Marcelo Tosatti wrote:
> On Tue, May 11, 2010 at 06:29:48PM +0800, Xu, Dongxiao wrote:
>> From: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
>>
>> SDM suggests VMXON should be called before VMPTRLD, and VMXOFF
>> should be called after doing VMCLEAR.
>>
>> Therefore in vmm coexistence case, we should firstly call VMXON
>> before any VMCS operation, and then call VMXOFF after the
>> operation is done.
>>
>> Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx>
>> ---
>> arch/x86/kvm/vmx.c | 38 +++++++++++++++++++++++++++++++-------
>> 1 files changed, 31 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index c536b9d..dbd47a7 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -168,6 +168,8 @@ static inline struct vcpu_vmx *to_vmx(struct
>> kvm_vcpu *vcpu)
>>
>> static int init_rmode(struct kvm *kvm);
>> static u64 construct_eptp(unsigned long root_hpa);
>> +static void kvm_cpu_vmxon(u64 addr);
>> +static void kvm_cpu_vmxoff(void);
>>
>> static DEFINE_PER_CPU(struct vmcs *, vmxarea);
>> static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
>> @@ -786,8 +788,11 @@ static void vmx_vcpu_load(struct kvm_vcpu
>> *vcpu, int cpu) { struct vcpu_vmx *vmx = to_vmx(vcpu);
>> u64 tsc_this, delta, new_offset;
>> + u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
>>
>> - if (vmm_exclusive && vcpu->cpu != cpu)
>> + if (!vmm_exclusive)
>> + kvm_cpu_vmxon(phys_addr);
>> + else if (vcpu->cpu != cpu)
>> vcpu_clear(vmx);
>>
>> if (per_cpu(current_vmcs, cpu) != vmx->vmcs) {
>> @@ -833,8 +838,10 @@ static void vmx_vcpu_load(struct kvm_vcpu
>> *vcpu, int cpu) static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
>> {
>> __vmx_load_host_state(to_vmx(vcpu));
>> - if (!vmm_exclusive)
>> + if (!vmm_exclusive) {
>> __vcpu_clear(to_vmx(vcpu));
>> + kvm_cpu_vmxoff();
>> + }
>> }
>>
>> static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
>> @@ -1257,9 +1264,11 @@ static int hardware_enable(void *garbage)
>> FEATURE_CONTROL_LOCKED |
>> FEATURE_CONTROL_VMXON_ENABLED);
>> write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug
>> safe */ - kvm_cpu_vmxon(phys_addr);
>>
>> - ept_sync_global();
>> + if (vmm_exclusive) {
>> + kvm_cpu_vmxon(phys_addr);
>> + ept_sync_global();
>> + }
>>
>> return 0;
>
> The documentation recommends usage of INVEPT all-context after
> execution of VMXON and prior to execution of VMXOFF. Is it not
> necessary?
After adding the patch, when vCPU is scheduled in a CPU, it will call
tlb_flush() to invalidate the EPT and VPID cache/tlb for the vCPU.
Therefore the correctness for KVM is guaranteed.
Thanks,
Dongxiao--
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