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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-04-16 02:07:39 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-21 15:13:09 +0200 |
| commit | b8d295f96b6c9745d7eebee622690e0e835c63af (patch) | |
| tree | 1ea185121d41d5ec121422bf758397870f05b554 /arch/x86/kvm/vmx/evmcs.c | |
| parent | KVM: x86/mmu: Avoid an extra memslot lookup in try_async_pf() for L2 (diff) | |
| download | linux-b8d295f96b6c9745d7eebee622690e0e835c63af.tar.xz linux-b8d295f96b6c9745d7eebee622690e0e835c63af.zip | |
KVM: nVMX: Remove non-functional "support" for CR3 target values
Remove all references to cr3_target_value[0-3] and replace the fields
in vmcs12 with "dead_space" to preserve the vmcs12 layout. KVM doesn't
support emulating CR3-target values, despite a variety of code that
implies otherwise, as KVM unconditionally reports '0' for the number of
supported CR3-target values.
This technically fixes a bug where KVM would incorrectly allow VMREAD
and VMWRITE to nonexistent fields, i.e. cr3_target_value[0-3]. Per
Intel's SDM, the number of supported CR3-target values reported in
VMX_MISC also enumerates the existence of the associated VMCS fields:
If a future implementation supports more than 4 CR3-target values, they
will be encoded consecutively following the 4 encodings given here.
Alternatively, the "bug" could be fixed by actually advertisting support
for 4 CR3-target values, but that'd likely just enable kvm-unit-tests
given that no one has complained about lack of support for going on ten
years, e.g. KVM, Xen and HyperV don't use CR3-target values.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200416000739.9012-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/evmcs.c')
| -rw-r--r-- | arch/x86/kvm/vmx/evmcs.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c index 303813423c3e..73f3e07c1852 100644 --- a/arch/x86/kvm/vmx/evmcs.c +++ b/arch/x86/kvm/vmx/evmcs.c @@ -160,14 +160,6 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = { HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL), EVMCS1_FIELD(VM_ENTRY_MSR_LOAD_ADDR, vm_entry_msr_load_addr, HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL), - EVMCS1_FIELD(CR3_TARGET_VALUE0, cr3_target_value0, - HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL), - EVMCS1_FIELD(CR3_TARGET_VALUE1, cr3_target_value1, - HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL), - EVMCS1_FIELD(CR3_TARGET_VALUE2, cr3_target_value2, - HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL), - EVMCS1_FIELD(CR3_TARGET_VALUE3, cr3_target_value3, - HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL), /* 32 bit rw */ EVMCS1_FIELD(TPR_THRESHOLD, tpr_threshold, |