diff mbox series

[4/8] KVM: pfncache: base offset check on khva rather than gpa

Message ID 20230914084946.200043-5-paul@xen.org (mailing list archive)
State New, archived
Headers show
Series KVM: xen: update shared_info and vcpu_info handling | expand

Commit Message

Paul Durrant Sept. 14, 2023, 8:49 a.m. UTC 
From: Paul Durrant <pdurrant@amazon.com>

After a subsequent patch, the gpa may not always be set whereas khva will
(as long as the cache valid flag is also set).

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
---
 virt/kvm/pfncache.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

David Woodhouse Sept. 14, 2023, 12:42 p.m. UTC | #1 
On Thu, 2023-09-14 at 08:49 +0000, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@amazon.com>
> 
> After a subsequent patch, the gpa may not always be set whereas khva will
> (as long as the cache valid flag is also set).
> 

No functional change intended.

> Signed-off-by: Paul Durrant <pdurrant@amazon.com>

Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
diff mbox series

Patch

diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 17afbb464a70..37bcb4399780 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -83,15 +83,18 @@  bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len)
 	if (!gpc->active)
 		return false;
 
-	if ((gpc->gpa & ~PAGE_MASK) + len > PAGE_SIZE)
+	if (gpc->generation != slots->generation)
 		return false;
 
-	if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva))
+	if (kvm_is_error_hva(gpc->uhva))
 		return false;
 
 	if (!gpc->valid)
 		return false;
 
+	if (offset_in_page(gpc->khva) + len > PAGE_SIZE)
+		return false;
+
 	return true;
 }
 EXPORT_SYMBOL_GPL(kvm_gpc_check);