This is a result of the patches being applied out of order. We'll fix it up.
On Sat, May 12, 2018 at 4:40 PM, Wanpeng Li <kernellwp@xxxxxxxxx> wrote:
> 2018-05-10 4:56 GMT+08:00 Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>:
>> From: Jim Mattson <jmattson@xxxxxxxxxx>
>>
>> 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 <jmattson@xxxxxxxxxx>
>> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
>> ---
>> arch/x86/kvm/lapic.h | 14 ++++++++++++++
>> arch/x86/kvm/x86.c | 31 +++++++++++++++++++------------
>> 2 files changed, 33 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
>> index edce055..ed0ed39 100644
>> --- a/arch/x86/kvm/lapic.h
>> +++ b/arch/x86/kvm/lapic.h
>> @@ -16,6 +16,13 @@
>> #define APIC_BUS_CYCLE_NS 1
>> #define APIC_BUS_FREQUENCY (1000000000ULL / APIC_BUS_CYCLE_NS)
>>
>> +enum lapic_mode {
>> + LAPIC_MODE_DISABLED = 0,
>> + LAPIC_MODE_INVALID = X2APIC_ENABLE,
>> + LAPIC_MODE_XAPIC = MSR_IA32_APICBASE_ENABLE,
>> + LAPIC_MODE_X2APIC = MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE,
>> +};
>> +
>> struct kvm_timer {
>> struct hrtimer timer;
>> s64 period; /* unit: ns */
>> @@ -89,6 +96,7 @@ u64 kvm_get_apic_base(struct kvm_vcpu *vcpu);
>> int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
>> int kvm_apic_get_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s);
>> int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s);
>> +enum lapic_mode kvm_get_apic_mode(struct kvm_vcpu *vcpu);
>> int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu);
>>
>> u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu);
>> @@ -220,4 +228,10 @@ void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu);
>> void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu);
>> bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu);
>> void kvm_lapic_restart_hv_timer(struct kvm_vcpu *vcpu);
>> +
>> +static inline enum lapic_mode kvm_apic_mode(u64 apic_base)
>> +{
>> + return apic_base & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE);
>> +}
>> +
>> #endif
>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>> index 51ecd38..5f5874c 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -318,23 +318,30 @@ 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)))
>> - return 1;
>> + if (!msr_info->host_initiated) {
>> + if ((msr_info->data & reserved_bits) != 0 ||
>> + new_mode == LAPIC_MODE_INVALID)
>> + return 1;
>
> This is opposite to commit d3802286fa (kvm: x86: Disallow illegal
> IA32_APIC_BASE MSR values), any good reason this time?
>
> Regards,
> Wanpeng Li
>
>> + 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;
>> --
>> 2.9.5
>>
