KVM: nVMX: Do not mark vmcs02->apic_access_page as dirty when unpinning

vmcs->apic_access_page is simply a token that the hypervisor puts into
the PFN of a 4KB EPTE (or PTE if using shadow-paging) that triggers
APIC-access VMExit or APIC virtualization logic whenever a CPU running
in VMX non-root mode read/write from/to this PFN.

As every write either triggers an APIC-access VMExit or write is
performed on vmcs->virtual_apic_page, the PFN pointed to by
vmcs->apic_access_page should never actually be touched by CPU.

Therefore, there is no need to mark vmcs02->apic_access_page as dirty
after unpin it on L2->L1 emulated VMExit or when L1 exit VMX operation.

Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Liran Alon 2019-11-21 00:31:47 +02:00 коммит произвёл Paolo Bonzini
Родитель 46f4f0aabc
Коммит b11494bcab
1 изменённых файлов: 3 добавлений и 3 удалений

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@ -268,7 +268,7 @@ static void free_nested(struct kvm_vcpu *vcpu)
vmx->nested.cached_shadow_vmcs12 = NULL;
/* Unpin physical memory we referred to in the vmcs02 */
if (vmx->nested.apic_access_page) {
kvm_release_page_dirty(vmx->nested.apic_access_page);
kvm_release_page_clean(vmx->nested.apic_access_page);
vmx->nested.apic_access_page = NULL;
}
kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);
@ -3070,7 +3070,7 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
* to it so we can release it later.
*/
if (vmx->nested.apic_access_page) { /* shouldn't happen */
kvm_release_page_dirty(vmx->nested.apic_access_page);
kvm_release_page_clean(vmx->nested.apic_access_page);
vmx->nested.apic_access_page = NULL;
}
page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->apic_access_addr);
@ -4267,7 +4267,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
/* Unpin physical memory we referred to in vmcs02 */
if (vmx->nested.apic_access_page) {
kvm_release_page_dirty(vmx->nested.apic_access_page);
kvm_release_page_clean(vmx->nested.apic_access_page);
vmx->nested.apic_access_page = NULL;
}
kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);