Commit 8332f0ed authored Nov 19, 2022 by David Woodhouse Committed by Paolo Bonzini Nov 23, 2022

KVM: Update gfn_to_pfn_cache khva when it moves within the same page



In the case where a GPC is refreshed to a different location within the
same page, we didn't bother to update it. Mostly we don't need to, but
since the ->khva field also includes the offset within the page, that
does have to be updated.

Fixes: 3ba2c95e ("KVM: Do not incorporate page offset into gfn=>pfn cache user address")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: stable@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent c2b8cdfa

virt/kvm/pfncache.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -297,7 +297,12 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm kvm, struct gfn_to_pfn_cache gpc,
		if (!gpc->valid \|\| old_uhva != gpc->uhva) {
		ret = hva_to_pfn_retry(kvm, gpc);
		} else {
		/* If the HVA→PFN mapping was already valid, don't unmap it. */
		/*
		* If the HVA→PFN mapping was already valid, don't unmap it.
		* But do update gpc->khva because the offset within the page
		* may have changed.
		*/
		gpc->khva = old_khva + page_offset;
		old_pfn = KVM_PFN_ERR_FAULT;
		old_khva = NULL;
		ret = 0;