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KVM: nVMX: Split off helper for emulating VMCLEAR on Hyper-V eVMCS

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To avoid overloading handle_vmclear() with Hyper-V specific details and to
prepare the code to making Hyper-V emulation optional, create a dedicated
nested_evmcs_handle_vmclear() helper.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-9-vkuznets@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Vitaly Kuznetsov 2023-12-05 11:36:22 +01:00 committed by Sean Christopherson
parent af9d544a45
commit b2e02f82b7
1 changed files with 24 additions and 14 deletions
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38
arch/x86/kvm/vmx/nested.c
View File

@ -243,6 +243,29 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
}
}
static bool nested_evmcs_handle_vmclear(struct kvm_vcpu *vcpu, gpa_t vmptr)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
/*
* When Enlightened VMEntry is enabled on the calling CPU we treat
* memory area pointer by vmptr as Enlightened VMCS (as there's no good
* way to distinguish it from VMCS12) and we must not corrupt it by
* writing to the non-existent 'launch_state' field. The area doesn't
* have to be the currently active EVMCS on the calling CPU and there's
* nothing KVM has to do to transition it from 'active' to 'non-active'
* state. It is possible that the area will stay mapped as
* vmx->nested.hv_evmcs but this shouldn't be a problem.
*/
if (!guest_cpuid_has_evmcs(vcpu) ||
!evmptr_is_valid(nested_get_evmptr(vcpu)))
return false;
if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr)
nested_release_evmcs(vcpu);
return true;
}
static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx,
struct loaded_vmcs *prev)
{
@ -5286,18 +5309,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
if (vmptr == vmx->nested.vmxon_ptr)
return nested_vmx_fail(vcpu, VMXERR_VMCLEAR_VMXON_POINTER);
/*
* When Enlightened VMEntry is enabled on the calling CPU we treat
* memory area pointer by vmptr as Enlightened VMCS (as there's no good
* way to distinguish it from VMCS12) and we must not corrupt it by
* writing to the non-existent 'launch_state' field. The area doesn't
* have to be the currently active EVMCS on the calling CPU and there's
* nothing KVM has to do to transition it from 'active' to 'non-active'
* state. It is possible that the area will stay mapped as
* vmx->nested.hv_evmcs but this shouldn't be a problem.
*/
if (likely(!guest_cpuid_has_evmcs(vcpu) ||
!evmptr_is_valid(nested_get_evmptr(vcpu)))) {
if (likely(!nested_evmcs_handle_vmclear(vcpu, vmptr))) {
if (vmptr == vmx->nested.current_vmptr)
nested_release_vmcs12(vcpu);
@ -5314,8 +5326,6 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
vmptr + offsetof(struct vmcs12,
launch_state),
&zero, sizeof(zero));
} else if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) {
nested_release_evmcs(vcpu);
}
return nested_vmx_succeed(vcpu);