iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: nSVM: fix few bugs in the vmcb02 caching logic

Browse Source 
* Define and use an invalid GPA (all ones) for init value of last
  and current nested vmcb physical addresses.

* Reset the current vmcb12 gpa to the invalid value when leaving
  the nested mode, similar to what is done on nested vmexit.

* Reset	the last seen vmcb12 address when disabling the nested SVM,
  as it relies on vmcb02 fields which are freed at that point.

Fixes: 4995a3685f1b ("KVM: SVM: Use a separate vmcb for the nested L2 guest")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210503125446.1353307-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Maxim Levitsky 2021-05-03 15:54:43 +03:00 committed by Paolo Bonzini
parent deee59bacb
commit c74ad08f33
3 changed files with 14 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/kvm_host.h
View File

@ -113,6 +113,7 @@
#define VALID_PAGE(x) ((x) != INVALID_PAGE)
#define UNMAPPED_GVA (~(gpa_t)0)
#define INVALID_GPA (~(gpa_t)0)
/* KVM Hugepage definitions for x86 */
#define KVM_MAX_HUGEPAGE_LEVEL PG_LEVEL_1G

11
arch/x86/kvm/svm/nested.c
View File

@ -872,6 +872,15 @@ void svm_free_nested(struct vcpu_svm *svm)
__free_page(virt_to_page(svm->nested.vmcb02.ptr));
svm->nested.vmcb02.ptr = NULL;
/*
* When last_vmcb12_gpa matches the current vmcb12 gpa,
* some vmcb12 fields are not loaded if they are marked clean
* in the vmcb12, since in this case they are up to date already.
*
* When the vmcb02 is freed, this optimization becomes invalid.
*/
svm->nested.last_vmcb12_gpa = INVALID_GPA;
svm->nested.initialized = false;
}
@ -884,6 +893,8 @@ void svm_leave_nested(struct vcpu_svm *svm)
if (is_guest_mode(vcpu)) {
svm->nested.nested_run_pending = 0;
svm->nested.vmcb12_gpa = INVALID_GPA;
leave_guest_mode(vcpu);
svm_switch_vmcb(svm, &svm->vmcb01);

4
arch/x86/kvm/svm/svm.c
View File

@ -1235,8 +1235,8 @@ static void init_vmcb(struct kvm_vcpu *vcpu)
svm->current_vmcb->asid_generation = 0;
svm->asid = 0;
svm->nested.vmcb12_gpa = 0;
svm->nested.last_vmcb12_gpa = 0;
svm->nested.vmcb12_gpa = INVALID_GPA;
svm->nested.last_vmcb12_gpa = INVALID_GPA;
vcpu->arch.hflags = 0;
if (!kvm_pause_in_guest(vcpu->kvm)) {