From 060065111a71922ab2126ed46f44668d53510665 Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Wed, 9 May 2018 16:56:04 -0400 Subject: kvm: vmx: Introduce lapic_mode enumeration commit 588716494258899389206fa50426e78cc9df89b9 upstream. The local APIC can be in one of three modes: disabled, xAPIC or x2APIC. (A fourth mode, "invalid," is included for completeness.) Using the new enumeration can make some of the APIC mode logic easier to read. In kvm_set_apic_base, for instance, it is clear that one cannot transition directly from x2APIC mode to xAPIC mode or directly from APIC disabled to x2APIC mode. Signed-off-by: Jim Mattson Signed-off-by: Krish Sadhukhan [Check invalid bits even if msr_info->host_initiated. Reported by Wanpeng Li. - Paolo] Signed-off-by: Paolo Bonzini Cc: "Jitindar SIngh, Suraj" Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 484afd667d1c..4927d0f5be13 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -306,23 +306,27 @@ u64 kvm_get_apic_base(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_get_apic_base); +enum lapic_mode kvm_get_apic_mode(struct kvm_vcpu *vcpu) +{ + return kvm_apic_mode(kvm_get_apic_base(vcpu)); +} +EXPORT_SYMBOL_GPL(kvm_get_apic_mode); + int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { - u64 old_state = vcpu->arch.apic_base & - (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE); - u64 new_state = msr_info->data & - (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE); + enum lapic_mode old_mode = kvm_get_apic_mode(vcpu); + enum lapic_mode new_mode = kvm_apic_mode(msr_info->data); u64 reserved_bits = ((~0ULL) << cpuid_maxphyaddr(vcpu)) | 0x2ff | (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE); - if ((msr_info->data & reserved_bits) || new_state == X2APIC_ENABLE) - return 1; - if (!msr_info->host_initiated && - ((new_state == MSR_IA32_APICBASE_ENABLE && - old_state == (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) || - (new_state == (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE) && - old_state == 0))) + if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID) return 1; + if (!msr_info->host_initiated) { + if (old_mode == LAPIC_MODE_X2APIC && new_mode == LAPIC_MODE_XAPIC) + return 1; + if (old_mode == LAPIC_MODE_DISABLED && new_mode == LAPIC_MODE_X2APIC) + return 1; + } kvm_lapic_set_base(vcpu, msr_info->data); return 0; -- cgit v1.2.3