KVM: nVMX: do not pin the VMCS12
Since the current implementation of VMCS12 does a memcpy in and out
of guest memory, we do not need current_vmcs12 and current_vmcs12_page
anymore. current_vmptr is enough to read and write the VMCS12.
And David Matlack noted:
This patch also fixes dirty tracking (memslot->dirty_bitmap) of the
VMCS12 page by using kvm_write_guest. nested_release_page() only marks
the struct page dirty.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[Added David Matlack's note and nested_release_page_clean() fix.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 714d436..082cdb9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -416,9 +416,6 @@ struct nested_vmx {
/* The guest-physical address of the current VMCS L1 keeps for L2 */
gpa_t current_vmptr;
- /* The host-usable pointer to the above */
- struct page *current_vmcs12_page;
- struct vmcs12 *current_vmcs12;
/*
* Cache of the guest's VMCS, existing outside of guest memory.
* Loaded from guest memory during VMPTRLD. Flushed to guest
@@ -7182,10 +7179,6 @@ static inline void nested_release_vmcs12(struct vcpu_vmx *vmx)
if (vmx->nested.current_vmptr == -1ull)
return;
- /* current_vmptr and current_vmcs12 are always set/reset together */
- if (WARN_ON(vmx->nested.current_vmcs12 == NULL))
- return;
-
if (enable_shadow_vmcs) {
/* copy to memory all shadowed fields in case
they were modified */
@@ -7198,13 +7191,11 @@ static inline void nested_release_vmcs12(struct vcpu_vmx *vmx)
vmx->nested.posted_intr_nv = -1;
/* Flush VMCS12 to guest memory */
- memcpy(vmx->nested.current_vmcs12, vmx->nested.cached_vmcs12,
- VMCS12_SIZE);
+ kvm_vcpu_write_guest_page(&vmx->vcpu,
+ vmx->nested.current_vmptr >> PAGE_SHIFT,
+ vmx->nested.cached_vmcs12, 0, VMCS12_SIZE);
- kunmap(vmx->nested.current_vmcs12_page);
- nested_release_page(vmx->nested.current_vmcs12_page);
vmx->nested.current_vmptr = -1ull;
- vmx->nested.current_vmcs12 = NULL;
}
/*
@@ -7622,14 +7613,14 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
}
nested_release_vmcs12(vmx);
- vmx->nested.current_vmcs12 = new_vmcs12;
- vmx->nested.current_vmcs12_page = page;
/*
* Load VMCS12 from guest memory since it is not already
* cached.
*/
- memcpy(vmx->nested.cached_vmcs12,
- vmx->nested.current_vmcs12, VMCS12_SIZE);
+ memcpy(vmx->nested.cached_vmcs12, new_vmcs12, VMCS12_SIZE);
+ kunmap(page);
+ nested_release_page_clean(page);
+
set_current_vmptr(vmx, vmptr);
}
@@ -9284,7 +9275,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
vmx->nested.posted_intr_nv = -1;
vmx->nested.current_vmptr = -1ull;
- vmx->nested.current_vmcs12 = NULL;
vmx->msr_ia32_feature_control_valid_bits = FEATURE_CONTROL_LOCKED;