diff options
author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2020-03-09 16:52:12 +0100 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 18:19:29 +0100 |
commit | e942dbf8c58e1bf1ccfe18eb2713e3b360ec2e7f (patch) | |
tree | 2219fa2d008cc7ff1e83d38cf180e6c912133e8e /arch | |
parent | 0c546725eecf5fb37bcbb60717d2f465f565e8d3 (diff) |
KVM: nVMX: stop abusing need_vmcs12_to_shadow_sync for eVMCS mapping
When vmx_set_nested_state() happens, we may not have all the required
data to map enlightened VMCS: e.g. HV_X64_MSR_VP_ASSIST_PAGE MSR may not
yet be restored so we need a postponed action. Currently, we (ab)use
need_vmcs12_to_shadow_sync/nested_sync_vmcs12_to_shadow() for that but
this is not ideal:
- We may not need to sync anything if L2 is running
- It is hard to propagate errors from nested_sync_vmcs12_to_shadow()
as we call it from vmx_prepare_switch_to_guest() which happens just
before we do VMLAUNCH, the code is not ready to handle errors there.
Move eVMCS mapping to nested_get_vmcs12_pages() and request
KVM_REQ_GET_VMCS12_PAGES, it seems to be is less abusive in nature.
It would probably be possible to introduce a specialized KVM_REQ_EVMCS_MAP
but it is undesirable to propagate eVMCS specifics all the way up to x86.c
Note, we don't need to request KVM_REQ_GET_VMCS12_PAGES from
vmx_set_nested_state() directly as nested_vmx_enter_non_root_mode() already
does that. Requesting KVM_REQ_GET_VMCS12_PAGES is done to document the
(non-obvious) side-effect and to be future proof.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kvm/vmx/nested.c | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 98b82ccdf5f0..424d9a77af86 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -1996,14 +1996,6 @@ void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); - /* - * hv_evmcs may end up being not mapped after migration (when - * L2 was running), map it here to make sure vmcs12 changes are - * properly reflected. - */ - if (vmx->nested.enlightened_vmcs_enabled && !vmx->nested.hv_evmcs) - nested_vmx_handle_enlightened_vmptrld(vcpu, false); - if (vmx->nested.hv_evmcs) { copy_vmcs12_to_enlightened(vmx); /* All fields are clean */ @@ -3062,6 +3054,14 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) struct page *page; u64 hpa; + /* + * hv_evmcs may end up being not mapped after migration (when + * L2 was running), map it here to make sure vmcs12 changes are + * properly reflected. + */ + if (vmx->nested.enlightened_vmcs_enabled && !vmx->nested.hv_evmcs) + nested_vmx_handle_enlightened_vmptrld(vcpu, false); + if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { /* * Translate L1 physical address to host physical @@ -5904,10 +5904,12 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, set_current_vmptr(vmx, kvm_state->hdr.vmx.vmcs12_pa); } else if (kvm_state->flags & KVM_STATE_NESTED_EVMCS) { /* - * Sync eVMCS upon entry as we may not have - * HV_X64_MSR_VP_ASSIST_PAGE set up yet. + * nested_vmx_handle_enlightened_vmptrld() cannot be called + * directly from here as HV_X64_MSR_VP_ASSIST_PAGE may not be + * restored yet. EVMCS will be mapped from + * nested_get_vmcs12_pages(). */ - vmx->nested.need_vmcs12_to_shadow_sync = true; + kvm_make_request(KVM_REQ_GET_VMCS12_PAGES, vcpu); } else { return -EINVAL; } |