Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fix from Paolo Bonzini: "This single patch fixes a regression caused by one of the optimizations introduced in 3.11, which is generally visible only on AMD processors" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: MMU: avoid fast page fault fixing mmio page fault

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fix from Paolo Bonzini: "This single patch fixes a regression caused by one of the optimizations introduced in 3.11, which is generally visible only on AMD processors" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: MMU: avoid fast page fault fixing mmio page fault
Linus Torvalds
2 parents b7356abb9f 1c118b8226
Showing 1 changed file Side-by-side Diff
arch/x86/kvm/mmu.c
@@ -2811,6 +2811,13 @@
 static bool page_fault_can_be_fast(struct kvm_vcpu *vcpu, u32 error_code)
 {
 	/*
+	 * Do not fix the mmio spte with invalid generation number which
+	 * need to be updated by slow page fault path.
+	 */
+	if (unlikely(error_code & PFERR_RSVD_MASK))
+		return false;
+
+	/*
 	 * #PF can be fast only if the shadow page table is present and it
 	 * is caused by write-protect, that means we just need change the
 	 * W bit of the spte which can be done out of mmu-lock.
...	...	@@ -2811,6 +2811,13 @@
2811	2811	static bool page_fault_can_be_fast(struct kvm_vcpu *vcpu, u32 error_code)
2812	2812	{
2813	2813	/*
	2814	+ * Do not fix the mmio spte with invalid generation number which
	2815	+ * need to be updated by slow page fault path.
	2816	+ */
	2817	+ if (unlikely(error_code & PFERR_RSVD_MASK))
	2818	+ return false;
	2819	+
	2820	+ /*
2814	2821	* #PF can be fast only if the shadow page table is present and it
2815	2822	* is caused by write-protect, that means we just need change the
2816	2823	* W bit of the spte which can be done out of mmu-lock.