KVM: Retry fault before vmentry
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3cd4d09..71beb27 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6138,6 +6138,20 @@
}
EXPORT_SYMBOL_GPL(kvm_set_rflags);
+void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
+{
+ int r;
+
+ if (!vcpu->arch.mmu.direct_map || is_error_page(work->page))
+ return;
+
+ r = kvm_mmu_reload(vcpu);
+ if (unlikely(r))
+ return;
+
+ vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true);
+}
+
static inline u32 kvm_async_pf_hash_fn(gfn_t gfn)
{
return hash_32(gfn & 0xffffffff, order_base_2(ASYNC_PF_PER_VCPU));