028,6 +4039,13 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 


		msr_info->data = vcpu->arch.guest_fpu.fpstate->xfd;

		break;

	case MSR_IA32_XFD_ERR:

		if (!msr_info->host_initiated &&

		    !guest_cpuid_has(vcpu, X86_FEATURE_XFD))

			return 1;



		msr_info->data = vcpu->arch.guest_fpu.xfd_err;

		break;

#endif

	default:

		if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
@@ -6465,6 +6483,7 @@ static void kvm_init_msr_list(void) 
				continue;

			break;

		case MSR_IA32_XFD:

		case MSR_IA32_XFD_ERR:

			if (!kvm_cpu_cap_has(X86_FEATURE_XFD))

				continue;

			break;